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Gallery, Projects and General => Project Logs => Topic started by: NormanV on February 28, 2014, 01:16:16 PM

Title: Building a milling machine
Post by: NormanV on February 28, 2014, 01:16:16 PM
Some of you may have noticed my questions regarding problems that I have been having setting up to cast aluminium. I have been doing this as I am planning to build a milling machine. I have based the design on the body of Dave Gingery's shaper as it allows adjustments to be made to the build to achieve the accuracy needed (I hope). Here is a sketch of what I am planning.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 01:24:49 PM
The main body will be aluminium castings and I will recycle parts from old machines where it will achieve accuracy. For example the fine vertical feed is a lathe topslide mounted on a thick wall steel tube that also carries the motor. I have used the tube as it allows me to adjust the verticality of the head in relation to the table. Any comments would be appreciated.
Norman
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 01:33:57 PM
I may use a coordinate table for the X and Y axes in order to save time but I have made the patterns to cast my own in aluminium if I decide to. Here are some of the patterns.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 01:45:45 PM
The first casting that I did was for mounting the lathe topslide to the steel tube across the top. I had been having problems getting my moulding sand to the right consistency and the casting turned out very rough so I had to machine it all over. Since then I have not had those problems.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 01:58:08 PM
After machining the casting I attached the cross slide with a steel disc that I had as a mounting plate between the two.
The next casting was for the front of the machine where the angle plate shown in the diagram will mount. My first attempt warped but a second try was successful.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 02:02:05 PM
The castings are getting more straightforward to produce as I get more practice at it. It is a couple of years since I last did any casting. Here's a collection the I have done over the last ten days or so.
Title: Re: Building a milling machine
Post by: mattinker on February 28, 2014, 02:05:02 PM
Casting is such fun!
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 02:05:20 PM
Yesterday I assembled the base of the body. The holes are were in the pattern to provide support for the sand over the large area of it. I will be casting the upper sections of the body over the next few days.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 02:07:15 PM
Yes Matt it is fun. When I was doing it before I was searching around for things to cast just for the pleasure. I still have a tee handled allen key that I made simple because I could.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 02:11:26 PM
This morning I loosely assembled the top onto the base just to see what it will look like. The extra side pieces will be in there eventually.
Title: Re: Building a milling machine
Post by: superc on February 28, 2014, 02:11:55 PM
Hi Norman.
I like your concept.  I note that you too feel an overhang of the mill head is (or should be) allowing greater Y axis travel.  That was the approach in my own speculation at http://madmodder.net/index.php/topic,9585.0.html about how parts from an X2 (or SX2) could be used to build a better milling machine.  I had already mentioned to a third party how where my design suffered was in my inability to come up with a ram head type mount for the mill head that would allow swiveling or angle adjustments.  Looks like you solved it and also the issue of designing a knee for yours. 

My biggest concern is your decision to make the body out of aluminum.  I forsee both acoustical and rigidity issues.  I believe going with green sand cast iron may be a better choice, but I will shut up now.  I look forward to seeing how this develops.
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 02:19:02 PM
Yes Superc I read your post about your milling machine. The tube that I have used is long enough for me to adjust the overhang but it is not my intention to have it as an adjustment to use in the operation of the machine. I intend to set it the once and lock it in position when it is set in the best position.
As for rigidity I am making the aluminium quite thick, typically 18mm and I will fill all the voids with concrete or an epoxy based filler when it is complete. I hope that that will be sufficient.
Norman
Title: Re: Building a milling machine
Post by: NormanV on February 28, 2014, 02:25:22 PM
I was particularly pleased with how the casting for the hold down caps on the tube turned out. It is the most complicated pattern so far and I was concerned over how easily it would release from the sand but I had allowed plenty of draught and it released easily. I used the steel tube as a former for the curved section to save having to machine it. I smoked it with a candle and it released easily.
Title: Re: Building a milling machine
Post by: superc on February 28, 2014, 03:54:23 PM
Sir, regardless of intended use today, I salute you for coming up with a doable design that does indeed allow both Y axis adjustment and also angling of the head if so desired.  You may wish to think about putting a key way into the clamp and a key into the pipe so as to prevent any tendency for the head to cause the pipe to pivot (i.e., angle).
Title: Re: Building a milling machine
Post by: rick barnes on February 28, 2014, 06:13:59 PM
I really like that idea.  Is there any problems with moving the Z axis from below the table as far as rigidity is concerned? 
Title: Re: Building a milling machine
Post by: NormanV on March 01, 2014, 02:24:47 AM
The idea is to use the under table adjustment to set the table height approximately and then lock it in position. The top Z axis slide will then be used for fine adjustment.
Title: Re: Building a milling machine
Post by: rick barnes on March 01, 2014, 02:48:17 AM
Well, definitely a thread to watch.  I've been trying to build one for years.
Title: Re: Building a milling machine
Post by: chipenter on March 01, 2014, 03:05:36 AM
Have you looked at the Dore Westbury machine http://www.lathes.co.uk/dore%20westbury/index.html of a similar design with a epicyclylcic pully for slow speeds ?
Title: Re: Building a milling machine
Post by: NormanV on March 01, 2014, 04:06:19 AM
I am familiar with the Dore-Westbury machine. A good friend of mine built one many years ago but without the gearbox. I shall be using a two step pulley combined with a variable speed drive to achieve speeds of 2300-100 RPM
Title: Re: Building a milling machine
Post by: shipto on March 01, 2014, 06:00:42 AM
I too would like to build one I just dont have a mill to make it  :doh:
Title: Re: Building a milling machine
Post by: NormanV on March 01, 2014, 07:46:23 AM
Nor do I just a lathe and a drill.
Title: Re: Building a milling machine
Post by: NormanV on March 02, 2014, 08:17:05 AM
How frustrating! The weather has been good for the last week and I have been able to make castings every day. Today it is wet and windy and I am getting impatient. The forecast for tomorrow isn't too good either, it looks as if I will have to wait till Tuesday to get started again. It's probably not a bad thing though, my sand was getting a bit dry and I had a couple of moulds drop out as I turned them. I damped the sand down yesterday and the delay is allowing it to settle down again.
I have spent some time this morning making patterns for the pulleys. I am planning to use multi-groove belts as one of the pulleys is going to be quite a small diameter and a vee belt would struggle to get around it.
Title: Re: Building a milling machine
Post by: awemawson on March 02, 2014, 08:41:27 AM
Norman,

My routine used to be, knock out the sand from the moulding box onto a swept floor, water with a watering can, cover with pvc sheet and leave over night, then give it a good turning over with a shovel the next morning adding more water if needed, then return it to the storage container (where it was reasonably sealed) via a suitable sieve ready for next time. When  I get set up again I'll make a muller.

I've been known to have it turning in a cement mixer with a large gas flame impinging when I've over done the water  :lol:
Title: Re: Building a milling machine
Post by: Arbalist on March 02, 2014, 09:47:16 AM
Looking good Norman!
Title: Re: Building a milling machine
Post by: NormanV on March 02, 2014, 10:40:09 AM
Thank you Arbalist.
Andrew, I need to do that. I have been putting the sand back into its storage box without tempering it and it has gradually got drier. I'm trying to be tidy!
Title: Re: Building a milling machine
Post by: NormanV on March 04, 2014, 12:23:21 PM
It's been a good day today, the enforced delay due to the weather has given me time to plan the next stages which meant that I was working efficiently and got far more done that I had anticipated.
Firstly I cast the second of the top body sections and after fettling I got them bolted together.
Title: Re: Building a milling machine
Post by: NormanV on March 04, 2014, 12:24:59 PM
I then mounted the top section onto the bottom and bolted them together.
Title: Re: Building a milling machine
Post by: NormanV on March 04, 2014, 12:29:16 PM
I then fitted the top casting to the main frame and bolted that into place.
So far none of the assembly has been precision work, an angle grinder and a drill is all I've needed. The next part is to fit the front, this has to be done accurately to ensure that the front is at right angles to the top tube.
Title: Re: Building a milling machine
Post by: mattinker on March 04, 2014, 01:03:50 PM
Thanks for posting, I'm looking forward to seeing where this is going!

Regards, Matthew
Title: Re: Building a milling machine
Post by: awemawson on March 04, 2014, 02:53:55 PM
 :thumbup: Looking good Norman  :thumbup:

You must be emptying the local scrap yard of gearbox cases and wheels  :lol:
Title: Re: Building a milling machine
Post by: NormanV on March 05, 2014, 11:38:08 AM
One casting that I have been having trouble with is the spindle mount, it is basically just a 4" hollow cube. I tried twice to mould it in sand but both times the centre broke away. I then made a core box and tried to make a core using sodium silicate. Somehow the CO2 did not penetrate and it was unsuccessful. I then tried a baked sand core but that failed too.
Then I had a "eureka" moment, I had some ceramic fibre insulation board left over from making my furnace and I cut a piece to size to use as a core. I was concerned that as it is so light it would move as I poured the molten metal in so I anchored it in the sand with a couple of woodscrews in the back. It was a successful pour and the fibre board was very easy to remove from the casting.
I also needed a cover for this part to keep the oil in for the bearings, as a bit of fun I cut my initials from thin ply to decorate the front of the cover. I half expected the sand to break up but that cast well also.

