MadModder

The Shop => Tools => Topic started by: bogstandard on June 26, 2009, 04:16:18 PM

Title: Belt up!
Post by: bogstandard on June 26, 2009, 04:16:18 PM
You have read about these before when I have mentioned about them.

Most people who replace belts on their machinery, usually put a new v-belt on them or if they have a difficult installation, maybe a link belt. I have been using this product in industry for at least the last 20 years, and in my old shop I used this type of belt on both my mill and lathe, and found it superior to everything that I had used before.

I don't know if it is available in other parts of the world under a different name, but here in the UK it is called Redthane (or as I have now noticed, Greenthane). I buy it from my local engineering supplier, who always has it in stock (that shows just how popular it is with the maintenance guys).

http://www.poly-products.co.uk/beltext.htm

I purchase it in multiples of metre lengths, and it comes in a variety of sizes. The normal ones I use are 10mm or 12mm. It costs about 7 squid a metre, roughly the same cost as a good quality v-belt. I think it goes down in size to about 5 or 6mm for those really small pulley drives, and of course a lot larger, for real big stuff. The main advantage is that it can easily be made into any belt length that is required and can be joined AROUND say a lathe spindle rather than having to do a strip down to change the belt.

This shows what is left of my little stash, with enough left to finish off the die filer and the very long belt that is used on my surface grinder.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt01.jpg)


The die filer really requires a 12mm belt size, but because I don't have enough left, 10mm will be perfectly OK. As long as the belt doesn't touch the bottom of the groove, it will work perfectly well.
What I do is pull the belting around the pulleys as tight as I can, if you notice at the back of my hand, around the small pulley it doesn't look too tight, this was as tight as I could pull it. I marked it up with a gap of about 1.25" (32mm). The belt was cut at that mark.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt02.jpg)


This is a major component that is required to weld the two ends together. This is just a piece of steel plate with a twist in it to put it into the correct position for use. Also required is a blowtorch to heat the top end of the plate up to a very dull red colour.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt03.jpg)


Because I don't have three hands, it is very difficult to show you how the next bit is done, so I will have to explain it to you.
A bit of imagination has to be used here.
First, the plate is brought up to dull red, then the torch is taken away and using TWO hands, the belt is allowed to form into its natural round shape and once in that position each end of the belt is pushed against each side of the hot plate. It needs to be held there for about 5 seconds, during which time the ends will melt and start to 'run', you can see previous runs on the plate. Then in one motion, still with the ends being pushed towards the plate, both ends are slid up the plate and off the end, and the two melted ends are pushed together.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt04.jpg)


I then transfer it into a bit of old v-groove stock, you could just use a bit of angle iron. Then keeping pressure to push the joint together and also down into the v groove. I am showing it being done with two fingers, you would do it with two hands, it isn't because I am superman, just that I am using my other hand to take the piccy. Hold it in that position for about five minutes (if you can).
By using two pairs of hands, it is just as easy to assemble the belt around a shaft, as I mentioned before, saves having to strip down the lathe spindle. The spare pair are there to warm up the plate and hold it while you push the ends against it, and get things out of the way when you are finished with them.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt05.jpg)


Do NOT pull, push, stretch, twist, poke, or even fart near the joint at this stage, just place it gently onto the bench for 15 to 20 minutes for the joint to cure.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt06.jpg)


After you have waited the allotted time, then you can pull, push, stretch, twist, poke, or fart on the joint. If it doesn't come apart, you have got a good weld, if it does fall apart, then repeat the exercise. I have about a 99% success rate now. When I first started doing it, I got a few more failures than I really wanted. It is all to do with the melt, slide and hold bit.
Assuming all is well, carefully dress away the bulgy out bits with a very sharp knife or razor blade. Job done.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt07.jpg)


So that is two 12mm ones for my lathe and a 10mm one for the die filer.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt08.jpg)


Now fitted.
But it has couple of advantages that normal v-belts don't possess.

