By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

3 Jaw Chuck Internal jaws - looking for a home

All Topics | Latest Posts

Search for:  in Thread Title in  
IanH11/11/2018 20:44:00
avatar
63 forum posts
44 photos

Hi,

I purchased a “new old stock” Pratt Burnerd 200mm 3 jaw chuck a few months ago, it came with both external and internal jaws. Unfortunately when I put it on the machine I found that the internal jaws were wrong.

Just to be clear here, the internal jaws are what I consider the “normal” chuck jaws.

The jaws look right and are the right “scale” for the chuck, but somehow they are not quite right being very stiff....I think the scroll form is different, the jaws perhaps being for a slightly larger or smaller chuck.

I set off to find replacement jaws, and to cut a long story short...eventually sourced a new old stock set from the US that are perfect - this leaves the jaws that came with the chuck redundant.

The jaws are unused as far as I can tell and look a quality job...if they would suit you, then let me know and they are yours for the cost of the postage or just come to Cheshire and pick them up. They are marked R148.

Ian

56c43e85-494f-4478-90bc-ecbf95ab8de1.jpeg

Mike Poole11/11/2018 21:20:09
avatar
2311 forum posts
52 photos

The number on the jaws should match the number on the chuck, if they don’t then you have a mismatch. It must be a tribute to PBs tolerances that a random set of jaws are a satifactory fit.

Mike

Bandersnatch11/11/2018 22:56:37
avatar
1396 forum posts
40 photos
Posted by IanH on 11/11/2018 20:44:00:

I set off to find replacement jaws, and to cut a long story short...eventually sourced a new old stock set from the US that are perfect - this leaves the jaws that came with the chuck redundant.



.... while I, from Canada, needed a set of jaws for my 4" PB and ended up having them shipped from Rotagrip in the UK.

Funny old life.

Chris Trice12/11/2018 11:05:58
avatar
1362 forum posts
9 photos

With the change from imperial to metric chuck sizing (4" to 100mm for example), I found the tooth spacing on the jaws also changed. That could be the source of the confusion. Newer sets of replacement jaw won't fit old chucks.

Pete Rimmer12/11/2018 17:44:44
562 forum posts
25 photos
Posted by IanH on 11/11/2018 20:44:00:

Hi,

I purchased a “new old stock” Pratt Burnerd 200mm 3 jaw chuck a few months ago, it came with both external and internal jaws. Unfortunately when I put it on the machine I found that the internal jaws were wrong.

Just to be clear here, the internal jaws are what I consider the “normal” chuck jaws.

The jaws look right and are the right “scale” for the chuck, but somehow they are not quite right being very stiff....I think the scroll form is different, the jaws perhaps being for a slightly larger or smaller chuck.

I set off to find replacement jaws, and to cut a long story short...eventually sourced a new old stock set from the US that are perfect - this leaves the jaws that came with the chuck redundant.

The jaws are unused as far as I can tell and look a quality job...if they would suit you, then let me know and they are yours for the cost of the postage or just come to Cheshire and pick them up. They are marked R148.

Ian

56c43e85-494f-4478-90bc-ecbf95ab8de1.jpeg

Maybe they are not originals, but replacements. Replacement jaws from PB come with a note that they might need work to ease the fit as they are machined 'tight' to allow for wear in the chuck.

IanH13/11/2018 07:40:05
avatar
63 forum posts
44 photos

Good news! A new home has been found for the jaws.

Ian

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
emcomachinetools
Warco
Allendale Electronics
Eccentric July 5 2018
cowells
Ausee.com.au
ChesterUK
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest