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Gallery, Projects and General => Project Logs => Topic started by: Spurry on December 04, 2016, 02:12:36 PM

Title: Lathe mounted slotting attachment
Post by: Spurry on December 04, 2016, 02:12:36 PM

In order that I can avoid the possibility of arrest for Cruelty to Lathes,   :palm: (see the vice speed handle thread), to make any future square holes or keyways I thought it best to make a proper slotting attachment, instead of using the lathe carriage.

I have found an old toolpost that I made for a large? 22mm boring bar. Just fits in place of the QCToolholder. A thought passed through my mind that this could be a good basis for a slotter, with the ram on one side and a pivot on the other.

Looking round the internet there seem to be many variations on a theme. One I looked at, even had what appeared to be four pivoting links, so not quite sure how that worked in practice.
Has anyone any tips or advice especially handle/ram ratio and placements of pivot points. I am looking at mounting a 22mm ram in a 100mm long x 60mm square of cast iron bar mounted in one side of the toolpost. (Size chosen as I have a 22.00 reamer.  :wave: )

The toolpost is 75mm square with a 12.00 central hole and is 50mm tall. The old boring bar sat at lathe centre height, (in the rusty bit.)

TIA
Pete
Title: Re: Lathe mounted slotting attachment
Post by: DavidA on December 04, 2016, 04:20:37 PM
Just wondering how the assembly will stand up to the rather jarring action of the cutter being used. Won't it tend to try and rotate around it's central bolt ?

Dave.
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 04, 2016, 05:58:09 PM
Thanks Dave, I had wondered that too. On the QC toolpost there is a pin that locates the block in line with the top slide. With some careful measuring I could add such a pin to this toolpost, but not sure if in it's design it was meant to resist possible turning motion, or just as a locator for squareness.  :scratch:
Pete
Title: Re: Lathe mounted slotting attachment
Post by: mexican jon on December 05, 2016, 01:04:17 AM
I'm not at home so can't take a picture of mine  :( but it is based around this 1 which I found on the net  :thumbup: it uses an original top slide but is similar in design as to your thinking  :headbang:

Title: Re: Lathe mounted slotting attachment
Post by: Pete. on December 05, 2016, 03:01:41 AM
Just wondering how the assembly will stand up to the rather jarring action of the cutter being used. Won't it tend to try and rotate around it's central bolt ?

Dave.

Can't see it being a problem. Cutting a few thou deep every stroke doesn't require much force.
Title: Re: Lathe mounted slotting attachment
Post by: BaronJ on December 05, 2016, 10:15:22 AM
Hi Guys,

I thought that you might like to see mine.  I built it to put keyways into bronze gear bores.  It is built to fit directly onto the Myford QCTP.

Title: Re: Lathe mounted slotting attachment
Post by: jcs0001 on December 05, 2016, 11:28:37 AM
Neat project - I will be watching.

If you could reduce the distance from the mounting point of the toolpost (the bolt through the centre) to the sloter ram, it would reduce the amount of torque when using the slotter.   Not sure if that's needed but just my $.01.

John.
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 05, 2016, 11:55:55 AM
Thanks for the interest.  :clap:

Baron - could I ask what the total ram travel is, distance between the centres of pivot and the handle, and length of handle. Is the ratio about right for the amount of effort needed?

Pete/Dave, I cannot fit the pin as it would go through the slot corner. However the top-slide itself is 76.18mm wide, so would be a simple matter to add a restraining bar on one, or both sides of the actual toolholder, to prevent it from pivoting...... should it be necessary.

The ram will have to go on the inside slot of the toolholder, as the cross-slide runs out of travel before the ram would get anywhere near centre if it was on the outside. I was hoping it would fit the other way round. :scratch:

Pete
Title: Re: Lathe mounted slotting attachment
Post by: DavidA on December 05, 2016, 02:00:59 PM
Pete,

Yes, some kind of retaining bar/block should do the trick.

Baron,

I like it. Must add that to my to-make list.

