Standard dead length Crawford collets

[Pete.Participant @pete-2]

I've been searching for some collets for my Portmac miller, Lathes.co describes them as 'standard dead length 1.5" crawford collets' that range in size from 1/8 to 1/2,

I've not managed to find any from this description, am I searching the wrong thing? are these style given an 'F' designation of some description that I need to search, any help much appreciated.

[Pete.Participant @pete-2]

[Michael GilliganParticipant @michaelgilligan61133]

Peter,

Have a browse through this album: **LINK**

https://www.model-engineer.co.uk/albums/member_album.asp?a=39260

MichaelG.

[Martin ConnellyParticipant @martinconnelly55370]

Sorry about the scribbling on some pages. I didn't know at the time that it was going to be a useful historic document.

Martin C

[Michael GilliganParticipant @michaelgilligan61133]

I didn't know it was your scribbling, Martin

… I had assumed it was defaced by the apocryphal "previous owner"

MichaelG.

[Martin ConnellyParticipant @martinconnelly55370]

I think I gave a copy to Tony at lathes.co.uk Thought it would go well with his archives. That may be how you got a copy. I downloaded it and printed it off years ago but have not found it online since then.

Martin C

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Martin Connelly on 04/05/2019 15:15:18:

I think I gave a copy to Tony at lathes.co.uk Thought it would go well with his archives. That may be how you got a copy. I downloaded it and printed it off years ago but have not found it online since then.

Martin C

.

No Martin, I got it directly from you [as PDF, if I recall correctly] and I converted it to jpg for this forum.

You are duly credited at the bottom of my album page.

I'm sure you can find our original conversation if you look.

MichaelG.

.

Your eMail 16/12/2015 at 08:06

Edited By Michael Gilligan on 04/05/2019 15:27:08

[Martin ConnellyParticipant @martinconnelly55370]

I have obviously forgotten about it, I'll put it down to age and time passing.

Martin C

[Michael GilliganParticipant @michaelgilligan61133]

**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=112438

[Pete.Participant @pete-2]

Hi, thanks for the replies, but unfortunately I can't find anything on there that matches the description on lathes.co

[Michael GilliganParticipant @michaelgilligan61133]

Peter,

Try this catalogue: **LINK**

http://www.rotagriponline.com/datasheets/5C.pdf

.. ignore the 5C file-name !

MichaelG.

[Pete.Participant @pete-2]

Posted by Michael Gilligan on 05/05/2019 07:21:40:

Peter,

Try this catalogue: **LINK**

http://www.rotagriponline.com/datasheets/5C.pdf

.. ignore the 5C file-name !

MichaelG.

Thanks again, I did actually come across that in my search before, they all seem to be larger than what the machine needs, I was speaking to Tony at Lathes.co a few weeks ago about this mill, I said I'd send him some photos of the machine when it's restored for his site, so I messaged him today to see if he can put any light on the collet situation.

[Pete.Participant @pete-2]

I received a msg back from Tony, he said if you find any, buy them all and trade duplicate sizes with others etc, others? I think I've only seen 2 others for sale, ever, which basically makes me think hen's teeth.

However, had a rummage through some collets I have, found some Schaublin F16 collets that appear almost identical in some aspects, they are a 15 degree taper, from the links you provided for Crawford, their dead length collets also use a 15 degree taper, the part that protrudes through the collar is the same size, the widest part of the taper is the same, I've tried checking the original collet, but it impossible to tell with 100% certainty using my protractor.

Down side, the collets are a bit too long, not much, might only need shortening 3/4 mm

You'll see on the photos, the polished back end on the Schaublin collet is slightly too wide to fit in the bore, but again not much, I measured the top of the bore inside the spindle, and it's 15.6mm, the Back end of the Schaublin collet is the thickest part at 16mm,

what I'm thinking, shorten the Schaublin collets about 4mm, while the machine is stripped down, take a small amount off the inside of the spindle bore, the original collet never went this far up anyway,

What the general consensus on the the original being a 15 degree taper, does anyone know if Crawford would have used this on a 1950ish British machine?

Original on the left,

Below, the original collet in the Collar.

Below the Schaublin F16 collet in the Collar

Below the 2 collets.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Peter F on 05/05/2019 23:48:39:

I received a msg back from Tony, he said if you find any, buy them all and trade duplicate sizes with others etc, others? I think I've only seen 2 others for sale, ever, which basically makes me think hen's teeth.

.

Ahh … That sort of 'Standard'

Thanks for posting the follow-up … and good luck

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Peter F on 05/05/2019 23:48:39:

What the general consensus on the the original being a 15 degree taper, does anyone know if Crawford would have used this on a 1950ish British machine?

.

Crawford was a Collet maker … so would have made 'anything and everything'

Bespoke items for one machine were 'adopted' by others, and some became de facto 'standards'

You probably need to find what other machines used this 'standard' … and then search old catalogues to confirm the design dimensions.

MichaelG.

Edited By Michael Gilligan on 06/05/2019 06:35:37

[Pete.Participant @pete-2]

Posted by Michael Gilligan on 06/05/2019 06:26:12:

Posted by Peter F on 05/05/2019 23:48:39:

What the general consensus on the the original being a 15 degree taper, does anyone know if Crawford would have used this on a 1950ish British machine?

.

Crawford was a Collet maker … so would have made 'anything and everything'

Bespoke items for one machine were 'adopted' by others, and some became de facto 'standards'

You probably need to find what other machines used this 'standard' … and then search old catalogues to confirm the design dimensions.

MichaelG.

Edited By Michael Gilligan on 06/05/2019 06:35:37

Having a think, I'd rather not alter the machine itself as this was more about restoring a rare old machine designed by a model engineer, than creating a machine I need to use.

so I've thought if I shorten the schaublin collets say 4mm, I can hold the collet in the lathe somehow, and turning very very slowly, use an ezelap credit card periodically press on the polished thicker end of the collet, to lap it so it will fit, I only need to take off 0.2mm to bring it down to the same OD as the original Crawford collet, and it's only the shiny part, the black part on the schaublin collet is smaller OD than the Crawford.

I used this method to deburr a B16 drill spindle with good results.

[AJAXParticipant @ajax]

Posted by Pete. on 03/05/2019 22:14:52:

I've been searching for some collets for my Portmac miller, Lathes.co describes them as 'standard dead length 1.5" crawford collets' that range in size from 1/8 to 1/2,

I've not managed to find any from this description, am I searching the wrong thing? are these style given an 'F' designation of some description that I need to search, any help much appreciated.

Pete,

I hope you don't mind me resurrecting such an old post but did you ever make any progress with finding any of these "standard" collets? I now have a Portmac miller and so maybe we should start an owners club.

Out of interest, what motor do you have on yours? I'm tempted to change to 3 phase with VFD (that's what I have on everything else) but may possibly stick with the Servis (I think) motor that's on there now.

Brian

Brian

[Pete.Participant @pete-2]

Hi Brian,

Unfortunately I had to sell mine to make some space, If I remember correctly I put 1/3hp motor on it, a 3 phase and vfd would be a better option.

I never found any second hand collets for sale as I presume anyone who owned any probably had no idea what they were so the chances of finding any are non existent.

I did find somewhere that would make these collets to order, D & J Workholding, hope this helps

[AJAXParticipant @ajax]

Posted by Pete. on 04/10/2021 23:12:26:

Hi Brian,

Unfortunately I had to sell mine to make some space, If I remember correctly I put 1/3hp motor on it, a 3 phase and vfd would be a better option.

I never found any second hand collets for sale as I presume anyone who owned any probably had no idea what they were so the chances of finding any are non existent.

I did find somewhere that would make these collets to order, D & J Workholding, hope this helps

Thanks for your reply, Pete. I have three collets (1/4, 3/8 and 1/2&quot so it will get me by for the moment. I'm guessing custom made collets would cost more than I paid for the machine and all the tooling it came with.

[AJAXParticipant @ajax]

Posted by AJAX on 04/10/2021 23:21:04:

Posted by Pete. on 04/10/2021 23:12:26:

Hi Brian,

Unfortunately I had to sell mine to make some space, If I remember correctly I put 1/3hp motor on it, a 3 phase and vfd would be a better option.

I never found any second hand collets for sale as I presume anyone who owned any probably had no idea what they were so the chances of finding any are non existent.

I did find somewhere that would make these collets to order, D & J Workholding, hope this helps

Thanks for your reply, Pete. I have three collets (1/4, 3/8 and 1/2" ) so it will get me by for the moment. I'm guessing custom made collets would cost more than I paid for the machine and all the tooling it came with.

[Pete.Participant @pete-2]

The cost was £50 each, so not too bad for small number made to order tooling, but not cheap.

If you're not bothered about originality, you could have somewhere with a cylindrical grinder change the spindle bore to an ER collet maybe, just an idea.

[jimmy bParticipant @jimmyb]

Pete,

I'll email you a copy of the Crawford catalogue from back in the day.

I've sent a PM

Jim

[AJAXParticipant @ajax]

Posted by jimmy b on 05/10/2021 05:36:36:

Pete,

I'll email you a copy of the Crawford catalogue from back in the day.

I've sent a PM

Jim

Hello Jim,

If you've sent a personal message then I'm unable to find it. I've checked my inbox.

Brian

[Pete.Participant @pete-2]

Hi Jimmy, Thanks very much for the thought, I've actually sold my machine, It's Brian above now in the same dilemma.

[Author]

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