Bridgeport Manual to CNC conversion...

[Davek0974]

Yes, I was working through this on the drive to work this morning ;)

There will be play, must be or it would seize, plus being umpty years old i guess there will be a measurable amount.

The setup is perfect on the 2mm tools or engraving etc so it seems somewhere between 2mm and 5mm tooling is a point where cutter force and reaction come into play and bite me in the arse.

I am leaning towards a fully custom Z axis now, this brings about its own set of issues of course -

Will have to move machine away from rear wall,
..Can't move machine away from rear wall as the head hits the roof truss,
....Will have to radically modify roof truss to make clearance,
The list goes on - sometimes i hate my garage shop.

Next is - steel or aluminium build??

I am visioning it as being just a larger version of the Z axis on my mini-mill so two flat plates with rails and a screw sandwiched between, servo motor to drive and a toothed belt?

It does not need massive rails as the biggest tool is likely to be 5-6mm max so probably the same 20mm HiWin and a 1605 screw, maybe use stuff with a pre-load this time??

The hard part is working out the connection to the rear of the ram and where to put strengthening trusses/plates etc - the rear of a BP ram is a spigot maybe 50mm tall, 110mm wide and 100mm deep with a 20mm hole central - that is all i have to mount off of.

So, something like 25mm tooling plate all round or go steel and weld etc where possible.??