Title: Re: Building a milling machine
Post by: NormanV on March 05, 2014, 11:44:36 AM
I've also been working on the front casting. I had made it oversize to ensure that there would be no gaps and I had to reduce the width by 3mm to make it fit. I started with an angle grinder but soon discovered that a "Surform" plane removed the metal very quickly and I was able to keep the sides straighter than I could with the grinder. No pictures yet.
Title: Re: Building a milling machine
Post by: NormanV on March 07, 2014, 01:02:34 PM
More progress on the front casting. I got it down to width and fitting between the sides nicely. Then came the first critical part of the build. The front surface has to be flat and the only means at my disposal was to scrape it. I have a large angle plate that could serve as a surface plate and I set to scraping. I spent the whole of yesterday on it and made some good progress. It went from touching on two diagonally opposite corners only to about 30% of the surface touching the surface plate. This morning I started afresh but soon realised that with the amount of metal that I still had to remove I had a good week of scraping ahead of me. I am not that patient! I phoned a local engineering company and the agreed to mill it flat for 30. I thought that that was a bargain and now the job is done.
Title: Re: Building a milling machine
Post by: NormanV on March 08, 2014, 12:59:59 PM
Had a frustrating morning, I drove 30 miles to my nearest fastening supplier and found that they were shut! However on my way back home I passed a farm supplies shop and they had all that I needed. I'll go there in future as they are only 15 miles down the road.
With the screws that I bought I was able to fit the front casting to the body complete with a piece of 4" x 1/2" CRS that is going to act as the vertical slide. This had to be at 90 degrees to the mounting for the top tube and this was achieved using a "rafter square". Not the most precise piece of equipment but near enough at this stage as I will put shims under the top tube to set it accurately on final assembly.
There was an awful lot of drilling and tapping today, there is a total of 56 fasteners on it so far.
Title: Re: Building a milling machine
Post by: Arbalist on March 08, 2014, 01:38:20 PM
This is progressing nicely!  :thumbup:
Title: Re: Building a milling machine
Post by: NormanV on March 08, 2014, 04:32:12 PM
I mentioned in an earlier post that I intend to fill the body of this machine to reduce vibration. I could use concrete which would be cheap or a mixture of epoxy and gravel. My concerns over using concrete are shrinkage and retention of moisture. Epoxy will be much more expensive, or how about polyester resin (as used for fibreglass).
Has anybody any experience of doing this who could offer advice?
Thanks, Norman
Title: Re: Building a milling machine
Post by: chipenter on March 09, 2014, 03:46:33 AM
If you used strong concrete and vibrated it to remove air bubbles , it will be waterproof and ridgid not to menshon heavy .
Title: Re: Building a milling machine
Post by: NormanV on March 09, 2014, 07:27:08 AM
What do you mean by strong concrete?
Title: Re: Building a milling machine
Post by: Arbalist on March 09, 2014, 01:00:33 PM
Polyester Resin should be fine I would have thought, mixed with sand and gravel.
Title: Re: Building a milling machine
Post by: awemawson on March 09, 2014, 02:45:31 PM
If you can get some chilled iron shot, as used for sand blasting, it will be significantly more dense than aggregate. And I agree that polyester resin should be fine.
Title: Re: Building a milling machine
Post by: Arbalist on March 09, 2014, 05:28:37 PM
Actually I did see a thread somewhere where someone used old steel fasteners as part of the mix for their mill.
Title: Re: Building a milling machine
Post by: chipenter on March 10, 2014, 04:07:31 AM
Strong concrete a mix of 5or 6 to 1 the smaller the agregate more cement is needed to cover the gaps , and should go a very light grey almost white .
Title: Re: Building a milling machine
Post by: NormanV on March 10, 2014, 10:08:16 AM
Sorry Jeff but you are speaking to a thicko here regarding concrete. Could you explain more fully please.
Norman
Title: Re: Building a milling machine
Post by: NormanV on March 10, 2014, 02:08:59 PM
For the platform that supports the x and y axis I had originally planned to make an aluminium casting but I soon realised that would give me two large flat surfaces to level off and to get at 90 degrees to each other. It would also be too big to fit on my lathe to machine it. Instead I bought a large (18" x 12" x 8") angle plate that would give me the built in accuracy without any problems of machining it. All I had to do was to cut it in half. This I did with my rubbish angle grinder which burnt out under the strain (thank heavens for a two year guarantee) and a hacksaw for where I couldn't get the angle grinder to fit.
Here it is before I attacked it with the hacksaw.
Title: Re: Building a milling machine
Post by: NormanV on March 11, 2014, 10:55:11 AM
This machine is getting quite heavy now and when I fit the table I will not be able to lift it. It is time to build the bench upon which it will live. I had originally planned to make it from metal but that would first mean that I would have to buy a welding machine. The cost of that combined with the cost of the steel made me look at timber construction. I have built this bench using 3" x 2" timber for the frame with 1/2" particle board for the cladding. It seems very stable but time will tell. At least I have got somewhere semi-permanent to keep it for now. I will be giving it a coat of paint to make it look a little better and I'll get some handy storage in the sides.
Title: Re: Building a milling machine
Post by: chipenter on March 11, 2014, 03:32:47 PM
one part cement to 5 parts aggrigate by volume , I would recoment 10mm aggrigate flint or granite for waterproof , and vibrated with say a hammer drill on the outside of the shuttering will make the wet cement almost flow and fill all the corners .
Title: Re: Building a milling machine
Post by: NormanV on March 11, 2014, 04:08:52 PM
So, no sand?
Title: Re: Building a milling machine
Post by: chipenter on March 11, 2014, 04:41:00 PM
sand yes comes with the ten mm aggrigate or ballest sometimes called grano  for hard floors .
Title: Re: Building a milling machine
Post by: Pete W. on March 11, 2014, 05:50:25 PM
Hi there, Norman,

If you have a branch of B&Q or Wickes near you, you should be able to find a 'How To' leaflet on concreting.  Otherwise, try Google.

The type of aggregate available will vary a bit according to your location.  For instance, up the Thames valley, it's usually pit ballast from gravel-pits on the flood-plain.  In South Devon, where my parents lived after they retired, it used to be gritty stuff rejected by the Cornish china clay industry while here in East Hampshire, some builders' merchants supply aggregate dredged from the sea bed.  It gets washed and graded (aka sieved) to separate different grain sizes.  In other parts of the country it might be crushed stone or even ex-demolition crushed concrete.  It all depends on the local geology.  If you ask your local supplier I'm sure they will explain what is common in your area.

When I lived in Essex, I used to use 'as dug' ballast which is everything from " down (except that it was washed to remove the clay) so that was coarse plus fine combined.  Some recipes will call for the coarse and fine constituents separately - you combine them during the mixing.

You need enough fine aggregate (sand and fine gravel) to almost fill the spaces between the coarse aggregate, otherwise you'll need to add more cement.  I agree with Jeff's advice about the aggregate to cement ratio but it isn't too critical, you don't need a laboratory balance to weigh the ingredients!  (Well, actually, I expect you'll find most recipes measure by volume, not weight.)  Actually, a builder's shovel is a recognised measure in some older tables of weights and measures.  I'd suggest that for your quantities, a domestic coal shovel will do fine.

If you're mixing by hand, you turn it over three times dry and then three times wet, adding the water little by little.  If you're using a mixer, you need to add at least some of the water first.

You shouldn't add too much water, else you'll get shrinkage.  If you're going to vibrate as Jeff suggested, it should almost seem too dry as you put the mix into the mould (shuttering) and the vibration will mobilise it.  (Have you seen that video of liquifaction of the soil beneath a building foundation during an earthquake?!?)  If it doesn't mobilise, you can always tip it out and add a little more water, mix and re-pour.  However, you mustn't let it dry out for at least three days.  The chemical reaction of the concrete setting requires available water until the concrete has cured, so visit it regularly with the watering can or keep it covered with wet sacking and in the shade.

Once it's cured and really dried out, there might be some slight shrinkage but you could maybe introduce some polyester or epoxy resin into the cracks between the concrete and the metal. 
Title: Re: Building a milling machine
Post by: NormanV on March 12, 2014, 07:07:25 AM
I have now fitted the knee (I think that is the right name for it) and am pleasantly surprised how freely it slides up and down the column and lock without any shake. There is a block of wood under it to keep it in position, the next job is the screw that will raise and lower it. I am planning to use a 28mm acme threaded rod that is sold as a screw for a woodwork bench vice. After considering various geared methods of operating it I have settled on a ratchet mechanism to do it. It may be slow but it is within the cost restraints.

Thank you for the advice on concrete, I may do that soon but must be careful not to do it before I am finally certain that I won't need to dismantle anything.
Here's the screw and a pic of the machine as it now stands.
Title: Re: Building a milling machine
Post by: Lykle on March 17, 2014, 11:38:41 AM
Nice build!

Whatever you use as a filling, do not use polyester resin. It shrinks about 5% so there will be gaps and voids.
Especially along the edges, just where you want it to be.

Epoxy does not shrink so much, so use that if you want to use a resin.

Lykle
Title: Re: Building a milling machine
Post by: NormanV on March 17, 2014, 12:17:45 PM
Thank you for that information Lykle. I think that I will most likely use concrete as epoxy is rather expensive if it needs it. I intend finishing it and testing it before I decide whether to fill it or not.
Title: Re: Building a milling machine
Post by: awemawson on March 17, 2014, 01:01:43 PM
Filling with dry sand without a binder will deaden it and stop vibrations and is reversible.
Title: Re: Building a milling machine
Post by: NormanV on March 20, 2014, 11:15:23 AM
I like the idea of filling it with sand, I can get all I need for free off the beach!

Today I fitted the motor, I needed a mounting plate so I cast a flat plate 250x150x10mm. I'm getting hooked on casting.
The mechanism for raising and lowering the knee took some thought. I have a worm gearbox that I thought would be good for turning the nut on an Acme thread leadscrew that I can buy. Unfortunately the gearbox ratio is 50:1 which would have entailed many thousands of turns of the handle to go from top to bottom. I decided to motorise it and as I already have a 1/2HP motor that was straight forward, even with the motor it will take three minutes to go from top to bottom. this shouldn't be a problem as I will normally be making relatively small adjustments in height.
I have made it so that I can also use a handle for fine manual adjustment. One turn of the handle raises it 0.1mm which will give me very precise setting.
Does anyone have a leadscrew of 25mm or 1" dia with a thread length of at least 500mm that they want to dispose of?

Title: Re: Building a milling machine
Post by: awemawson on March 20, 2014, 12:42:31 PM
After all the Chinese usually leave sand inside their castings so it MUST be good  :ddb:

Seriously though beware of the salt content of beach sand or your aluminium will go all furry.
Title: Re: Building a milling machine
Post by: NormanV on March 20, 2014, 02:07:03 PM

Builders sand and gravel can contain salt as well. I once used builders gravel in a fish tank and all the fish died. I washed the gravel and tried again and the second lot of fish survived.
Title: Re: Building a milling machine
Post by: NormanV on March 20, 2014, 03:19:32 PM
Tom, I'm not sure that I understand what you mean by a sliding gear. I already had the gearbox and the motor.
Title: Re: Building a milling machine
Post by: Manxmodder on March 20, 2014, 08:55:05 PM
After all the Chinese usually leave sand inside their castings so it MUST be good :ddb:

Seriously though beware of the salt content of beach sand or your aluminium will go all furry.
You ain't kidding there. The worm & wheel gearbox on my Axminster bandsaw was full of grit and sand and the oil felt like abrasive paste.

