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wierdscience
03-03-2008, 02:43 PM
Someone here posted a pic once of a modified tailstock.It allowed lever feed in additon to the normal handwheel feed in the same unit.

Could not find it in the archives any clues?

JRouche
03-03-2008, 04:39 PM
Was it this one?? JRouche



http://bbs.homeshopmachinist.net/showthread.php?t=25528
http://img.photobucket.com/albums/v366/Jrouche/1188.jpg

John Stevenson
03-03-2008, 05:26 PM
This post is of interest to me as my small TOS, 14 x 40 has a MT4 tailstock but only 100mm [ 4"] of travel.

What makes it worse is that with normal MT4 tooling anything less than 20mm ejects the tool.

If I chop the thread down so it gets to zero then it will only reach 80mm [ 3" and a bit ] travel.

I would dearly like to fit a rack and pinion feed with capstan type handles but still retain a fine feed for odd jobs.

What really pisses me off is two weeks ago I had a stepped shaft in out of a crane gearbox, 50mm down to 40 and the last 2" had snapped off the 40mm bit.

The 50mm part was a ground finish and my barrel is 50mm diameter.

By the time I realised, it had gone back and a phone call to the plant failed to find it [ big chemical plant ]

If you have ever used a tailstock with lever feed you will never go back to winding hand wheels.

.

IOWOLF
03-03-2008, 05:49 PM
I may be a little Dense today, but Just how is that supposed to work?

Will the handwheel act like a stop?

wierdscience
03-03-2008, 09:00 PM
Not the one I was thinking about,but along those same lines.The one I remember was built around a SB9 tail IIRC.


Jay,not much good as a stop,but it allows the original handwheel and screw to be used for heavy drilling and holding a center for turning,but can be unlocked to allow a lever feed similar to a Hardinge 2nd op turret lathe.

I had to drill through 14" of 2" cold rolled the otherday with a 1/2" drill.That was a lot of cranking.Peck drilling with a TS sucks.

wierdscience
03-03-2008, 09:04 PM
This post is of interest to me as my small TOS, 14 x 40 has a MT4 tailstock but only 100mm [ 4"] of travel.

What makes it worse is that with normal MT4 tooling anything less than 20mm ejects the tool.

If I chop the thread down so it gets to zero then it will only reach 80mm [ 3" and a bit ] travel.

I would dearly like to fit a rack and pinion feed with capstan type handles but still retain a fine feed for odd jobs.

What really pisses me off is two weeks ago I had a stepped shaft in out of a crane gearbox, 50mm down to 40 and the last 2" had snapped off the 40mm bit.

The 50mm part was a ground finish and my barrel is 50mm diameter.

By the time I realised, it had gone back and a phone call to the plant failed to find it [ big chemical plant ]

If you have ever used a tailstock with lever feed you will never go back to winding hand wheels.

.

John,down near the bottom on this page is a mini lathe conversion I stumbled over while looking last night.Not a bad idea,just dunno how good dragging the tailstock would be.

http://www.stellar-international.com/lathe.html

I supppose making another barrel and fitting a rack in the bottom would solve the problem as well,just be more work.

BobWarfield
03-03-2008, 09:08 PM
Here are some pix of a Hardinge set up this way:

http://www.cnccookbook.com/img/OthersProjects/Tools/HardingeTailStop.jpg

http://www.cnccookbook.com/img/OthersProjects/Tools/HardingeTailStop2.jpg

http://www.cnccookbook.com/img/OthersProjects/Tools/HardingeTailStop3.jpg

Cheers,

BW

boslab
03-03-2008, 09:14 PM
i did have a little myford ml10, it came with a capstan attatchment for the tailstock, you removed the handwheel by taking out the retaining plate screws and a cast block fitted into the same place, it had a pinon gear that engaged with the thread on the tailstock barrel, it looked like a three arm handwheel off a drill press, very sensitive so great for small stuff, sold the lathe a while ago and dont have a photo
regards
mark
http://www.myford.com/pricelist/General%20Accessories/Section%205%20-%20Rack%20Operated%20Tailstock%20Attachment.pdf

Carld
03-03-2008, 10:06 PM
http://i82.photobucket.com/albums/j276/yeathatshim/Drillingattachment.jpg

This is a drilling attachment I made for my Logan lathe my son has now. I used the original quill and made a shaft that threaded into the quill and a new end cap for the tailstock the shaft goes through. I made a cap for the end of the shaft and all the linkage in the photo. It works very good and I want to make one for my current lathe but haven't gotten a round tuit yet as they say.

S_J_H
03-04-2008, 08:41 AM
I did a lever feed mod on my old 9x20. Except for drilling with large bits it was great. So much faster than screw feed.
http://i109.photobucket.com/albums/n48/S_J_H/misc/lathemods005.jpg

Steve

lazlo
03-04-2008, 10:12 AM
Weirdscience (and John) are looking for the Holy Grail: a tailstock lever attachment that keeps the handwheel/leadscrew (fine) feed.