The first being that to change to a different pulley size, just stretch it over to the new pulley, no need to slacken off the motor and retension.
The next is that I have never had one of these belts slip, even when covered in grease and oil, as long as it has tension on it, it will drive, and unlike what you maybe think, it doesn't act like a big rubber band, and 'twang' all over the place, in fact I find that it smoothes out machine drives and makes them quieter.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt09.jpg)


I was going to make and fit a tensioner onto my lathe to allow me to swap over the belts between the speed ranges, but now, I will just stretch and reposition.

(http://i202.photobucket.com/albums/aa102/bogstandard_photos/Belt10.jpg)

These belts can be bought as two types, either solid all the way thru, or with a hole in the middle, as in tube. If you are welding it, you can use either one, the solid would give a much stronger joint (I use the tube, and have never had a joint fail in use in my shop, I can't tell you if any other of my joints have failed, as I no longer work for the companies). But if ever a joint did fail, just reweld it back together again.
For the tubular type, you can buy special little barbed couplings, that joins the two ends together. I have had those joints fail after a time in industry, so I would always recommend the welding technique if possible.


Bogs
Title: Re: Belt up!
Post by: Darren on June 26, 2009, 05:35:28 PM
Nice, I really must try some of that stuff...I just wish they did it in flat as well.

I know you can get modern flat join together belts, but I can't find a supplier in the UK.
Title: Re: Belt up!
Post by: John Stevenson on June 26, 2009, 06:00:19 PM
You can also get this type of belting in a proper V section as well as round.
Comes in M or Z, A,B and C still weld together.

Darren, ask you local bearing stockist for the green flat belting, ours stocks it in 10, 20 and 30 meter rolls of different widths.
You need a special cement for it and it has to be vulcanised.

Last place I worked we had the proper gear but it can be done without. We had a proper grinder than scarfed the joint, by that I mean it went from full thickness to a feather edge over about 2". It was pig to use so all the fitters just used to support the belt on a flat piece of wood and linish it to a scarf joint.
Do both ends but make sure you have the ends handed  ::)  Don't ask.

Thread it thru where it has to go, lay it out on a flat brass or alloy bar, apply the glue and stand the missus's best iron on it set at max for 20 minutes, take off, leave to cool and jobs a good un.

.
Title: Re: Belt up!
Post by: Darren on June 26, 2009, 06:18:07 PM
Hi John,

I ordered a belt from Benson Belting last year that was fitted as you described. Supplied cement with instructions etc.

It didn't last long, just slowly came apart next to the glue joint. The glue itself held. But they did say vulcanizing would be the proper way to do it. It was a leather/nylon belt. I had a lot of problems with slip too.

The best belt I have tried so far is a car serpentine belt, grips like a good un and seems very quiet. Don't laugh but it's held together with 5mm bolts and a bandage strip to straddle the joint. The heads sink into the grooves so don't touch the pulleys.
It's been on for a good while now, but I can see it failing eventually. The heads of the bolts seem to be pulling through slowly. I could re-do it but would like to fit a once and for all belt.

Bog's round belts look good, I wonder if two together would work on a flat pulley?

I would like to try a Fenner flat link belt, like the v-belts but flat. I just can't seem to find a UK supplier. 

I'd be quite happy to take the spindle out, I did once to fit the serpentine belt, but the bed goes right under the spindle too. Only way would be to cut a section of the bed out and I'm not about to do that......
Title: Re: Belt up!
Post by: bogstandard on June 26, 2009, 06:19:09 PM
John,

We used to use flat belting and vulcanising equipment on the envelope machines I used to work on. But that was more of a hardish heat resistant rubber with a fabric back, about 2.5mm thick, and as you said, a PITA to scarf it. More of a conveyor type of belting.

I have seen Redthane in the v-belt format but never as a flat belt.

The reason I use the round, it is much easier to roll on and off pulleys, plus you can get away with a 'not quite correct' size for those non critical jobs.

