12” x 37” Lathe Tailstock Clamp Improvement

[Gary A. Wills]

Nice job bet it works like you want now. My worry would be the metal may start bending with use till it won't hold again , but then it may last forever and never loosen up . Basically you made a big tee nut . Thanks for shareing

[C-Bag]

In thinking about how to make the plate for myself it also occurred to I'll bet your setup is not so messy too when you have to pull the tailstock off for whatever reason. That silly short plate that's on there now wants to get all shwangle. I'm glad to see I'm not the only one who has one of these lathes that the ways this locking plate run in under the lathe are not really consistent in height and finish. I guess that's why more than once I've seen them referred to as kits. I have to say it's taught me a lot about how to check alignment and adjustments. It's a little weird though to do so many machining projects to get these things to work right.

[Paul Jones]

C-Bag,
The improved tailstock locking plate (i.e., the "big tee nut" as Gary calls it) on my 12" swing lathe is 5" (127 mm) long and has approximately 0.015" sliding clearance on each side when sliding in between the lathe ways and approximately the same clearance in the wider cast section below the ways (you can see the clearances in the last photo "Rear View of Tailstock Improved Clamp Plate"). The tailstock is heavy but it slides along the ways very easily and the lowered locking plate does not get all "shwangle" as you put it (sounds like one of Tom Lipton's terms). However, I choose the 3/8" 1018 CRS plate thickness because this thickness clears the tops of the lathe cross rib castings when the locking bolt is in its lowest position. That is something to check before deciding on the CRS plate thickness.
Thank for your comments,
Paul Jones

[wormil]

I have this problem with an old Craftsman lathe, will have to see if I can adapt your solution.

[Eagle_view]

This a great Idea and well done solution. I have a similar lathe and the nut is always loosing up so that I have to finger tighten it when loose to get a solid grip on the bottom of the rails. While looking at your solution to one of the problems it occurred to me that if I put a jam nut on the cam bolt it will not loosen up as easily.
Lowell

[bstanga]

Paul, great mod I need to do this on my 13x40, looking at the photos I have that exact tail stock on my shop floor, rescued from a scrap yard along with most of the entire saddle with the gears, cross slide, and compound , so if you ever need those let me know.

Brian Stanga

[Paul Jones]

Brian, thank you for the offer for the spare parts. One of these days I plan to disassemble my lathe carriage and check for worn parts but keep postponing the work. Lately I have been drilling 1018 CRS on my lathe with 1" diameter Silver & Deming drill using a drilled 3/8" pilot hole and the new tailstock clamp keeps the tailstock from moving. I really like this improvement. By the way, I like your YouTube videos. Thanks, Paul

[Paul Jones]

Since installing the improved tailstock clamp I have replaced the single ½”-13 nut used to hold the clamping plate with a 1/2"-13 Nyloc nut. This change prevents the nut from loosening over time from vibration. Thanks to one of the viewers for this suggestion.

[Michael Venni]

Great idea I shall be using it on my Chester 920 lathe Thanks

[Paul Jones]

Thank you Michael and this modification will work well for many types of lathes.

I have been using the tailstock clamp for more than 6 months and pleased with how well it consistently locks the tailstock in alignment with the headstock. Last weekend I checked to make sure the lathe was still correctly leveled, used a Morse taper lathe alignment test bar to verify the headstock alignment and then aligned my favorite tailstock live center with the headstock. I found that I could remove and reinsert the MT3 live center into the tailstock more a half a dozen time and each time lock down the tailstock with no more than 0.0003" in alignment error over 12" (I even had to turn off the lathe halogen light because the extra heat changed the measurements). I had the same consistent results with a keyless chuck. I found using a consistent clamping pressure on the tailstock clamp produced the best tailstock alignment (I now lock the tailstock clamping lever in the same position each time). I can see why gunsmith lathes can use a torque wrench to produce consistent clamping pressures when holding extremely close tolerances. It really makes a difference.