The Hardinge 2nd Op tailstock that Bob W posted, for example, doesn't have a handwheel, and the HLV-H tailstock has a handwheel but not a lever.
The Schaublin lathes had two tailstocks available: one lever-driven, and one handwheel driven.

I've never seen a tailstock that had both -- I'd love to see one!

I've thought about adding a rack and pinion feed to a conventional handwheel tailstock: you could make a telescoping leadscrew driving the quill, with a rack cut into the bottom of the quill. Then you could use the rack and pinion driving the quill directly and the handwheel/leadscrew at the same time.

Carld
03-04-2008, 10:21 AM
Not so Lazlo, had I made the threaded area longer on the shaft I made and designed the end cap on the end of the shaft different I could have had a handwheel to use with the lever. The down side is if I used the lever to extend the quill and then used the handwheel to further extend the quill it would push the quill out of the tailstock.

With that in mind, one would have to use the lever with the handwheel screw fully in the quill. Then if using the handwheel the lever would have to be fully retracted and locked with a pin or screw into the shaft.

It can be done and I considered doing just that but since I still had the handwheel system intact and could easily switch between lever assy or handwheel assy I didn't make it a combo lever/handwheel system.

With my lever system I had to make a wedge to remove the tapers from the quill so one has to be aware that if they can't screw the handwheel in to pop the taper out they will have to wedge it out.

lazlo
03-04-2008, 10:49 AM
Not so Lazlo, had I made the threaded area longer on the shaft I made and designed the end cap on the end of the shaft different I could have had a handwheel to use with the lever.

That's intriguing Carl, but I'm not following how that would work: the handwheel leadscrew nut is fixed to the tailstock quill, and the leadscrew pushes the quill away from the thrust bushing that's screwed into the tailstock body.

I don't see how you could move the quill with the lever action if the leadscrew is screwed into the quill nut, without something like a telescoping leadscrew?

BobWarfield
03-04-2008, 11:28 AM
These lever feed attachments make we wonder if there is not some way to also gain a slotting ability. Would need a slotter attachment to hold the tool that goes in the tailstock taper and can be offset. I guess ultimately not as nice as the more typical slotter attachments, but perhaps simpler in a pinch.

Best,

BW

Carld
03-04-2008, 12:46 PM
This may be hard to understand but here goes.

If you look at my setup the shaft that is screwed into my quill has a cap on the end that the lever moves back and forth.

If I were to put a bearing in the cap and a thrust washer on each side of the cap and run the shaft at a reduced diameter but now a little longer through the thrust washers and bearing in the cap and put the handwheel on the end, the shaft would turn in the cap.

Now, if I extended the thread that goes into the quill to the same length of the original tailstock screw and screw it into the quill all the way, the lever would move the quill in and out of the tailstock. If I retract the lever and lock it in place so the shaft will turn but will not move back and forth then I can turn the handwheel to feed the quill out and back in.

That was one way I had planed to go but I needed the lever feed for a project and didn't want to waste time when I could switch to the original setup easily. I would have had to make everything more rigid and make a stop to rigidly hold the cap in a fixed spot as it can't move at all when using the handwheel.

wierdscience
03-04-2008, 10:45 PM
What Steve and Carl have posted is very close to what I have in mind.Steve has the same lathe(9x20) in fact as I want to modify.I want three things actually from this mod.First lever or rack feed,second keeping the screw feed intact,not so much for drilling,but setting centers and third increased stroke length.The 9x20 only has 1-1/2"?IIRC,not enough really.

I am leaning towards boring the TS body out to 1-1/4" to accept a length of chrome cylinder rod which I would also bore one end to accept the old TS barrel.I figure set it up complete with screw and knockout stub.The only thing the screw adjustment would be used for is setting centers and knocking out the tool,so it really only needs a 1" total travel.The new barrel I would make 9" long OAL.That would yield about 4" of total travel not counting the screw feed.

I figure the old barrel lock can be used to lock the extended outer barrel and a collar can be added to the front of the new barrel to act both as a lock and a positive stop to maintain position when turning in the lathe between centers.

The new extended barrel I might run with rack and pinion since there is enough beef in the bottom of the TS casting to accept a slot for it to run through.That would also solve the short comings of the typical pin and slot barrel location.

Or,I might just make another TS top half,it might be easier.

This could be fun:D

oldtiffie
03-05-2008, 07:31 AM
There is a square (paradigm?) that needs to be thought outside of here.

That you need the function of a basic tail-stock does not mean that you need a tail-stock as normally used.

The TS is one of the weakest and worst designed of any part on a lathe, so using a tail-stock may just be "putting lip-stick on a pig".

If I did want to use the tail-stock, I would be inclined to put it ahead of the carriage, connect it to the carriage - similar to carriages on a train, re-manufacture the tail-stock clamp plate so that it was longer and ran smoothly on the machined surfaces that it normally clamps on, fit a large strong spring-washer under the TS clamping nut and we are set to go. Adjust the TS clamp nut and spring so that the TS ran smoothly without lifting under load.