Now fitted with new bearings and gearbox internally coated with epoxy to seal all loose grit into the surface....OZ.
Title: Re: Building a milling machine
Post by: Manxmodder on March 20, 2014, 09:07:31 PM


Builders sand and gravel can contain salt as well. I once used builders gravel in a fish tank and all the fish died. I washed the gravel and tried again and the second lot of fish survived.

Norm,an easy and cheap route to a concrete mix for filling castings is to buy a bag or 2 of ready mixed postcrete from one of the DIY outlets.

This is a dry mix for installing fence posts with cement and aggregate in correct proportions,all you have to do is mix with some water and fill your casting.

Go easy on the water content as too much weakens the concrete and takes longer to dry....OZ.
Title: Re: Building a milling machine
Post by: tom osselton on March 20, 2014, 11:25:57 PM
Lol sorry that should have gone in "surface grinder thingy"  :doh:
Title: Re: Building a milling machine
Post by: mattinker on March 21, 2014, 05:14:59 AM

Norm,an easy and cheap route to a concrete mix for filling castings is to buy a bag or 2 of ready mixed postcrete from one of the DIY outlets.

This is a dry mix for installing fence posts with cement and aggregate in correct proportions,all you have to do is mix with some water and fill your casting.

Go easy on the water content as too much weakens the concrete and takes longer to dry....OZ.

Portland cement based concrete shrinks.

Regards, Matthew
Title: Re: Building a milling machine
Post by: shipto on March 21, 2014, 08:21:18 AM
looking pretty good so far, watching for updates  :mmr:
Title: Re: Building a milling machine
Post by: superc on March 29, 2014, 04:02:02 PM
I think you will be much better off long term with pre-washed sand from a store than with salty beach sand.  Agreement the first 2 or 3 years your machine's insides won't notice it.  Eventually however the salt will find metal and atmospheric moisture and the fun will begin. 

I am really curious to see how the knee joint plays out as far as slop and maintaining a specific height to a few thousandths goes. 
Title: Re: Building a milling machine
Post by: NormanV on March 29, 2014, 05:10:43 PM
I have been quiet for a while, that is not because I have been idle. I have been making slow progress but I may have to cast the head casting again. I relied on my memory when boring for the main bearing and managed to make it oversize. I could make a sleeve which would probably be cheaper but take a lot more time.
Superc I'm not sure what you mean by the knee joint. If you mean the vertical slide I have already found a problem. I thought that I had adjusted it to the minimum slop but when I checked it yesterday I did find some movement in it. I think that I need to remove some of the paper shim that I have used. This is a major dismantling. I will do it when the leadscrew arrives as I will have to take it all apart to fit it.
Title: Re: Building a milling machine
Post by: superc on March 31, 2014, 11:59:32 AM
Well yes, I meant the vertical feed.  Looking at the original sketch, since I see only one screw raising the table, slop becomes a concern, especially if there is no way of firmly locking it in position.  Second potential problem I see is what supports the sides of the table to keep the arrangement from rocking?  Is there more than one 'angle plate' perhaps affixed to the table slides riding in grooves in the 'aluminum casting', or is there just one centrally affixed connection between the table and the main body?
Title: Re: Building a milling machine
Post by: NormanV on March 31, 2014, 01:28:14 PM
The table slides on a 4" wide x 1/2" thick vertical runner. When it is set to height I will lock it with screws on the gib strip so I don't think that there will be any rocking. Fine height adjustment will be done with the dovetail slide on the head. More of a concern is forward sag, at present there is some movement but I am hoping to improve on that by adjusting the shims in the box slide.  I will do that after I receive the Acme leadscrew as both jobs will require dismantling it to fit them and I don't want to have to do it twice.
Title: Re: Building a milling machine
Post by: NormanV on April 11, 2014, 10:15:38 AM
The lead-screw for elevating the table is fitted. I connected it up temporarily and found that it operates very smoothly under power but when I tried to reverse it the motor got a bit smoky. Fortunately I turned it off quickly and now that it has cooled down it is still working, phew! Since that happened I have bought a reversing switch which I still have to sort out the wiring for. When the motor was running the wooden cabinet resonated, it was a bearable noise but I will try to make a resilient mount for the motor to try to quieten it.
The table moves quite slowly under power so setting it accurately in position should be quite easy, I am also able to hand crank it for fine setting. The screw is fixed and the nut rotates around it. The height of the head can also adjusted precisely.
I have obtained the main spindle and bearings and fitted them. It was an interesting piece of machining for the head casting. Firstly I bored it with it mounted on the cross-slide and the made a mandrel and turned the bearing recesses with it mounted between centres. The bearings are taper-roller, I also fitted oils seals top and bottom.
Title: Re: Building a milling machine
Post by: NormanV on April 16, 2014, 04:59:24 PM
I am getting quite excited by my milling machine. From the beginning I have had doubts about the practicality of what I am trying to do. But, I was looking at it today and feel more confident that I am going to produce a machine that will be capable of producing accurate work. Any comments on what I have done so far?
Title: Re: Building a milling machine
Post by: Arbalist on April 17, 2014, 04:56:58 AM
Looking good so far Norman. That looks like about a 1hp motor so that should be fine. What colour are you going to paint it once it's finished!
Title: Re: Building a milling machine
Post by: superc on April 17, 2014, 01:27:36 PM
That's very impressive to me.
 :thumbup:
Title: Re: Building a milling machine
Post by: vtsteam on May 15, 2014, 09:07:48 PM
Really enjoying this project Norman, nice casting work. too!

I have a concern about concrete filling -- which may or may not be valid. Up to those with experience combining these two materials to say.

Portland cement is highly caustic and aluminum is particularly subject to attack by alkalis. Will this cause problems, not only during the filling stage, but also down the road? I think even cured concrete remains basic for quite a long time. With moisture from condensation (aluminum a great conductor, concrete much less so, and porous) I just wonder if problems like corrosion would cause either separation, or the opposite, expansion, or both in different places?

Could be I'm wrong -- hope so -- concrete would be a nice inexpensive vibration damping mass if not.

ps, I remember reading in an old ME about a large lathe built after the War out of concrete as the main material. And here in Vermont, at the Precision Museum in Windsor, there is a late constructed of marble (quarried here).
Title: Re: Building a milling machine
Post by: RotarySMP on May 16, 2014, 09:36:24 AM
Your castings are much better than mine. Nice work.
Title: Re: Building a milling machine
Post by: NormanV on May 16, 2014, 10:06:51 AM
Thanks SMP. I have been reading, on another machining website, of problems that people have had with bubbles in their castings. There has been a discussion about the various degassing chemicals that can be used. I do not do any degassing, I just scrape off the slag and pour. I haven't noticed any bubbles in my castings. I am using mild steel for the crucibles, apparently that can cause problems with the castings. I haven't seen any problem with that either.
Steve, I share your concern about using concrete as a filler. I rather like Andrew's idea of using lead shot, First I will finish the machine and try it out to see if it suffers from vibration and then decide what to do. 
Title: Re: Building a milling machine
Post by: mattinker on May 16, 2014, 10:20:30 AM
Apart from the chemical problems Al concrete, concrete shrinks, if you put it inside a tube, it will shrink away from the walls, having no damping effect! To use concrete effectively, it needs to be outside. If you make the bed out of concrete, with the reinforcing bars and sleeves to bolt the ways to you won't have any problems. Lead shot sounds much better than concrete.

Regards, Matthew
Title: Re: Building a milling machine
Post by: vtsteam on May 16, 2014, 03:24:13 PM
Lead shot does seem like the ideal.

I was thinking about the problem of concrete and it seems like there could be inexpensive solutions if cost was the determining factor.

Coating the inside of the aluminum with epoxy before doing the concrete pour would protect the aluminum, while using a relatively small amount of epoxy.

To deal with the shrinkage problem, there are a few possibilities -- one would be to use "hydraulic cement" which doesn't shrink.

Another would be to actually cast the concrete separately and just fasten it in place -- after all the rest of the machine is held together with fasteners. This would also allow you to remove it, if ever needed, which might be kind of handy. You might cast in pipe, or studs or nuts to facilitate fastening -- lots of different possibilities.
Title: Re: Building a milling machine
Post by: Pete W. on May 16, 2014, 03:53:12 PM
Hi there, Norman,

I think someone has already suggested this (wasn't it Andrew?) but just filling with sand would probably be a good method of damping (vibration damping, that is!).

Back in the 1060s, when I first got interested in Hi-Fi, some enthusiasts would build loudspeaker enclosures with double plywood walls and fill the intermediate space with DRY sand.  This made the cabinet acoustically dead because any sound (=vibration) energy that tried to flex the cabinet walls would be robbed of its energy by the friction between the individual sand grains.

It really does need to be dry sand - there were tales of blokes wives arriving home unexpectedly and finding baking dishes of sand 'cooking' in the oven!  The sand would also need to be first washed to remove any salt - that would attract moisture from the atmosphere and cause corrosion.

It would have the advantage that if it didn't work, it would be easy to remove to make room for something else.  Of course, you'll have to block up all of the holes in your frame except for the very top one.  Over time, the vibration from the machine would make the sand compact and settle so you'd probably need to top up the filling after a while. 
Title: Re: Building a milling machine
Post by: NormanV on May 16, 2014, 05:39:56 PM
Hi Pete, you're old   "Back in the 1060s"

Sand would be a good idea, certainly cheaper than lead.

