proper place to ask

ttm · Mar 31, 2013

about a 4 jaw chuck I have, there is no name on it, but it is missing the screws that hold the jaws in place, I ahve the jaws, not sure how they misplaced the screws for them, and it is not a south bend 4 jaw chuck (or I don;t think it is anyhow) so I don't really know where to ask this question,

thanks for any help, I do have a picture of the 4 jaw head

thanks!

edkolt · Apr 1, 2013

This is the place... what is the question?

Ed S

clr8ter · Apr 1, 2013

He wants to know how to replace the screws, and where to get them. And, probably, how to find ones that will fit his chuck. Ask for a photo?

ttm · Apr 1, 2013

clr8ter said:
He wants to know how to replace the screws, and where to get them. And, probably, how to find ones that will fit his chuck. Ask for a photo?

yes, that is what I need to know, where to find the screws,

I will take a better picture of it nthis AM and upload it - it does have a part number on it

traditional-tools · Apr 1, 2013

If you could post a picture or describe it better, you can get a better answer. If the jaws are 2 piece and the screws you talk of are the ones that hold the tops on the masters, those would be one option. Also, many chucks have screws that extend through the chuck and hold on the backplate. Some chucks will remove those screws from the front and others from the back. Typically those don't hold jaws on...so will kinda figure you want the screws to hold the tops on the masters.

For either you will need to know what size screw you need, and if you measure the diameter you should be able to go get a couple TPIs of that size to try. I would go to a hardware store to figure out what size it is.

Either way, you might want to take your chuck and/or both jaws with you. When you know the size, then you can order the proper type online from McMaster-Carr, Fastenal, Enco/MSC, etc...if you can't find them locally. Some of the socket head cap screws or similar might be difficult to find locally.

Cheers,
Alan

ttm · Apr 1, 2013

traditional-tools said:
If you could post a picture or describe it better, you can get a better answer. If the jaws are 2 piece and the screws you talk of are the ones that hold the tops on the masters, those would be one option. Also, many chucks have screws that extend through the chuck and hold on the backplate. Some chucks will remove those screws from the front and others from the back. Typically those don't hold jaws on...so will kinda figure you want the screws to hold the tops on the masters.

For either you will need to know what size screw you need, and if you measure the diameter you should be able to go get a couple TPIs of that size to try. I would go to a hardware store to figure out what size it is.

Either way, you might want to take your chuck and/or both jaws with you. When you know the size, then you can order the proper type online from McMaster-Carr, Fastenal, Enco/MSC, etc...if you can't find them locally. Some of the socket head cap screws or similar might be difficult to find locally.

Cheers,
Alan

thank you, I will take pictures of front and rear of chuck, and the jaws - the jaws have a flat spot on the back side I assume where part of the screw rrides to move them...

doug8cat · Apr 1, 2013

Easy: just go to the junk bin find a bolt that fits, now you know the geometry (screw size). Determine what style is needed & phone up Mcmaster Carr.

P.S. I would get the best grade fastener they have, & I personally brush off everything prior to, during and after changing jaw positions + apply anti-seize every other change.

Don't know if it is right but works great for me.

ttm · Apr 1, 2013

pics of chuck and jaws

I think I did this correctly, here are pics of the 4 jaw chuck, jaws front and rear, each of the jaws are numbers 1 - 4 thher eis a number on all of them 208, the only number on the chuck itself is 1--885-1

not sure whhy it turned all the pics sideways, but it did it during upload for some reason, annyhow, there must be something else missing between the jaws and the threaded part in the chuck? I'm not sure really... Thank you!
Tom

ttm · Apr 1, 2013

dont think that will do in this case, it must be some sort of special bolt with something that mounts or rests on to the jaws too move them, I did get pics attached now

ttm · Apr 1, 2013

pics at attached
thank you

traditional-tools · Apr 1, 2013

It looks like you're missing the pinion(s). Are you calling a screw what drives the jaws? If so, those are called pinions and are specific for each chuck and you may need to fabricate them yourself. Might be easier to get another chuck, since they are fairly plentiful on the used market.

Can you elaborate more on what it is you need? If something else please state.

Cheers,
Alan

ttm · Apr 1, 2013

traditional-tools said:
It looks like you're missing the pinion(s). Are you calling a screw what drives the jaws? If so, those are called pinions and are specific for each chuck and you may need to fabricate them yourself. Might be easier to get another chuck, since they are fairly plentiful on the used market.

Can you elaborate more on what it is you need? If something else please state.

