Im At The Fork In The Road

[NCjeeper]

So hive what do you guys (and gals) say. I have a 8" 3 jaw chuck for my lathe that could use its jaws ground. I don't have a tool post grinder. So For the cost of winning a decent Dumore on E-bay I could just buy a new chuck. So do I just buy a new chuck or try and win one on E-bay? For those of you that have a grinder do you use it enough to justify the purchase?

 

[34_40]

I had one given to me and I've never even mounted it!

But I guess if I wanted to - I could try it out since I have it. Perhaps you could find one on C-list? I see them on there every now and again.

 

[derf]

Instead of grinding, you might try a big ole carbide boring bar.

 

[GarageGuy]

A number of folks here have ground chuck jaws with a Dremel or high speed (air or electric) die grinder securely mounted to the tool post. Those are generally available dirt cheap ($10 on sale at Harbor Freight). If you use it once and have success, it's worth more than 10 times what you paid for it.

I have a tool post grinder, and in all honesty I don't use it much. Cool to have, but gets used once in a great while.

Good luck!

GG

 

[tomh]

Need more information.
Do you just need a plain back chuck? If so there not that expensive, unless you need super accuracy.
Unless you are experienced or real confident in grinding, you may be better off buying a chuck rather than spending the money on a grinder and then having to buy a chuck in the end. Just my thinking

 

[Wreck™Wreck]

Is the old chuck adjustable or have 2 piece jaws? If the former adjust it if the latter buy some soft jaws and have at it. If it's an inexpensive chuck the jaws are probably not that hard, turn a ring of appropriate size, chuck it on the ID leaving the jaws open at the largest possible diameter and turn the jaws with a boring bar using a hard turning insert if available but a plain steel grade carbide insert will work with very low spindle speeds and smallish DOC. If this does not work to your particular satisfaction you have lost little more then a $15.00 insert. Then buy a new chuck that is adjustable and has 2 piece jaws, this I can not stress enough. Adjustable with 2 piece jaws.

If you have the typical hobbyist penchant for accuracy why would you go the cheapest route with workholding tools for a lathe? A lathe scroll chuck that is not adjustable and will not accept soft jaws is a fixed tool which can not be easily made accurate. A mill vice on the other hand is adjustable and soft jaws may be easily made from any suitable material at hand.

 

[kd4gij]

Do a search on here . There is several threads on using a dermal od die grinder to grind chuck jaws. But hay if you want a Dunmore go fore it, never pass up an opportunity to by a new tool.

 

[Wobbles]

A number of folks here have ground chuck jaws with a Dremel or high speed (air or electric) die grinder securely mounted to the tool post. Those are generally available dirt cheap ($10 on sale at Harbor Freight). If you use it once and have success, it's worth more than 10 times what you paid for it.

Dremel makes a mounting bracket that you can afix to the cross-slide. You take tiny cuts. Take you about an hour. Results vary by the condition of the chuck you start with.

This is NOT a perfect fix, since the jaws in this setup (expansion inside a large washer) run on the inside of the scroll gear, whereas in normal use (clamping) they run on the outside. If you want to spend hundreds and be assured of getting your accuracy back, then IMHO a new chuck is the only way to go.

 

[T Bredehoft]

Mount a washer Just larger than the bore through the chuck in the back of the chuck and clamp on it. then, with your Dremel tool lashed onto your tool post, grind the three jaws. When they've all cleaned up, and you've taken a light finish pass, open the chuck, take the jaws out and snag grind where the washer was in the back. You will have clamped on the active side of the scroll, and your jaws will be true except for the very back, which doesn't matter anyway.

 

[Chuck K]

So hive what do you guys (and gals) say. I have a 8" 3 jaw chuck for my lathe that could use its jaws ground. I don't have a tool post grinder. So For the cost of winning a decent Dumore on E-bay I could just buy a new chuck. So do I just buy a new chuck or try and win one on E-bay? For those of you that have a grinder do you use it enough to justify the purchase?

I have a tool post grinder that doesn't get used very often. I have ground the jaws on two chucks and didn't have great results either time. What I found was the scroll was worn in both also. Like an earlier poster, my grinder was given to me. If I was in your position, unless I was certain the scroll wasn't worn, I would put the cash toward a new chuck.