 




 


Title: Re: Building a milling machine
Post by: Pete W. on May 17, 2014, 03:59:10 AM
Hi Pete, you're old   "Back in the 1060s"
SNIP

Now, now, Norman, you mustn't be pedantic!  I was only one key out!   :D   :D   :D 

   :offtopic:  Actually, I was born a couple of weeks before the Hindenberg disaster and a few weeks before King George VI coronation.
                   That doesn't count as 'old', it counts as 'mature and wise'.  Sort of more Stradivarius than Stratocaster!   :lol:   :lol:   :lol:     
Title: Re: Building a milling machine
Post by: awemawson on May 17, 2014, 12:54:17 PM
Ah yes but old age is a hell of a price to pay for being mature and wise  :lol:
Title: Re: Building a milling machine
Post by: NormanV on May 17, 2014, 01:11:34 PM
We just have to go with what we have.
Title: Re: Building a milling machine
Post by: NormanV on May 28, 2014, 05:31:29 AM
I've done a bit more today. I had to wait for a period without rain which was rather frustrating.
Today I cast a part for mounting the pulleys for the drive. It is a lot lighter than most of the other parts I have cast for this machine. It is only 10mm thick.
It was a bit more complicated to mould than the previous parts I have made and I was pleased how my way around it worked out.
Title: Re: Building a milling machine
Post by: NormanV on May 28, 2014, 05:37:09 AM
I made the pattern in two parts, the main part being the item itself and then the separate part that fits under the main part to fill the awkward cavity underneath. I moulded it with it standing upright on the mould board and when I had rolled it over I removed the filler piece and completed packing the sand in. I rolled it back to open it leaving the cavity filling sand on the base. The sand broke away a little at the base but that is unimportant as it can be trimmed off when I tidy up the casting.
Title: Re: Building a milling machine
Post by: awemawson on May 28, 2014, 01:04:00 PM
Nothing there that a bit of fetling won't sort out  :thumbup:
Title: Re: Building a milling machine
Post by: NormanV on May 28, 2014, 03:45:15 PM
Buoyed up by my success this morning I thought that I would do some more casting this evening even though the weather was looking a bit dodgy. I tried to be clever and cast three items in one pour. I know(?) that I cut gates between all three patterns but when I poured it seemed as if I hadn't. I got two of the castings OK but with a lot of flashing around the edges.
That will teach me not to try to rush and to beat the weather!
Title: Re: Building a milling machine
Post by: vtsteam on May 28, 2014, 03:47:49 PM
Nice work Norman. Kinda hard to stop casting when you're on a roll!   We need parts, parts..... :dremel:
Title: Re: Building a milling machine
Post by: NormanV on May 29, 2014, 03:05:11 PM
I need some advice, I hope that someone can help. I intend taking the drive belt to the spindle on this machine above the horizontal tube that carries the head and motor. The head can be adjusted vertically, it does not have a quill as in a pillar drill but moves on a vee slide.
What I was proposing to do is mount a fixed pulley at the top of the spindle and the belt will be driven from an idler pulley mounted on a splined shaft. Do you think that the idler pulley will follow the pulley on the main spindle and automatically align itself?
Here is a sketch showing what I wish to achieve, any comments would be appreciated.
Norman
Title: Re: Building a milling machine
Post by: Manxmodder on May 29, 2014, 11:34:15 PM
Hi Norm, looking at your drawing it may work if the pulley sheaves are a fair bit larger in diameter than the belt track diameter,otherwise I think it may try to shed the belt of the edge of the pulleys as they get momentarily misaligned.

Maybe you could rig up a rigid arm from the top of the head and extending to the pulley on the splined power  shaft.
 On the end of the arm nearest the splined pulley you could have a guide fork arrangement with a couple of bronze thrust slippers bearing on the top and bottom bosses of the spline pulley,this should keep the 2 pulleys in better alignment with each other rather than just relying on the belt....OZ.
Title: Re: Building a milling machine
Post by: Arbalist on May 30, 2014, 05:09:03 AM
Gosh Norman, you must have quite a stockpile of scrap alloy for all these parts!  :D
Title: Re: Building a milling machine
Post by: awemawson on May 30, 2014, 07:11:16 AM
Gosh Norman, you must have quite a stockpile of scrap alloy for all these parts!  :D

... all those cars up on piles of bricks in the supermarket car park ....  :lol:
Title: Re: Building a milling machine
Post by: NormanV on May 30, 2014, 08:14:25 AM
Oz, I had considered that idea but I haven't yet worked out a way to mount it on the head. I didn't design it with such a thing in mind and I don't really want to make a complete new one as there is a lot of work in the one I made.
Arbalist and Andrew, I was very law abiding and bought approx. 60kg of aluminium from a local scrap yard. It cost me 80p/kilo which is quite dear but at least it was clean and stripped of all ferrous parts. I am down to 10kg so may need to go for some more soon.
Title: Re: Building a milling machine
Post by: PekkaNF on May 30, 2014, 12:26:17 PM
What is the big idea of putting the parts other way out normal order? I sort of get but then again - I don't get it.

Something like this:
http://www.lathes.co.uk/elliott%20mini%20jig/img8.jpg

I think that the Eliot mini jig borer is a beauty and I have collected courage to start planning of building something like it, because original ones are buffed to death and/or silly money.

Pekka
Title: Re: Building a milling machine
Post by: NormanV on May 30, 2014, 01:01:14 PM
The "big idea" for doing a different way round is because I have used a milling spindle for the main shaft and I cannot see how to fit a splined shaft to it and the mount for the pulley without having to remake the whole head.
Yes, I should have planned it in advance but I didn't.
Title: Re: Building a milling machine
Post by: tom osselton on May 30, 2014, 02:53:24 PM
It's a dollar a pound out here for scrap aluminum I bought about 40 pounds last year to make some ingots.
Title: Re: Building a milling machine
Post by: kayzed1 on May 30, 2014, 03:59:41 PM
What about a spring fither side of the pulley.
 Lyn.
Title: Re: Building a milling machine
Post by: NormanV on May 30, 2014, 05:47:26 PM
Lucky you Tom, that's half the price I had to pay and I believe that it has gone up since I bought my scrap.
Lyn, that's something I hadn't thought of. I can see the value of a spring underneath the pulley to counteract gravity.
Title: Re: Building a milling machine
Post by: PekkaNF on May 31, 2014, 06:42:01 AM
The "big idea" for doing a different way round is because I have used a milling spindle for the main shaft and I cannot see how to fit a splined shaft to it and the mount for the pulley without having to remake the whole head.
Yes, I should have planned it in advance but I didn't.

OK. I get it. I think (not sure, but I should consult my friend) that this construction might have a problem trough a belt tension putting strain on splined shaft. Also this would have a tendency to stick the pulley onto splined shaft. I think that the both problems would trivialize, if you could mount an arm to drilling head and use a bearing on the moving v-belt pulley to retain the pulley and absorb the belt tension. Probably deep grove ball bearings with pretty big clearance should be good for it. Or is there very minimal space for a arm?

I hope I don't approach this at obtuse angle, it is not my intention. I like to put bearing as close to load vector as I can, because my mechanical engineering skils don't amount much to go boldly where no-one dares.

Pekka

Title: Re: Building a milling machine
Post by: NormanV on May 31, 2014, 12:27:45 PM
Pekka, the point you make about belt tension "sticking" the pulley onto the splined shaft is something that I hadn't thought about. I think that this could be a real stumbling block with my idea.
It would not be possible to mount an arm between the two shafts as the vee slide is in the way, I will have to use 100mm pulleys to enable the belt to pass either side of this.
I think that I will have to revisit the normal way of doing things. I would have to rely on the torsional strength of a 10mm thread to make it work, I will look into it more closely.
Thank you for your input, I was irritated by what I perceived as sarcasm in your original response but now realise that you were trying to help. Thank you.
Title: Re: Building a milling machine
Post by: PekkaNF on May 31, 2014, 03:59:58 PM
I'm really sorry about irritation I caused, English is not my first language and I have tendency to use wrong wording even when my intention is help.

One more thought....I'm mot sure how much you have space there, but how about using the head design as it is and put poly-v belt on it (easy on draw bolt and such). And offset a jack shaft that is this splined shaft. Would that allow you to move the belt out of way?

Pekka

Title: Re: Building a milling machine
Post by: hanermo on June 01, 2014, 01:49:00 PM
I made a very rigid lathe bench for my little 7x lathe, filled with concrete.

I had no shrinkage.

Bench is 120 mm high mild steel, 12 mm thick, in a welded box, with crossed 15 mm rebar in center, welded to each other, 3 each of x and y crossing, in the center.
I put a 200-500 kg preload in the box, by heating the rebar with propane, before welding the last end pieces in.
Steel about 50 kg, total mass about 150 kg.

Results about 95%.
Works extremely well.

A bigger 8x lathe would have been better.
Cost about 250 in materials, in Spain, 2005 or so.

Title: Re: Building a milling machine
Post by: vtsteam on June 01, 2014, 07:04:08 PM
That was steel with concrete, this is aluminum-ium, um light alloy.
Not alkali friendly.
Title: Re: Building a milling machine
Post by: NormanV on June 03, 2014, 02:34:45 PM
I have been busy today. I gave quite a bit of thought to Pekka's comments and decided that I would be able to do it the "normal" way after all. The milling spindle has a 12mm thread (not 10mm as I originally thought) to which I can attached the splined shaft, that should be plenty strong enough to transmit enough torque for even a large fly cutter.
I have made the patterns for the mounting brackets for the pulley and I think that they will do the job. The attached photo shows the patterns mounted in place to show how it would fit together.
Unfortunately the weather forecast for the next couple of days is not too good so I will have to be patient.
I do not plan to make the splined shaft myself and was thinking of trying to find a shaft from a gearbox that might suit as my original search found one that was priced at over 50. I searched some more today and found a supplier who can provide what I need for only 20. I shall get it ordered tomorrow.
Norman
Title: Re: Building a milling machine
Post by: NormanV on June 06, 2014, 11:57:35 AM
I've just had a bit of a disappointing pour. All seemed to be going well but nothing came up the riser. I assumed that the mould had collapsed and went back inside to watch the Canadian Gran Prix practice session on TV. Things got worse, Lewis Hamilton is not the top of the board!
When it had cooled down I opened up the mould ant to my surprise I had a complete casting, it appeared that when I poked a rod into the sand to rap the pattern I had loosened some sand right on the exit corner and blocked it enough to stop the metal but it allowed the air to escape.
There was a bit of a collapse but I think that I can clear that with a grinder. I had to have two goes at making the mould, I don't want to have to do the whole thing again. Once I've cut it back with the grinder it will do fine, plus it won't show!
Title: Re: Building a milling machine
Post by: NormanV on June 08, 2014, 06:03:45 AM
Here are the four castings that I need to mount the pulley above the head of the machine. The two square pieces are for the bearings. The two main castings are too big for me to machine so I made the bearing mounts separate so that I can easily machine them and then align them accurately before fixing them in position.
Title: Re: Building a milling machine
Post by: PekkaNF on June 08, 2014, 06:57:52 AM
I really wish I had courage to try casting and had even 1/4 of your skills. To me those look incredibly good. Casting really saves effort on turning/milling from solid and gives much freedom on design.

Pekka
Title: Re: Building a milling machine
Post by: awemawson on June 08, 2014, 07:00:51 AM
 :thumbup: Looking very good Norman - you must be pleased  :thumbup:

I take it you've been back to the scrappy and got some more aluminium?
Title: Re: Building a milling machine
Post by: NormanV on June 08, 2014, 08:40:53 AM
Pekka, you should give it a try, it is not really all that difficult. Once you've done your first one you will wonder what all the fuss is about. The most important part is getting the patterns right, I am not very patient and my patterns are not particularly neat or accurate but they are just about good enough.
Not yet Andrew, but my stocks are getting low!
Title: Re: Building a milling machine
Post by: NormanV on June 10, 2014, 06:41:00 AM
The bearings for the drive pulley arrived this morning and it was a pleasure to do some work on the lathe for a change. I have machined the castings to mount the bearings and this afternoon I will get the castings mounted on the bracket that I made last week. I'm still waiting for the splined shaft to arrive so that I can get the backet fixed to the top of the machine.
Title: Re: Building a milling machine
Post by: NormanV on June 10, 2014, 12:44:55 PM
I'm cheesed off with suppliers, the bearings that I mounted today were ordered yesterday and arrived by post today, postage cost 1.50. Great! Thank you www.simplybearings.co.uk
On Friday morning I ordered and paid for the splined shaft I had to pay 9.50 for next day delivery (that is all they offered, they would not post them), today is Tuesday and they still haven't arrived. When I tried to chase them up the supplier wasn't interested. Aargh!!!
Title: Re: Building a milling machine
Post by: NormanV on June 20, 2014, 02:14:28 PM
I made a great leap forward today! The splined shaft had caused me problems, it needed to have one end turned down and threaded 12mm. I have an imperial lathe so I tried to thread it with a die, of course it turned out crooked! I admitted defeat and went to a local engineering firm who quoted me 15 to thread it for me. It sounded a bargain so I left it with them. I collected it today and rushed home to fit it, perfection!!!!!
I have now mounted the castings that support the top pulley and everything is turning freely.
The next job is to machine the pulleys, I have decided to use poly V belt as the thinness gives me more clearance around the top casting.
After much searching I managed to find the dimensions for the pulley grooves, now I have to grind a tool to cut them. Does anybody have suggestions on how I can grind it accurately enough to fit the belt?
Title: Re: Building a milling machine
Post by: NormanV on June 20, 2014, 02:22:07 PM
You may notice the "flywheel" looking object above the head casting. That is a bit of the design of which I am rather pleased. The main spindle is a 25mm spindle with an E32 collet chuck built in. It is mounted in taper roller bearings and needs some way to preload the bearings.
I bought a taperlock bush and pulley. I drilled and tapped the bush to take 4 grub screws that bear on the rim of the top bearing, this enables me to adjust the preload precisely. I turned the flanges off the pulley as they were getting in the way.
Title: Re: Building a milling machine
Post by: Manxmodder on June 20, 2014, 02:32:43 PM
Hi Norman, it is certainly looking very much like a functional milling machine now.

I agree with your sensible choice to use poly V belts for the drive and I wonder if there are any of the propriety brands of carbide inserts that are the correct angle for machining the multiple Vees.

What are the angles and dimensions in the info you have obtained?......OZ.
Title: Re: Building a milling machine
Post by: NormanV on June 20, 2014, 02:49:24 PM
Hi Oz, attached is the details that I have found. The groove is 40 degree angle, which unfortunately does not fit any thread gauge.
Title: Re: Building a milling machine
Post by: philf on June 20, 2014, 03:36:17 PM
Hi Norman, it is certainly looking very much like a functional milling machine now.

I agree with your sensible choice to use poly V belts for the drive and I wonder if there are any of the propriety brands of carbide inserts that are the correct angle for machining the multiple Vees.

What are the angles and dimensions in the info you have obtained?......OZ.

OZ,

There was some discussion on Poly V pulleys some time ago. http://madmodder.net/index.php/topic,8306.msg89232.html#msg89232

Carbide inserts are available but for one groove at a time - http://www.premierformtools.co.uk/pdf/EZG24.pdf - I've no idea how much they cost or if they are available in one-offs.

I've ground a tool up for J section belts which I've used to machine many Poly V pulleys. It can't generate the radius on the crest of the grooves but that never seems to have caused me any problems.

Cheers.

Phil.
Title: Re: Building a milling machine
Post by: NormanV on June 20, 2014, 04:17:00 PM
Phil, how did you get the angle correct?
Title: Re: Building a milling machine
Post by: Manxmodder on June 20, 2014, 04:23:12 PM
Cheers for the links Phil,

The earlier Madmodder article is really good but would have been really interesting to see how the OP's homemade pulleys turned out.

I note that John Stevenson reckons 55 degree tools are ok and the belts will adapt themselves and bed in with use.

If that is the case then a 55 deg. threading insert or a 55deg DCMT rhombic style insert would be suitable....OZ.

Edit to add link to DCGT 55 degree rhombic inserts best for aluminium turning and available with 0.2- 0.8 mm nose radius.
http://www.shop-apt.co.uk/carbide-inserts-for-turning-aluminium-alloys-non-ferrous-metals-plastics/dcgt-11t304-alu-ak10-carbide-inserts-for-turning-ground-and-polished-for-aluminium-uni-tip.html


Title: Re: Building a milling machine
Post by: philf on June 20, 2014, 04:59:34 PM
Phil, how did you get the angle correct?

Hi,

I had access to a huge profile projector where I could project a magnified image of the tool onto a screen to which I clipped a 20:1 or 50:1 (can't remember exactly) template drawn on to translucent drawing film. I ground and stoned the 40 degree profile and root radius to the template.

Now I'd use my Quorn T&C grinder to do the 40 degree form but would probably still stone a radius on the end.

For hobby use I don't think the angles and radii are super-critical but I would imagine that 55 degree grooves are a bit too far out and would lead to vastly accelerated wear and slippage.

Phil.

Title: Re: Building a milling machine
Post by: NormanV on June 20, 2014, 05:14:51 PM
I saw JS's comment that 55degrees would do. That happens to be the size of the only carbide tip that I have. I could use it but I have quite a lot of work invested in one of my pulleys and have no desire to mess it up. So, what depth should I cut each groove?
Phil, I fear that you are correct concerning the wear.
45 years ago I worked as a draughtsman at an engineering company and one task I had was to produce drawings at 10 times size to an accuracy of 100th inch to place on a "Shadowgraph" machine to check the profile of parts to 1000th inch. I had good eyesight in those days!
Title: Re: Building a milling machine
Post by: vtsteam on June 20, 2014, 10:04:25 PM
If you have access to an ordinary computer scanner, put the tool you are grinding on it and scan it. You can then just blow it up in any paint program to measure angles and check profiles. 

Distortion is minimal compared to a camera, and even a cheap scanner these days will scan at 2400 DPI or better, which can be blown up tremendously. Photos on this forum are probably displaying on your monitor at 96 DPI, to give you some idea of the degree of enlargement possible.
Title: Re: Building a milling machine
Post by: NormanV on June 21, 2014, 01:24:55 AM
Good idea Steve, I hadn't thought of that. It's a bit slower than the shadowgraph machine but will do the job.
Thanks.
Title: Re: Building a milling machine
Post by: vtsteam on June 21, 2014, 08:41:46 AM
Norman, I've often used my scanner as a microscope for small objects. I once wanted to identify seeds that mice were storing -- it's amazing the detail you can get.

Also if you lay a rule alongside the object, you can scale from it.

You can also work out a calibration from a scanned standard for future use. Screw threads can be looked at, etc. Gets a little more use out of an old scanner than it usually gets otherwise.
Title: Re: Building a milling machine
Post by: NormanV on June 21, 2014, 09:32:21 AM
I did lay a ruler alongside it on the first scan but didn't bother on further scans as it was just the angle that I was interested in. It took a few goes but I got there.
Machining the pulley was straightforward enough, I just had to keep a close check on the tools increments.
It turned out well.
Title: Re: Building a milling machine
Post by: philf on June 21, 2014, 12:45:47 PM
That didn't take long Norman!
Title: Re: Building a milling machine
Post by: vtsteam on June 21, 2014, 09:29:18 PM
Looks good!  :thumbup:
Title: Re: Building a milling machine
Post by: NormanV on June 22, 2014, 06:16:39 AM
I machined the motor pulley this morning. It did not go as well as the first pulley. You can see from the photo that the sides of the grooves broke up on the smaller part of the pulley. I'm not sure why that was, it wasn't caused by a blunt tool as I cut that section first and you can see that I didn't have the same problem on the larger diameter. It may be a casting fault.
Since machining it I have cleaned it up with a file and emery, it looks better.
This afternoon I was planning to cast the motor mounting plate, I'll cast a new motor pulley at the same time.
Title: Re: Building a milling machine
Post by: NormanV on June 22, 2014, 10:16:11 AM
I got lazy and decided not to do any casting today. Instead of making a  mounting plate for the motor to allow it to pivot when adjusting the belt tension I decided to mount the motor on four studs. It will take longer to adjust but it's not a job I expect to have to do too often.
Everything is now ready for the belt, that should be here on Tuesday.
Now I have to do the wiring for the drive motor with it's speed controller, the reversing switch on the motor for  raising and lowering the table and the tachometer.  It's mounting the switches that is giving me problems. Where should I put them? I suppose I could cast a nice box to fix to the side of the head. I am not keen on putting the switches on the mounting bench due to the danger of swarf getting in.
Title: Re: Building a milling machine
Post by: NormanV on June 24, 2014, 03:24:38 PM
Here's an overall view of the machine as it stands now. The poly V belt arrived this morning and I was relieved to find that it fitted the grooves that I had machined.
The next job it to adjust the head so that it is square to the table.
Once that is done I'll cast the box to contain the switch gear and then I will have no excuses left to avoid starting on the wiring!
I will probably buy a compound table for the XY slides rather than making aluminium castings and having to do lots of scraping.
Title: Re: Building a milling machine
Post by: NormanV on June 24, 2014, 03:26:46 PM
I am also going to make a cast aluminium hand wheel to replace the bodged up handle at the top for adjusting the height of the head.
Title: Re: Building a milling machine
Post by: DavidA on June 24, 2014, 04:48:49 PM
Norman,

I hope you don't mind me making an observation.