Cheers,
Alan

yes, that is what I was calling the screw, I saw it called a operating screw on msc, but I do not think that is the style I need for my 4 jaw, that particular one was threaded with a "gap" then more threads, im not sure I understand how this particular chuck is setup though, some type of "scrw or pinion, then I think something that rests on the jaw itself, I could take a better pic, priceing some of the 4 jaw chucks that are not self centering I was really hoping to find these parts,

thanks

ADFToolmaker · Apr 1, 2013

It looks a lot like a small chuck I have where the manufacturer chose to use a standard set(grub) screw with a hex hole for a key. There is a chance yours uses a standard size also. What is the thread pitch and thread internal diameter?

SteveBerry · Apr 1, 2013

Chuck should say made in England on back side , #on front is 21581. Is this an 8" diameter? They were sold for atlas 12" lathes long ago. I doubt you will find just the screws, but search 8" atlas chuck on eBay and there is usually there , excellent chuck on my 9" sb.
Steve

traditional-tools · Apr 2, 2013

ttm said:
yes, that is what I was calling the screw

You might get lucky and be able to find some pinions, but I wouldn't hold your breath for that to happen. If you could get a section of the right sized pinion, or make one, you could then make it fit. There are many differences in the space for the non-threaded portion of the pinion, and that is why I mentioned they are pretty specific to each chuck.

An 8" 4 jaw is not very practical on an SB9, IMO, but I'm sure it could be made to work. a 6" is a much better size, or even a 5". I have a 5" 4-jaw on my SB9. All of our mileage varies.

I'm not clear how the pinion is held in, there needs to be a way that it won't pull out of the body. Sometimes they are held in when you insert the jaw. This is also how they get lost, someone takes them out.

Cheers,
Alan

iwananew10K · Apr 2, 2013

ADFToolmaker said:
It looks a lot like a small chuck I have where the manufacturer chose to use a standard set(grub) screw with a hex hole for a key. There is a chance yours uses a standard size also. What is the thread pitch and thread internal diameter?

+1
check that thread form- if it`s 60 degree threads that is most likely the ticket.

packrat2 · Apr 2, 2013

yes the pinion is held in by the jaw, the pinion has a grove cut in it that moves the jaw in and out...
ttm the treads are not 60 deg standard set screw. you will need to make them or have made.
maybe just look at a new 4 jaw.?

vandis · Apr 2, 2013

That chuck uses a "free" Acme threaded screw. If you look at the jaws, the screw is trapped between the two lugs on the back of the jaw and the screw rides up and down with the jaw. This is the...um....less expensive solution to moving the jaws. The screw sits in the threaded hole which is enough of a circle to actually hold the screw if you want to thread it in but I think it relies on the presence of the jaw itself to keep it centered in the threaded portion of the hole. The screw itself is hardened on all surfaces. Mine is about 8 threads per inch and is in a chuck I bought 40 years ago. While a bit simple and sometimes cumbersome because the screw comes out of the chuck if you want to reverse the jaws, it's been a perfectly satisfactory tool.

Having said all that, I'm not sure where to find such screws. There are some companies who do chuck repair and you might find replacements from one of them.

ttm · Apr 2, 2013

packrat2 said:
yes the pinion is held in by the jaw, the pinion has a grove cut in it that moves the jaw in and out...
ttm the treads are not 60 deg standard set screw. you will need to make them or have made.
maybe just look at a new 4 jaw.?

im not sure I understand this, the jaw, has a square area cut into it, are you saying the pinion will only be the length of that area cut into the back of the jaw? here is a pic of one jaw, I also see more inormationon the chuck

it says made in england, on the back it says VF677, in another spot just a number 2 it is 8" in diameter

ttm · Apr 2, 2013

vandis said:
That chuck uses a "free" Acme threaded screw. If you look at the jaws, the screw is trapped between the two lugs on the back of the jaw and the screw rides up and down with the jaw. This is the...um....less expensive solution to moving the jaws. The screw sits in the threaded hole which is enough of a circle to actually hold the screw if you want to thread it in but I think it relies on the presence of the jaw itself to keep it centered in the threaded portion of the hole. The screw itself is hardened on all surfaces. Mine is about 8 threads per inch and is in a chuck I bought 40 years ago. While a bit simple and sometimes cumbersome because the screw comes out of the chuck if you want to reverse the jaws, it's been a perfectly satisfactory tool.

Having said all that, I'm not sure where to find such screws. There are some companies who do chuck repair and you might find replacements from one of them.

View attachment 73607

oh yes that looks exactly like this setup then, (and I just posted a reply to packrat, Thank you! now to see where I can find comething lime that, there is a place here that has acme rods, but they are long, no square key hole in them,

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