John
Title: Re: Belt up!
Post by: John Stevenson on June 26, 2009, 06:39:58 PM
No I have not seen the redthane in flat only the green rubber fabric flat belt.
We had proper fittings for vulcanising the belts. They were electric with a kettle type plug and two spring clip, one either end to hold the belt whilst you closed the hinged top.

Once vulcanised they literally wore out first.

.
Title: Re: Belt up!
Post by: Darren on June 26, 2009, 06:49:59 PM
This is the stuff

http://www.shopfloortalk.com/forums/showthread.php?s=82df363ff1c5e53c0e524199b838ce3c&t=18326&page=2

Anyone know where it can actually be purchased from, cos i have drawn a blank.

John S, I don't doubt you for a moment, Benson Belting almost insisted that they joint the belt before sending it to me due to the need of vulcanizing. But as I said that would have been useless.
The vulcanizing tool seems to be a rare beast as I've yet to find one.

John, Bogs, sorry I seem to have taken this thread over, I will try the Redthane and thanks for showing, it looks like good stuff.  :thumbup:
Title: Re: Belt up!
Post by: Bernd on June 26, 2009, 08:40:35 PM
Just did a quick search on the McMaster Carr catolog and found they sell this type of belting. It comes in green, orange and clear. Sold by the foot. The green goes for $5.19 per foot, Orange and Clear for $0.95 per foot. Why the difference I couldn't find out. Their welding kit goes for over $400.

I had to chuckle because I think Bogs may have spent $1.95 for his welding equipment.  :lol:

So there's one supplier. I'm sure the other major catalogs also carry something similar.

I remember my dad had some of that belting, it was green, for his pillar drill. Neatest stuff I had ever seen back then.

Bernd
Title: Re: Belt up!
Post by: bogstandard on June 26, 2009, 10:48:49 PM
Darren,

I don't mind it being taken over as long as a bit of good comes from it. All info, no matter how trivial, might be able to help someone one day. So don't worry about it.



I was very surprised Bernd, I hadn't realised I had spent that much, maybe a patent is called for seeing it is such an expensive bit of kit.

Maybe I should charge extra for having a left hand twist in the plate rather than a right hand one. :lol:


Bogs
Title: Re: Belt up!
Post by: Darren on June 27, 2009, 04:56:36 AM
Thanks Bernd,  McMaster Carr says this about their orange solid core

"Multiple strands of belting can even be used to replace conventional flat belts. To join ends together, use a weld-splice kit. "

And they have a Urethane flat belt too.......now that would be worth trying...


Cept we don't have a McMaster Carr in the UK...... :bang:

http://www.mcmaster.com/#drive-belts/=2huy2f
Title: Re: Belt up!
Post by: Bernd on June 27, 2009, 07:45:42 PM
Bogs,

That's why I got such a big chuckle out of the price. If people only were a little bit more mechanical inclined. But some need buy those tools to do it right. Oh well.

Darren,

I saw some of that other belting too. I did a search on another company and all they had was the belting with barb that Bogs was talking about.
McMaster Carr does have a lot of stuff.

Bernd
Title: Re: Belt up!
Post by: John Hill on June 28, 2009, 03:24:14 AM
Thats interesting Bogs that you have double-double sheaves on your lathe,  does the fibreglass cover still fit on?

Title: Re: Belt up!
Post by: bogstandard on June 28, 2009, 03:55:57 AM
Yes John, the cover still fits.

It was the very easy way Chester UK managed to take it from a 9 speed machine to an 18 speed one. Put two sets of pulley sheaves on there.

That was great, but they gave you no belt tensioning device to allow the belts to be swapped over easily.

You have a choice, gorilla tendencies and move the belts over by brute force without removing tension, chopped off or trapped fingers spring to mind. Or slacken the motor mounts off to allow the belts to be easily swapped over, then reset the motor and belt tensions, maybe a half hour and a two man job (unless each of your arms is four feet long). My way, once the cover is removed, about 30 seconds. Just like stretching a big elastic band.

Which method would you prefer?

