Well crud. I popped my laser It just will not focus anymore.
So Junction deviation, or S curve. If you guys can try turning that off in the firmware, I am willing to bet it is one of those.
M3…no good for lasers it has to be M106. So on the mini just change fan pin to 10 and use Z min as your port.
Jeff… YOU’RE THE MAN!
[attachment file=88214]
I’m running Garfield right now – the miniRAMBO board hooked up exactly as before (I never dismantled it…) – and the image is sharp and crisp, just like the RAMPS runs I did before. What changed?
I reflashed the miniRAMBO board with the same MPCNC813-GLCD firmware as on the RAMPS boards… changing only the board name, remapping the FAN pin to pin 10 (Z-MIN), and cutting all the steps/mm settings to accommodate the 1/16 microstepping.
That’s all I changed.
I’m stoked! I need to go pour a glass of wine and wait for this engraving to finish. I post the results in a bit…
– David
I ran a series of tests with just about every combination of discussed firmware settings. The only ones of note were 7, 8, and 9.
7 was with Junction Deviation disabled.
8 was with S Curve disanled.
9 was with both disabled.
All 3 with Spindle-Laser disabled and using M106 commands with the fan pin remapped to pin 44.
I guess this is improvement? This was a different material so I need to test with the same material I was using before.
This was all with the Marlin 2.0 firmware.[attachment file=“IMG_08022019_191906_(1080_x_525_pixel).jpg”]
[attachment file=“IMG_08022019_191917_(1080_x_525_pixel).jpg”]
Hmmm.
I am trying to wire up my other laser now, strap it on with a few zip ties. It has to be one of those two settings. I will be following along in a few minutes again.
David, can you post a zip of the two versions? Working and non working?
miniRAMBO reflashed with the MPCNC813_GLCD firmware downloaded from this site… probably a year ago.
[attachment file=88226]
[attachment file=88227]
I changed only the board name, remapped the FAN pin to pin 10 (Z-MIN), and cut the steps/mm in half to accommodate the 1/16 microstepping.
– David
Where can I download the MPCNC813_GLCD firmware?
Here’s the good one…
[attachment file=88231]
The other is too big to attach… but it was downloaded from Github…
Marlin-MPCNC_MRambo_T8_16T_LCD.zip
MPCNC813_GLCD.zip (759 KB)
Well, I have every “new” marlin 2.0 setting off, matched accels/jerk between firmwares. Mine is not perfect but not as bad as some that I have seen.
What settings are you using for imagetogcode? Or are you using the same file from early in this thread?
What really gets me is all the accelerations that are happening, fan speed changes should not induce an acceleration change in motion.
I’ve not changed the Garfield gcode file at all… it has been the same exact file for all the testing I’ve done. And it’s the same one I shared earlier…
Okay using that file in this version of 2.0 I am getting a good burn (I think, hard to see in these glasses). I will turn each setting back on one at a time and see where it breaks.
Last dinner away (did not buy a boat…yet 
I’ve been watching this develop over the past two days and am amazed by each and every one of you. I hope in the coming weeks and months I learn enough to start contributing to these conversations. S-M-R-T…
Heath if you are still messing around, can you try everything off, turn junction deviation on and set it at 0.1
My ninth set of Garfield’s feet are looking much better.
Shoot, never mind, compared to yours David this still is not right.
When all the kids are in bed, I’ll go tinker some more. I do have the MPCNC813_GLCD that David provided configured, compiled, and ready to flash and try out.
didn’t marlin “fix” the jerk or acceleration limits? Maybe the same settings are now causing problems.
Man, I am completely baffled. The old one (1.1.9) works perfect. I have dug through so many files. It has to do with the fan speed somehow. We have proven the board, the file, and the pin all work. I have matched every setting and turned off all new “features”. There is some sort of acceleration or averaging going on with the fan.
I saw something that looked sort of like the fan might have a lower priority to fill the buffer (I can’t find it again)?
Ok, I’m giving this a shot right now. Would someone mind posting the settings they are using? Even at 1mm/mm this thing is running too fast. I’m having to turn the feedrate down to 30% in repetier.
