lathe .just got the 4 jaw chuck today. i still have some pre-formed lucite stem
that i want to use. i tried chucking the stems in the chuck a number of times and they still wobble!!! want can i do!!
thanks, timchucking a pre-formed stem
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timothy thorpe
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- Location: new jersey
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chucking a pre-formed stem
hi guys, thanks again for all your help!!! i have been practicing with the micro
lathe .just got the 4 jaw chuck today. i still have some pre-formed lucite stem
that i want to use. i tried chucking the stems in the chuck a number of times and they still wobble!!! want can i do!! thanks, tim
lathe .just got the 4 jaw chuck today. i still have some pre-formed lucite stem
that i want to use. i tried chucking the stems in the chuck a number of times and they still wobble!!! want can i do!!
thanks, tim
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timothy thorpe
- Posts: 167
- Joined: Mon Jun 11, 2007 6:20 am
- Location: new jersey
- Contact:
thanks nick, but the jaws are self-centering. could they still be off?Nick wrote:have you double checked your chuck's alliagnment? I used to do this with two brad point drill bits. Chuck one in the headstock using your 4 jaw, and the other in your tailstock's jacobs chuck. The two points should be right on each other. If not, adjust the jaws of your chuck until they are.
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timothy thorpe
- Posts: 167
- Joined: Mon Jun 11, 2007 6:20 am
- Location: new jersey
- Contact:
How are you chucking them in?
My method with preformed stems is as follows. I'm assuming you're chucking up a tapered stem as opposed to a saddle or some other type:
Make sure the live center is in your tailstock and that it is centered. It should be, but I always check anyway.
Insert stem, bit end first, into headstock chuck as far as you can without damaging the bit or binding up the headstock. Gently tighten the chuck jaws until they hold the stem but you have a bit of play.
Move tailstock/live center up to tenon and apply gentle pressure.This *should* true up the stem in the headstock. Lock the tailstock in place to hold the stem in place while you...
Tighten the chuck. You're going to have to bear down a bit. It's going to leave marks in your stem, but they will come out when you're filing/sanding after it's been fitted. It has to be tight because of the taper in the stem. Even well tightened, those preformed tapers have a tendency to squirt out of the jaws and cause problems.
Loosen the tailstock and slide it back out of the way for the moment. You're going to need this in the next step, but you're going to want to turn on the lathe at this point and see if you're turning true. It should be pretty obvious and most likely you'll get it on the first try. If not, make an adjustment and check again until it's turning true.
Once you're confident it's turning true, slide the tailstock back up to the tenon and lock it in place. Load a righthand cutting tool in the tool post. Make sure you have enough room to move the carriage far enough to the right to clear the end of the tenon. It doesn't need to be a bunch of room, just enough to start your cuts at the end of the tenon. For preformed stems, I've found that I must use the tailstock and live center or the stem squirts out of the jaws after a few passes with the cutting tool. This, obviously, causes some problems. YMMV with this, but it's the best way I've been able to cut good tenons on preformed stems with the Taig.
Set your carriage stop for your leftward travel.
Turn on your lathe and cut that tenon. I use the slowest speed. When you get close to where you need to be, stop the lathe, make sure the stem is still nice and tight in the headstock chuck and move the tailstock out of the way. Test the fit of the tenon-to-mortise. Keep doing this until you've got a good fit. Don't forget to replace the tailstock if you're going to cut anymore. Flying stems are not our friends.
Hope this helps!
Matt
My method with preformed stems is as follows. I'm assuming you're chucking up a tapered stem as opposed to a saddle or some other type:
Make sure the live center is in your tailstock and that it is centered. It should be, but I always check anyway.
Insert stem, bit end first, into headstock chuck as far as you can without damaging the bit or binding up the headstock. Gently tighten the chuck jaws until they hold the stem but you have a bit of play.
Move tailstock/live center up to tenon and apply gentle pressure.This *should* true up the stem in the headstock. Lock the tailstock in place to hold the stem in place while you...
Tighten the chuck. You're going to have to bear down a bit. It's going to leave marks in your stem, but they will come out when you're filing/sanding after it's been fitted. It has to be tight because of the taper in the stem. Even well tightened, those preformed tapers have a tendency to squirt out of the jaws and cause problems.
Loosen the tailstock and slide it back out of the way for the moment. You're going to need this in the next step, but you're going to want to turn on the lathe at this point and see if you're turning true. It should be pretty obvious and most likely you'll get it on the first try. If not, make an adjustment and check again until it's turning true.
Once you're confident it's turning true, slide the tailstock back up to the tenon and lock it in place. Load a righthand cutting tool in the tool post. Make sure you have enough room to move the carriage far enough to the right to clear the end of the tenon. It doesn't need to be a bunch of room, just enough to start your cuts at the end of the tenon. For preformed stems, I've found that I must use the tailstock and live center or the stem squirts out of the jaws after a few passes with the cutting tool. This, obviously, causes some problems. YMMV with this, but it's the best way I've been able to cut good tenons on preformed stems with the Taig.
Set your carriage stop for your leftward travel.
Turn on your lathe and cut that tenon. I use the slowest speed. When you get close to where you need to be, stop the lathe, make sure the stem is still nice and tight in the headstock chuck and move the tailstock out of the way. Test the fit of the tenon-to-mortise. Keep doing this until you've got a good fit. Don't forget to replace the tailstock if you're going to cut anymore. Flying stems are not our friends.
Hope this helps!
Matt
I do all my work on a wood lathe, but here's what I do to chuck up a pre-made stem:
Thread the tenon end of the stem onto a drill bit that just fits in the airway. The stems I use normally have an 1/8" airway but this might be different on different stems. Chuck the drill bit/stem into my Jacobs chuck mounted in the tailstock. Use this to center the stem in the 4 jaw chuck mounted on the headstock and tighten the jaws! The use of the drill bit and tailstock should have the stem centered and straight in the chuck. Twist and pull out the drill bit and jacobs chuck. I use delrin tenons so I can't comment on how to turn a tenon!
Thread the tenon end of the stem onto a drill bit that just fits in the airway. The stems I use normally have an 1/8" airway but this might be different on different stems. Chuck the drill bit/stem into my Jacobs chuck mounted in the tailstock. Use this to center the stem in the 4 jaw chuck mounted on the headstock and tighten the jaws! The use of the drill bit and tailstock should have the stem centered and straight in the chuck. Twist and pull out the drill bit and jacobs chuck. I use delrin tenons so I can't comment on how to turn a tenon!