I'm a beginner to CNC and so far I have progressed to having my router up and running in a fashion.
It's a home built wood frame machine with skate board bearings on aluminum tracks for each axis, and using a Stepperworld board and -23 stepper motors, with Mach3 software to drive.
I've had it running for a day so far, but I'm in trouble with the repeatability of the travel. I'm trying the Mach3 feature of asking for a test motion in an axis (I used 5 inches as a test case), then measuring the travel, telling Mach3 the answer and readjusting the steps per inch value for the axis. I then repeat this to check the motion is correct. The problem is I get a wide range of results, for instance I input 5 inch travel, measure 5.14" travel, Mach 3 updates the steps per inch and I try again and get 4.85" or 5.3". from my view there could be two issues, One; loosing steps in the process, or Two; slippage in the drive between the motor and the lead screw. I currently have a short length of hose clamped to the motor shaft and lead screw end. I 'm planning to switch to a real flex coupling as soon as it arrives. I don't know what to do about loosing steps, do I slow the speed down, (I'm at 6 inches per minute right now), or what?
As a separate question, the motor seems to get quite hot after doing these five inch jogs and back with pauses while I measure. After a half hour of this the motor is hot enough I don't want to touch it. Is this normal?
Thanks for any help in advance.
Ivor