Quick Change Toolpost and Holder systems

[Peter EParticipant @petere]

OK, so repeating the post from the previous page but now with usable images/links.

===== Repeat ====

Adding Model Engineers Workshop no 140 to the list of info and drawings for a QCTP of the sought after style. Jim W made one for a mini lathe-ish size as well as for a Unimat sized machine. Good descriptions and drawings. I used those as base for my work.

I have understood it so that it is important to be quite accurate when doing the dove tailing to get the desired precision and repeatability while at the same time get the easy fit required for easy use.

For my Unimat clone I made a slimmed down version of the Norman Patent type as can be seen in the following two pictures. They also work very well, and I am very pleased with their perfomance. The only draw-back I think is that the setting screw poking out below makes it a little cumbersome to efficiently store many toolholders.

The holder for ordinary tool bits, and ….

…. the boring tool holder.

===== /Repeat ====

BR

/Peter

[Michael GilliganParticipant @michaelgilligan61133]

Does anyone know a good source of the classic square-headed screws in small sizes ?

… Hex Socket screws are great in many respects, but they do collect little chips of Brass rather too well.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 31/08/2012 08:08:48:

From this page, I quote: "In 1888, Mr. Charles E. and Fred D. Van Norman founded the Waltham Watch Tool Company, to manufacture tools for use in the Jewelry trade."

… "WW" being the standard for the "inverted vee" lathe bed, as used by Pultra and many others.

Edited By Michael Gilligan on 31/08/2012 08:21:10

 

.

Apologies … I posted in haste, and repent at leisure!

"WW" originates from Webster Whitcomb, not from Waltham Watch.

MichaelG.

Edited By Michael Gilligan on 31/08/2012 20:34:09

[Sub MandrelParticipant @submandrel]

Dang! The longer I wait, the less obvious a solution beocmes. Has anyone else had issues with the piston type?

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Neil,

Whilst you are pondering the way forward … have a look at this little gem of a 3 station milling spindle to fit on the cross-slide of a watchmaker's lathe.

MichaelG.

[DMBParticipant @dmb]

Hi all,

Take a look @ this! –

youtube.com/watch?v=IPBeoVEGZKY

[DMBParticipant @dmb]

The youtube video of a retracting lathe tool on a German website, appears to be able to lift up and glide over the work like a shaper tool. My guess is that if Gray Meek`s rapid reverse for the carriage is used with this shaper style toolholder with a threading tool installed, a screw thread could be very rapidly cut. NB, the rapid traverse mechanism incorporates a single dog tooth clutch drive, enabling correct pick-up every time and no stop-starting lathe.

[BazyleParticipant @bazyle]

I think the lifting toolholder requires the lathe to run backwards on the return not just feed backwards using the modified leadscrew drive.

[KWILParticipant @kwil]

Bazle is correct, it will only lift if the spindle is running in reverse.

K (very satisfied user of a Graham Meek device)

[KWILParticipant @kwil]

MichealG, I like that multi milling spindle, just right for cutting screwdriver slots on custom made screws, or gear teeth.

[ZiggarParticipant @ziggar]

Posted by DMB on 01/09/2012 23:12:56:

Hi all,

Take a look @ this! –

youtube.com/watch?v=IPBeoVEGZKY

The video you have requested is not available.

If you have recently uploaded this video, you may need to wait a few minutes for the video to process.

[Sub MandrelParticipant @submandrel]

Michael, that watch device is deeply confusing…

I've now started having my own thoughts about holders. I have an idea that should work, and be nice and solid while being tolerant of a small variation in the dovetail width, but i neeed to think more.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Stub Mandrel on 02/09/2012 20:12:25:

Michael, that watch device is deeply confusing….

Neil

 

 

Sorry Neil, it was only meant as an interesting diversion.

…. there is a six-way version illustrated on lathes uk, if that helps.

Looks like it is intended to take a different wheel-cutter, slitting-saw, or whatever; on each of the vertical axis spindles. The drive pulley plugs into the end of whichever spindle is in use … and would be driven from an "overhead", and idler pulleys to change the direction.

The lathe headstock would effectively just be used as a dividing head [unless there is something really devious going on]

I will see if I can find a picture of one in action, and report back.

MichaelG.

 

The second picture on this Pultra page should help.

… or perhaps this Levin page.

Both only show single spindles, not a turret … but you get the idea.