Dave.
Title: Re: Lathe mounted slotting attachment
Post by: RobWilson on December 05, 2016, 02:25:04 PM
Evening Pete


This be my lathe slotting attachment , cuts a 1/4 keyway in steel no bother,thats not to say it will not cut larger ,its just the larges I have cut with it .

(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P1040910_zpsdpw20aak.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P1040910_zpsdpw20aak.jpg.html)
(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P2220005_zps25e447dd.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P2220005_zps25e447dd.jpg.html)
(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P1080306_zps2471p5ne.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P1080306_zps2471p5ne.jpg.html)


Stainless steel steering wheel boss splines .

(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P1020074_zpsab588c71.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P1020074_zpsab588c71.jpg.html)


Cast iron gear


(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P1010568_zpsb529843c.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P1010568_zpsb529843c.jpg.html)
(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P1010574_zpsf87byjdw.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P1010574_zpsf87byjdw.jpg.html)
(http://i1066.photobucket.com/albums/u410/RobWilson100/Lathe%20slotting%20tool/P1010583_zpsf38a70e7.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Lathe%20slotting%20tool/P1010583_zpsf38a70e7.jpg.html)

File attached ,scale as required  :thumbup:


Rob
Title: Re: Lathe mounted slotting attachment
Post by: mexican jon on December 05, 2016, 02:44:42 PM
Rob that is some impressive work there  :drool: :drool:
Title: Re: Lathe mounted slotting attachment
Post by: PekkaNF on December 05, 2016, 03:56:47 PM
Those slotting gadgets are interesting and many of them seem to ownd design to graduating tool.

This type:
http://www.hemingwaykits.com/acatalog/Keyway_Slotting_Attachment.html
http://s1247.photobucket.com/user/don1966/media/KEYWAY%20SLOTTING%20ATTACHMENT/IMG_1750_zps515a6f0e.jpg.html
http://mikesworkshop.weebly.com/toolpost-slotting-tool.html

There is some designs build to tail stock, much like lever drilling feed, can't rememeber maker.
This one was used for drilling, but looks strong enough for slotting
http://www.bikepete.f2s.com/pics/hardinge-tailstock03.jpg

Some years back I read about one clever design that moved the whole big slide assembly (to avoid rocking of the tool post type thing when you hang on the loever), arms were pretty long on that one. I liked the design, but after reading descrioton I bought a set of standard keyway broaches and later a hydraulic press.

Still thinkking of making a gradutaing tool, possbly stong enough to make those nonstandard keyways...

Pekka
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 05, 2016, 06:22:06 PM
That's a lovely bit of gear Rob.  :clap:  Thanks for the link too. Have you kept to the pivot ratios as per the drawing?

Pekka. We must move in similar circles.  :thumbup: The first one I looked at was the Hemingway one, but thought it very expensive. I had looked at Mikes one too. That one gave me the idea of using the old toolpost. The tailstock one looks interesting, but I was hoping to save a bit of work. That's probably the strongest setup though.

Thanks again to All, for the hints and tips.

Pete
Title: Re: Lathe mounted slotting attachment
Post by: RobWilson on December 06, 2016, 01:21:00 AM
 His Pete

Mine is built exactly to the drawing no changes . It's a well designed tool.  :dremel:


Rob
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 06, 2016, 06:11:48 AM

......built exactly to the drawing no changes . It's a well designed tool.  :dremel:

Rob
Mmm. Not quite, your handle is much more posh than the original, for a start.  :bugeye: :bugeye:. I had forgotten all about that item in the issue of MEW from 1991. Pity it did not even make it onto the front page.

Having translated some of those dimensions to metric, there is only 1.38mm between the edge of the main mounting hole and the edge of the ram bore, whereas in my initial thoughts, mine was looking at somewhere around 40mm. As has been pointed out, this could cause a problem.... back to the drawing board. :scratch:

Pete
Title: Re: Lathe mounted slotting attachment
Post by: BaronJ on December 06, 2016, 12:36:03 PM
Thanks for the interest.  :clap:

Baron - could I ask what the total ram travel is, distance between the centres of pivot and the handle, and length of handle. Is the ratio about right for the amount of effort needed?