John
Title: Re: Belt up!
Post by: John Hill on June 28, 2009, 04:37:50 AM
Very interesting, so far I have not really felt the need for more speeds but if I did your red belts is sure attractive considering those other options!   BTW,  I only use one belt anyway, they gave me two but one is quite a bit longer than the other! :scratch:  Meanwhile I have been happy to accept that one belt might be a bit of a safety valve if I do something really stupid!

I have another speed problem in that I cannot use the higher speeds as the starting current trips my circuit breaker and if I change anything it will be to resolve that, one idea has been to use a manual belt tensioner as a starting clutch and such a thing might fit in very well with another pulley ratio,  so many projects, so many days at the office! :doh:
Title: Re: Belt up!
Post by: DavesWimshurst on June 28, 2009, 11:42:50 PM
I have been using the red belting from McMaster Carr for experimental purposes for a while.  I have used the flat tip that came with my soldering gun to make the joints.  Held the gun in a vice with the switch wired on and used an auxiliary foot controlled switch to turn it on and off, otherwise same method as Bogs.
 :worthless:
Used it here for an overhead drive for milling spindle:

(http://i596.photobucket.com/albums/tt46/DavesWimshurst/tests%20and%20experiments/june28%20uploads/IMG_0399.jpg)
On several electrostatic machines such as this 12" Bonetti machine:

(http://i596.photobucket.com/albums/tt46/DavesWimshurst/tests%20and%20experiments/june28%20uploads/IMG_0388.jpg)

And this finger engine with decorative governor:

(http://i596.photobucket.com/albums/tt46/DavesWimshurst/tests%20and%20experiments/june28%20uploads/IMG_0398.jpg)

You can see the semi-untrimmed joint through the flywheel.

I've experimented with the 2 inch wide flat belting and found it is hard to join smoothly.  Had to make a special tip for the soldering gun.

Dave
Title: Re: Belt up!
Post by: bogstandard on June 29, 2009, 02:18:07 AM
You are a bit of a dark horse Dave, hiding all these wonderful machines from us.

But a nice post on just how versatile this belting can be.

People seem to think that such a long belt as you have used for your milling spindle would not be able to drive properly because of it's rubber band characteristics, but I have never found that an issue.


John
Title: Re: Belt up!
Post by: Darren on June 29, 2009, 07:28:56 AM
Polyproducts don't keep the flat belt Redthane type in stock.... :(

I tried..... :bang:
Title: Re: Belt up!
Post by: Bernd on June 29, 2009, 09:50:57 AM
Dave,

That overhead milling drive looks like an item that Guy Lautard discusses in one of his Bedside Readers.

BTW, nice looking finger engine.

Bernd
Title: Re: Belt up!
Post by: DavesWimshurst on June 29, 2009, 10:41:14 PM
Bernd,
Thanks, finger engines are fun bait to lure them what like shiny things!

Yes the overhead was in one of the bedside readers.  I find it useful for little milling jobs and for running this drilling spindle:

(http://i596.photobucket.com/albums/tt46/DavesWimshurst/tests%20and%20experiments/june28%20uploads/IMG_0402.jpg)

It's very quick to set up and small drills seem happier at the higher speed since the lathe tops out at about 1400 rpm.

For the milling spindle I use a heavier counterbalance weight to tension the belt but usually use it for light work.  It's also handy to use the chuck jaws to index work:

(http://i596.photobucket.com/albums/tt46/DavesWimshurst/intro%20pics/IMG_0081.jpg)

Nose of spindle with some collets 3/16, 1/4, 5/16, and 3/8 inch:

(http://i596.photobucket.com/albums/tt46/DavesWimshurst/tests%20and%20experiments/june28%20uploads/IMG_0401.jpg)

Dave
Title: Re: Belt up!
Post by: Bernd on June 30, 2009, 09:18:30 AM
Dave,

Thanks for the extra pictures. Really appreciate it.

Very nice tooling you have made for your lathe. And speaking of lathes, is that a South Bend? It looks like you've adapted a cam lock for that chuck.