Edited By Michael Gilligan on 02/09/2012 21:45:16

Edited By Michael Gilligan on 02/09/2012 22:05:42

[DMBParticipant @dmb]

Woops! Sorry about incorrect previous posting. Use my original but exchange "V" for U. Have tried this tonite `n` it works OK. The German website is –

http://www.rb-werkzeuge.de Teil 2 and Teil 3 18/08/2009

Gewindedrehen ohne Ruckzugshalter 14 videos loading need Adobe Flas Player to view

I originally saw this as a link somewhere and like I often do, click on it and bookmark it to read/view later. I then just click on it in favorites(Yahoo) and up it comes with no typing. When I posted about this on 1/9, I wrote Youtube ref on piece of paper then copy typed it in to my posting, misreading "U" as "V"

[Michael GilliganParticipant @michaelgilligan61133]

Missing link from my previous post …

Moseley Six-Way

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

A great collection of articles about the Waltham Watch Factory.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Remaining rather off-topic:

I forgot to mention … Mr. Moseley was a very clever chap, and we owe him a lot.

He devised the Split-Chuck [Collet] and hollow headstock spindle !

… Where would we be without those ?

There is an excellent old book, here, with many references to his designs.

MichaelG.

[Sub MandrelParticipant @submandrel]

I decided to go for the nakamura design in the end, but with some adaptations.

Two sets of dovetails and pistons at 90 degrees – so you can switch between facing/turning/boring without losing a setting.

The block is only 2" sqaure to match the square on the mini-lathe top slide. This means the dovestails over lap the top slide, but as you never need to set a tool lower than centre height, this doesn't matter as long as you don't use tools bigger than 5/16".

My pistons are flat ended- to give a line of contact, rather than using rounded ends.

i counterbored the piston holes and used small flanged on the inside of the pistons so they don't fall out – this was not needed as:

I machined a groove inside the central hole level with the middle of the pistons. I drilled the end of each piston No.58 and put a thin spring wire through each one, this locates in the groove and withdraws the pistons without interfering with the cam. I had to filed two bevels on the bottom of the cam so it pushes the cams out of the way.

I fitted a handle that is a longer copy of the standard mini-lathe handles (and the ones fitted to me leadscrew clutch and tailstock lock).

I can't actually test it yet, as I haven't dovetailed any toolholders yet. With about 1.25mm of piston movement I will have to be very careful to get these just right.

I hope it all works, as assembly was a one-way process once the pistons clicked into the cam! To dis-assemble I will need some way to pull the cams outwards -perhaps I should have given them a central 8BA hole?

Neil

[chris jParticipant @chrisj]

Stub

Pictures are required

[Sub MandrelParticipant @submandrel]

Hi Chris,

My digital camera plays up if the batteries aren't freshly charged

This is the best I can do with my phone:

Neil

[Peter EParticipant @petere]

Hi Niel,

I had larger bits vailable so I made my version slightly longer to get the dovetailed bit is outside the top slide surface, I hope it is visible om the picture.

I also intend to mill the top slide surface round like David Fenner did in his article on this subject and hope that I get even more flexibility when it comes to height setting.

Your idea with two dovetails is very good!

Waiting to see your toolholders …

BR

/Peter

[Michael GilliganParticipant @michaelgilligan61133]

Neil,

Looks good so far.

MichaelG.

Edited By Michael Gilligan on 09/09/2012 22:20:07

[SverreEParticipant @sverree]

I bought plans to make a QCTP which is available as a kit (or only drawings) from METAL LATHE in USA, the MLA-23. This seems to be a very nice design, simple and stable. See the following link:

**LINK**

The design is also described in the "Home Shop Machinist" May/June 2006, and also a brilliant description in the "Practical Machinist" forum:

**LINK**

Since I live in Norway, I ordered only the drawings from METAL LATHE, due to the cost of shipping the heavy hardware from USA.

Regards Sverre

[Sub MandrelParticipant @submandrel]

Made my first tool holder – I used an aluminium template to make sure the dovetail is a good fit, and of course it is, but that limits the handle's required movement so much I had to drill a new hole for it!

Very pleased that it locks dead solid with only very gentle pressure. I tried it in anger with a 1/8" width parting tool and it seems fine in use.

The holder is are from 1" square bar, and seems to have plenty of metal where its needed.

I am now thinking of all the possibilities and dreading having to machine another nine dovetails

On the plus side, my X2 mill is working much better now it has the added rigidity plate at the back.

Neil

[chris jParticipant @chrisj]

Posted by Stub Mandrel on 09/09/2012 21:41:08:

Hi Chris,

My digital camera plays up if the batteries aren't freshly charged

This is the best I can do with my phone:

Neil

Nice !!

[Author]

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