Pete

Hi pete,

From memory without having to go into the workshop tonight.  :coffee:

The travel is about 1" (25mm)  The handle to pivot ratio is 12.  FWIW the ram was made from an old pulley key, machined to give a square section and the end drilled to take the tool bit with a 1/4" BSF allen grubscrew to hold it in place.  The body is made from a tool holder that fits into the QCTP.  The brass adjusting screw was fitted to remove any play whilst giving free movement.

Note that the ram runs on thin brass (0.4mm thick) strips inserted top and bottom.  This prevents steel on steel galling under pressure.  The handle is a 13" length of silver steel with a heat shrink hand grip.

I have some pictures of its construction if you want to see its bits.

Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 06, 2016, 03:00:37 PM
Hi Baron
Thanks for the info. :thumbup: I have already ordered some stuff for my original design, some of which arrived today. A piece of cast iron bar 60mm sq x 150mm and 4 pivot bolts. I await the 22mm silver steel for the ram. Currently trying to rearrange things to suit a new design, a bit in line with the one Rob shows above.
Thanks again
Pete
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 09, 2016, 07:34:39 AM
The new design will be based loosely on Rob W's slotter from the original MEW article from 1991.
Main difference will be no casting used. (CES appear bashful about price and availability of stock.) Their casting is designed to be fitted to the cross slide, whereas I prefer the top slide placement.
Main disadvantage of mine is that I cannot have the ram and pivot points on opposite sides of the main retaining stud, as the cross slide runs off it's thread.
Some sizes have been altered for material I had in stock. The pivots will utilise allen headed shoulder bolts.
A start has been made on the handle, and pivot links so far. The two sets of pivot links were drilled and reamed separately using DRO, fitted with the bolts to confirm accuracy.
Pete
Title: Re: Lathe mounted slotting attachment
Post by: John Rudd on December 09, 2016, 07:54:26 AM
Looks good Pete, I did look at the casting on CES, but like you couldnt see the price....annoying really!
I would  have suggested it but for that reason.....I have one on my list somewhere.... :scratch: the casting is currently wrapped in newsprint under the bench.... :dremel:
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 09, 2016, 08:10:01 AM
Looks good Pete, I did look at the casting on CES, but like you couldnt see the price....annoying really!
Thanks John. I got as far as sending them a price-request email. A second email requesting the last price it sold for, goes unanswered. I also asked for the units mentioned under cast iron bar, no response on that either. You can select 1 or more units, but no mention of what - mm, cm, inch, foot, yard or metre. :doh:
Pete
Title: Re: Lathe mounted slotting attachment
Post by: John Rudd on December 09, 2016, 08:51:36 AM
So, all in all pretty helpful?....not!
They were so much better before they were taken over/ sold on.....

I emailed them not long since for some cast iron billet, got a reply, phoned them up and got it delivered almost two days later...service was great...not now tho'.....
Title: Re: Lathe mounted slotting attachment
Post by: stvy on December 10, 2016, 07:28:10 AM
Hi,

This is an interesting project. So I rang CES and they told me that this casting (and a few of the others you can't currently add to your basket on the website) are out of stock and the foundry should deliver in January 2017.

I also asked about getting a bit more stock on it for increasing the center height. I need 76mm + some machining allowance up from the stated 52.4mm if I put it on the top slide. I don't have a t slotted cross slide so I think the top slide is a better compromise. He was none committal and suggested I put it in an email. I have a between centers boring bar but the minimum size it can bore is 13/16", so I should either upscale the whole casting or have to make another between centers boring bar.......  So I conclude no casting for me  :doh:, instead I need to buy a block of cast iron.

