lever or cam operated parting off tool

[Neil LickfoldParticipant @neillickfold44316]

[Neil LickfoldParticipant @neillickfold44316]

Is there such a thing for Myford 7 or similar sized lathes , that have a parting off tool that is operated with a lever or cam ? IE you do not need to move the cross slide to part off , but the parting tool is moved with it's own slide. Something that mounts onto a tool post or is mounted onto the rear side of the cross slide.

Any ideas or suggestions will be appreciated.

Neil Lickfold

[Keith LongParticipant @keithlong89920]

Neil – try "lever operated cut-off slide" as an internet  search term and then have a look at the pictures that should come up. Plenty of food for thought.

Edited By Keith Long on 23/12/2016 21:22:56

[Michael GilliganParticipant @michaelgilligan61133]

Neil,

The one for the Pultra is very well designed … It fits to the bed of the Pultra, but is about the right size to do as you suggest, on a Myford.

MichaelG.

.

Some decent photos, here: http://www.myford-lathes.com/other_acc4.html

Edited By Michael Gilligan on 23/12/2016 21:31:38

[Brian OldfordParticipant @brianoldford70365]

You might also view http://www.myford-lathes.com/accessories19.html

[RainbowsParticipant @rainbows]

I am imagining one of these, attached to a vertical post on the cross slide with a square instead of round moving ram to take a parting blade.

[Nick HulmeParticipant @nickhulme30114]

Posted by Rainbows on 23/12/2016 22:24:46:

I am imagining one of these, attached to a vertical post on the cross slide with a square instead of round moving ram to take a parting blade.

And wobbly as Blancmange it would be too!

[Neil LickfoldParticipant @neillickfold44316]

Thanks all for the replies. It looks like none are available as an off the shelf item. One day I'll make one up.

Merry Christmas everyone.

Neil

[John HaineParticipant @johnhaine32865]

I'm not sure what the application would be, given that it would likely be significantly less rigid. Also parting needs quite a fine feed that is easiest applied by a screw?

[Anonymous]

I have a couple of the Pultra lever operated cutoff slides. They are indeed nicely made, but I suspect they're a bit small for a Myford.

Andrew

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Andrew Johnston on 24/12/2016 10:11:08:

I have a couple of the Pultra lever operated cutoff slides. They are indeed nicely made, but I suspect they're a bit small for a Myford.

.

That's why I thought they might be 'just right' for Neil's requirement, Andrew

… If I understood the opening post correctly: He wants something to mount on the cross slide.

MichaelG.

[Neil LickfoldParticipant @neillickfold44316]

Yea, Im looking for something on the cross slide or tool post mounted. I got a series of parts to make,and they can be really easily made if I have a fixed cross slide position, but use a lever or cam operated sliding something with the 1mm wide parting tool moving radially about 15mm of movement. Saves winding a handle. Maybe an air cylinder and velocity valve may work also. If I find something or make it, I'll post back.

Andrew, have you got any info like size etc of the Pultra slide?

Are they still available and how much are they? Do you want to sell one?

Thanks very much, Neil Lickfold

[BazyleParticipant @bazyle]

Have a look at a retractable screwcutting tool, fitted to a rear toolpost. There are some commercial versions around though tend to be expensive. Also variations on the theme of graduating or slotting tools. Hemingway do the castings for several designs by George Thomas.

[Anonymous]

Posted by Neil Lickfold on 24/12/2016 19:45:02:

Andrew, have you got any info like size etc of the Pultra slide?

Are they still available and how much are they? Do you want to sell one?

In due course I'll take a couple of pictures along with a linear scale.

As far as I know Pultra went out of business some years ago. So the cutoff slides are not available new at any price. I suspect that the main issue may be rigidity, so you might be best off making a retracting style toolholder, as suggested above? However, I wouldn't rule out selling a cut off slide. Although I may need therapy first, as I'm not used to idea of selling machine tools and accessories.

Andrew

[NJHParticipant @njh]

Hey Rainbows

Never mind ! – what you have shown is a sensitive drilling attachment for feeding small drills from the tail stock ( which I'm sure you know) I have one and it is much better for drilling those little holes as you can feel the cut – which is not possible when winding in the tail stock hand-wheel. (No broken drills – or worse, broken drill jammed in work!)

Norman.

[BWParticipant @bw]

Neil,

I was wondering the same thing.

Am attempting to make a jig to copy chess pawns and was wondering if I could also use it to part off.

See attached photos for concept. Basically replace toolpost T-nut with a tightly fitting sliding T-nut …… see photos.

Started off with Delrin because its easy to cut and I had a scrap handy – might be a bit bendy though – depends how far it extends ? I cut it to be a very very tight fit and then added a few drops of oil to help it slide – gotta admit I dont really know what I'm doing here. For my chess pawns its unlikely to extend very far.

Wanted to keep the toolpost handy and didnt want to go through all the palaver of removing leadscrew from cross slide to follow the pawn contour but having second thoughts now.

This thread has made me wonder about having the sliding part in the toolpost rather than under it.

Any tips hints comments welcome re whether jig is practicable.

Currently 37C outside, and the tin roof of the shed absorbs all that heat and radiates in into the shed, you can feel it like a giant gas heater above your head, so am quite jealous of all you white christmas folk.

Havent got control of these photos yet but getting there.

Bill

[HopperParticipant @hopper]

Sounds like you need an independent cut off tool as used on some capstan lathes. This one is a homemade job for a Southbend lathe. Fitted here with a V grooving tool, it can just as easily be used with a parting tool. Something similar could be made up to fit on to your toolpost or rear slide if it suited better. You pull the lever on top, just where it disappears out the top of the photo and the eccentric pushes the lever down, which actuates the tool blade, giving high force yet fine control. Perfect.

Hardinge made one that bolted on to the front of the headstock. It too could be replicated and modifed to mount on the toolpost or rear slide as best suited your needs.

The Hardinge looks like it uses a rack and pinion set up along with proper dovetail slides etc so quite more elaborate to make up than the first example using and eccentric and couple of levers made from flat bar.

Edited By Hopper on 25/12/2016 07:28:52

Edited By Hopper on 25/12/2016 07:35:12

[John HaineParticipant @johnhaine32865]

If you can turn the topslide through 90 degrees so it can move parallel to the crosslide, and make a lever feed for it, would probably be more rigid than fitting yet another slide.

[BWParticipant @bw]

Posted by John Haine on 25/12/2016 09:29:59:

If you can turn the topslide through 90 degrees so it can move parallel to the crosslide, and make a lever feed for it, would probably be more rigid than fitting yet another slide.

 

Thanks,

That does make sense – everything gets easier.

I did the search recommended above and found the lever operated tools on lathes.com – thought they were great – I suppose they became less common because leadscrews are more convenient for hitting exact diameters ? – but for some jobs the cam/lever operated tools must be ideal – have many of you still got them and use them regularly ?

Bill

Edited By Bill Wood 2 on 25/12/2016 10:14:46

[Brian OldfordParticipant @brianoldford70365]

Has anyone suggested a rear tool-post on the cross-slide with an inverted parting tool?

[Neil LickfoldParticipant @neillickfold44316]

Thanks for the other suggestions. I want a system that I can leave the cross slide in a set position or one of the operations, and then I can feed the carriage along a set amount, in my case 2 turns of the feed when and then groove the part. It will have about 9 grooves per part. The groove depth is not that critical. All the lever stuff I have seen is usually in a fixed position, although it can be positioned along the bed, is still fixed. I cam across a cam design for thread cutting, but is too short a stroke, but all the ideas are there. So I'm thinking of using some pins and bushes instead of a dovetail, and also having the sliding block very close to the base block.

[Anonymous]

As promised here are a couple of pictures of the Pultra cutoff slide:

Andrew

[John HaineParticipant @johnhaine32865]

Neil, why don't you just use the topslide to apply the feed for the grooving?

[not done it yetParticipant @notdoneityet]

Explained in a previous post, I thought.

.

[Neil LickfoldParticipant @neillickfold44316]

That's perfect Andrew. I sent you a PM message.

John Haine, I will be using a tool in a fixed position with the tool post and want a sliding grooving tool.

Let me know Andrew,

Thanks, Neil

[Author]

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