Lathe manufacturers certainly do make saddle stops. The expensive Myford version (flat bed) fixes to the rear of the bed in a position which seems less than optimal given the direction of the forces involved.

A stop is a near-necessity on a manual lathe.

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Thanks for the clarification

MichaelG.

Interesting.

My indispensable 6 way stop of unknown origin has been on 4 lathes in my hands and seemed to fit the beds perfectly adequately. No idea what it was made for but its worked fine on my SouthBend Model A 9" (too big for the machine really), SouthBend Heavy 10, Pratt & Whitney Model B and Smart & Brown 1024. I never bothered to check angles, just used it.

One day I shall finish the design of Clives improved version with a built in microswitch for automatic stop on the 1024 VSL. Which has direct drive an no clutch.

If angle variation were an issue it would get some floating D shape rails let into the Vee sides to self adjust over small variations. Brass I thing to avoid marking the beds. Maybe 1/4" on the flats would be fine for adequate grip.

Hafta say I'd always thought bed Vee angle was either a symmetrical 90° or the very asymmetric shallow one side steep the other shape adopted by some makes when the design staff started overthinking angular force distribution. Always though that, like many clever schemes, the shallow & steep combination advantages are more theoretical than real. If its not a gap bed then Holbrook style long way covers pretty much completely protecting the ways so decent, clean lubrication is assured seemed a better way of refining things. Way I see it is that if the forces resolved to the bed were that large that such refinements were important the any conventional toolbit would be snapped clean off the moment it hit the work. Even on a superlathe its still a relatively slender cantilever.

Close to 90°and variable between machines / production batches is just plain careless on the makers part. Rule 1 of production engineering is to use reliable jigs and gauges for repeat set ups.

Clive

Edited By Clive Foster on 08/11/2020 11:52:10

My Warco GH1322 came with one, I've yet to find a use for it…

It will be of paramount importance that the lathe bed mating angular faces match to a high degree of accuracy so being 'prissy' about said angles is mandatory in decent machine tools.

Tony

So true with most things Clive. The Warco does have a travel dial on the saddle that I use when boring blind holes. For precision measurements I tend to use a DTI onto the topslide once checked for parallel to the bedways. The stop that came with the Warco is a micrometer type but is s a bit of a fiddle to set up. When I was on the handles the only lathes I used that had stops were the capstans for repetition work of course.

As for Bazyle's comment, there are a couple of things that could have been done much better as a trade off for the "fancy" things like the awful metal handles (changed) and the stop without affecting the bottom line. For the money though I'm happy enough with the machine.

Different type of work requirement to me. I use my bed stop on nearly every job I do, but then I do seem to make more bolts for motorcycles than is healthy for a chap…..

My lathe bed appeared to be 90 degrees, so I made a Saddle Stop with a micrometer barrel.

It clamps to the bed with just a plain piece if steel, just like the Saddle lock built into the saddle. Clamping force is applied by a M8 setscrew.

When the clamp is pulled down to lock, if the clamp and bed angles differ by a degree or so there will still be two point contact against which the clamping screw can react . The clamp will behave in the same manner as the Saddle Clamp, and prevent movement.

The forces likely to act on a Saddle Stop are very likely to be less than those exerted on a Saddle Lock (Since it has to withstand forces resulting from cutting action ) It is unlikely that we would want to subject a Saddle Stop to forces as great as those.

This could raise the question of whether the angle of the Saddle will exactly match that of the prism on the Lathe bed. Given the angles already quoted by the O P, that might not be guaranteed!.

After all, we are using it as a Stop rather than a Lock.

Howard

..

Since my Saddle travel indicator is on the Handwheel that ultimately drives the pinion engaging with a rack, I do not expect absolute accuracy. Indeed, I am surprised by the accuracy that it does provide, but do not regard it as a high accuracy measuring instrument.

In contrast, my stop, clamped to the bed and with a micrometer barrel is regarded as being more accurate, and is used where closely controlled lengths are required..

No doubt, if the power feed were not disengaged, or hand feed was were pressed home with vigour, the clamp might be displaced, or inaccuracy creep in because of the changes in clearances or deflections brought about by greater forces.

Maybe I am wrong in power feeding to just short of the stop and then hand feeding to bring the Saddle to rest gently against the stop. But that seems to work for me.

Howard

I have a spare micrometer head that I was thinking of using in much the same was on my Myford. However what is stopping me is protection against swarf and coolant…

Regards to all

Derek