I've got a Logan and need to get a new chuck for it some time soon.

Thanks again for the nice pictures.

Regards,
Bernd
Title: Re: Belt up!
Post by: DavesWimshurst on June 30, 2009, 10:07:21 AM
Bernd,
Yes, it's a heavy 10 bought new in 1980.  Camlock spindle was standard then with threaded spindle or long taper spindle being extra cost options.  The only mod to the lathe is a cam lever lock for the tailstock.  It is sort of visible in the last pic.
I also have an old Logan as sold by Montgomery Ward in 1944. 
Three of the chucks for the South Bend are made by Buck.  I have two Bison chucks made in Poland that seem pretty good.
Dave
Title: Re: Belt up!
Post by: Darren on July 25, 2009, 07:05:17 AM
I've rang around all my local (loose term) engineering supplies trying to find some Redthane belting.

Oh course no joy, they know about it, but don't stock it....bloomin' typical...!!

Same old story....

I'll have to try the manufacturers and see if they will send out smaller orders.


My new mill has that old type 'orrible Brammer link belt, the studs are touching the pulleys and causing some vibration in the spindle.
Whilst the surface finish is very even, it's not particularly smooth.
Title: Re: Belt up!
Post by: sbwhart on July 25, 2009, 01:01:06 PM
Darren

I could try and get you some from Crewe Engineering Supplies and bring it over with me next week

Stew
Title: Re: Belt up!
Post by: bogstandard on July 25, 2009, 02:32:50 PM
Stew, as you go into the counter area, look over to your left and down. It is all on a rack there. They usually have plenty in stock.

Make sure you get the right one for the size of belt groove.

If you want to be shown how to join it, I need to get the surface grinder out and fit a new redthane belt to that. I had to put the old belt back on there when I needed some redthane for a rush job a while ago.


John
Title: Re: Belt up!
Post by: Darren on July 25, 2009, 02:52:02 PM
That would be great Stew,

The mill needs an A sized belt which I believe is 12mm? I might have a go with it on the lathe as well when the current belt lets go. Two runs on that should do it.

It doesn't help that the Brammer belt someone has fitted on the mill is a B size, so it's dropping into the bottom of the pulleys and that's why the studs are clattering about.
Funny though, cutting steel seems fine, get a nice finish with that. But with alloy although it's not bad you can see something is amiss.

I'll have a measure up later and see how much I'd need.

Anyone have any idea how much this stuff is, it will have a bearing on quantity..... :dremel:


Edit:

A size belts are smaller than B section, please read a couple of posts down for an explanation.
Title: Re: Belt up!
Post by: bogstandard on July 26, 2009, 03:27:45 AM
Bank on around 10 to 12 squid a metre. I've haven't bought any that large for a few years.

I would just like to add, that I think this belting is great, and I have used it for many years in many applications and never had a problem.

Unfortunately, I am having my first problem with it on my lathe, and have had to swap back to the old belting system for the time being, until I have time to investigate further.
Both belts are exactly the same length, but for some unknown reason, the one nearest to the head is either throwing the belt out of the groove, or breaking the welded joint. I have swapped the belts over after rejoining, and the same thing is happening again, same inner pulley groove.
I suspect it has something to do with the pulleys themselves. It only happens when starting the lathe in very high gear, so I suspect that coupled to something wrong with the pulleys, and the intial stretch of the hi torque start brings on this strange phenomenon.

I thought I would mention it, just in case you want to revert back to putting on the link system, which in your case is a tried and tested system (when the right size is used).
I wouldn't want to fall foul of recommending a system to you that has a problem that I have never come across before.

John
Title: Re: Belt up!
Post by: John Hill on July 26, 2009, 04:31:30 AM
John,  re the two belts on your lathe.


Now,  you have two belts, I suspect  the pair of sheaves of at least one pulley is not identical, well we know they are not identical dont we as one pair of sheaves breaks the belt and the other does not.  Because the pulleys are not identical one gets slowly ahead of the other and this is a situation that cannot continue so one belt breaks.   

