Older Jet Mini problem

[Tom Albrecht]

I have an original Jet Mini lathe sitting around that I'd like to get set up for my granddaughter. It has a tailstock that just will not stay put even with loads of force on the arm, and certainly not for a kid. Does anybody know of a fix for this?

 

[Richard Coers]

You need something that looks like this. Replaces the round washer under the tailstock so you have more contact area. It's been a known issue for a long time!
http://www.monster-lathe-tools.com/cart.php?target=product&product_id=331&category_id=67

 

[Bill Boehme]

Can you post some detailed pictures that show what the lock mechanism looks like? Is the lathe the really old medium gray or the newer blue color or the even newer dingy-not-quite-Tide-white? Also, is it creeping when the quill is cranked to apply pressure? Or just plain loose all the time? The best solution is a T-slot nut custom fitted to the gap between the ways, but it probably has a round disk that has worn over time or worn the bottom of the ways. Another possibility is that the cam or the sleeve or the holes could be worn since I don't believe that they were bushed.

 

[Tom Albrecht]

Can you post some detailed pictures that show what the lock mechanism looks like? Is the lathe the really old medium gray or the newer blue color or the even newer dingy-not-quite-Tide-white? Also, is it creeping when the quill is cranked to apply pressure? Or just plain loose all the time? The best solution is a T-slot nut custom fitted to the gap between the ways, but it probably has a round disk that has worn over time or worn the bottom of the ways. Another possibility is that the cam or the sleeve or the holes could be worn since I don't believe that they were bushed.

I'll post a pic tomorrow, but it is white and the the whole tailstock just creeps as you crank on the wheel.

 

[Barry Crowder]

I fixed this problem on my Excelsior lathe by making a larger tailstock lock plate. If yours is like mine, the original tailstock lock plate has a surprisingly small surface area where it contacts the underside of the bedways. Even a modestly larger plate will make a big difference. With a larger lock plate, mine doesn't slide any more.

Something like Richard Coers linked to should work, if it is the right dimensions. I made mine round, like the original, so I don't have to fuss with aligning it when I put the tailstock back on.

 

[john lucas]

that's exactly like the locking plate I made for mine many years ago. They work perfectly and really lock the tailstock in place.

 

[Mike Johnson]

One of my lathes has a tail stock that will creep along when turning the hand wheel, I usually need
to apply a little extra pressure on the locking lever when setting the tail stock.

 

[Bill Boehme]

You need something that looks like this. Replaces the round washer under the tailstock so you have more contact area. It's been a known issue for a long time!
http://www.monster-lathe-tools.com/cart.php?target=product&product_id=331&category_id=67

... Something like Richard Coers linked to should work, if it is the right dimensions. I made mine round, like the original, so I don't have to fuss with aligning it when I put the tailstock back on.

I agree that is probably the best solution unless something else is broken or worn out. That is like the T-slot nut that I mentioned, but the only difference is the locking plate isn't threaded. T-slots are commonly used on metalworking machines to hold fixtures and worth pieces.

 

[Leo Van Der Loo]

Tom that round disk under your tailstock has only two very small areas rubbing under the ways to keep the tailstock from moving, and my little LA200 Delta lathe did the same thing, so I got a piece of flat steel (1/4" or 5/16” thick and the width that could fit under the ways, longer than wide) also added a spring to keep it down and keep it from rotating, it worked just fine with that, 2 pictures here will show what I added.

That little lathe is on its 3th owner and still working fine.

 

[Barry Crowder]

There seems to be a consensus as to the cause of the slippage...

 

[john lucas]

the other problem might be how flat the bed of the tailstock is as well as the lathe bed but scraping those 2 perfectly flat is a bear and not to be attempted by non skilled workers. I had that problem with an older J line lathe and scraped the tailstock bottom until it was flat. Took a lot of time and it did help. However making the bottom locking washer larger and flat is so much easier and is necessary anyway.
At one point I took a jet mini and added several mods to improve the machine. I put a full length locking plate under the tailstock. I added a roll pin and a spring to both keep the locking plate from rotating and to hold the front edge up which made it easier to slide the tailstock back onto the bed.
I added indexing on the handwheel with a spring loaded pin to actuate it. The tool rest on the mini has a weak square joint between the post and tool rest so I built a steel tool rest that also had a slightly rounded joint to keep it from breaking. I added a plate to the headstock that stuck out just a little bit and was drilled to accept the knock out bar which is also used to lock the headstock. This way you don't need both hands to lock the headstock and remove the chuck or faceplate.

 

[Tom Albrecht]

Thanks everybody. I'll add a rectangular flat plate to fix it.