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Author Topic: Help controlling a stepper motor as a lowRPM spindle  (Read 17589 times)

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #40 on: August 29, 2012, 07:36:14 AM »
Hi Russ,
Only axis B & C are green. Now I have lost the ability to jog XYZ or A from my keypad. I have never had that problem before.
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #41 on: August 29, 2012, 08:31:23 AM »
Hi Guys, I loaded up another Machmill job, and when I tried to jog the axis, the axis never physically moved, but the display increased and decreased in value for the axis I was jogging. I have gone back to my job and still have a problem with not being able to jog. I ran a G code program I have used previously and it ran fine. Just no jogging from the keypad.

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #42 on: August 29, 2012, 08:52:17 AM »
Jog control as in pic needs to be active (green LED round it like below)
Hoo
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #43 on: August 29, 2012, 09:18:56 AM »
Hi guys, sorry to mess you around, but I see the jog on/off in the Tool Information screen, I turned it on, now it is OK for jogging and axis calibration. I have a situation with my Z axis calibration though. I am driving the axis through a 10:1 gearbox, which put my pulses/unit to around 109,000. When I jog the axis an inch, it moves an inch and the display says 1 inch. If I try to calibrate it and I send it 1 inch, the motor sounds high pitch, the axis barely moves, yet the display reads 1 inch. I put in a code to send the Z axis to 5 inches at F10, again the motor went high pitch, the axis hardly moved, and the display read a move of 5 inches. Any ideas?
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #44 on: August 29, 2012, 11:00:23 AM »
Hi Hood. I can jog the Z axis at quite a decent speed .05 inch/sec when my low jog speed id set at 75%. Any higher and it acts the same as when I try to make a commanded move. The motor seems to stall but the positional counts increment. I was think that the rpm of the motor was too fast for these moves, but it does the same when I put my speed at 0.02. When I jog on the keyboard, the speed is faster than I will ever need, so I don't understand about the F0.02 giving me a problem.

Barry.
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #45 on: August 29, 2012, 12:00:20 PM »
Hi Hood,
I was testing the Z axis position from code with the code I got from the wizard for the spiral I wanted to do. I decided to do another code I had been working with earlier and move the Z axis in that. It worked fine unless I put the Feedrate greater than 10 IPM. I will never need the Z axis to go faster than that so it should not be an issue.

The code from the wizard included the lines before the Z move:
G0 G49 G40 G17 G80 G50 G90
G64
G20
G0Z1F0.2
M30

Is there anything in that code that would have affected it?

Barry.

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #46 on: August 29, 2012, 01:15:14 PM »
G0Z1F0.2 is not a valid command really as G0 is rapid speed so no matter what the F word is it will not take any notice of it.
Sounds like you just have your Velocity in Motor Tuning set too high.
« Last Edit: August 29, 2012, 01:16:50 PM by Hood »
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #47 on: August 29, 2012, 01:36:25 PM »
Thanks Hood, I thought G0 and G1 were the robot equivalents of Robot moves and Linear moves. A Robot move moves all 6 axis from one position to the next at the same time and the speed that they move can be set (how fast you want to get from one position to the next). In Linear move it keeps the Tool Centre Point along a straight path at a set speed of travel. I didn't know (now I do) that G0 moved all axis at maximum speed.

Thanks again.
Barry.
Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #48 on: August 31, 2012, 02:44:15 PM »
Hi Hood,
I am using a rotary positioner like a linear axis, I wait for robot complete, Mach 3 rotates to 0.03" (60 degrees) waits for robot complete, moves 0.06" (120 degrees) etc for the next moves to 300 degrees. Other than sending my axis back to 0 to start over, is there a code to set any individual or all axis to 0?

Thanks, Barry.

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Re: Help controlling a stepper motor as a lowRPM spindle
« Reply #49 on: August 31, 2012, 02:53:25 PM »
Is there a reason you are setting it linear rather than rotary?

You can set the machine coords to zero by homing and as long as you do not have a home switch it will zero wherever you call the home from.You can do that by button or macro by calling
DoOemButton (1025)

Hood