Need some help and advice, ideas for finishing a detail

[vargai]

I use my friends router, my first build, which is not a mill, but is very precise/0.01mm and still continues to surprise me/

Ok, i get it. I haven't thought of that. So what you say is mill a bed, and then one by one fix them, flip them and mill them. Horizontally yes? Sounds better than lathe and simpler. or you mean the part to be vertical and do it at once? Wouldn't it vibrate like that?

As far as i understand you mean to make all this vertically, so i open the vice

Vertically yes but I have not thought to do square 5 and dia6 in 1 step, however it may work -you now as you go down with the mill you have the wider cross section down along the Z path so the 5x5 mm does not have affect to resonate-I think in alu should work especially on your machine

PS:
The 6mm goes into triple bearing, so not that the diameter is so important as the center line of the piece, cause it must rotate dead on its center/2.5mm/ other wise when the bearings are encased, it will try to move them differently and friction will occure

Depends on what you have now:

If you do not have material the best seems from 8 mm thick material- horizontally do all with chamfer (upper figure)
flip mill back to 5 mm chamfer ready-problem the r2 radius

If corner must sharp you need to do the first step or rough then flip to vertical and do the helix or only remove the radius(lower figure)