Hello Ian,

Clarkson made straight shank FC3 cutter holders for using with an Autolock Chuck – 6mm and 1/4" diameters with 16mm and 5/8" shanks. I don't think they are available now though but may be wrong.

I have been using two home made versions that fit directly in my mill spindle for many years – they are easy enough to make just ensuring concentricity is all that really matters. Made from tool steel but unhardened they have more than lived up to expectation – been using the mm one this very afternoon

Hope that helps some

Ramon

Hi Mike, yes thats just what I was thinking of

I have just had a look on google – can't find an image of one anywhere but heres a picture of mine that may give Ian an idea

The two tool holders are bottom right beside the un-blacked 10mm dia version. All this tooling is 'soft' but made from tool steel – similar grade to silver steel, The five collets are from silver steel. I remeber my foreman at the time telling me they would be no good if they weren't hardened – well – they are still in use today

My old Linley mill has a spindle that takes Schaublin collets – basically a half size R8 – no tooling or collets were available when I bought the mill hence the need to make some. This is all well over 35years old, the collets even more so so has stood the test of time

Obviously the drill chuck, cutter and boring head are bought in

Hope that helps Ian a bit more

Ramon

I see other folk have been posting whilst I've been playing with a camera.
I also have the one Clarkson adaptor, shown here in my album of Milling cutter chucks to give a feeling for size.
I do sometimes use it in an ER25 chuck as it's less bulky than either my Clarkson or Tiitanic milling chucks, so sometimes allows easier access to the work in hand.

Amongst my other bits and bobs, I have a Quorn grinder, so I made an arbor for that, but rather than taking a wheel directly, it duplicates the collet chuck on one of my die grinders.
This allows me to use mounted points in the Quorn, the two collets being ¼" and 6mm.
I've not used it for much yet, but the idea was that I could use the Quorn head on the lathe as a toolpost grinder, with mounted points for internal work.
There's no reason why something similar couldn't be constructed with a parallel shank along the lines of the top one in the image, but shorter and slimmer.
I made the long one at the same time whilst I was set up for the smaller arbor, so I could use it for holding FC3 cutters for re-sharpening in the Quorn on a conventional wheel. My ER collet chuck is a 25, so the whole assembly is quite chunky for small grinding jobs, hence adding this one.

The official Clarkson 6mm one is shown lower right for scale.

Bill

Regofix say not less than 2/3 of collet gripping surface should be used.

My 6mm and 1/4" ER32 collets only have that size part way through and an FC3 just about contacts all that area stopping about 1mm short

Edited By JasonB on 09/10/2020 19:41:53

The diameter at which the collet is relieved also varies with the ER-series number.

For as close to gospel as you might easily obtain, have a look at Regofix' site as I believe they have dimensioned drawings.

For slimline, have you considered changing the closing nut? There are generally two types: the one with spanner flats or hex. and the type with a pronged spanner.

You could also buy an ER11 or 16 chuck on a straight shank and hold it in your ER25 chuck for reduced girth but increased length.

Bought an MT2 Autolock clone for my 4speed Emco head soon after purchase of same. Easy job to make Weldon "Adaptors" for both 6mm and 1/4" to screw into 1/2" chuck "Collet"

Can't beat positive cutter retention.

Regards Ian.

Is your spindle hollow?

If so you could make up a holder with the shallow angle of the ER25 and pull that into the nose with a drawbar, this would have the advantage of doing away with any form of nut so you could get closer to the work

Edited By JasonB on 10/10/2020 14:54:15

I think the floating ones are for use with the ER collets that have a square hole in them to take taps so they can ctr themselves.

You would be better with a plain 12mm shank ER11 and mini nut which is only 16mm OD, probably have to cut down a longer shank, ARC do them as well as Cutwel.

One cheat you can use with an ER collet system is the one I use when holding Rotabroach (3/4" Weldon) cutters in a 19mm ER32 collet. because the Rotabroach cutters' shanks aren't long enough to be fully engaged in the collet, I've made a 3/4" top hat that sits behind the cutter's shank and presents a 3/4" diameter to the bottom of the collet and a smaller diameter between there and the cutter's shank.

This allows the collet to close parallel and grip the cutters well even though they aren't long enough. This might work well when trying to get the last bit of length out of an FC3 cutter.