Jet mini tailstock lock

[Dean Center]

I dove into the vortex when my family gave me a Jet mini lathe about 15 years ago. In a couple years, I adopted a used Powermatic, but I still have the mini lathe and enjoy using it. It's just approachable and calm. Also in a heated space.

Over 4-5 years of occasional use, I've noticed the tail stock lock needing to be swung farther and farther over to secure it. It's at the point where it's in the way of the banjo and something has to be done.

Yesterday, I pulled, and broke, the c-clip holding the locking rod in place and was a little surprised at what I found. The locking rod has an asymmetrically shaped section where the clamping mechanism fits. As I hope can be seen in the photos, this section has been ground and rounded by the hole in the bolt of the clamp. You probably can't see, but the edges of this hole are 'sharpened' and have slightly protruding edges, presumably made during use rather than at the factory. It seems like the locking rod is soft steel and the bolt is harder, hence the bolt has ground down the rod.

In any case, I assume I'll need to buy a new locking rod, which is available from Jet for a tolerable price. Just in case, I'm asking all you experienced folks, is there an alternative to replacing it? Should I replace the bolt as well? (remarkably pricey from Jet) Also, how do I prevent this from happening in the future? Thanks for your help.

 

[hockenbery]

I replaced a locking bolt on an ancient delta Rockwell 30 years ago it had worn threads so the locking plate could not be set to the right height.

You know that the off center cam provides two functions
- It lifts the bolt - that brings the bottom plate in contact with the ways
- the cam also makes a mechanical lock when pressure is applied. The softer metal helps here

the worn rod provides less lift height and it doesn’t lock very well.

From the pictures - you will probably get 15 more years with just a new locking rod.

I’d probably round the sharp edges on the bolt eye by hand with some Emory paper.
I’d probably leave the inside scoring mostly alone. Maybe light passes with Emory paper.

Maybe someone who has fixed the same exact problem can chime in.

 

[Isaac Fisher]

With that much wear I would replace both pieces. The wooden extension on the handle is probably providing too much leverage when tightening, although it may be necessary in the current state. If you end up getting new parts I would opt for leaving it off. A small wooden sphere at the end of the handle would make it more comfortable without encouraging overtightening.

 

[Richard Coers]

Lack of lubrication on two pieces of rubbing steel will do that! That extension handle didn't help since it added more torque on the parts than what they were engineered for. Adding an oversized plate between the washer and the bottom of the bed is the way to lock it easier than leaning on the cam locking shaft.

 

[Isaac Fisher]

+1 for lubrication.

Paraffin wax (not too much) or similar would be a good choice there. Oil or grease not so much since they’ll attract dust and grit.

 

[Jamie Straw]

A recent student sent me information on a site where you can get a square clamp block for virtually any of the small lathes (see link below). I've found that most of the Jet lathe tailstocks, even the 1642, don't lock well despite numerous adjustments. That's why we keep a small fiberglass mallet in the drawer of each. Look at the link in the following forum thread, take a look at the catalog and you'll find info on the square blocks.

Rick's "Custom Made Tools" PDF Catalog

Attached is the recently Updated PDF Catalog of Rick's "Custom Made Tools". Revised 10-2-24 It replaces the previous lengthy thread. (Old linked to this thread) Includes a table of contents All links, web, internal and document are live links It is searchable [Ctrl F] Images are large...

www.penturners.org

 

[Isaac Litster]

The locking mechanism of my Harbor Freight 10x18 did the same, and I bought a replacement from Rikon. Many companies, such as Wen, Rikon, Grizzly, Jet, all make nearly the same lathe, so looking at the spare parts from any of those companies.

 

[Earl McLain]

A recent student sent me information on a site where you can get a square clamp block for virtually any of the small lathes (see link below). I've found that most of the Jet lathe tailstocks, even the 1642, don't lock well despite numerous adjustments. That's why we keep a small fiberglass mallet in the drawer of each. Look at the link in the following forum thread, take a look at the catalog and you'll find info on the square blocks.

Rick's "Custom Made Tools" PDF Catalog

Attached is the recently Updated PDF Catalog of Rick's "Custom Made Tools". Revised 10-2-24 It replaces the previous lengthy thread. (Old linked to this thread) Includes a table of contents All links, web, internal and document are live links It is searchable [Ctrl F] Images are large...

www.penturners.org

I've bought a handful of items from Rick Herrell over the past several years. All high quality, and capable of creating tools/devices if there's a specialized need. Almost seems like he gets satisfaction in solving a problem. No direct interest, just a satisfied customer.

 

[John K Jordan]

This may not be the answer for you (and I can't quite see the exact problem from the pictures) but if it's something made from steel that is worn so it's unusable one fix is run a series of weld beads to build up the area (I'd prob use heliarc (TIG) but MIG would work, then machine the part to restore the function. This would be easier if you can borrow an undamaged one to use as a guide.

It's common to use welding to build up steel where needed and it's not all that difficult. (Clean well first) It does require welding equipment and skills. It also requires metal machining equipment and experience which may be harder to come by, but sometimes reasonable working parts can be made by hand. A local machine shop could probably restore that one in short order, especially if you had a spare to take measurements from.

Sometimes it's easier to just make replacement parts from scratch. They may look different but still be functional. In this case, if I'm interpreting the photos correctly, the hole in the bolt lock may also need to be repaired - drilling larger and inserting a sleeve is one way.

But if a replacement is available and reasonably priced, I'd choose that!

JKJ

 

[Dean Center]

With that much wear I would replace both pieces. The wooden extension on the handle is probably providing too much leverage when tightening, although it may be necessary in the current state. If you end up getting new parts I would opt for leaving it off. A small wooden sphere at the end of the handle would make it more comfortable without encouraging overtightening.

Thanks to Isaac and Richard for this observation. I can't recall when I added that extension, but I'm pretty sure it was because the tail stock would slip in use. I guess I'll have to accept responsibility for causing this problem. Slipping tailstock due to using a cheap washer for the lock is on Jet.

And thanks to John and Jamie for their suggestions. Both good ones, but I don't have the skills or equipment to try the welding/machining DIY approach. I'll look into Ricks block. And maybe shop for a better locking block, which I should have done years ago.

 

[John K Jordan]

I've found that most of the Jet lathe tailstocks, even the 1642, don't lock well despite numerous adjustments. That's why we keep a small fiberglass mallet in the drawer of each.

Zounds, I've never experienced that with either of my 1642s or two jet minis. (one 1642 had heavy use for years then occasional use since). Hand pressure (not even bumping with the heal of the hand) always made the tailstocks on mine immovable. Makes me curious about what the difference was.

JKJ

 

[Leo Van Der Loo]

it is quite common for tailstocks to slip when high pressure is used to force pieces together, this problem came up quite frequently.

When I got a small 10" lathe, I noticed the tailstock would creep if/when the clamping was not as high as possible, I did not like that and investigated why this was.

I found the round washer contacted the ways with a really small area, so I took a piece of 8mm (5/16) flat steel and drilled a hole for the bold to go through, replaced the round disk/washer with the rectangular steel plate.

It worked perfectly and I made a picture and showed it when someone had a slipping tailstock problem.

since I am away from home, I have to pull the picture from the web, small and not sharp, but it is ok I think.