Rookie Question

[jkeithrussell]

Ok, I bought a Jet mini lathe and started making pens. So far, so good. For variety, I picked up some gear to make bottle stoppers. I got a starter kit with the mandrel, drill, and some kits. I also got a Jacobs chuck. Here's the problem:

The guy (at Woodcraft) who sold me the Jacobs chuck told me to buy a bolt to run through the headstock to secure the chuck. It seems weird to me that there is not a manufacturer-produced piece of hardware for that, but I went to Home Depot and bought a bolt. It won't hold the chuck. If the bolt is tightened just a smidge too much, the mandrel portion of the chuck pulls out. Any time the chuck is in use (lathe is turned on), the mandrel portion works its way loose.

I'v tried banging the mandrel portion of the jacobs chuck into place with a deadblow hammer, but it doesn't seem to make any different.

What am I doing wrong?

 

[maxwell_smart007]

The fit between the chuck and the mandrel should be tight..I can't see how you can make it any tighter than using a mallet and wood block, but if you've already tried that, it's a connundrum.

Did you make sure that the Jacobs Taper and the recess are both very very clean? Even little specks of dust can get in the way and prevent a tight fit...

As for the drawbar - I think the HD guy is right. I have a bolt in mine that I bought from the hardware store, as there didn't seem to be a commercial solution. Regardless, it works very well.

Hope you get it figured out.

Andrew

 

[Skye]

I had the same problem. Keep in mind, the nut won't do anything for that setup. They're just pressure fitted together, then that assembly is pressure fitted into the headstock.

It'll help with one piece mandrels, but not two piece setup you got going on. I eventually just faced the fact that I'd probably never remove that morris taper from that jacob's chuck, so I just hit it with some loctite and jammed them together.

Now a day, I just use the cone style bottle stoppers and use an one piece chuck from Arizona, it's a whole lot easier because it threads onto the headstock and it's not going to suffer from that problem. It's also shorter and thicker so it's not going to get bent like the one you're dealing with now.

 

[jkeithrussell]

Thank you. Both good ideas. I had not thought of loctite. The one-piece mandrel is sensible, but I hate to abandon the jacob's chuck after I just bought it. May just have to return it.

 

[toolcrazy]

Don't return the Jacobs chuck, you can use it in the tail stock to drill with. Will always come in handy.

 

[rherrell]

Ok, I bought a Jet mini lathe and started making pens. So far, so good. For variety, I picked up some gear to make bottle stoppers. I got a starter kit with the mandrel, drill, and some kits. I also got a Jacobs chuck. Here's the problem:

The guy (at Woodcraft) who sold me the Jacobs chuck told me to buy a bolt to run through the headstock to secure the chuck. It seems weird to me that there is not a manufacturer-produced piece of hardware for that, but I went to Home Depot and bought a bolt. It won't hold the chuck. If the bolt is tightened just a smidge too much, the mandrel portion of the chuck pulls out. Any time the chuck is in use (lathe is turned on), the mandrel portion works its way loose.

I'v tried banging the mandrel portion of the jacobs chuck into place with a deadblow hammer, but it doesn't seem to make any different.

What am I doing wrong?

Something ain't right. I'm ASSUMING that both your lathe and drill chuck have Morse 2 tapers, am I right so far? If that's the case, when you tighten the drawbar the M2 taper on your drill chuck arbor is forced into the M2 taper in your lathe headstock and is held tight. Tightening the drawbar SHOULD NOT seperate the drill chuck from the drill chuck arbor, no way!! It sounds to me like the drill chuck arbor is too small and instead of tightening up in the headstock taper, when you tighten the drawbar it's passing straight through and the drill chuck itself is making contact with the headstock and pops off when you tighten the drawbar.
You also said......."Any time the chuck is in use (lathe is turned on), the mandrel portion works its way loose. "

Are you saying the drill chuck and drill chuck arbor work their way loose FROM EACH OTHER or that the drill chuck arbor works its way loose from the headstock? If you mean the latter, that's normal and the very reason you need the drawbar. If it's the former then it sounds like the tapers on the drill chuck and the drill chuck arbor don't match.
Pictures would help ALOT. :wink:

 

[Russianwolf]

I'm with Rick, Something isn't right.