Regards,
Steve

Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 10, 2016, 02:05:26 PM
Steve
I got my block of cast 60mm x 60mm from a chap on EB. His name can be PM'ed if required. I don't know if we are allowed links in public here.
The ram on mine will be 22mm, so slightly upscaled from the original.
Pete
Title: Re: Lathe mounted slotting attachment
Post by: krv3000 on December 10, 2016, 05:23:26 PM
I have seen rob's up close and its as good as the pics its like tool porn im on making one but mine is fitting in the tool post as my lathe is only a liltel one 
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 15, 2016, 02:27:08 PM
Some slight progress.
1. Parted off the handle, drilled 12mm. Turned a 12mm spigot on the 1" x 1/2".
2. Two parts fitted.
3. Following being attacked with the mig welder.
4. Cleaned up with roll sander.
5. Roll sander
6. Poor mans surface grinder? (with the roll)
7. Finished effort. Just got a slight undercut where the weld started/finish on the 1" x 1/2".  :scratch: Any ideas how to avoid that?

Pete
Title: Re: Lathe mounted slotting attachment
Post by: RobWilson on December 15, 2016, 03:46:09 PM
 :clap: :clap: :clap: Nicely done Pete  :thumbup: 


Looks like your making good progress  :dremel:


Rob
Title: Re: Lathe mounted slotting attachment
Post by: PekkaNF on December 16, 2016, 05:33:20 AM
Very nice work. Looks like it is going to one solid tool.

.... Just got a slight undercut where the weld started/finish on the 1" x 1/2".  :scratch: Any ideas how to avoid that?

Pete

I have experienced same thing with hand held tools. When sanding into step/stop just can't controll it well enough. Sometimes it helps a little to grind from the other side....sanding drum will try to lift a little instead of digging in. I'd just leave it as it is. It shows that it has been hand finished lovingly and not mass produced. It looks good. And anyone done the same thing appreciates it - fools don't see nor understand the difference.

Pekka

Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 17, 2016, 12:22:52 PM
Thanks for the comments.
Just waiting for a new piece of cast iron to arrive. After a re-design of the re-design  :scratch:, I have decided that the best way of ensuring that there can be no possibility of sideways movement of the ram is the have a lip on three sides of the body, so that in effect it hooks-over the top-slide. It does mean though, that the hole for the securing stud will have to be very accurately placed and drilled... :scratch:
Pete
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 22, 2016, 02:13:37 PM
A little progress after the new chunk of cast iron arrived. Pic 1 Nominally it is 130 x 60, but is slightly hollow on the width.

Pic2 shows the recess being rough cut with a 20mm Little Hogger, after marking out.

I deliberated for quite a while as to whether to drill the stud hole first or last, and decided to drill it first.
 
The stud was locked into the top-slide by a hex-keyed screw from underneath, so was easy to remove.

Pic3. The recess was finished to size with a 6mm carbide 2 flute, usually used on my router, and it worked well. Also used to finish the whole depth to size.
 
The part-finished chunk fits the top slide like a glove. I would like to say that the stud just dropped in...but cannot. :(
After using a 1/2" drill to enlarge the 12mm hole..it now fits, as pic4.

Pete
Title: Re: Lathe mounted slotting attachment
Post by: krv3000 on December 22, 2016, 05:29:04 PM
its coming a long
Title: Re: Lathe mounted slotting attachment
Post by: Manxmodder on December 24, 2016, 06:48:57 AM
I have a lever operated capstan attachment which came as part of the accessories for my L6 Harrison.

I have,on a couple of occasions, considered fitting an indexable boring head to one of the turret sockets and using it as a lathe bed slotter. It would involve disabling the automatic rotary indexer mechanism,but I think the idea has merit......OZ.

Title: Re: Lathe mounted slotting attachment
Post by: Spurry on December 24, 2016, 08:09:39 AM
its coming a long
Albeit...slowly  :thumbup:
I have a lever operated capstan attachment which came as part of the accessories for my L6 Harrison.

I have,on a couple of occasions, considered fitting an indexable boring head to one of the turret sockets and using it as a lathe bed slotter. It would involve disabling the automatic rotary indexer mechanism,but I think the idea has merit......OZ.

That mechanism looks as it would make a very nice slotting unit. I have never seen anything like that for my Harrison M250.
Pete

Title: Re: Lathe mounted slotting attachment
Post by: Manxmodder on December 24, 2016, 08:30:32 AM
The design for the M300 is more traditional with the capstan wheel to operate it and the turret set at an angle.

