Milling tool removal: advice required

[Rob Meades]

I have a small (High-Z/S-400T CNC) milling machine with a Suhner (UAD 30 RF) milling motor (picture attached). The motor has a 17 mm-threaded collet chuck with collet nut and the selection of collets that came with the motor (picture of the nut and a few of the collets attached); the machine is used only occasionally, probably less than once a year, but part of the reason for this is that it is difficult to use and I'm looking for advice on either (a) what I'm doing wrong or (b) what to change to fix it.

The issue is that the milling tools are an utter pain to remove. The collets aren't held very well in the collet nut: there is _some_ snap-in, but not a lot (the collet is easily removed from the nut again by hand), and the collets never come out with the collet nut when it is released, I end up spending some considerable time with a mole grips on the shaft of the milling tool and a large flat screwdriver between the shaft and the extraction groove of the collet persuading them both to come out. The shafts of the milling tools fit nicely into, e.g., the 6 mm collet before the nut/collet/tool assembly is screwed onto the machine, they just never want to leave.

The whole lot was purchased together (7 years ago) so there shouldn't be any compatibility issues.

What might I do to ease the situation, including dumping the Suhner motor for something else if that is a sensible option? Might the collet nut be damaged somehow? Could I be fitting things wrongly?