Put a drill in the TS, start the head-stock spindle and use the apron hand-wheel and/or power feed to pull/drive the TS and you are drilling with the TS under power.

You still have all you normal fine feeds etc. intact on the TS and it is only a few minutes to revert to full normal functionality.

Other than that I would make a body not unlike the basic TS that will clamp to the bed as normal. But I would scrounge an old pedestal-drill quill (with tang cavity) and rack and pinion. I would have a cylinder bored to suit the quill and the new body drilled and bored for the gear-shaft to engage the rack on the quill. It is no more than a basic pedestal drill with the quill spindle welded to or other-wise rendered unable to rotate in the quill and mounted horizontally instead of vertically.

An old vertical mill head can be similarly adapted as well.

Both of these concepts are no different in principle to that of a capstan or turret on a capstan or turret lathe.

If I recall correctly, I think Evan did something similar.

There is no need to be too concerned about alignment of the tail-stock either as it will surprise you just how "slack" or worn a TS can be and still do a fair job of drilling concentrically. It mainly depends on the self-centering features of a centre drill and the rigidity of the head-stock.

J (Jerry) Tiers recent post on the "slop" between the TS body and the quill on his lathe in a recent post is testament to this. He had no complaints about the drilling (or reaming) efficiency of his lathe that I recall - just the problems he had with taper turning.

Even the clunky old pedestal drill - or even a portable drill used free-hand - have no problems following either a centre drill or a pilot drill that is located/started on a centre-punched mark.

There is a lot of stuff said on here as "Gospel" that either may not be or is not "Gospel"- period. It might be ideal and it might always work, but it may not be the best or only way - but on the other hand it may be.

This may well be a good instance or example of this thinking.

S_J_H
03-05-2008, 08:36 AM
I also used the lever feed to hone small cylinders. Turn the spindle at a nice slow pace and install a hone in the tail stock. Use the lever feed for a nice crosshatch pattern in a cylinder.
Steve

oldtiffie
03-05-2008, 09:03 AM
It is also feasible to mount a block either in the QCTP or directly onto the cross-slide. Fix it firmly. Fit a drill into the head-stock and drill and bore the block and incorporate a locking/fastening method to suit a spare drill/mill quill spindle - ideally with an MT2, MT3 or MT4 taper and a tang slot.

Fix the quill spindle into the block, fit a MT drill or chuck into the quill. Start the head-stock spindle. Advance with the carriage and start drilling using the carriage hand-wheel or longitudinal feed - and you are drilling for as deep as the drill will go and without using the tail-stock at all.

The fundamentals are here.

Just modify it to suit yourself.

lazlo
03-05-2008, 09:06 AM
If I were to put a bearing in the cap and a thrust washer on each side of the cap and run the shaft at a reduced diameter but now a little longer through the thrust washers and bearing in the cap and put the handwheel on the end, the shaft would turn in the cap.

I see what you're saying Carl. Somewhat like a lever-operated collet closer. But the handwheel would have to ride in and out along with the quill when driving it with the lever -- seems like that would be pretty awkward.

I think that's the reason there are no commerical dual-action (lever and handwheel) tailstocks.

With the splined leadscrew I mentioned earlier, I was proposing that the handwheel and thrust bearing stay mounted to the tailstock body, but the leadscrew itself would telescope away from the nut when you're using the lever (or capstan) drive.

Mike Hunter
03-05-2008, 09:56 AM
Obviously I’m missing something here..So somebody please help me out.

Why would you want a lever operated tail stock?

If I have a bunch of holes to drill in the lathe, I mount a MT holder on the QC tool post and use the carriage. It’s as quick as turning a hand wheel, need a certain depth? Carriage stop or dial indicator. Want a constant cross hatch pattern…power feed.

So what am I missing?? Obviously something

Mike
www.Hunterrestorations.com

IOWOLF
03-05-2008, 02:09 PM
Mike, Some would rather make something, anything, than buy it.

I have a M2 and M3 socket for My QCTP as well as a Drill chuck. But I still Like my turret lathe Because of the Handle.

I did, at one time Build a lever tailstock for a 10" Atlas,Which I still Have.

ttok
03-05-2008, 03:08 PM
Guys -

Check out the lever action tailstock pictured in this link:

http://practicalmachinist.com/vb/showthread.php?t=140313&highlight=lever+tailstock

It appears that this lever action apparatus is mounted IN THE TAILSTOCK RAM TAPER and is removable! I cannot see enough of the "operator end" of the lever, but it appears that the drill chuck is mounted on a long rod, which is inserted in the body of the apparatus. The side of the apparatus is milled so that some form of depth stop could be attached to the rod (side away from the operator).

This is really cool! The long rod can extend a little into the tailstock ram barrel, and the fit between rod and hole in the apparatus in this picture must be fairly good. It looks well engineered to me - what do you guys think?