The quill  seems to be right out over the outer edge of the table.  I can't see how you can adjust it closer to the middle as things are.

What am I not seeing here ?

Dave.
Title: Re: Building a milling machine
Post by: NormanV on June 24, 2014, 04:54:36 PM
 Yes David you are correct. The compound table that I am planning to get will be centred around that position, unless I can trim the rear end of it down to bring it closer to the main vertical slide.
Title: Re: Building a milling machine
Post by: awemawson on June 25, 2014, 01:34:23 AM
That was also my thought on seeing that last picture. Then I realised that Norman hasn't started the actual table yet. I assume that it's traverse mechanisms in X&Y will sit on the 'bracket'
Title: Re: Building a milling machine
Post by: NormanV on June 28, 2014, 03:41:16 PM
I have just made the worst casting that I have ever done. I knew that the sand was a little damp but when I poured it I immediately knew that all was not well.
Just take a look at this!
Title: Re: Building a milling machine
Post by: awemawson on June 28, 2014, 04:11:15 PM
But the beauty of casting is it can be melted down to hide the evidence and rise phoenix like in a new form  :thumbup:
Title: Re: Building a milling machine
Post by: DavidA on June 29, 2014, 01:50:43 PM
Norman,

Looking again at the picture of the machine.

If the whole top section was moved to the right of the left hand frame securing bracket then the quill would be more or less in the centre of the knee table top.

Dave.
Title: Re: Building a milling machine
Post by: NormanV on June 29, 2014, 05:10:36 PM
David, I have more or less decided to buy a compound table rather than make the X & Y axes myself. The position of the quill is centred over where the mid point of the Y axis falls on the table that I intend to buy.
Title: Re: Building a milling machine
Post by: NormanV on July 01, 2014, 01:50:30 PM
I dried the sand in the sun yesterday and recast my dreadful failure. This time it turned out fine, there was a bit of a cavity in it but it machined out fortunately.
Title: Re: Building a milling machine
Post by: PekkaNF on July 01, 2014, 03:15:26 PM
That is the same part? I must say that the first one was artistically whole more interesting. Later one is whole lot more functional though.

Tough call? :lol:

You are making a steady progress.

Pekka
Title: Re: Building a milling machine
Post by: NormanV on July 05, 2014, 04:08:54 PM
 Earlier this week I cast an aluminium box to house the switchgear and mounted it on the side of the head.
today I more or less completed the wiring, the last task is to replace the temporary plywood switch mounting panel when I can find some sheet aluminium.
 I can now raise and lower the knee under power or manually, and I have had the spindle running also. I had problems initially with the pulley alignment causing the belt to run out of line but that was easy to correct.
The last remaining problem is the tachometer, it shows random speeds when the machine is running. I had the sensor within 2mm of the magnet and had no reading but when I moved it further out I got these erratic readings. The magnet is glued in a shallow hole in the cast iron pulley shown in the second photo. Could the iron be causing this?
Title: Re: Building a milling machine
Post by: vtsteam on July 05, 2014, 04:23:23 PM
I don't think the magnet should be recessed like that. It's probably being shielded by the cast iron. Can it be moved flush or slightly proud?

Or maybe moved to another location where it is attached to aluminum?
Title: Re: Building a milling machine
Post by: NormanV on July 05, 2014, 04:32:26 PM
That's what I was wondering, I meant to mount it flush but drilled the hole a bit deep.
The only rotating aluminium is the pulley and there is no space to mount it.
Title: Re: Building a milling machine
Post by: tom osselton on July 05, 2014, 05:45:42 PM
What kind of magnet is it would a rare earth magnet be better?
Title: Re: Building a milling machine
Post by: NormanV on July 05, 2014, 06:15:48 PM
It's a neodymium magnet. I made sure that I had it the right way round. I'll try a bigger one tomorrow.
Title: Re: Building a milling machine
Post by: John Hill on July 06, 2014, 02:55:03 AM
If you have another the same just stick it on top of that one..
Title: Re: Building a milling machine
Post by: NormanV on July 06, 2014, 04:12:36 AM
That's what I was planning to do, if it works then I will glue it to ensure that it doesn't move.
Title: Re: Building a milling machine
Post by: awemawson on July 06, 2014, 06:19:08 AM
Norman,

All the proximity sensors that I've used (and that's quite a few!) don't need a magnet to operate. The sensor senses the iron presumably using it's own magnetic field. So for instance you can bring one up close to the teeth of a gear wheel and sense each tooth.

Try removing your magnet and sensing the hole where it was - I suspect the strong magnet that you are using is stopping the proximity sensor working.
Title: Re: Building a milling machine
Post by: Arbalist on July 06, 2014, 07:35:10 AM
Good info Andrew.  :thumbup:
Title: Re: Building a milling machine
Post by: NormanV on July 07, 2014, 03:33:11 PM
Andrew, I have not been able to remove the magnet, it is stuck in with high strength retainer and the hole is close fitting. I tried a larger magnet (20mm) but the centripetal force threw it off.
I have no idea what to do next with the tachometer.
Everything else is working fine but now I have to wait until I can sell some photographic equipment in order to raise the cash to buy a combination table to complete this machine. ( is anyone interested in buying a Mamiya RB67 with a few lenses?)
In the meantime I will go back to the Stirling Traction Engine that I started a few months ago.
Title: Re: Building a milling machine
Post by: tom osselton on July 07, 2014, 03:41:06 PM
Can't you shatter the magnet with a punch? All the magnets  I have had break easily.
Title: Re: Building a milling machine
Post by: Baron on July 07, 2014, 04:11:16 PM
Or you could leave the magnet as is and go back to your idea of using a hall device...

Will this pdf help ?
Title: Re: Building a milling machine
Post by: awemawson on July 07, 2014, 04:23:34 PM
Norman,

We need to know what the sensor is on your rev counter. If it is a normal proximity switch it doesn't need the magnet. However just possibly it may be a Hall Effect sensor, although it looks like a normal proximity switch.

Can I suggest that you untangle it from your milling machine, power it up, and hold the sensor in your hand near the spinning chuck of your lathe. The chuck key holes should be enough to trigger a proximity switch. If this gives no response  we need to investigate further.
Title: Re: Building a milling machine
Post by: NormanV on July 07, 2014, 04:57:48 PM

Here's the spec of the thingamajig that I bought:-
Power requirement:DC  8--12V
 Measure range : 5-9999RPM.
 Clear zero: Automatic.
 Clear zero time:about 10s. the greater the RPM value,the longer the clear  zero time.
 Refresh frequency: 0.2-0.5S@120-1200RPM;0.25-0.06S@2400-9999RPM.
 Measure indication:RPM<5000,2;RPM>5000,3.
 Display:RED 0.56 LED
 Sign:Pusle signal,NPN 3 wires normally open.
 Response frequency: 100HZ
 Tachometer dimension:72x36x20mm,panel cutout Dimension:68x33mm.
 Sensor dimention: M12x10x55mm.
 Detection distance: 4mm
 Sensor wiring: brown-Power+;blue-Power-;black-signal.
 Operating temperature: 0 to 50C.


 Packaging include
 Tachometer x 1
 NPN proximity sensor x 1 
Title: Re: Building a milling machine
Post by: awemawson on July 07, 2014, 05:05:23 PM
Try it on the lathe and report back
Title: Re: Building a milling machine
Post by: philf on July 07, 2014, 05:16:58 PM
Norman,

I agree with Andrew. It's a proximity sensor and not a Hall effect sensor so no magnet is necessary - just a hole. The problem with 1 hole is that you may have balance problems. If your Tacho has a divide by 2 function 2 holes would be better.

On my mill I did use a Hall Effect sensor and 1 magnet in an aluminium Poly V pulley. To balance it I glued a piece of same size stainless steel 180 degrees from the magnet. It quite happily runs at 10,000rpm.

Phil.
Title: Re: Building a milling machine
Post by: vtsteam on July 08, 2014, 11:31:59 AM
Drill out the magnet, tap, replace with a grub screw about half the depth of the hole in length. You should be able to balance with the screw proud, which should also trigger the sensor. When both balanced and registering on the tach, Loctite it.

Watch out for the magnet dust -- it isn't healthy stuff.

ps. but first check the sensor on lathe per Andrew.
Title: Re: Building a milling machine
Post by: NormanV on July 20, 2014, 10:10:55 AM
I followed Steve's advice and the tachometer is now working. I've also completed the switch panel, I added some graphics to remind me which way to turn the knobs. I'm quite pleased with it.
I've now got to save up to buy a compound table to finish it off.
Title: Re: Building a milling machine
Post by: awemawson on July 20, 2014, 11:20:01 AM
Glad it's now working  :thumbup:

But from a safety point of view I'm not keen on the protruding screw. Have you tried triggering off the hole that the screw occupies? It should work.
Title: Re: Building a milling machine
Post by: NormanV on July 20, 2014, 11:56:11 AM
Andrew, it didn't trigger from the hole alone. I was concerned about the screw sticking out also, I will build a guard to cover the it.
Title: Re: Building a milling machine
Post by: Arbalist on July 20, 2014, 02:02:25 PM
Looking good Norman!  :thumbup:

Where did you get the tachometer and proximity sensor?
Title: Re: Building a milling machine
Post by: vtsteam on July 20, 2014, 02:18:04 PM
What is the pulley made from -- I had thought you had cast it from aluminum, Norman. If ferrous, I can see why Andrew says it could be done with a hole. Or do these things merely need a conductor of any sort passing by?

It seems like there is a fairly large gap to the transducer -- did you try it closer with the hole?
Title: Re: Building a milling machine
Post by: awemawson on July 20, 2014, 03:44:03 PM
Most proximity sensors will work on a 1/4" hole in a rotating wheel or whatever. But they do vary in sensitivity. most work in the 1 to 3 mm range.

