Lathe Intervention

[e Markle]

My name is Ernie, and I have a broken lathe. There's something wrong with my tailstock; I have to readjust/realign *every* time I drill.

At first I thought all of my drill bits were bent because they would almost never line up to true. Now I think it's either the jacob's chuck or the tailstock itself. Regardless, each time I drill I have to line everything up using those Allen screws at the base of the tailstock (it's a Jet BD 920N). For the life of me I can't imagine what is causing this variance. Although the summer is insanely hot here, the temp doesn't vary that much during the day, and this started in the fall anyway.

Any ideas?

[RadDavis]

I have no idea. Hope this helps.

Rad

[e Markle]

I knew posting this where Rad could read it would be a mistake. Wait, can Rad read? OK, I knew posting this where Rad's computer could read it to him would be a mistake.

[DMI]

I had exactly the same problem when my lathe was new out of the box, it turned out that the alan bolt was slightly longer than allowed for in the threaded hole, no matter how much I tightened it the tail stock would move. My solution was a simple thick washer.

David.

[JHowell]

I had exactly the same problem when my lathe was new out of the box, it turned out that the alan bolt was slightly longer than allowed for in the threaded hole, no matter how much I tightened it the tail stock would move. My solution was a simple thick washer.

David.

That sounds like a good answer. When you center the tail stock, the adjustment screws need to oppose each other with a bit of tension. You can't just put it there, you need to snug it into center.

As you noted, Ernie, your chuck or chuck arbor could be messed up. I have a couple of chucks like that; I have to keep one tool in them and put a mark at TDC so I put them in the taper the same way every time. Make sure your tail stock taper is clean. Might not be a bad idea to take the tail stock apart, just clean it up and have a look around. Make sure the dovetail between the tail stock and base is clean. To check for chuck problems, try changing bits and doing what you'd normally do without actually drilling holes. Use a dead center in the tail stock to set the center to begin with, don't trust the chuck you're checking. Chuck a piece of stock and turn a 60 degree cone to a sharp point. Align your tail stock using the dead center to this point. Install the chuck and a twist drill, check for center. If it's not on center, there's your problem.

Jack

[RadDavis]

That sounds like a good answer. When you center the tail stock, the adjustment screws need to oppose each other with a bit of tension. You can't just put it there, you need to snug it into center.

As you noted, Ernie, your chuck or chuck arbor could be messed up. I have a couple of chucks like that; I have to keep one tool in them and put a mark at TDC so I put them in the taper the same way every time. Make sure your tail stock taper is clean. Might not be a bad idea to take the tail stock apart, just clean it up and have a look around. Make sure the dovetail between the tail stock and base is clean. To check for chuck problems, try changing bits and doing what you'd normally do without actually drilling holes. Use a dead center in the tail stock to set the center to begin with, don't trust the chuck you're checking. Chuck a piece of stock and turn a 60 degree cone to a sharp point. Align your tail stock using the dead center to this point. Install the chuck and a twist drill, check for center. If it's not on center, there's your problem.

Jack

Hope this helps.

Rad

[baweaverpipes]

Here in Tennessee, we never have those problems. We have two Jets at the Briar Studio and I have a Grizzly in my shop. It's normally operator malfunction. In other words, ERemarkable, you're an imbecile, .
Hope this helps.

FYI-Rad's my hero!!!!

[e Markle]

Jack & David,
Thanks for your helpful posts - I'll do some investigating. Hopefully that will turn something up. I was hoping to get more opinions from some seasoned pipe makers, but looks like none are responding.

Kurt,
Isn't there some kind of "ignore", or "ignore all posts", or perhaps "ignore the existence of" function that I can implement here? That would be super. Thanks.

[JHowell]

Well, Rad and Bruce certainly are more "seasoned" than I am.

[RadDavis]

Did Ernie say something?

I placed him in my "Burning in Hell" file after his smart-ass response to my first helpful post, so I probably missed it.

Rad

[e Markle]

Well, Rad and Bruce certainly are more "seasoned" than I am.

Just to clarify, I was merely trying my hardest to insult Rad and Bruce (cause it's so much fun), not to take away from your response - it was helpful. Thank you.

Did Ernie say something?

I placed him in my "Burning in Hell" file after his smart-ass response to my first helpful post, so I probably missed it.

Rad

Oh, I'll have to go back and review your "helpful post". In the meantime...

[ignore]
[ignore RadDavis]
[ignore all RadDavis]
[erase RadDavis from memory]

Did it work?

[JHowell]

Did Ernie say something?

I placed him in my "Burning in Hell" file after his smart-ass response to my first helpful post, so I probably missed it.

Rad

Oooo, where's THAT button?

[JHowell]

[

Just to clarify, I was merely trying my hardest to insult Rad and Bruce (cause it's so much fun), not to take away from your response - it was helpful. Thank you.

Just to clarify, I was merely joshing our elders. Happy birthday, Bruce!

[KurtHuhn]

Kurt,
Isn't there some kind of "ignore", or "ignore all posts", or perhaps "ignore the existence of" function that I can implement here? That would be super. Thanks.

Rad's Burning in Hell button would be great! Hopefully he'll share the process.

[e Markle]

[

Just to clarify, I was merely trying my hardest to insult Rad and Bruce (cause it's so much fun), not to take away from your response - it was helpful. Thank you.

Just to clarify, I was merely joshing our elders. Happy birthday, Bruce!

Oh - ha! I completely missed that. Thanks for joining in - they deserve more mockery than one soul can provide

[RadDavis]

Rad doesn't like being joshed.

Rad

[baweaverpipes]

Rad doesn't like being joshed.

Rad

Nor do I, Rod.
Having turned 60 years young yesterday, Rod and I are old enough to be the father to most on this board. I'm certain Rod would concur, but to claim any of you would be repulsive.
Being a senior and of more advanced years than I, Mr. Davies deserves all the respect he deserves. I really don't care since I find most of you (especially eRemarkable and Simon) to be pugnacious and loathsome.
Hope this helps

Bring back Messer!!!!

[SimeonTurner]

Rad doesn't like being joshed.

Rad

Rad has started referring to himself in the third person? This pleases me.

Bruce, did you get my birthday card in the mail yet? If not...it's in the mail. If it's ticking when you get it...don't worry! It's a...Uh...new blocking briar with a...Uh...clock in it.

[SimeonTurner]

Rad doesn't like being joshed.

Rad

Rad has started referring to himself in the third person? This pleases me.

Bruce, did you get my birthday card in the mail yet? If not...it's in the mail. If it's ticking when you get it...don't worry! It's a...Uh...new block of briar with a...Uh...clock in it.

[baweaverpipes]

Simon,
You're so redundant!