collet chuck vs collet arbor used on lathe headstock spindle

My Emco Compact 8 lathe is equipped with a ER25 collet chuck which can hold workpieces of diameter up to 16 mm. The spindle has a MT3 taper bore so it should be possible to put in a MT3 ER32 milling arbor to hold larger workpieces. I am wondering if this is a good idea because if this works Emco would not have made a collet chuck. Inquiring mind will appreciate some answers .

The collet chuck will allow you to pass long pieces thru the spindle bore. A 3MT-ER32 will hold larger diameters but not pass anything thru the bore. Both have their advantages. An ER32 collet chuck is a better option

Edited By Paul Lousick on 14/07/2022 09:21:48

Presumably your collet chuck allows long pieces of bar to pass through the spindle.A chuck which is mounted on an MT would prevent this

Sounds OK for short work pieces, but check the MT3 socket will take a full length MT3 taper because many of the 5 series spindles need a reduction for a small length of the taper diameter at the small end.

Emgee

Make your own spindle mounted collet chuck or buy an er25 flange mount collet chuck and make a backplate , also get oversize collets to 20 mm.

Bernard. The first line of the post states " My Emco Compact 8 lathe is equipped with a ER25 collet chuck"

Edited By Paul Lousick on 14/07/2022 11:21:27

SORRY MISREAD

If you go for a MT3-mounted chuck, you will need a drawbar if you are to subject it to anything but axial compression loads.

You might be able to get a MT3 er40 collet chuck if larger size is important.