I've worked on many machines where the detector is sensing the hole for a grub screw that retains the part on a shaft
Title: Re: Building a milling machine
Post by: NormanV on July 20, 2014, 03:47:20 PM
Arbalist, I bought the tachometer on Ebay, item number 261307045946.
Steve, I have just been out to the workshop to check it again. The transducer does not see the hole even when it is just 1mm from the pulley. The pulley is in fact cast iron, it is a taperlock pulley that I turned the groove off as I just wanted it for locking onto the spindle of the collet chuck to allow me to fit the screws for adjusting the preload in the main bearings.
Title: Re: Building a milling machine
Post by: philf on July 20, 2014, 04:41:31 PM
The transducer does not see the hole even when it is just 1mm from the pulley.

Norman,

Try the sensor further away. The sensing area is usually a Gothic arch shape as wide as the sensor diameter at the face of the sensor to a point at some distance from the face. As you move the sensor further away (but still within the sensing range) you might be able to sense the hole.

The sensing distance varies greatly with material with iron being approx 3 times better than aluminium.

Phil.
Title: Re: Building a milling machine
Post by: awemawson on July 20, 2014, 05:13:47 PM
The eBay advert says the sensing distance is 4 mm. Quite tempting at that price to fit one to the Bridgeport, but with your experiences Norman I think I'd put a different proximity sensor on it.
Title: Re: Building a milling machine
Post by: NormanV on July 21, 2014, 03:25:25 PM
Joy oh joy! I tried again with the sensor reading the hole but with the sensor further away. This time I got readings throughout the speed range that agreed with the theoretical speeds of what the motor should achieve and the speed ratios of my pulleys. The readings I got are certainly accurate enough for my purposes.
Also, I have found a S/H compound table at a price that I can afford. I had previously bid on a milling machine table and slides (that would have required a lot of work) but was outbid. The compound table should only require tidying up and then I should be ready to start cutting metal!!!!!
If it all works out I have to start thinking about what I am going to make with my milling machine.
This all sounds a bit premature, let's get this machine working properly first.
Title: Re: Building a milling machine
Post by: awemawson on July 21, 2014, 03:52:22 PM
Hoo - blooming - ray  :thumbup:


Norman, you'll be amused to hear I ordered one last night just to play with it - probably end up on the Bridgeport  :ddb:
Title: Re: Building a milling machine
Post by: philf on July 21, 2014, 05:11:03 PM
Joy oh joy! I tried again with the sensor reading the hole but with the sensor further away.

Norman,

I'm pleased it worked for you. It must look a lot better as well.

 :beer:

Phil.
Title: Re: Building a milling machine
Post by: NormanV on July 21, 2014, 06:39:11 PM
I don't care about it looking better, it's certainly a lot safer. It doesn't need a guard now.
Title: Re: Building a milling machine
Post by: Arbalist on July 22, 2014, 04:50:25 AM
Nice job Norman, it's all coming together now!  :thumbup:
Title: Re: Building a milling machine
Post by: NormanV on July 26, 2014, 09:55:37 AM
I took two steps forward and four steps back today!
First I squared the head (trammed it). I followed John Doubleboost's instructions using a car brake disc. It worked but was more fiddly than I had anticipated. As I was tightening the bolts to hold it all in place I found that it altered the setting so I had to tighten the bolts alternately whilst keeping an eye on the dial gauge, but I got there in the end.
Then the big moment, I placed my newly acquired compound table onto the knee, it looked great. Then I saw the problem, a few posts back Steve commented on how far forward the spindle was in relation to the column. I had placed it there intentionally as the (new) compound table that I had intended purchasing needed it to be in that position. I have instead bought a second hand table at a third of the price of a new one but the front to back dimension is much smaller. As a consequence the spindle is too far forward. I have two options, I could fix a piece of thick sheet steel on the knee and just mount the table protruding forwards but centred under the spindle. Alternatively I could remove all of the castings above the spindle, slide back the mounting tube upon which the head and the motor are fitted and then modify the castings to suit.
It's going to be a lot of work but I think that the latter is the best way to go, at least my time costs nothing and I saved a lot on the table.
Here is a pic of it with the table in place, it really looks like a milling machine now!
Title: Re: Building a milling machine
Post by: Meldonmech on July 26, 2014, 11:41:36 AM
Hi Norman

                      The mill is looking great, you have achieved a lot, I think the decision you have made is the right one. The              machine will look better and you will be happier with the result.

                                                        Good Luck with the mod      Cheers David
                                                                                     
Title: Re: Building a milling machine
Post by: awemawson on July 26, 2014, 12:04:05 PM
Norman,

It's looking good - you've travelled a long way making this epic casting journey  :bow:

One advantage of making an adaptor plate is that larger work can over hang to the rear of the table. When I had a 'Mill Drill' years ago I did a lot of work on 19" instrument panels, and the lack of space behind the table was always a frustration on the deeper ones.

If you are not too short of 'daylight' under the spindle, you could cast a plate to adapt the table to the knee, and if in the long term you want another solution it could just be unbolted.
Title: Re: Building a milling machine
Post by: NormanV on July 26, 2014, 12:17:39 PM
Thank you David.
Andrew, I take your point about the extra spindle/column distance being useful but I am concerned about the rigidity or lack of it. I know that I will want more space at some time but I expect most of what I plan to do will fit within the available space with the table closer to the column.
I have examined things a little more closely and it appears that I will not have to modify any parts, just rearrange them on the tube. The only drawback will be that the motor will protrude a long way out of the back, but if I position the machine in a corner it may not be obtrusive. As a last resort I can shorten the tube.
Title: Re: Building a milling machine
Post by: NormanV on July 26, 2014, 02:56:16 PM
I have just stripped it down and reassembled it with the head pushed back. It almost fits. The casting marked A will have to be recast but with an overhang in the position shown by the arrow. In a way I am quite pleased as I am having withdrawal symptoms because I have not cast anything for a couple of weeks!
Title: Re: Building a milling machine
Post by: vtsteam on July 26, 2014, 05:57:13 PM
It's getting exciting Norman! Won't be long now before you'fre making swarf.  :clap: :clap:
Title: Re: Building a milling machine
Post by: PekkaNF on July 27, 2014, 08:07:27 AM
It's looking very good. I'm sure you can produce some swarf with it. Try it out before painting, you find something to tinker with but after a little swarffing you know that you can do it. All machines have some limitations. Skill is that you can get the work done within those limits. If we really would make rigid enough machine, work envelope would be 100*100*150 mm, it would weight a ton and not fit into garage.

You are doing some very good work here and it has some unique features.

Pekka
Title: Re: Building a milling machine
Post by: NormanV on July 27, 2014, 10:14:12 AM
Thank you Pekka, I doubt that I will paint it. It will need a lot of stripping down to do that and I quite like the look of bare aluminium.
I made the new casting today. It came out better than most of my previous castings, I suppose that I must have learnt something about casting by now!
For the first time I used some aluminium swarf and bits of can in the melt and when I poured it I found loads of crud at the bottom of the crucible. The top of the melt was quite clean, it only needed minimal scraping off. It poured well but there was all this stuff at the bottom. I won't be remelting swarf in the future.
Title: Re: Building a milling machine
Post by: awemawson on July 27, 2014, 12:47:06 PM
The surface area to volume ratio is huge for swarf and cans, so you get a disproportionate amount of dross (oxides).

You can best melt them by forming  a molten pool from ingot, then plunging them under the surface with a poker or de-gassing plunger (shaped like the thing my mum called a poss and pounded her washing with in the 1930's and 40's)
Title: Re: Building a milling machine
Post by: vtsteam on July 27, 2014, 08:02:59 PM
I've never seen oxides go to the bottom of an aluminum melt -- at least none that I've ever done. They float and get skimmed off.  I can't imagine fine swarf like that residue wouldn't have melted in a pot full of molten aluminum.

That looks like steel swarf and pieces -- was it mixed metal swarf to begin with, Norman?
Title: Re: Building a milling machine
Post by: chipenter on July 28, 2014, 03:22:51 AM
I have cast swarf with no problems just have to compress it well , tin cans on the the outher hand have printing on them , and something on the inside to stop the tast of the alie , and a melt of just tins leave a grey dross on the bottom I just make ingots of them second melt is fine .
Title: Re: Building a milling machine
Post by: Meldonmech on July 28, 2014, 04:21:20 AM
Norman

                I have melted swarf and cans in the past and had the same experience. By the time you have melted the scrap into ingots and the percentage of actual useable metal that results, plus the cost of fuel and your time, it is not worth the effort. Last time I visited the scrap man I got six kg of pristine aluminium for nine pounds. It did not even need to be cast into ingots, and there was no dross.
 
                                                          Cheers David

Title: Re: Building a milling machine
Post by: NormanV on July 28, 2014, 04:41:02 PM
Steve, I was pretty sure that it was all aluminium but I tested it with a magnet anyway. There is no steel in it. I imagine that it just formed an oxide but I am surprised that it did not float with the usual dross to be skimmed off.
I won't bother to try to reuse my swarf or old cans again, I only did it this time to see how it would go.
David, I only paid 80p per kilo for my aluminium scrap, you should find a cheaper scrap man!
Mind you, I did buy nearly 60kg.
Title: Re: Building a milling machine
Post by: Meldonmech on July 29, 2014, 07:01:22 AM

                       Norman  I am shocked !! Feel like I have been ripped off, no wonder he has a new car.

                                                 I must get out more          Cheers David
Title: Re: Building a milling machine
Post by: NormanV on July 29, 2014, 10:15:22 AM
Off topic but the comparison of scrap costs made me think about the cost of casting in general.
A few years ago I lived in the Falkland Islands, charcoal or gas were both imported so were very expensive so I used peat as a fuel as it was free. Peat is difficult to light but does a perfectly good job.
On my return to UK I built a furnace and first of all used charcoal which was very expensive and worst of all it was difficult to find plain charcoal, the manufacturers messed about with to make it easy lighting and it produced clouds of smoke on first lighting.
I considered a waste oil burner but was put off by what appeared to be overly complicated burners, valves and procedures. Instead I made a burner for propane, which was very simple and have used it for all the castings for my milling machine and for preparing ingots. I was initially concerned at the cost of fuel but have been pleased to find that it is not as bad as I had originally thought plus it is very convenient. For all the castings that I have produced I have used less than two 19kg cylinders of gas, at 27 per cylinder I don't think that is too bad, certainly not enough to break the bank.
I did make enquiries at my local kebab house about his waste oil expecting that he had to pay someone to remove it but was surprised to find that he was paid for it, so it is not a free source.
Title: Re: Building a milling machine
Post by: NormanV on August 02, 2014, 11:44:56 AM
Today I made swarf!!!!!!!!
There are just a couple of little jobs to finish off and then it is done
What shall I make with it? Another machine?
Title: Re: Building a milling machine
Post by: PekkaNF on August 02, 2014, 11:53:03 AM
What shall I make with it? Another machine?