It is not unlike the effect of you get driving an early model Land Rover on the road with 4WD engaged, one axle goes 'further' than the other and the difference is taken up by winding the suspension until eventually the stress gets too much and one wheel looses traction and you get that rather startling bang from under the vehicle.
Title: Re: Belt up!
Post by: bogstandard on July 26, 2009, 06:08:52 AM
John,

Thanks for the insight.

That is the same sort of conclusion I came to, mismatched groove sizes. Because these belts have so much grip over a standard type, they just don't slip like a normal belt would in that situation, and balance themselves out, so something has to give. Depending where the joint was, either tighten up on one side, overstretch the joint and break it, or go too slack on the other side so the belt is thrown off.

I still don't know why it only happens with just the one pair. Why isn't it alternating between the two? Why is one belt always being classed as the master set that the other has to try to follow?
Maybe it has something to do with the surface finish down the grooves. Unless of course, it is the machine doing the most logical thing, giving the belt which always has the least stress on it priority over the other, leaving the one with the imbalance to take care of itself. Who knows?

I can see a good debate coming out of this.

Unfortunately I can't do a take out and fix at this time because I need the lathe for other work, and when I do get them off, I think Stew will be having a visitor to his already crowded little shop.

But I thought I had better warn Darren just in case he would suffer the same fate if he was using twin pulleys. As I said, it isn't nice when you thoroughly recommend something, and it all goes pear shaped. You tend to gain a rather bad reputation, and a few new unrepeatable names.

John
Title: Re: Belt up!
Post by: Darren on July 26, 2009, 06:30:34 AM
No worries John,
Can only have a go eh?

Re your problem, I agree the two pulleys are not exactly the same and it proves just how much grip this Redthane has as the punished one is obviously not slipping...!!




My current problem is finding out what section size I need.... :scratch:

I thought it was B, but now I think it's A after doing a bit of research.

The confusion came about by looking at the markings on some newish belts on other machines. In this case Halfords branded. According to them A is bigger than B...this is clearly wrong.

After looking at some belting charts I came up with these figures for the top width of V belts

A=13mm
B=17mm

And the depth

A=8mm
B=11mm

Armed with this info it seems I need an A sized belt for the mill.

The equivalent diameter for Redthane seems to be

A=10.2mm
B=12.7mm

So I believe most of our type of machines would use 10.2mm diameter Redthane on our A section pulleys.



I'm still trying to work out what Z & M sections are, I have a little drill that uses a small section belt...... :scratch:



Please if any info above is wrong then give me a  :poke:. I wouldn't want to mislead anyone that may read it.  :(

Title: Re: Belt up!
Post by: Darren on July 26, 2009, 06:33:39 AM
John,

Does the difference in Rethane section size actually make that much difference?

10/12 mm don't sound like enough to worry about if you get it wrong?
Title: Re: Belt up!
Post by: John Stevenson on July 26, 2009, 06:34:06 AM
John,

Had this many times on large saws.

What you need to do is take all the belts off and choose one belt.
Put it on pulley track 1 and mark the motor pulley with a paint marker and the belt, then mark the belt on centre of the driven pulley but not the pulley. Measure that distance.

Now turn the motor pulley 10 times and measure from that mark on the motor pulley to the driven the distance you measured and mark the driven.

Do the same in all the grooves with the same belt and in theory you will get the driven marks all in line.
in practice they will be out, By how much is dependant and the groove width and depth.

The trick is then determining which one, or both are out.

I used to have a two brass blocks that were a section of a B series belt [ only worked on B series so didn't need any others ] these were popped into a groove and measured across the backs and the readings compared and the grooves machined so they all matched the lower reading.

John S.

EDIT for Darren,
To all intents and purposes Z and M are the same at 3/8"
Title: Re: Belt up!
Post by: Darren on July 26, 2009, 06:37:41 AM
John,



EDIT for Darren,
To all intents and purposes Z and M are the same at 3/8"


Ah....that explains why the conflicting info I have been finding......well not conflicting if you know what I mean......

