Author Topic: Chucks (Read 7908 times)

Trebor · « **on:** July 20, 2013, 02:33:54 AM »

Is it worth buying second hand chucks or am I asking for trouble ?
I should have said Lathe chucks !

tekfab · « **Reply #1 on:** July 20, 2013, 03:51:14 AM »

If you give it a good check over there shouldn't be a problem with a s/h chuck. Inspired by John's (Doubleboost) video i scored a nice 12" 4 jaw for £40 and having machined/adapted it to fit my lathe i haven't looked back. Trust your judgement !

Mike

Trebor · « **Reply #2 on:** July 20, 2013, 03:53:55 AM »

What about
When your buying of eBay ?

tekfab · « **Reply #3 on:** July 20, 2013, 03:57:42 AM »

I got mine of Ebay, if the advert pictures aren't clear enough you can always contact the seller for more/different pictures . I suppose if it's not close to you someone here might be able to have a look for you, in fact you can always post a link and i'm sure you'll get help from members.

Mike

Trebor · « **Reply #4 on:** July 20, 2013, 04:05:53 AM »

Trouble with that I could be getting more competition if I posted links !! My 3 jaw scroll chuck no3 s teeth are cracking. Being a Pratt one its difficult to replace, I got told the jaws are matched and I could waste my money getting jaws that might not fit.

tekfab · « **Reply #5 on:** July 20, 2013, 04:29:53 AM »

Aha, first question is : is it a metric or imperial chuck ? Pratt are not making new jaws for imperial chucks anymore but can supply replacement jaws for metric chucks. I'm led to believe that there are companys in the USA that can supply jaws that will fit your imperial pratt chuck but by the time you add shipping it's not cheap !
As for worrying about bidding competition that's a tad paranoid. Anyway you should be buying/using a 4 jaw chuck !

Mike

Trebor · « **Reply #6 on:** July 20, 2013, 04:33:50 AM »

Why a 4 jaw ? Do you mean an independent one ?

tekfab · « **Reply #7 on:** July 20, 2013, 04:46:15 AM »

Sorry, yes an independent 4 jaw chuck. They are much more accurate, useful and versatile than a 3 jaw chuck and with a bit of practice easy to set up. See doubleboost's video it's really helpful.

Mike

Trebor · « **Reply #8 on:** July 20, 2013, 04:55:10 AM »

Don't suppose you could link me

Trebor · « **Reply #9 on:** July 20, 2013, 05:00:09 AM »

Is this the one ? http://madmodder.net/index.php/topic,8504.0.html

tekfab · « **Reply #10 on:** July 20, 2013, 05:02:53 AM »

Thats the one, hopefully someone else will chip in here rather than you relying on just my opinion !

Mike

Trebor · « **Reply #11 on:** July 20, 2013, 05:29:20 AM »

Ok I was looking at this for my Myford but are the four holes for mounting the back plate ? If I need a back plate and have to machine one to fit without much tooling I'm not going to be able to do it. I might as well go for one with a back plate already fitted.
http://www.ebay.co.uk/itm/111118398691?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648#ht_24wt_981

tekfab · « **Reply #12 on:** July 20, 2013, 07:08:43 AM »

You'll get a "blank" backplate to suit a Myford no problem so dont discount that chuck

Mike

philf · « **Reply #13 on:** July 20, 2013, 07:15:46 AM »

Quote from: Trebor on July 20, 2013, 05:29:20 AM

Ok I was looking at this for my Myford but are the four holes for mounting the back plate ? If I need a back plate and have to machine one to fit without much tooling I'm not going to be able to do it. I might as well go for one with a back plate already fitted.
http://www.ebay.co.uk/itm/111118398691?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648#ht_24wt_981

Hi Trebor,

This 4-jaw chuck's a tad small for a Myford. (Assuming you've got an ML7 or Super 7 - it may be OK for an ML10.) You'd be better with a 6" or 160mm which would be more versatile. You can get a part machined backplate (which would screw on to your spindle) which would need very little machining and you could locate the tapped holes from the chuck itself.

For most, non-critical, work I use a self centering 3-jaw.

New replacement jaws can be more expensive than buying a 2nd hand chuck with both sets of jaws and, as you say, they might not be perfectly matched. (They would fit the chuck but you may get some eccentricity.) If you're lucky enough to find a cheap set of replacement jaws they can be ground to match your chuck but then you need a toolpost grinder and you say you haven't much tooling.

Cheers.

Phil.

Trebor · « **Reply #14 on:** July 20, 2013, 07:22:37 AM »

Thanks for the advise !!

vtsteam · « **Reply #15 on:** July 20, 2013, 08:08:29 AM »

Just as one more possibility for you -- and handy to know for trueing jaws even with a factory matched set which have worn after some time:

See Varmint Al's lathe page here, and go about 1/3 the way down the page to the part about trueing chuck jaws with a Dremel type tool. It worked for me.

http://www.varmintal.com/alath.htm

Trebor · « **Reply #16 on:** July 20, 2013, 09:47:47 AM »

Just spotted this at the last minute !! Does it look any good ? Any advice appreciated.

lordedmond · « **Reply #17 on:** July 20, 2013, 10:45:14 AM »

That one does NOT have a back plate its a threaded body model as supplied by Myford nottingham to reduce the over hang

its about 50% of the new cost when new if you see what i mean

Stuart

andyf · « **Reply #18 on:** July 20, 2013, 01:24:44 PM »

I see it went to a single bidder: t***o. Would it be rude to ask if that was you?

Andy

Trebor · « **Reply #19 on:** July 20, 2013, 01:42:04 PM »

Ayeeee 'twas me hope its going to be ok !
One can never be to careful I'm sick of bl@@dy hackers and viruses !

Jonny · « **Reply #20 on:** July 20, 2013, 03:23:13 PM »

Just replace the jaws with soft jaws been there done it on a 4" Pratt 21 yrs ago and two current Bisons.

Wont matter much with 4 jaw people rarely use them so stands a good chance they will be ok.

3 jaw really iffy and certainly cannot tell whether any good or not until it goes on your machine. Jaws open up tapered, visually look ok but will have runout.

Had a Bison/Tos 5 1/4" on my scrapped ML7, relegated to RT 14 years ago.

John Hill · « **Reply #21 on:** July 21, 2013, 03:40:10 AM »

Don't every buy a 3 jaw chuck that someone has made giant sized chuck key for! DNAHIKT!

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Author Topic: Chucks (Read 7908 times)

lordedmond