Finding chuck jaws

[mowersman]

Hi all
I'm after a set of external jaws for my Colchester Student. Easy, or so I thought!
I think the chuck is a Pratt Burnard, but the sticker is missing. It is 7.5" diameter with a built in L0 back plate.
According to my best Chinese vernier, the current jaws are 24.98-25.04mm wide, 73.56mm wide, 9.86-9.90mm wide slot, 14.17mm width from slot bottom to slot bottom and at best guess 8.45mm thread pitch.
Any thoughts on what these jaws might be? I'm not worried about buying a 2nd hand set, I don't do anything of massively high precision.
Thanks
Andrew

 

[Dieselman 63]

Hi all
I'm after a set of external jaws for my Colchester Student. Easy, or so I thought!
I think the chuck is a Pratt Burnard, but the sticker is missing. It is 7.5" diameter with a built in L0 back plate.
According to my best Chinese vernier, the current jaws are 24.98-25.04mm wide, 73.56mm wide, 9.86-9.90mm wide slot, 14.17mm width from slot bottom to slot bottom and at best guess 8.45mm thread pitch.
Any thoughts on what these jaws might be? I'm not worried about buying a 2nd hand set, I don't do anything of massively high precision.
Thanks
Andrew

I have seen jaws second hand at tool shops, always ridiculously expensive (but most old British made stuff here is anyway). Might be worth phoning around, visiting places, machine tool repairers, eng firms, tool shops. Also a picture could help

 

[The_Yellow_Ardvark]

@mowersman
Try the machinery auction house at Standerwick, a few weeks ago some one posted a link to a auction they had. I am sure some one will be along to re post the link.

They have spare jaws come through.

 

[awemawson]

http://www.rotagriponline.com/index...mart&page=shop.browse&category_id=1&Itemid=29

 

[penfold]

Send me a PM and I'll email you a copy of Pratt Burnerd's chuck handbook, it's got details of most of the chucks they've ever made including jaw dimensions.

 

[ollied1981]

@mowersman I am looking for exactly the same set of jaws as you as I've got a Mk1 Colchester Master. I couldn't find any external jaws, but you do seem to be able to buy soft jaws for this chuck that you could make into external jaws. I'm pretty certain they're type 'ELI' soft jaws http://www.rotagriponline.com/datasheets/Soft Jaws.pdf (the 7.46mm in the pitch line must be a typo) and Kennedy seem to make them if you search inline.

Regards,

Oliver