i am wanting to build a fixed gantry 3axis machine. it will be small with a working area of 15x15x6-7". i understand that the bearing, leadscrews and support shafts w/ be expensive but i want this machine to have the ability to cut some decent Al - 6061 or 7075-t6 or so.
i was thinking the machine will be made out of 6061-t6 Al - 1" thick if that will work (have a friend that owns an industrial cnc machine shop so after i give him drawings he can cut the parts out for me, so precision will be in from the beginning).
what diameter shafts should i use? same w/ leadscrews? also, how much torque per axis is needed?
when i say i want to be able to cut Al, it doesn't need to be done fast, just accurate to ~+/-.010" or better if possible.
will probably start off using a trimmer router as the cutting device for the beginning.
i have been reading a ton and another question i had was -
are the end shaft supports needed or could i have the holes cut say 1/2" into the alumimun sides for the supports? or should the base be say 1" aluminum (w/ cleanup cuts on both sides to make sure it is 100% flat) and then the end shaft supports be mounted to that?
should the lowest axis have 4 support shafts or two supported support shafts if i do the large Al base?
thanks in advance,