Sonny deserves a lot more thanks than our small contribution.
And the offer always stands for boards. Sending out Jorge’s Cohesion3D board set now.
@Brett_Fleming Here’s a few quick tests on grayscale. I have to read up more on how to adjust the settings for this, but my test settings are written next to each test.
+Peter van der Walt I have M4 in the start gcode.
+Peter van der Walt do you think these results are good for first tests? Seems to be ok in my view. I can see gradual increase in darkness as power goes up. I did not get good results on mdf, that’s why I switched to this plywood to test
Agree, it’s a good start. Not all laser power supplies handle the PWM well. You’re at looks better than ours did.
Question regarding $140,$141,$142. Isn’t the stepper motor current set with the pot on the motor driver boards? Is this an alternate method of controlling motor current vs wherever the pot on the driver boards are set to? I set $140, $141 to 0.5. not sure what the stock stepper motors in the k40 are rated at. Thanks.
No digipots on C3D. Manual adjustment covered on the new troubleshooting guide.
@raykholo I see, thanks.
Also the cheap A4988 drivers don’t have any way of interfacing to the board to do that. So self fulfilling prophecy of sorts there.
@Arion_McCartney Also play with the $33 setting (PWM frequency). Default is set to 5000Hz. 2500Hz could potencially deliver better grayscale, 20’000Hz would be better for cutting.
@cprezzi thanks for that info! I will give different pwm values a try this weekend.
Following
@Arion_McCartney Please can you send me your Settings ($$) … i’ll will implement this as standard settings for an c3d mini/K40 in the firmware. More easy for users w/o grbl knowledge.
@Frank_Herrmann Here are my settings. Keep in mind I have not tested the homing direction mask $23 completely. https://drive.google.com/file/d/0B3A9wmWsyWK1MWhzMDJJU004Mm8/view?usp=sharing
I can report that grbl-lpc without I2c boots up on the panacutt re-arm board. No problems connecting with grblpanel and changing config settings. I have no steppers connected on this board yet but I can see the step/dir pins toggling when doing a move
Laserweb4 also connects and reports grbl version.
Next step is to flash the Cohesion3d/K40 and do laser testing.
This is great thank you.
@Frank_Herrmann In addition, I have changed $1 to equal “255” as I do not find it beneficial for the stepper motors to release after a given time period. Setting to 255 will enable stepper motors indefinitely. I don’t think most would want their steppers to disengage any time after homing. I just noticed that mine were disengaging this afternoon.
Is the corexy kinematics ported to this version? If it is then I need to setup lpc compile to enable. Have a corexy test machine that is currently running AVR grbl1.1. Would e nice to see if the re-arm board can run it instead.
@cprezzi Some tests with PWM at 2500 vs 5000. 2500 is much better for grayscale. Thanks for recommending the PWM value change!
Been lasing most of the day today and came across an issue, which is even more evident with lack of homing capability. When a job finishes, the position of the laser head is shifted at what seems like a random amount (actual position is lost). It could be a few mm off, or it could be tens of mm off from where the job finished. Seems like GRBL reports the position at the end of the job incorrectly. When the job finishes, you can see the head in LW4 suddenly move to a new spot. I was making a mothers day gift and ran across this when I had two separate jobs on one work piece. Anyway, thought I’d share that as it seems relevant. Other than that, I am loving this! Took minimal effort to get good results on a slate engraving…