If the hole through the taper is runs the full length of the taper, then you also have to make sure that the bolt isn't too long and pushing the chuck off. That can be remedied simply by putting an extra nut or too on the bolt up near the head.

Are you sure that the taper is a #2, as the Jet mini is a #2. If they sold you a #1 taper, you'll need to take it back for the proper one.

 

[jkeithrussell]

Rick -- I guess my question was goofier than I thought. The arbor and headstock are MT2. At Woodcraft, I was told to turn the chuck upside down and tap the arbor into the hole on the bottom; then, insert the arbor into the headstock and apply the bolt. The bolt simply pulls the arbor back out of the chuck. Are you saying that the arbor goes through the chuck first -- do I have the entire thing backward? Thanks for your help.

 

[Russianwolf]

Rick -- I guess my question was goofier than I thought. The arbor and headstock are MT2. At Woodcraft, I was told to turn the chuck upside down and tap the arbor into the hole on the bottom; then, insert the arbor into the headstock and apply the bolt. The bolt simply pulls the arbor back out of the chuck. Are you saying that the arbor goes through the chuck first -- do I have the entire thing backward? Thanks for your help.

the bolt should enter from the left hand side of the headstock and screw into the taper, which enters from the right side of the headstock, "inside" the headstock.

It sounds to me more and more like the bolt is too long.

 

[rherrell]

I'm with Rick, Something isn't right.

If the hole through the taper is runs the full length of the taper, then you also have to make sure that the bolt isn't too long and pushing the chuck off. That can be remedied simply by putting an extra nut or too on the bolt up near the head.

Are you sure that the taper is a #2, as the Jet mini is a #2. If they sold you a #1 taper, you'll need to take it back for the proper one.

GREAT point Mike! Instead of tightening a bolt get yourself some threaded rod, 3/8" is pretty common but take your chuck with you to the store. Thread it into the chuck arbor about 1/2", NO FURTHER!. Now take the whole thing and put it in your lathe. Mark the other end about an inch longer than your handwheel and cut it off. Now put a fender washer and a nut on and tighten the NUT ONLY. MAYBE that will work!:wink:

 

[byounghusband]

I went to http://www.littlemachineshop.com/products/product_view.php?ProductID=1751&category=874479994 and bought a MT2 collet in the 1/2" size. the thread inside the MT2 portion are 3/8"x16. I used 3/8"x16 all-thread, a fender washer, and hex nut to make my draw bar. It works flawlessly....

 

[jkeithrussell]

I will try a few different things tonight and let you know how it goes. I'm not clear on how the length of the bolt will impact me here -- I'm pretty sure that the bolt is the correct length. But I'll try some threaded rod and see what happens.

I've looked around on-line to make sure that the basic layout is correct and I think I have it right. The arbor goes into the back side of the chuck with a tap from a mallet. Only one end of the arbor is threaded, so it has to go with that end into the headstock. Nut/washer at the opening of the handwheel. I guess that only leaves the length of the bolt as the remaining factor.

Thanks again for your helpful suggestions.

 

[jkeithrussell]

All right. I bought the "all thread" rod and cut it to length. Re-tapped the arbor, and tightened everything up. Much improved grip on the key chuck at the headstock. So far, so good.

When I turned the stopper blank, however, it came out lopsided. My guess is that the lathe is not sufficiently weighted down or bolted down to the work table. There was considerable vibration with the workpiece supported only by the chuck.

I will keep working on it.

Thanks for the help on the thread rod -- that corrected most of the problem.

 

[nava1uni]

I made a draw bar from 1/4" x 20 rod, cut it to length and use it to hold my chuck so I can finish the end of the bottle stopper. But to turn most of the stopper I also use my tail stock to hold the wood until I turn off the little end. Mainly the drawbar is used for finishing so the chuck doesn't fling out of the headstock. I turned a wooden handle and glued it onto the rod so it is easy to tighten and loosen.

 

[rherrell]

Like Cindy said, use your tailstock and a live center to support your work for as long as you can.

 

[YoYoSpin]

There are lots of off the shelf solutions...here are several different bottle stopper mandrels. Two on the left are 1/4" x 20tpi and the three on the right are 3/8" x 16tpi: