3 Jaw chuck broken

[dbq49]

:thinking:I am just starting to get my Atlas 10"-48" up and running. I have finally gotten most of my tooling and I found sites saying that a check bar is useful in resetting the tail stock when I need to. I started making the bar and I could not get my 3 jaw chuck to work correctly. It would not let me unchuck the metal. I could only rotate the chuck key one turn. I took the chuck off the lathe and started to disassembled the chuck. I got it apart and found hardened lube every where. I had to chisel the lube from everywhere. Yes I had chips, grit, and hard chunks of lube in the workings. What found in the ring was a tooth from the chuck gear stuck in the ring. The only thing that I had done to the chuck was fill it with oil and wiped it down. The tooth slot looks like it must have happened some time ago, no shinny metal. The chuck only has the numbers 6613-1 on it. No manufacture name. Long question short. Can I get a part, have it made, take my mig and weld a tooth and regrind, or pitch it? I am going to try to post a pic. I know you have ideas. Lets hear what you have to say!
As always thanks!

 

[pineyfolks]

Re: 3 Jaw chuck briken

Braze it and file to fit unless you have a mill, cutters, index head, and whatever else you might need. Then I'd probably still just braze it. I don't think mig is the way to go here but I'm no welder.

 

[Terrywerm]

Re: 3 Jaw chuck briken

I agree with Bill, clean it up and braze in a small piece of stock, then file it to shape to match the other teeth. It may sound like a lot of work, but it will go faster than one might think.

 

[mattthemuppet2]

Re: 3 Jaw chuck briken

If it's that beat up I wonder what the rest of of it will be like. Might be worth writing while you're ahead and getting a new chuck if funds allow.

 

[dbq49]

Re: 3 Jaw chuck briken

Yes I can braze it. I failed to mention that I had the tooth, it was still in the mating plate. The plate looks good. I think that the gear was running up against the embeded sheered tooth and that is what stopped the jaws from moving. It is why I tore the chuck apart. Back to repairing, brazing would be softer than the mig welding since I would have to grind/file the finish anyway. Dose anyone know who makes the chuck with "6613-1" on it? My parts list for the lathe does not mention anything with that number.

 

[dbq49]

Re: 3 Jaw chuck briken

Just a thought, how about just putting it all back together and see. 8/7 teeth meshing with 80 teeth on the ring. I do not have a v/h mill to recut teeth, just some files, grinders and a dremel with diamond cutters. I was thinking that if I brazed a tooth that I would have to place some kind of blocker at the top and bottoms of the teeth to keep it from running on unwanted areas. What could I use as a blocker that would not get fastened to the gear it self. What say you brazer's.
Still thanks.

 

[ScrapMetal]

Re: 3 Jaw chuck briken

Yes I can braze it. I failed to mention that I had the tooth, it was still in the mating plate. The plate looks good. I think that the gear was running up against the embeded sheered tooth and that is what stopped the jaws from moving. It is why I tore the chuck apart. Back to repairing, brazing would be softer than the mig welding since I would have to grind/file the finish anyway. Dose anyone know who makes the chuck with "6613-1" on it? My parts list for the lathe does not mention anything with that number.

I found a reference for a 6" chuck "made in England" with that serial number -

230A. 6” close to new, outside jaws only, integral 1 ½ x 8 back, #6613-1 made in England, $145.00

. My assumption from that would be that it is a Pratt Burnard chuck (or most likely just a Burnerd depending on age).

I also found this listing for Atlas chucks where there is a listing for a 6" chuck model #6613



Hopefully some of that will give a clue as to it's origin.

-Ron

 

[chips&more]

Re: 3 Jaw chuck briken

Just a thought, how about just putting it all back together and see. 8/7 teeth meshing with 80 teeth on the ring. I do not have a v/h mill to recut teeth, just some files, grinders and a dremel with diamond cutters. I was thinking that if I brazed a tooth that I would have to place some kind of blocker at the top and bottoms of the teeth to keep it from running on unwanted areas. What could I use as a blocker that would not get fastened to the gear it self. What say you brazer's.
Still thanks.

I would not put it back together with the missing tooth. Chances are it would bind up where the tooth is missing and you would then break more teeth off. I would with your Dremel and an abrasive wheel and a steady hand grind a slot the width of the tooth and say about 0.100” deep right in the center of that broken area. Then get a piece of steel the width of the tooth and length and all of that and braze it in place. If the steel blank is a little too thick don’t file it down, but instead hit it with a hammer and smash it thinner. After all has cooled. Then grab that Dremel again and with your steady hand shape the profile of the tooth and maybe a little filing too…Good Luck.

 

[Tony Wells]

Re: 3 Jaw chuck briken

I'd look at a different approach, under some circumstances. If this chuck has only the one pinion, then obviously this will be no help. I would make a blank, sans any gear teeth and just use one of the remaining 2 to tighten the chuck. Then I would shop for another chuck. In the mean time, unless there were high speed balance issues, I'd use as is.

 

[dbq49]

Re: 3 Jaw chuck briken

Great effort Ron!!! I did find a "made in England" on the back. After cleaning all the gunk from the inside, I wire wheeled the jaw, polished the ring and tried the fits. I found that the jaws would not slide in the grooves. I had to take the dremmel and a thin metal cutting disc and deburr all the parts till they slid easily. I was surprised how much better is works now. 60 years of binding?? I am still trying of figure out if I want to braze in a tooth. The broken tooth fits well but getting it to sit there while I braze it is an other issue.
Thanks to all that are helping!