Thanks for the clarification....John.... :thumbup:
Title: Re: Belt up!
Post by: bogstandard on July 26, 2009, 07:25:53 AM
John S,

Many thanks for the checking info, I will use it when I get to doing the pulleys.

It might only be a couple of thou difference between the two, but it can cause major problems when things like this occur.


Darren,

When we used to use Redthane at work, we had it in stock most of the time. You can in fact get away with a smaller size if pushed, as long as it doesn't sit in the bottom of the groove, then it will drive OK, and can get you out of a situation if you run out of stock of the correct size, but it does overload the belt a little so is only a temporary measure until you get the right size.

This is all getting to a point of interest.

We wouldn't fit the belt by saying it is such and such a size for a given groove. We would measure the width at the top of the V groove and fit the next available sized Redthane down. So say it measured 14mm at the top we would fit your 12.7mm belting.
This is assuming you can have the belting sitting proud of the pulley. We did it that way because we knew that even though it isn't following the manufacturers guidelines, we were in fact fitting the strongest belt we could have on there. You did as much as you could to make the drive system more robust.
If you have very close fitting guards, then you have to go by the recommended sizes, which are to allow the belt to sit in the groove and not have the top edge protruding above the V groove. So the example of 14mm, you would most probably use the 10.2mm diameter.

John
Title: Re: Belt up!
Post by: shred on July 27, 2009, 09:10:34 AM
One other thought-- do you need both belts?  A number of the 12x36 crowd here just run one most all the time, and it sounds like the redthane can transmit more power than one ordinary belt.
Title: Re: Belt up!
Post by: John Hill on July 27, 2009, 04:22:59 PM
One other thought-- do you need both belts?  A number of the 12x36 crowd here just run one most all the time, and it sounds like the redthane can transmit more power than one ordinary belt.


I believe John needs all the power he can get when turning down old truck crankshafts making chew toys for Bandit.
Title: Re: Belt up!
Post by: bogstandard on July 27, 2009, 06:38:46 PM
Bernd,

As John has said, I need all the transmission power I can get.

Not because of the size of the jobs I do, but the speed I run the machine at. Because I make mainly very small brass and ali parts, I usually run at high speeds to assist in getting good finishes.

Even though I fitted a one sized larger belt, and had it sitting above the V groove top, I still wouldn't like to start up in a high gear with just one belt. It takes a lot of torque to run the machine up on initial start with a high gear selected.

For some reason, my machine is fitted with a 2HP motor than the one at 1.5HP as shown in the manual and all the literature, another reason not to have a weak transmission system on there.

I'm not unduly worried at the moment, the old belts are working OK, and when I get the time and inclination, I will get the pulleys matched up. The only problem I have is swapping between gear ranges, it is a real PITA with the old belts on.

Bogs
Title: Re: Belt up!
Post by: John Hill on July 27, 2009, 06:54:08 PM
John, I cant even get my started in the high speed ranges, not even after running for a while and warming the oil etc.  Mine is 2 HP two though I guess they are little under nourished Chinese horses.

Starting in a high speed range trips the circuit breaker which is only 10 amps.  Of course I could up the circuit to 20 amps but I fear for the longevity of the motor which has already failed once (though not from start up loads).  So I am seriously considering mounting the motor of a hinge (gate hinges look promising) so that with a lever I would have a slip clutch for starting in high speed ranges.  (So many things to do, including going to the office each day! :coffee:)
Title: Re: Belt up!
Post by: bogstandard on July 27, 2009, 07:16:13 PM
John,

Mine goes into full bore straight away, even on the highest range.

I did blow the caps on the motor a while back, and Chester UK replaced the motor, but forgot to ask for me to send the old one back, so not to waste anything, it was sent to the local council recycling facility.

Very soon after, I picked one up from the council recycling area, F.O.C., an identical motor match for my machine, but the caps were blown. Wasn't I lucky?

