lathe X axis calibration

[tat2joeelliott]

ok i have been banging my head against the wall all morning. trying to calibrate the x axis. i bring up the wizard, move the x to a starting position, zero the axis in the wizard, jog to the end of travel which is 5.0745", input that into the wizard and hit calibrate. i have a 4mm pitch ball screw so my dpr is .15748, my pulses per rev is 400 but the dro says i have moved 10.1165 can some one please help?

 

[zombieengineer]

Are you able to move the axis for a single revolution?

The 400 pulses per revolution seems a bit odd unless this is a servo motor bases system.

Typically a stepper motor is 200 steps per revolution although there are 400 step motors they are rare (suspect 90% of stepper motors are 200 steps/rev, 5% are 400 step/rev, remainder are something else). Micro-stepping can increase the number of pulses per revolution - is your stepper motor driver configured for 1/2 or 1/4 stepping?

Is the ball screw a single start or has two grooves? My 3D printer has a dual start lead screws for the Z axis.

Using the jog mode check for the presence of backlash - the ratio between the inferred and actual is almost 2:1 but not quite (1.9935).

Finally what is the incremental resolution of the DRO? It might be a metric based DRO that has some rounding errors.

 

[ecs]

@tat2joeelliott - masso works on diameter, so if your travel is 5.0745" then you would half this when entering in your figures.

If you know all your specs on your ball screws and motors input this data first and get the lathe operational. Then fine tune if needed.

Set up a dial indicator and just check 1" to start off with. Then if its close you can start on testing it at larger lengths.