I wanted to find out if anyone else has had issues with the drivers on the controller board over heating to the point of failure?
This is my second controller and I thought the first time was due to a bad motor. I changed the motor and again the Y axis melted down the driver.
I have a cooling fan mounted on the back of it as recommended. However, the driver chips still seem to get very warm.
I am only running the drivers at about 50% on the current setting or 6 O’ clock position… I’m wondering if its possible to use thermal adhesive and just mount heat sinks to the tops of the drivers as a work around.
I would also like to know if anyone has any recommendations for external drivers they have had success with…
Admittedly I do run the machine for very long stents as I am mostly cutting aluminium at low speeds 90-127mm/min or 3-5-5" per min so the machine is not over loaded.
Are you driving Y axis with dual motors and dual drivers?
You can for sure add a small heatsink to the driver, but keeping the bottom of the PCB cool with air flow is much more effective - the driver is in a heat slug package that is thermally tied to the ground plane.
Slow speed is likely essential for milling, but in fact since you are likely running with $_pm=2, in-cycle, it is the motors being constantly energized, moving or holding, that contributes to heat.
Yes, the drivers do get warm, but we don’t see many folks reporting driver meltdown.
What PS voltage do you run?
Voltage close to 28V (30V is the limit) will actually run cooler than 24V. But hard to predict that would be a fix.
no. Its a single nema 23. 176 oz/in. I really hate to abandon the controller but, this is getting costly at around 140 each…
In the wiki is said specifically not to put a heatsink on the driver, but that just seems backwards to me as long as I’m using non conductive thermal adhesive.
@John_Johnston If you are to put a heat sink on, putting it on the chip is a waste. You’ll want to put it on the bottom of the board on the built-in heat sinks that are there already. (The rectangles of bared metal on the bottom are the heat sinks.)
That said, it’s extremely rare to overheat one of these boards, even without fans or extra cooling. Something is amiss.
Do you have a fan blowing across the bottom of the board? Sometime just mounting it vertically and not enclosing it so air can flow up along the back of the PCB is enough.
The 50% position doesn’t necessarily mean “half power.” It’s a complex relationship between the motor, power supply, and driver chip. The 50% position could be way too high for some combinations. Generally you want it as low as you can without missing steps.
The Jerk setting play into this too, they may need lowered as well.
understood about the motor tuning… I followed the exact procedures in the wiki to tune them and they work fine in that regards.
Thanks for the info about the heat sink. I am going to run one on the bottom for sure… I wished I could get the boards repaired with out having to buy a completely new board. right now ill just keep running the A axis as Y…
I do have a fan blowing across the bottom of the board. the mounting box was the first thing I made for the controller so I could do so… I was trying to be careful and take care of it as I had planned to use this for as long as possible.
The motors I’m running are the one from Open builds that is sold with the C-Beam kit…
perhaps the motors aren’t all that good.
like most things I assume you get a bad apple every now and then. So I don’t want to point fingers. I just want to find answers so I can keep making parts…
its a good power supply so perhaps I should crank up the voltage a bit… I have it set at 24.5 volts right now… What’s odd is I never feel the motors getting warm… maybe something bad in the coils and they are shorting… no idea other than to try and different brand of motor all together…
Not so far… Everything seems good. I will keep cutting parts like this and see if this driver lets go.
crossing my fingers. I really hope it doesn’t and after I finish this part I will be making a heat-sink for the controller even though its not likely the problem. Id like to at least eliminate one potential problem…
I did just adjust the voltage on the power supply to 28V. That should have some help… I didn’t want to pus it to 30v as I wanted some headroom on that.
I have been running the controller all day long with the A axis as my Y and it has been with out any problems…
I am wondering if its not due to the fact that when I had the controller wired up that the X, Y were so close to one another that the heat is building up to much in one area and the copper can’t dissipate the heat well enough running those nema 23’s I have on it… This is food for thought…
Perhaps it should just be good practice that if anyone in the future is going to run their machine as I do… A.K.A. long hours with out a break and with the bigger motors. They should just start with a heat sink… I will continue to monitor this very closely, but I am nearly 100% sure moving the X and Y axis apart to motor1 and motor4 is allowing the copper on the back to do its job with out reaching its thermal limits…