Hi,
I need to drill a small hole (I selected 2mm) in a steel plate and aluminium plate.
I then put some 2mm rod through both to create a pivot point.
The problem is the pivot is very sloppy – the hole I drill (with Sieg equivelent x2/x3 milling machine and R8 taper) in the alloy is obviously bigger than the jobber bit I'm using.
I've measured the run-out of possible parts:
1-10mm 3 jaw chuck 0.07mm (arc euro part)
ER 16 collet holder 0.01 (ebay part)
2mm collet when fitted in holder 0.07
So I'm thinking the 2mm ER16 collet adds 0.06mm run out – the problem is with buying any of these parts I don't see a run-out specification.
Is 0.07mm normal/acceptable? I'm a bit dissapointed in the arc euro chuck but maybe all 3 jaw chucks are very poor?
Also – I can't measure the hole I drill… maybe its much further out than +0.07?
I thought maybe I can try to get some ~2.1mm rod or make some but the 2mm rod seems a reasonably tight fit in the steel so I think (but can't measure) the hole in steel is closer to the 2mm and the hole in alloy is 2.07mm or more…
Any tips or am I expecting far too much?
I thought about making a bigger hole but it would still have the same error in the size wouldn't it?