Can you not get a collet holder to fit your ML7 ?, not that expensive.

George.

MT2 collet, available in Imperial and Metric sizes, fits directly into ML7 spindle, will need draw bar or suitable length of studding. Don't bother with the thread, hold the end mill by the plain shank.

Edited By daveb on 10/01/2016 12:04:25

As DaveB says just by a MT collet and make a simple drawbar which only needs to be a length of studding, nut and thick washer. Forget about the screwed shank

Edited By JasonB on 10/01/2016 13:17:04

Or grind a small flat on the cylindrical portion of the cutter shank, drill/ream a 1/2" hole in the end of an MT2 blank, and use a set screw to hold the cutter. The thread is not meant to hold the cutter concentric, it normally screws into the Autolock collet to pull it snug – the collet holds the cutter true.

If you are tight on space, use a Morse Taper Collet.

If you wish to hold other sizes of End Mill, Slotting Drill, or workpiece, my advice would be to buy a holder for ER collet holder, and a set of collets. They will definitely come in handy in the future, for holding tools or round workpieces.

Howard

Posted by daveb on 10/01/2016 15:56:32:

… I wonder why Crawfords went to all the trouble of grinding a thread inside

MichaelG.

Endmills can and often do pull out of plain collets, the main advantage of using them is that the cutter is supported within the spindle so much more rigid, also maximises headroom. < etc. >

.

Thanks, Dave

I must confess that my rhetorical question was slightly sarcastic … The Crawford Collet [which cost me quite a lot, nearly 30 years ago] has proved its worth, on many occasions, for the reasons you mention. My only regret is that I did not also buy the Metric one.

MichaelG.

.

Good question, John

All the ones I have ever used are only slit one way [like Watchmaker's collets] and are therefore strictly 'single size'.

MichaelG.

Hold the end mill in the three jaw chuck,it works,costs nothing,and thats what everyone dud before the various modern collet systems were available,

.

Neil,

I's time to come clean:

The BCA uses 11mm shank collets [Crawford 55 pattern] and that special threaded collet takes 3/8" shank milling cutters. Despite the supeb quality, this leaves a very thin wall on a plain bore. … I believe that at least part of the reason they included the female thread was to 'beef-up' the torsional strength in the area nearest the drawbar thread and the keyway.

I love my Osborn too … but it wouldn't fit the BCA.

MichaelG.

Edited By Michael Gilligan on 13/01/2016 21:48:29

.

I offer the following solely for the amusement of those who are lucky enough to have purchased acceptable quality ER Collets and Holders at today's bargain prices …

I have just been sorting some old paperwork, and found the receipt for the aforementioned special Crawford Collet [purchased New, from Tenga Engineering]

On 11-Feb-1988 : I paid £45.50 +15% VAT

MichaelG.

Edited By Michael Gilligan on 17/01/2016 13:45:11