I asked for a description of the other end of the operator's handle, but none was posted. What do you guys think it looked like?

I have an MT2 on my 11" Sheldon. I would love to make something like this with a small Albrecht chuck. Would seem to be limited to a small chuck and drills, because too much weight on the handle would loosen the male taper on the apparatus in the tailstock ram bore.

A.T.

Carld
03-05-2008, 03:10 PM
Mike, I did this when I had a lantern tool post not a QC tool post.

Lazlo, it's not like a collet closer at all and a hand wheel on the end of the lever assembly is not awkward at all. As a mater of fact you could use both at the same time with the way I had planed but there would be slop involved unless you lock the lever.

O'tiffle, no need to place the tailstock before the carriage. All you need is a link between the carriage and tailstock to drag the tailstock forward and force it back. I have used a lathe set up that way and it works for deep drilling. As to using the carriage and a QC tool post with a taper drill holder, it's much faster to use a tailstock lever drilling attachment than to move the carriage. If you ever have the oppertunity to use a lever drilling attachment you will know what I am saying. There is no way you can move the carriage as fast as you can the tailstock quill with a lever. It is by far the fastest and best way to drill with a lathe. It's just like a drill press with the lever attachment only faster than a drill press.

lazlo
03-05-2008, 04:43 PM
Hey A.T. -- good to hear from you! When are you up in Austin again? :)


Check out the lever action tailstock pictured in this link:

http://practicalmachinist.com/vb/showthread.php?t=140313&highlight=lever+tailstock

It appears that this lever action apparatus is mounted IN THE TAILSTOCK RAM TAPER and is removable!

That's a neat design -- close to the Holy Grail, but not quite :) Chris Heapy had build notes for a very similar one here (copy of his web page now hosted in Japan):

A TAILSTOCK SENSITIVE DRILL ATTACHMENT (http://kansai.anesth.or.jp/gijutu/kousaku/easyweb.easynet.co.uk/chrish/s-dnotes.htm)

http://kansai.anesth.or.jp/gijutu/kousaku/easyweb.easynet.co.uk/chrish/s-d-2.jpg

lazlo
03-05-2008, 04:48 PM
Lazlo, it's not like a collet closer at all

Think about it Carl: a lever-operated collet closer has a spindle sleeve that stays fixed while the main spindle rotates. The lever action operates against a large out-board thrust bearing. Same concept.


a hand wheel on the end of the lever assembly is not awkward at all.

The handwheel and tailstock quill thrust bearing would be hanging off the end of the tailstock quill extension (just like the lever operating mechanism on a collet closer).

The handwheel and thrust bearing on my Clausing tailstock weigh around 5 pounds -- that's a lot of weight to be swinging back and forth while you're driving the lever action. It'd be interesting to try though...

oldtiffie
03-05-2008, 06:13 PM
Mike, I did this when I had a lantern tool post not a QC tool post.

Lazlo, it's not like a collet closer at all and a hand wheel on the end of the lever assembly is not awkward at all. As a mater of fact you could use both at the same time with the way I had planed but there would be slop involved unless you lock the lever.

O'tiffle, no need to place the tailstock before the carriage. All you need is a link between the carriage and tailstock to drag the tailstock forward and force it back. I have used a lathe set up that way and it works for deep drilling. As to using the carriage and a QC tool post with a taper drill holder, it's much faster to use a tailstock lever drilling attachment than to move the carriage. If you ever have the oppertunity to use a lever drilling attachment you will know what I am saying. There is no way you can move the carriage as fast as you can the tailstock quill with a lever. It is by far the fastest and best way to drill with a lathe. It's just like a drill press with the lever attachment only faster than a drill press.

Thanks Carld.

Quite right - that's why I said "pull-push".

My idea concept was to get it done without a lot of work or altering the tail-stock.

I had in mind using larger drills - say 1/2" up to say 1" or more.

The weaknesses in the standard TS are the pin or key taking the twist of the torque re-active force from the drill, the minimum length of usable quill screw, "slippage" of the MT and scoring etc. etc. In most cases these problems - with the exception of the screw slowness and limited travel remain.

The TS quill and bore wear/abuse needs to be minimised - for taper turning at least. "Repair" is a real problem as per Jerry Tiers recent thread, which despite all the discussion, was not solved or resolved - well not that I saw/recall and Jerry's quote for a new casting was something of the order of:" $800 - take it or leave it" - for an old-ish but still otherwise serviceable lathe.

The "MT in a tool-post" or mounted directly on the cross-slide appeals to me fo4r the lighter drilling.

John Stevenson
03-05-2008, 06:36 PM
Sorry I have been away from this post and got to do a bit of catching up.
Mike asked why a lever tailstock as opposed to using a Mt holder on the toolpost and using the carriage.
No reason why that can't be done, just another way but you are then limited to one tool and having to get it on centre.

Many times for an operation you need to face the end, centre drill then drill. Using a tool post to do this is 3 operations and messing about between 1 and 2 to get on centre.