Here's a photo of one for an M300....OZ.


Title: Re: Lathe mounted slotting attachment
Post by: Spurry on January 16, 2017, 04:42:06 PM
A little more progress today. Project was stalled for the lack of a 21.50mm drill. Ordered one which came after Christmas.
Then I saw a cheaper one 27/32" on EB so bought that too. When I mounted the 21.50mm drill today, the parallel section at the end of the flutes was eccentric by what looked like a millimetre, so not much good.
Fortunate that I had the other one, which worked perfectly,(in the same 5MT-3MT and 3MT-2MT adapters)
As I had to use the lathe for other jobs, I had removed the body from the top-slide.
Before doing so, I measured the carriage to cross slide distance and wrote it on the top. This gave me a good start to ensure a concentric hole with the existing 21.00mm bore.
Followed by the 22mm reamer  and trial fitting of the 22mm ram.
TBC
Pete
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on February 09, 2017, 10:59:46 AM
The ram pivot caused me a few problems, experimenting with either machining the 10mm hole, slot, or thread first. eventually ended up with a usable one. (1)
The collection of bits (2)
Ram assembly complete (3)
Pete
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on February 09, 2017, 11:06:32 AM
At this stage it would have been good to say it worked fine, but when fitted to the lathe, the handwheel was in the way.  :scratch:
Alas, I had forgotten the extra thickness on the bottom of the ram pivot, so milled 3mm off, (pic 1) shows  temporary 10mm pin for checking clearance.
Now sorted (Pic 2)
Pete

PS Nearly forgot. Enormous thanks to Rob Wilson for his inspiration and assistance.  :thumbup:
Title: Re: Lathe mounted slotting attachment
Post by: RobWilson on February 10, 2017, 03:12:40 PM
Very nicely machined Pete  :thumbup:


Looks like your well on the way to having this finished  :dremel:

Rob
Title: Re: Lathe mounted slotting attachment
Post by: Biggles on February 11, 2017, 05:44:55 AM
Nice work pete, I see CES are advertising a casting but with no price!  :coffee:
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on February 11, 2017, 04:43:29 PM
Rob & Biggles, thanks for comments.
Rob, you cannot rush these jobs.  :bugeye:
Biggles, not much improvement to replies #19, #20 and #21 then. :doh: Their casting would not be much use, (to me) without a large mounting plate underneath it.
Pete
Title: Re: Lathe mounted slotting attachment
Post by: RichardShute on March 11, 2017, 01:51:11 PM
No point in rushing indeed, mine started as a lever operated tailstock that looked like a quick conversion, but obviously wasn't.

I then made the fabricated body and got bogged down with other stuff for ummmm, about 6 years! Well, I needed to let the fabrication settle down and stress-relieve, didn't want it moving about once I'd flattened the base now would I?

It's made to fit in place of the compound slide on my S&B Sabel and with minor modification can fit on either of my other lathes. it'll obviously also fit a Boxford or SB9 as is. The link bearings are a bit small for preference, but with the work load it's likely to get I don't see it as an issue.


I finally only finished it last week because someone else wants to borrow it. It goes without saying that the job for which I had it ear marked turned out differently and it wasn't needed and I now have a slotting head for the mill in any case......

Ho hummm
Richard
Title: Re: Lathe mounted slotting attachment
Post by: Spurry on March 11, 2017, 02:10:41 PM
Richard
That looks like a hefty old casting to start off with. Was the cast section much of a problem to weld?
Pete
Title: Re: Lathe mounted slotting attachment
Post by: RichardShute on March 12, 2017, 03:44:01 PM
Hi Pete,
sorry to have mis-led you, I didn't use the casting at all in the end, just the barrel and moving bits etc. The whole body is a fabrication, 2" steel round at the top, 5/8" 'something nasty' plate for the base and some 5mm black iron plates for the sides and end. What I had lying about in other words.

Cheers
Richard