So I think I will just replace the two caps and I will have one ready to go if the need arises.


John
Title: Re: Belt up!
Post by: John Hill on July 27, 2009, 08:01:49 PM
Hmmmmmm.....  maybe mine would start the high ranges if I took the chuck off,  I assume most high speed work would be done with the collet chuck anyway.. :coffee:
Title: Re: Belt up!
Post by: bogstandard on July 27, 2009, 08:05:48 PM
There is only one way to go John.

Try it.

It just might be the drain trying to spin up a heavy chuck that is causing your problems.


John
Title: Re: Belt up!
Post by: Bernd on July 27, 2009, 09:03:07 PM
Ah John, are you off your meds again.  :lol:

How did I get involved in this conversaion about how many belts you use. See reply #35. Some how I got mentioned.  :borg:

Bernd
Title: Re: Belt up!
Post by: bogstandard on July 27, 2009, 09:40:44 PM
Sorry about that Bernd, it is BECAUSE I am on meds that the problems occur.


Now what's that damned name I use?

Ah! got it.

Steve
Title: Re: Belt up!
Post by: John Hill on July 29, 2009, 02:49:20 AM

It just might be the drain trying to spin up a heavy chuck that is causing your problems.


John

Yep, if I take the heavy chuck off and it spins up ok in the top cog! :thumbup:
Title: Re: Belt up!
Post by: JohnC on November 20, 2010, 10:56:40 AM
Thanks to all for the info on this thread.  I had to renew the drive belt on my DW mill:

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0065.jpg)

It was 1/4 in in old money:

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0067.jpg)

So 6mm should do it.  A length of solid Redthayne belt arrived, 6mm:

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0068.jpg)

I looped the belt over the pulleys and marked off, just like Bogs did above.  I subtracted 7% as
per instructions.  I tried Bogs' high tech welding device but couldn't keep the joint still enough between heating
and getting to the angle iron.  So, a low tech jig.  Apologies to those of a nervous disposition - the jig uses the fibrous brown stuff
normally used for making sheds:

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0070.jpg)

I trapped the belt in each side so it could just be pushed together after heating.

I used an old hacksaw blade, heated up and cleaned with emery to remove any deposits,
then heated to cherry red and placed between the ends of the belting.  In the time between
removing the heat and getting to the jig the blade had cooled somewhat, but still easily melted the belt :

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0073.jpg)

I then gently pushed the ends together and went off for a brew

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0074.jpg)

I trimmed the joint with nail clippers (saw that on another post - due credit)

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0076.jpg)

And - result!

(http://i1094.photobucket.com/albums/i456/JCphotob/DSCN0077.jpg)

The 7% shortening seemed a lot, but the belt stretched nicely over the pulleys and the joint
shows no sign of weakening.

(And Neebs - if you read this, yes, that is your old machine, doing sterling work!! :beer:)

Again, thanks and due credit to all on here who provided inspiration.

John
Title: Re: Belt up!
Post by: andyf on November 20, 2010, 01:33:55 PM
Thanks to all for the info on this thread.  I had to renew the drive belt on my DW mill:

It was 1/4 in in old money:

So 6mm should do it.  A length of solid Redthayne belt arrived, 6mm......


That's posh, John!
My Mk1 DW had a car fan belt on when I got it, so when I re-motored it for variable speed and ended up with the pulleys a bit further apart, I just got a new one from the local car accessory place.

I think your pulleys have narrower grooves, though.

Andy
Title: Re: Belt up!
Post by: JohnC on November 20, 2010, 03:35:59 PM
Hi Andy,
The pulley grooves are semi circular section - not sure where they came from. I have another mill with 'A' section belt. That said,as has been mentioned above, the 'thane belt runs well and doesn't 'balloon' from the pulleys.   
John
Title: Re: Belt up!
Post by: Jonny on November 20, 2010, 04:15:27 PM
Slightly off topic whats the stuff you can buy to spray on the belt or V pulley to reduce slipping?