Using the carriage won't give you a sensitive feed.

The real advantages of a lever feed is sensitivity and speed.

Speed is of great importance when you are drill long holes and need to keep backing off to clear chips.

Myfords made one for the ML7 that just clamped on the end of the threaded spindle and you removed the hand wheel altogether.

http://www.lathes.co.uk/myford/img14.gif

There was another one made as an after market attachment that had a rack and pinion feed with a 3 lever capstan made my Cowell's but it was expensive.

I built this for my ML7 when I had a job making laser cutting nozzles.

http://www.stevenson-engineers.co.uk/files/powertailstock.jpg


I needed a sensitive feed as I was drill 20 thou holes and a greater top speed than the ML7 could offer.

With a 2 speed motor and pressure lubed feed to the headstock I could get 1250 rpm. The red motor which ran at 3,000 rpm in the opposite direction drove the small 3/16" capacity chuck by a shaft running thru the barrel.
This gave me a top speed of 3000 + 1250 = 4250 which although still very low for drill this size was better than stock.

The terminal box of the motor was fitted with a Tufnol [ phenolic ] rubbing pad that ran on the bed to give support.

In use this did sterling work and must have made in the 1,000's of these nozzles.

.

oldtiffie
03-05-2008, 08:41 PM
If you really are serious try this TS Turret tool adaptor:
http://www.littlemachineshop.com/products/product_view.php?ProductID=1877&category=

or

http://www.littlemachineshop.com/products/product_view.php?ProductID=3053&category=

They will cover most categories.

"Wolfie" (aka IOWOLF) and a few others here have the real answer as regards something that is specifically designed for high-torque multi-tool repetition work - a turret attachment that is fixed to the lathe bed in lieu of the tail-stock.

Perhaps they can/will comment and post a few picks.

In the meantime this link will give you a "heads up" on turret (and capstan) lathe principles:
http://www.google.com.au/search?hl=en&q=turret+lathe&btnG=Google+Search&meta=

Ian B
03-06-2008, 04:09 AM
John was looking for a way to feed the tailstock barrel with a capstan-type set of handles, and still retain fine feed & settings (for use of tailstock centres, etc). The "holy grail" of tailstocks. Have a look at the first photo in this post: http://bbs.homeshopmachinist.net/showthread.php?t=27846

A quill (in this case vertical) with a rack & pinion / capstan handle feed, plus a disengagable fine feed on the pinion. Just rack the tailstock spindle roughly into position, engage fine feed and you're done.

You'd need to make a longer tailstock barrel with rack teeth on the bottom and a unit to bolt on to the back end of the tailstock holding the capstan & fine feed. There's then no real limitation to the amount of stroke length you can have. Add a thread in the back end of the barrel for an ejector screw & extension rod.

Ian

John Stevenson
03-06-2008, 06:58 AM
Ian,
I have already come up with a similar idea but using an index pin to drop the worm wheel in and out of mesh.

Never thought about mimicking the operation of a mill / drill quill [ isn't this forum great ? ]

Next step is to get hold of about 15" of 50mm ground bar for a new barrel.

I believe they do silver steel that big [ drill rod ] but only in 13" lengths although 13" is enough for the barrel the extra can be plain jane mild steel where the rack needs to be.

I'll ring the suppliers for Silver steel and the importers of the mill drills to see if they carry these spares to save reinventing the wheel.

.

IOWOLF
03-06-2008, 01:26 PM
John, try to find some Hydraulic shaft.

lazlo
03-06-2008, 01:52 PM
A quill (in this case vertical) with a rack & pinion / capstan handle feed, plus a disengagable fine feed on the pinion. Just rack the tailstock spindle roughly into position, engage fine feed and you're done.

You'd need to make a longer tailstock barrel with rack teeth on the bottom and a unit to bolt on to the back end of the tailstock holding the capstan & fine feed.

That's very clever Ian. The mill/drill has a lever-operated rack and pinion quill feed with a dog clutch that engages a worm gear for the fine feed. So you'd be getting rid of the tailstock leadscrew altogether, and using the worm driving the rack and pinion for the handwheel feed, and the capstan driving the rack and pinion directly for turret-lathe feed ("lever fee" -- whatever you want to call it).

You should be able to use your existing tailstock quill: Just cut rack teeth on the bottom, and mount the capstan in the middle where the Schaublin tailstock capstan goes:

http://www.lathes.co.uk/schaublin/img51.gif

lazlo
03-06-2008, 01:58 PM
John, try to find some Hydraulic shaft.

Russ Kepler made a replacement quill for his 10EE with a piece of 1144 (Stressproof):

http://www.practicalmachinist.com/vb/showthread.php?t=100057

bikepete
03-06-2008, 02:04 PM
Anyone mentioned this yet?

http://www.lathes.co.uk/cazeneuve/page2.html

http://www.lathes.co.uk/cazeneuve/img5.gif

lazlo
03-06-2008, 03:39 PM
Wow, very cool! Leave it up to the French! :)

"an unconventional tailstock fitted with a powered, two-speed spindle"

By the way, if you look at the arrangement of the capstan and the fine feed, I bet they've got a rack and pinion shaft starting at the capstan and running 60° into the tailstock casting, with a worm drive at the end where it approaches the front (like Ian was suggesting).

