The collets from Proxxon are expensive and in my opinion limited in use. I bought a set dirt-cheap Chinese ER40 spring collets, bored a 13mm through hole in the collet chuck and made an accompanying hollow draw bar. More possibilities, les costs. How will it perform? Will I reget it?
Lets find out!
I purchased the chuck at € 26 here: [ Ссылка ]
And the collets at € 99,85 here: [ Ссылка ]
However, prices vary on a daily base.
*** NEW ***
After watching my compatriot Rollingmetal's review of the cheap Chinese spring collets (see: [ Ссылка ]) I realized there is a slight chance I was jumping to conclusions.
In this video I only tested the collet runout (0.01mm) and the 5, 14, 18, and 20 mm collets (all good) once. However, it is possible that I was lucky. To be sure of the results I will test all 24 collets more thoroughly, and doing a visual inspection of each collet. The chuck will be tested at various depths in the tapered hole.
If I find important differences, I wil let you know.
0:00 Introductie
1:54 24 ER spring collets, one collet chuck. Neatly packed
3:07 Nasty chips!
3:15 Now a 38 mm wrench has a good grip
3:25 Just an 8 mm through hole. I want 13 mm.
3:37 My super simple soft jaw solution.
3:52 Remove magnets before turning
4:12 Boring the cuck to 13 mm through hole
4:43 Supported by the fixed tailstock taper
5:50 Cutting external thread M18 x 1
6:05 Had to sharpen the HSS chisel twice
6:23 Simple magnet based center height gauge
6:52 Draw bar, internal threading M18 x 1
8:43 last test fit draw bar and collet chuck
9:03 fits like a glove
9:16 other side draw bar external M 20 x 1
9:24 Chuck in reverse, chisel upside down
9:58 Turning the retaining nut to size
11:54 boring the hole to size
14:27 My way to cut thread with decent rpm and 'brake' in time
16:25 Make a nice knurl with my souped-up dirt cheap Chinese knurler
17:39 cold blueing the retainer nut and crank handle
22:33 reduce the diameter to 18 mm
23:24 insert 18 mm collet and flip the bar
25:15 flip the bar again and measure the run-out
26:24 a MT3 collet chuck with hollow drawbar for my Proxxon PD400
