Issues with the Y-Axis A and Pulse Units

[Tech_Marco]

How fast did you run when the Y was not escaping?
Try different speed till it stalled

You may try small value on space speed and the acceleration

Marco

[kietcallies]

It moves slow on the home, but not on the jog. It seems that only the jog movement is causing stalls and mis-steps or is miscalibrated.

When I first turn on the machine, it homes with no issues. Its speed seems to correspond relatively to the pulse unit settings. Higher settings, slower movement; lower setting, faster movement.

When I run a job, it moves with no issue.

However, when I jog from the machine or the computer, the Y-axis stalls or mis-steps. Light quick button presses on the machine seems to get it moving on the machine, but eventually I run out of space.

The stepper motor doesn't feel hot to the touch.

I don't think it's the motor or the stepper driver as it homes fine. Just jogging.

[kietcallies]

I currently have Um/Pulse for X-Axis set for 6.317262 and Y-Axis set for 6.365, which works, but the scale is 50%.

Based upon my test job (100mm x 100mm square), my settings should be 3.317262 and 3.365, X and Y respectively.

I have reduced these setting by 1 and the Y-Axis begins to stall at 4.365

[Techgraphix]

Aside of guessing the um/step you can calculate it:
number of teeth of your timingpulley times the pitch of the timingbelt gives you the travel per rotation.
that number you divide by the microstepsetting (something like 1/16) and the number of pulses/rotation of the motor (normally 200)
example:
If the timingbelt has a pitch of 3mm and your timingpulley has 30 teeth, your microstep is set to 1/16 and your motor has a fullstep of 1.8 degrees = 200 steps/rev you get:
3(pitch) x 30(NoTeeth) / 16 (microstep)x 200(motorsteps) = 0,028125 mm/step.. this is in mm so times 1000 gives you 28.125 um/step

Kees

[kietcallies]

I have been using the calculator in the LaserCAD software to determine units.

What I am having a hard time reconciling is that it only happens in jog mode, not when homing or running a job.

[kietcallies]

I made a video of what I am describing and posted on YouTube:

- homing sequence works
- running a job works
- X-axis jog works
- Y-axis jog stalls


http://youtu.be/VJsxsXO0GOI

[Techgraphix]

I notice a few things:
When you move in Y direction, it sounds like you press the button repeatedly. If you did, please don't.. if you didn't you have a bad contact (or just a bad fingertip
I can't see if it stalls from the start or after it started. If it stalls from the start the values for speed, acceleration and startspeed (and values for spacejerk etc) are too high, if it is started but stalls after it's running: speed is set too high, the bearings run dry, the gantry is driven from only one side so it will draw it self away from perpendicular which can cause stalls..
Is your gantry driven from one side only?
Jogging isn't useful at high speeds, to position the head, I use only 50mm/sec, that's fast enough

Kees

[kietcallies]

I did press the button repeatedly. It does stall immediately. However, I wanted to show that short burst of press can somewhat overcome the stall.

The gantry is driven by both sides. I checked for binding and saw no evidence.

I have tried reducing speeds, but still no resolve on the jogging function.

I did notice that the Move to Position function in LaserCAD works flawlessly, no stalling or mis-steps. Something tells me that it really is a function of jogging and no other functions.

Am I missing some setting?

[Techgraphix]

There is a separate Key-move-speed in the options/system settings/user parameters..
What value is there?
I think it should be no more than 50..
Can you make a screendump of your user parameters? (Alt-Shift-Print-Screen in Windows)
Kees

[kietcallies]

THAT WAS IT!

THANK YOU SO MUCH!