YES. YES. YESHHHH. :beer:

Pekka
Title: Re: Building a milling machine
Post by: NormanV on August 02, 2014, 12:27:39 PM
I know what I'll make. A machine vice to use on the mill!
Title: Re: Building a milling machine
Post by: philf on August 02, 2014, 01:12:33 PM
Today I made swarf!!!!!!!!

Well done Norman - you should be very proud! :clap:

:beer:

Phil.
Title: Re: Building a milling machine
Post by: S. Heslop on August 02, 2014, 01:20:53 PM
Today I made swarf!!!!!!!!

Nice! The machine looks fantastic.
Title: Re: Building a milling machine
Post by: Meldonmech on August 02, 2014, 02:03:52 PM

Well done Norman, I admire the way you solved each problem you encountered on the way, and deserve the success you have achieved.
          I agree a machine vice would make a nice addition to your mill.

                                                 Cheers David
Title: Re: Building a milling machine
Post by: awemawson on August 02, 2014, 02:20:52 PM
 :bow: :bow: SWARF  :bow: :bow:

Oh I know that feeling - you travel a long journey and in the end you get what you'd intended - oh SO satisfying  :ddb:

Now collect that swarf and melt it down  :lol:
Title: Re: Building a milling machine
Post by: vtsteam on August 02, 2014, 03:56:20 PM
Congratulations Norman!  :clap: :clap: :clap:

There must be very few people who have designed and built their own vertical mill from scratch, including making all the castings.

I also think a milling vise would add utility to your project. Toe cl(r)amps are pretty necessary too. Angle plates, etc, all needed, unless you have them already.

Collet spinner, rotary table, all desirable.

But the milling vise does seem like a really nice and not overly long project as the next thing to do with your new machine.

 :beer:
Title: Re: Building a milling machine
Post by: tom osselton on August 02, 2014, 08:07:12 PM
It's nice to see the swarf! Well done!
Title: Re: Building a milling machine
Post by: mattinker on August 02, 2014, 10:15:46 PM
Gratifying to see you get to this point!! I think Steves idea of making a vice is a good idea. I take chips to the scrap man and use "wheelium", car wheels whenever I can for structural stuff.

Well done, regards, Matthew
Title: Re: Building a milling machine
Post by: vtsteam on August 02, 2014, 11:03:50 PM
Norman's idea......  :dremel:
Title: Re: Building a milling machine
Post by: mattinker on August 03, 2014, 12:23:45 AM
Yes, your right!!

Matthew
Title: Re: Building a milling machine
Post by: NormanV on August 03, 2014, 03:25:11 AM
Thank you for your nice comments, it feels good to have finished but I also have a bit of an empty feeling. I'll just have to get on with the vice!
Title: Re: Building a milling machine
Post by: vtsteam on August 03, 2014, 07:48:36 AM
I've got a milling vise, but also always wanted one of the Atlas shaper pattern. I'd like to find drawings of that one.
Title: Re: Building a milling machine
Post by: nel2lar on August 18, 2014, 12:27:51 AM
Norman
Congratulation on your success. Casting has a great feel good feeling when a job comes full cycle. Very nice build.
Nelson Collar
Title: Re: Building a milling machine
Post by: awemawson on August 18, 2014, 06:27:22 AM
Norman, there's just shy of 2kGs of Sodium Silicate on the way to you via MyHermes

Enjoy!
Title: Re: Building a milling machine
Post by: Arbalist on August 18, 2014, 10:08:23 AM
Well done Norman.  :thumbup: Let's see a nice full shot of the machine.
Title: Re: Building a milling machine
Post by: NormanV on August 18, 2014, 01:42:53 PM
Thank you for your kind comments.
Thank you Andrew, I'll let you know when it has arrived.
Arbalist here is a full length photo, if you look closely you will see a 12" ruler propped on the front of the table.
The working envelope is X 290mm Y 150mm Z 210mm
I need to get a door made for the electrics compartment.
Title: Re: Building a milling machine
Post by: Neubert1975 on February 07, 2015, 04:54:32 AM
first  post in here, but a lot af looking arround.

Thats some extremly nice work you have done there, congratulation with the machine.
I was on that route my self some 5-6 years back, hard work, but rewarding.

As for casting, i am doing a little of it my self, and decidet on a little different way to heat it.
i use a oil burner from a house heating system, for several reasons 1 gas is expencive here in Denmark 2 i dont feel that safe with gas.
the oil burner starts it self, if it goes out, it will try to restart, if not succedet it turns off automaticly, and best of all, i was for free  :clap:

ps. sorry if my english isent correct, the most i have lirned from tv and from using the internet.
Title: Re: Building a milling machine
Post by: NormanV on February 07, 2015, 07:14:00 AM
Thanks Neubert. I considered a central heating burner but was not able to source one. My gas blew out in the wind once and then reignited a few seconds later. I was surprised that it didn't blow the lid off considering the size if the bang!
Title: Re: Building a milling machine
Post by: Neubert1975 on February 07, 2015, 08:28:07 AM
Hi NormanV
The thing with the gas blowing out, is actualy one og the reasons that i didnt wanted to use gas.
And the good thing for me is, that almost all oil burners in Dk are being replaced, beacuse they are to expencive to use.
But not realy that bad for a furnace, i think i use around 3 liters of diesel pr hour, and from cold, i can melt around 10Kg in one hour  :D
Title: Re: Building a milling machine
Post by: Jonfb64 on February 08, 2015, 04:52:16 PM
Hi Neubert,

That is an interesting looking furnace you have their. Could you start a new post of your own with more details and photos for us casters out there.

 :worthless:

Cheers

Jon
Title: Re: Building a milling machine
Post by: Neubert1975 on February 08, 2015, 06:51:11 PM
Hi Jon
I sure could, it just have to wait some time, we are revating all 50 houses in the area i live in, so every thing is packed away and stacked.
and i defenetly must take come new pics, since it has changed a fair bit  :thumbup:

Regards
Martin
Title: Re: Building a milling machine
Post by: NormanV on June 21, 2017, 12:48:54 PM
An update on my milling machine.
I completed it over two years ago and it has seen some use since then, not daily but quite often. Most of my work has been with aluminium but strangely enough it seems to be more accurate when I am cutting steel. (maybe I am being more careful?) One thing that has pleased me is that I have not had to adjust the squareness of the head. I have always worried that when I am rather ambitious with the cut that I take and the cutter jams in the work that it will pull the head out of "tram" . That does not seem to have happened, The marks left by the cutter seem to be square. The biggest problem is the Z axis. For coarse adjustment I move the table and for fine adjustment can use the slide on the head. The leadscrew appears to be approx. 2mm pitch (note "approx.") I need to fit a digital readout to it but finances restrict my options.
Overall I am very pleased with my efforts, Definitely worth it!
Title: Re: Building a milling machine
Post by: vtsteam on June 22, 2017, 09:48:41 AM
Great to hear Norman. It's a fine thing to use a machine that you built yourself!  :beer:
Title: Re: Building a milling machine
Post by: NormanV on June 22, 2017, 09:53:31 AM
Yes, it certainly does feel good.
Title: Re: Building a milling machine
Post by: vtsteam on June 22, 2017, 09:59:14 AM
Honestly?

Collecting surface rust on all that hand scraping. Buried under bits and pieces of odd stuff like old lawnmower parts, house wire, trowels, etc.

 :doh:
Title: Re: Building a milling machine
Post by: NormanV on August 17, 2017, 12:02:10 PM
Oh woe is me!
After two years of using my milling machine I have a problem.
Twice in the past when taking a heavy cut the motor has cut out. I assumed this was a thermal cut-out in the speed controller as it sprang to life after leaving for some time to cool down.
Today it happened again, I have left it for a few hours but it refuses to work again.
Wiring this up was at the limit of my knowledge, trouble shooting it is a whole new ball game!
It is so frustrating, I am working on a new project that has come to a complete standstill. Wish me luck.
Title: Re: Building a milling machine
Post by: awemawson on August 17, 2017, 12:48:42 PM
Norman, do you know what type of motor it is? (DC with a chopping controller/ 3 phase AC with an inverter drive etc) I'm sure with a few specifics revealed we can sort it out between us  :coffee:

(A few pictures of the motor and driver would help)
Title: Re: Building a milling machine
Post by: NormanV on August 17, 2017, 01:40:22 PM
Andrew, I am in awe of you skill at trouble shooting. I am not so good at it. I knew that I would be asked technical questions. Please wait until I am sober and I will have a look. :lol:
Title: Re: Building a milling machine
Post by: awemawson on August 17, 2017, 02:15:42 PM
.... sobriety doesn't always help  :clap:


 :beer: :beer: :beer:
Title: Re: Building a milling machine
Post by: NormanV on September 10, 2017, 10:52:25 AM
It's alive! :D

I finally got around to having a look at it. I took the cover off the speed controller and found a fuse that had blown. Fortunately I have a duplicate controller and tried the fuse from that. It is now working but obviously the fuse blew for a reason, I will see how this one holds out.

I can't understand the markings on the fuse cap, it is either P4/L250 or P4AL250, can anyone tell me what I need to ask for when I go to buy a replacement?
Title: Re: Building a milling machine
Post by: Neubert1975 on September 10, 2017, 11:41:50 AM
glad you got it up and running again.
when doing a google search for P4AL250 it comes up with a 5x20mm slow250v 1A glas fuse, if thats the right one, they can be found in all electronic shops.
Title: Re: Building a milling machine
Post by: NormanV on September 10, 2017, 11:44:24 AM
Thanks Neubert, why didn't I think of Googling it? :doh:
Title: Re: Building a milling machine
Post by: Neubert1975 on September 10, 2017, 01:38:54 PM
any time.
well maby you had other things to think about, and to me it was just nice to direct my thoughts in an other direction for a moment.