So what is the big shaft running into the back of the tailstock? Where's the power feed?

Does anyone have a Cazeneuve manual?

lazlo
03-06-2008, 05:13 PM
Some more detail on the Cazeneuve 360 manual from PM:

4.) Triple feature tail stock-- it has a capstan wheel like a drill press, a gear-reduced hand-wheel, and a mechanism for using the power feed from the carriage for big drills. The three positions are activated by pushing the capstan wheel up or down. It has 3 detents.

wierdscience
03-07-2008, 12:00 AM
Well that's neat,I never though the French could come up with a good design for anything,must have been a German or a Yank in the woodpile:D

Well I found a block-o-steel today big enough to make a TS top out of and a section of 1-1/2 od x 1" ID hollow chrome rod for the barrel.Now all I need do is get off my arse and make it:D

IOWOLF
03-08-2008, 04:24 PM
One wing Bolt removes the whole thing, and I just slip the screw type one in its place.

http://img.photobucket.com/albums/v11/iowolf/PIC00001.jpg

http://img.photobucket.com/albums/v11/iowolf/PIC00002.jpg

I have 5" of travel.
http://img.photobucket.com/albums/v11/iowolf/PIC00004-1.jpg
The second collar is to stop the ram from pushing out the MT3 tool, remove it and it will go back enough to Knock out the tool.

I hate the shop camera.

John Stevenson
03-08-2008, 07:40 PM
Wolfie, doesn't look to have much mechanical advantage when extended ?

Looking at various designs and the work needed to incorportae a fine feed as well as a rack feed as opposed to the times I missed the fine feed when I had the Myford and I have decided to just go with the rack feed.

Bought 15" of 2" diameter half hard and will bore it MT4 then send it for grinding down to 50.00mm.
After that I'll cut the teeth and then send it for Nitriding which is a heat treatment that's done at low temperature in a vacuum and doesn't distort.

.

lazlo
03-08-2008, 09:50 PM
After that I'll cut the teeth and then send it for Nitriding which is a heat treatment that's done at low temperature in a vacuum and doesn't distort.

John, how much does it cost to get something nitrided, versus normal heat treat? Do you have you use Nitralloy, or can you use any mid- to high-carbon steel?

In Foundations of Mechanical Accuracy, just about every steel item that went into the jig bores and CMM's was nitrided Nitralloy, but the way they describe it, it sounds obscenely expensive.

oldtiffie
03-08-2008, 10:12 PM
John, how much does it cost to get something nitrided, versus normal heat treat? Do you have you use Nitralloy, or can you use any mid- to high-carbon steel?

In Foundations of Mechanical Accuracy, just about every steel item that went into the jig bores and CMM's was nitrided Nitralloy, but the way they describe it, it sounds obscenely expensive.


Thanks lazlo.

Why nitride it or use expensive or difficult to machine material?

Why not get a hard-wearing durable coating applied either by electro or spray coating?

I'd only treat one part (the rack on the quill?) and leave the other (pinion?) "as is" for/to wear. It should only need to be done for the gear-mesh parts.

To save or minimise damage due to a "slip" in the MT, why not incorporate a slot for the tang on the inner end of the female MT?

Anything to do with "jig borers and CMM's" is bound to be "obscenely expensive" given the accuracy required of them and conditions under which they operate. Its just like saying "boat/yacht/marine" for SS and brass/bronze etc. where the same items for common use are much less.

BadDog
03-09-2008, 03:29 AM
MANY moons ago, I worked in a tool and die shop (draftsman/"engineer" - primarily both hollow and flat extrusion tooling). Many components were made out of various "tool steel" alloys, then hardened and nitrided (nasty process with nasty chemicals). But no, it does not require any special alloy for basic surface nitriding. In our process the end result was basically through hardened and tempered tooling that was then case hardened (but not exactly) for and obscenely wear resistant tool. Particularly useful on very close tollerance wear surfaces that also had very high finish requirements (can't allow scratches even with molten abrasive material constantly flowing past under pressure).

John Stevenson
03-09-2008, 08:14 AM
Sorry,
That was a typo. I meant to type Tuftrided not Nitrided although I see I described the process :(

Never had any nitriding done and I'm not sure if our heat treaters can do it.

Tuftriding is also a low temp process so no distortion that puts on about 1/2 a thou of case which is ideal for a tailstock ram.
Cost is reasonable, usually under their minimum 1 hour labour charge but a few pound notes in the right direction gets a lot done :D

Yes Tiffie I will be fitting a tang slot to the ram as this machine does serious day to day work, in fact it's probably the most used lathe in the shop seeing as most of my work is in metric and this is a pure metric lathe.

