Hi: Im in Argentina, getting the rigth parts for a relatively accurate router in here is a tad difficult and the local money rate to the dollar does not make things simpler. I m in the process o upgrading mi home made cnc wich i use to drill and depanelize pcb.
The main problem currently is the screws, and the options there i have to improve accuracy are:
*-Hiwin C7 rolled ballscrews, with 1 nut per axis (the nuts are very expensive here)
*- Chai's (linearmotionbearing2008) C7 with 2 nuts and some preload betwen them
*- Standard acme with delrin nut (tensioned) and to buy a hiwin magnetic linear scale with 5um accuracy to map the screws. My steppers (3.1nm) have more than enough power to overcome the lower efficiency
How much accuracy do i need? I can live with 0.002in in repetitivity and maybe 0.001 backlash.
The X axis is made out ot rexroth (8020) aluminum profiles with 15mm hiwin rails. The Y and Z are the remains of my first cnc and they have a skate bearings guide, very smoth and suprisingly accurate moves.
the X and Y total length is 80 cms (+-31.5 inches) and 60cms of travel (+-23.6 inches)
the Z has 15 cms travel(almost 6').
Steppers are 3.1 nm driven by a gecko 540. Using EMC2.
Ill try to post some recent pictures tomorrow.
I have spent a LOT of hours reading post over and over but still can decide, any help-guidance will be very much apreciated.