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Jacobs chuck and MT questions

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Jacobs chuck and MT questions

#1

Jacobs chuck and MT questions

keith zimmerman, Normal, IL

>Greetings all,

I have a couple of questions about use of a Jacob's chuck/#2 MT combo on my Jet mini lathe.

1. When using this, the chuck comes off the end at times. I believe there is a screw hole in the chuck to secure it, the way they are connected to drills. Anyone tell what size screw is needed?

2. Other times, the entire chuck/MT slides out of my headstock. I know there is a way to hold it in place with a long screw. Anyone know where these are available or who sells them?

Thanks in advance.

keithz

Re: Jacobs chuck and MT questions

#2

Re: Jacobs chuck and MT questions

Wood Spinner

>Make sure each is very clean. When you put the chuck in the hole put the wood in and use a light hammer to tap it in tight. Also use the tail stock at the beginning of your turning.

I almost allways start between centers.

Good turning and be safe

Bill in Casa Grande, AZ.

Re: Jacobs chuck and MT questions

#3

Re: Jacobs chuck and MT questions

Bill Howatt

>The chuck shouldn't easily come off your arbor. Clean it and re-install. Try putting it in your tailstock and tightening it up against a wood block between your faceplate and the chuck.

another way would be to put the arbor in the freezer to shrink it and then quickly do the insertion. I am assuming that you do have the correct taper for the chuck on your arbor.

Jacobs chucks don't like to stay in a headstock without being held in place although you can get away with it depending on what you are doing. Normally the pressure from the tailstock center holds the Jacobs chuck arbor in the headstock.

To use the Jacobs chuck by itself you can get a threaded rod to fit a tapped hole in the Morse taper end of the arbor. Often these are threaded 1/4-20 but other threads do exist so you have to be sure when buying the rod. Screw the rod into the arbor, slide it into the headstock, put a washer and wing nut on the end and tighten. I use those plastic threaded knobs with the correct length of rod "locked" into the knob. I put the arbor in the headstock and then put the knob/rod through the back of the headstock and tighten.

You may find your arbor isn't drilled and tapped. If so, buy a new one since they are usually hardened and you will have trouble drilling and tapping.

Bill

Re: Jacobs chuck and MT questions

#4

Re: Jacobs chuck and MT questions

Fred in NC

>The thread in my #2 Morse taper is 3/8"-16. I bought a piece of threaded rod that size from Lowe's and long enough to go through the spindle. A washer and wing nut (which can be nylon) hold the outboard end. DO NOT overtighten !!! To remove, tap LIGHTLY on the end of the rod, and make sure it will not fly out the spindle and get damaged or cause damage. This threaded rod/nut combination is usually called a DRAW BAR.

If I interpret it correctly, your chuck is also unscrewing itself from the Morse taper. If there is a threaded hole for a set screw I would use that. One good trick, if the depth of the hole allows for it, is to use two short set screws. That way it is not necessary to overtighten the first one, the second holds the first in position. Otherwise use a little LockTite and screw the taper all the way in into the chuck.

Most of the time the reason why a taper does not hold in the spindle is because of dirt, wood dust, etc. I use a piece of cloth to clean inside of the taper.

I don't like hitting anything into the spindle. The least that can happen is damage to the bearings. Most lathes do not have a thrust bearing that can stand axial forces. Nor do I like reducing the diameter by freezing. Some people have had huge problems removing the taper later.

This is the way I do it, and other opinions might be different, which I respect.