I have made new rams for the CVA and the big TOS in the past.
The one for the big TOS was just mode out of decent steel, no heat treat and I did it when I first got the machine as all my leftover tooling from the old Herbert was MT4 and this puppy is MT5 and I had problems at the time getting enough arbors and adapters at the right price.

The CVA ram was made out of decent steel and tuftrided. This was done as the CVA only has a MT2 ram and to go over 7/8" in drill and reamers you need MT3 so it had a top hat left on for strength and machined up. [ pic later ] It's complete with it's own nut so it's a simple job to wind out and replace with whatever ram I need to use. This also has an extraction slot, many engineering books have the dimensions and it's only a slot mill exercise anyway.

.

IOWOLF
03-09-2008, 08:36 AM
John, this tuftriding sounds a bit like kasenite without the heat.

Also, You are correct there is very little Leverage on My T/S lever at the end, But in the middle There is plenty and it takes little to move it up closer to the work.

Norman Atkinson
03-09-2008, 09:11 AM
'Cleeve' started his Myford skewrack tailstock mechanism for the ML7 on 12 July 1956 in Model Engineer. It- and the ejector mechanism- was proved earlier in his ML4(?)
I was looking at the photos and noticed that he had 3 or more 'solid' turrets on his shelf. Again, I was bellyaching about the Super 7 hole in the saddle and noticed that he had a steel and not a cast iron saddle which was slotted- with a home made fabricated top slide which only needed a one sided fixing bolt.

This is all academic until one realised that this guy made his living without a mill and made specialist nuts and bolts on a lathe with only a 7" swing- until he raised it!

I suddenly realised that I have two Myford tailstocks- and the drawings for George Thomas's micrometer tailstock for the Super 7.

Call me a cannibal!

Norm

Peter N
03-09-2008, 09:14 AM
We nitride mould tooling all the time.
As standard we do it on sliding core carriers and heel blocks as these are continually moving parts inside the mould and need a tough wear surface, but we also do it on cores and cavities, predominantly on parts machined from P20.
P20 is pre-toughened steel and easier to machine for low volume tooling, and comes in around 30-35Hrc, but can be abraded particularly when moulding glass filled materials, so nitriding the surface takes this up to around 50-55Hrc.

For high volume tooling we through harden with steels like H13, or EN30B, or D2.

The advantage of nitriding, is that as it is a relatively low temperature process you don't get into the austenite/martensite structure changes, and no quenching is involved. Therefore parts can be finish machined to size before heat treating with no worries about subsequent distortion.

We use a company called Tecvac in the UK for our heat treatment, and they have some good information on various heat treat processes on their website.
http://www.tecvac.co.uk/heattreat03.php

Peter

Edit: Tecvac info on Tuftriding here: http://www.tecvac.co.uk/heattreat05.php

oldtiffie
03-09-2008, 09:16 AM
I have yet to be convinced that Wolfie and Torker's (Russ's) turret/capstan head/lathes are not the best way to go for all/any tail-stock work - other than taper turning - perhaps.

My next choice is a Mill/drill head with a "capstan" high-purchase/leverage quick feed and a fine feed for finer work. The spindle just needs t be fixed to the quill so that the spindle dose not not revolve. I would seriously consider installing a square keyway in the quill outer diameter and its mating bore in the head as the single "pin" is no better than the pretty poor effort on many lathes - including some "made in USA" and "Made in China" stuff.

Next would be the drilling head from a pedestal drill.

Both will need to be modified to fit on the lathe bed. There is no need for an inverted "vee" as on a tail-stock - just an accurately made projection/"key" that projects and accurately locates into the machined slot between the front and back guides on the lathe.

BadDog
03-09-2008, 01:46 PM
I have yet to be convinced that Wolfie and Torker's (Russ's) turret/capstan head/lathes are not the best way to go for all/any tail-stock work - other than taper turning - perhaps.

A typical turret won't work for any sort of center work as it has no way to positively locate and lock the slide. If it were not for that, I would be using my turret all the time instead of the standard tailstock.


Both will need to be modified to fit on the lathe bed. There is no need for an inverted "vee" as on a tail-stock - just an accurately made projection/"key" that projects and accurately locates into the machined slot between the front and back guides on the lathe.
I like the idea being discussed, but I think the TS v-way is going to be necessary for most lathes as the inner gap is rarely precision of any sort.

IOWOLF
03-09-2008, 01:57 PM
"A typical turret won't work for any sort of center work as it has no way to positively locate and lock the slide. If it were not for that, I would be using my turret all the time instead of the standard tailstock."

That is what the lever under the slide is for, to lock it.
http://img.photobucket.com/albums/v11/iowolf/Turrets/SANY0619.jpg

BadDog
03-09-2008, 02:02 PM
Sorry, I meant the "typical" bed turrets found on engine lathes (like mine). The ones usually found in HSM shops.

The only way to lock them (that I've seen) is with a gib lock or pinch/toggle bolt. And the only way to locate it is to crank the wheel, hold some pressure, and tighten the slide lock.

