Smart &Brown L.tailstock lever

Hello to all. I am in need of either sourcing a lever or making a eccentric lever for my Smart & Brown tailstock ,,clamp To bed.. Does anybody have a drawing I can copy please?

Would appreciate if anyone knows where I can obtain a drawing,or part for my S&B model L. I’m looking for the lockdown lever for The tailstock. Thanks

You seem to have hit a dead end here. Sorry I have no idea of measurements but I did find this post on another forum. S & B tailstock lever I hope it helps.

regards

Thanks,oldiron,that was a very interesting read,some of the American Colloquiums I didn’t quite get? I will just do a trial-and-error cam and see what happens! Best regards.

Which model Smart & Brown. I have a 1024 VSL and could measure mine if thats what you have.

Pretty sure that the generalised proportions, cam lift, lever angle et al are pretty similar across all maes of machine so, in principle, given a successful design adjusting dimensions to fit another breed shouldn't be unreasonably difficult.

Way I see it you fix cam lift per degree of lever movement and work from there.

My VSL seems to like something between 20° and 40° free movement with lock after about 60°. From memory the cam and lever are pretty much aligned.

Technically its an eccentric not a cam but cam is easier to spell.

Clive

I have a parts drawing of the model A tailstock, no dimensions unfortunately but it probably is similar to yours.

Thank you for posting the parts drawings..looks like I need to make the...L4/2062 bit.

Although my S&B is a simple model “L”. Most of the castings have a number that start with “L4/xxx” so I do think there are similarities between models.yes,Clive..eccentric is more difficult to spell. Thanks.

All the parts book diagrams I have show very similar mechanisms so its probably OK to assuming that the locking system design and relative proportions are the same for all the S&B designed machines. Hence a simple rescale of the 1024 system whilst keeping the same lift and angle relationships should work well enough.

If you want to try that I can measure mine over the weekend.

Clive

Clive, I would very much appreciate you doing that for me if it’s not too much trouble. I’m in no rush as It’s all in bits cleaned and waiting for paint ! I must admit, the headstock build is very impressive for such an old lathe. Thanks again.

At the bottom of the model A drawing is shown the head of a SHCS which is used to adjust the point of clamping, it screws into the L4 2063. Unfortunately, I would not want to take the museum's tailstock apart to measure the mechanism as there are a number of bits of shim steel inbetween the top and bottom castings to get the tailstock aligned with the headstock because of wear and it was not a job I want to repeat. We never change its alignment, with a taper turning attachment there is no need.

BB

Managed to find some time to look at my tailstock for you. Unfortunately no drawings because I'd have had to take the bottom off to disassemble the locking mechanism, hence loosing the on centre line adjustment of the tailstock poppet. Which I'd rather not do.

The mechanics are essentially as for the Model A shown on Old Marts post so it shouldn't be too hard to convert basic dimensions to a real design.

The locking action is via a simple circular eccentric cut into the cross shaft giving 0.070" travel.

On the 1024 the actuating cross shaft and connecting shaft between eccentric and locking plate are 7/8" diameter. The head of the connecting shaft will be of larger diameter to accommodate the eccentric. Its many years since I had it all apart but head diameter of 1 1/8" or 1 1/4" sounds about right.

The connecting shaft projects about 0.75" below the base of the tailstock.

The locking plate is 1" thick with the top 0.45`' made a loose sliding fit between the bed shears whilst the lower part has 3/8" overhang each side to clamp against the bed shears. Counterbores provided top and bottom for the connecting shaft and the 1/2" BSP socket caphead connecting bolt. No locking on the connecting bolt. Just screwed up or down by hand to get the locked position of the operating lever somewhere convenient. About 35° to 30° shy of vertical works for me.

I imagine the hefty locking plate is to give a nice positive weight actuated release. Unlike some machines I've had no issues with the plate hanging on the shears.

The actuating lever is 1/2" diameter with a 3/8" BSF thread on one end to fasten it to the cross shaft and a 1/4" BSF thread the other for a 1" Ø ball. The official operating lever is 3 1/2" long between cross shaft and ball. Mine is longer, 6 1/2" to be precise, as I got tiered of having to reach behind the tailstock for the locking lever every time. The longer lever sits up past the tailstock where I can see it. Less pull needed for a firm grip too.

Clive

Edited By Clive Foster on 15/05/2022 14:54:03

Clive, Thank you so much for taking the time and effort to provide me with such a wealth of information. I now have yet another excuse to spend time in my workshop away from rubbish tv. Best regards, BB.