- Joined
- Apr 30, 2012
- Messages
- 2,401
today i made a riser block from 1"x4" bar stock for the quick change tool post and the new breakout board got here, $1.95 on ebay it's perfect nothing but a plug and terminals. the numbered points in the center of the card are for volt meter testing each pin. this will solve my slow speed problem letting my go from 25000hz to 100000hz 4 times the speed or higher microstepping for smoother motor movement. when i get the old one out i will post a pic of it so if your reading this to do a build you wont use that one. i installed the tach pickup for threading and even at the speeds i'm running i could thread. the sensor i have is acting up though so i'm waiting for a new one then i'll post a vid of the lathe threading. thats the real test for a cnc lathe, "threading" if you get that working good everything else will work good.
with acme screws the lathes backlash is .002 with ridged couplings and i set mach3 to compensate. the spiral couplings were too weak for the tight gibs and were flexing giving me .010 backlash. the way i built the z axis the screw is supported by the nut and thrust bearing on the other end so a ridgid mount worked well there also.
if the steppers will be fast enough after the new breakout board to do course threads at 145 rpm i wont need to change to a dc motor.
steve
with acme screws the lathes backlash is .002 with ridged couplings and i set mach3 to compensate. the spiral couplings were too weak for the tight gibs and were flexing giving me .010 backlash. the way i built the z axis the screw is supported by the nut and thrust bearing on the other end so a ridgid mount worked well there also.
if the steppers will be fast enough after the new breakout board to do course threads at 145 rpm i wont need to change to a dc motor.
steve