A true turret/capstan lathe like that one is a totally different animal. But if I understand correctly, it's still going to be difficult to set sensitive pressure, particularly for dead center work. Or maybe it's just my lack of experience that makes it seem odd...

IOWOLF
03-09-2008, 02:20 PM
"Typical " Home shop turret lathe?

Kind of an oxymoron is it not?

BadDog
03-09-2008, 02:28 PM
I didn't say "turret lathe", I said "bed turret". I'm talking about the old 50/60s erra "Enco" (whoever made them) and Royal type bed turrets. And in that respect, not at all, at least in my experience.

I have one, and a few of my machinist type friends have one, quite a few on this forum have them. I also parted out a lathe that had one (nice one at that, got $150 for it). And I recently looked at a late model 1340 (patterned on Clausing) that had one. Seems to me like at least 15-20% of the old iron lathes (and some new ones) around here have them, and these are the lathes surfacing in HSM shops everywhere (including mine).

IOWOLF
03-09-2008, 02:38 PM
It is a very fine line. But ok whatever you say.

oldtiffie
03-09-2008, 11:43 PM
I still think that Wolfie has the real answer as it is a close as ................... to a modern multi-tool work-centre as you will get without going the whole bit. It is ideal for drilling, form-tooling and all the other "difficult" stuff that specialised tools in the turret/capstan can do so easily.

Most work with a TS is drilling, reaming etc. and not a lot of "Centre" work.

The "after-market" and capstan/turret "attachments" that are fitted on normal centre-lathes are easily removed and replaced by the tail-stock if an when required.

The capstan/turret has excellent leverage and sensitivity in the hands of a good operator. I loved them when I was younger. Many had large hand-wheels and some had spokes like a Paddle-wheel River boat - others had ball-grips like on the steering wheel on fork-lifts etc. Some were small units fitted to a small flat-belt driven "South-Bend" knock-off. The difference in time and quality consistency between the turrets and the "normal " lathe was huge with a lot less effort when you "got going". The larger "Herbert" and "Ward" capstan/turret lathes were great as engine lathes.

I expect that Wolfie and his machine as shown would leave most here in the dust as regards speed and quality for repetition work.

The accuracy of location of the turret for drilling etc. is not too important as a centre-drill is self-centering and everything after it will follow it.

BadDog
03-10-2008, 02:24 AM
As I said before, I have a turret, and it is VERY nice for certain things. But, I do use a center often enough that I found it frustrating and all too frequent swapping the tailstock on. And with a turret that weighs nearly 100 lbs, swapping it is not very much fun. Sometimes I can leave it hanging at the end, but in general, if your using a center, it's likely that you need more bed, and even my 37" bed becomes too short with turret hanging out back there. If it were not for that, yes, I would leave the turret in place all the time. Maybe I should just spend some time and figure out how to make it more useful (or rather easier to use) with a center.

The other thing is that turrets are far more "fiddly" to set up than an MT TS that ejects and loads in seconds. If the turret doesn't have what you need, those cotters and other locking systems can make tool changes quite frustrating.

lazlo
03-11-2008, 11:39 AM
That was a typo. I meant to type Tuftrided not Nitrided although I see I described the process :(

According to Peter's link, Tuftriding is just a tradename for nitriding. Good to know that you can use common sttel.

I'm curious to see how much it costs from my local heat treater. Based on other quotes I've gotten, the setup fees and the minimum order fees are going to be more than the actual nitriding cost.

lazlo
03-11-2008, 11:53 AM
I didn't say "turret lathe", I said "bed turret". I'm talking about the old 50/60s erra "Enco" (whoever made them) and Royal type bed turrets. And in that respect, not at all, at least in my experience.

Clausing had a factory bed turret as an option too, and it has the same issues you describe.

lazlo
03-14-2008, 12:05 PM
Wow, very cool! Leave it up to the French! :)

"an unconventional tailstock fitted with a powered, two-speed spindle"

By the way, if you look at the arrangement of the capstan and the fine feed, I bet they've got a rack and pinion shaft starting at the capstan and running 60° into the tailstock casting, with a worm drive at the end where it approaches the front.

One of our European brethren on PracticalMachinist was kind enough to scan the tailstock pages from the Cazeneuve 360 manual. My guess above was correct: there's no tailstock leadscrew -- the capstan drives the tailstock quill directly with a rack and pinion feed, and the shaft runs 60° into the tailstock casting, where it mates with a worm wheel for the fine feed.

There's no dog clutch like on the Mill/Drill coarse/fine feed mechanism, but instead there's an eccentric cam that brings the fine-feed worm into engagement with the rack and pinion shaft. This would have the added benefit that it would lock the tailstock quill, since the worm can't backdrive.

It's a really neat design -- seems very do-able as a retro-fit for an existing tailstock.

If anyone wants a copy of the Cazeneuve tailstock blueprints, drop me a PM with an email account.

Robert