I have a rotary stage with a manual knob that I was able to determine the gear ratio ie one stepper revolution is 2 degrees of stage rotation. I've verified the stepper is 1.8 per step.
But the moves are WAY off. When I send the command G1 F100 A1 it moves more than 360 degrees instead of one degree. I've determined that G1 A.007 gives me about one stepper revolution.
What am I doing wrong?
samples of my setup below.
thanks
Matt
;STEP ANGLE (physical step size built into a stepper motor)
$1sa=1.8 ;degrees
$2sa=1.8
$3sa=1.8
;TRAVEL PER REVOLUTION (accounts for gearing or drive shaft pitch)
$1tr=4 ; stage moves 4mm per revolution of stepper motor
$2tr=4
$3tr=2 ; degrees per revolution Newport rotary stage model #URM80APP
;MICROSTEPS (resolution of in-between steps, controlled by the electronics)
$1mi=8 ; option is between 1, 2, 4, 8, or 16
$2mi=8
$3mi=8
Not that it should really matter for this discussion, are we discussing a tinyG or G2core machine here? I ask because tinyG does not support $_mi=16, but you are not using $_mi=16 either.
Also, I will assume you are using the onboard tinyG drivers, or a Gshield/DUE hardware setup. If Gshield, the microstepping pins are all open, thus $_mi=8
Also assuming from what you show that $3ma=3, mapping motor 3 to A axis
Can you verify assumptions so far, or describe what is different?
Can you provide all the motor 3 and all the A axis parameters?
That would be results of $3 command and $a command
Or, Dump all parameters $$ , copy them to a Cloud drive and provide a URL for viewing.
You have both motor 3 and motor 4 mapped to A axis and enabled.
Is this really true?. I'm not sure it would make a difference if M4 were not connected to anything.
thanks cmcgrath5035, you have pointed out some critical points.
I thought I had the axis modes configured but I can't find them in my config file!
The rotary stage should be in mode 2 and act simply like the linear stages.
Also, the report may show everything but it doesn't show what I have failed to address. I will have to be more explicit about that fourth motor I'm not using, for example.
thanks again!
Gcode movements for rotational axes are in degrees, G1 A3 is a 3 degree movement in standard mode. $aam=1. Use $3tr (in your case, if A axis stepper is connected to motor 3) to implement gearing ratio from stepper to output shaft.
The Gcode specifies movement of the output shaft.