Is the cost of tooling to add to the adaptor still as highly priced ?

Quite a bit cheaper, but still not cheap.

MSC Industrial have the Coventry Easychange system – R8 adapter is £224 + Vat, ER holders around £88 + Vat with endmill holders a bit cheaper. The MT3 adapter is £300 + Vat !

Cutwel adapters are all £94.80 inc Vat (£79 + Vat) , and ER and endmill holders are all £58.80 inc Vat (£49 + Vat) . Cutwel web page for these items is here.

Cutwel are a good company to deal with – used them for years at work.

Nigel B.

There's a dog (or two?) on the face of the "master shank" that engages with a slot(s) in the holder. Nice system in principle but expensive, not so easy to change as first appears, and they eat daylight between spindle and work. My Novamill came with an Easychange BT30 shank and a couple of ER16 collet holders, but I quickly got a couple of ER16/BT30 chucks and later some BT30 split collets to make better use of the limited daylight.

The Coventry type system is also available for slightly less from engineeringsupplies.co.uk. I tried making an ER25 holder from 304 stainless, but although it was made accurately, it soon developed runout because of indentations in the taper from the locking balls. It would need to be hardened at least in that region to be successful.

Andrew.

Andrew Entwistle:

I see. The PDF helpfully linked by DC31k does indeed state that the tapers are hardened.

I assume that the balls bear on one flank of the taper groove rather than the main taper of the holder so that the holder is pushed into the master shank.