Good morning,
I am trying to clean the spooky ghosts out of my skr board by pushing the current up as high as I can. Unfortunately I cannot get VScode to build the project.
I’m curious A: if anyone knows the max value in SW that 2209s can push safely
and B: what this nonsense means.
Update 20 seconds later, scratch B:
Third time is the charm.
The current setting is in the eeprom, so changing the value in the firnware won’t change ut unless you reset all params with M502.
You can change the setting without flashing new firmware with M906
You can verify the setting with M122. You can save the edits to eeprom with M500
Given that ive ben doing this for like a year now, its kind of embarrassing that i have to ask… but how do I send commands manually?
Also, I didnt start this journey with 2209s but thats where I am now… I was going to do the firmware anyway… knowing that, do you think I still need to?
Are you using an skr pro v1.2? If so, then start with the firmware we have configured for it at MarlinBuilder releases. If not, then use it as a reference.
To send direct commands, you probably want to have a computer attached to the USB and use something like repetier host.
mine isnt setup for that, I played in marlin mode and changed the settings to match what I had planned to put. fingers crossed.
if it goes well i’ll flash the updated firmware.
Thanks Jefe
Did the thing, ran it to death (not literally) the x axis gets as hot as i expected… the Y is cool enough that i can say 100% that i have an issue somewhere. Its been a ‘known issue’ since the beginning, and is why im on 2209s and have high torque steppers… just never truly had any evidence
Suppose this is nolonger a firmware issue
900mA or so should be safe enough to keep the motors under 50C. How do you have the X and Y wired?
As per the manual. Series?
Using marlin mode, i set the values to 1400 X and 1700 Y and get 120f and 114f respectively… Y is my longer axis at 60in vs x at 30… so maybe the increase in resistance soaks up the extra heat? Seems extreme but im too lazy to look up values right now
I’ll verify continuity and resistance values today. Maybe i have a broken wire on my Y… i would assume the cnc would behave erratically though if it went to micro step a dead coil
I really need to work on my conversions… inches to metric is easy and i do it a million times a day #engineer… but temp is a rarity and i need google for c to f.
For the record, the cnc works. But a vaguely menacing glance will cause it to loose steps and ruin a cut
Now that i think about it, the cables should be nearly the same length…
Hell x might even be a bit longer
50C/5*9+32=122F. So that is about the upper limit.
The drivers can be thought of as constant current drivers which is pretty different to the constant voltage power supplies we use so often, so a lot of the regular electrical guidance goes out the window. Increased resistance in the wires doesn’t reduce the power consumed in the motors. It only increases the power used in the wires (and make the whole thing less efficient).
The TMC drivers will (in some conditions, I’m not sure what) reduce their max current if they overheat. If you have them set to 1500mA, they may be getting too hot and dropping to a lower set point. When they do that, they print about it on the serial console and the current setting can be seen with M122. But you need to get something connected to the serial console (like a computer).
The steppers should be pretty strong in this application. But any grown human can overpower them. The machine is designed to be more than enough, but not more than that.
Are you getting random skipped steps, or is it inadequate torque? Being sure about this will help a ton in troubleshooting.
Random skipped steps can be caused by wiring, but when you resist motion with your hand the motors should feel solid and not weak. If it’s inadequate torque, it will skip steps easily with a sorta light grab on the gantry as it moves. If you have strong torque and only random skipped steps during cuts, I’d totally turn my attention to wiring and mechanicals. I won’t retell the story of how I banged my head over tmc troubleshooting for months before learning it was actually an intermittent stepper dupont on my controller.