So the steppers on me new delta printer were very weak and they were skipping steps… I upped the voltage by 1/8-1/4 turn of the screw. Is that a good amount? The steppers aren’t hot and I don’t have a multimeter to measure voltage
first step would be to get a multimeter.
Pretty sure you want to be checking current draw not voltage, if you are seeing voltage drops, you might not be providing the motors with the amps they need, or you might have too thin wires (not likly) or a under powered psu. Do you have a heated bed going when you see the steps skipped? Those take alot of power.
Yes I have a heated bed, but even with all heaters off the motors were still very weak
Nema 17? What kinda motors you have? What’s you psu rated at?
No clue. It all came in a kit. Geeetech g2s pro
If the motors are cool or lukewarm after, say, a half hour, the current is WAY too low. Steppers are designed to run hot and the only reason to run them cool is protecting plastic mounting brackets. Unless you have PLA motor brackets, the motors should be hot but not painful to the touch.
The motors in my davinci get HOT but they are pre set from the factory. But yeah, I had a 30 min print yesterday and the steppers were room temp
What is the height of the motors, not including the shaft length?
Stepper motors will get hot, but should never go above an uncomfortable temp (like if you cant hold your finger on there for more than 5 seconds.) we typically underpower them, like my 1.9A steppers I run at 1.6A
If you can’t measure it, don’t adjust it and hope for the best. What control board and stepper drivers are you using?
Board is a geeetech gt2560… Not sure about steppers. It’s still in the safe area as of now
Here’s the thing… the rated current for every stepper is set by the manufacturer according to how hot the motor gets during operation. A class B hybrid stepper (the kind we all use) has coil insulation rated for 150C (internal motor temp) and the rated current is the current that heats the coils to ~130C (for a 20C safety margin) at the maximum rated ambient temp, typically 50C. In practice, at rated current, the motor coils are designed to heat up by 80C from the ambient temp.
The exterior of the motor, depending on mounting and airflow, will be somewhere roughly in the middle between ambient temp and the internal coil temp. 30-35C surface temp rise is perfectly normal at rated current. If your printer is not enclosed, that means ~55-60C motor temp, which is HOT to the touch. It’s also hot enough to warp PLA, but perfectly fine for ABS and probably ok for PET. This assumed the motor is sitting in free air with no extra heatsinking or forced airflow. If you want, you can drop the motor’s surface temp by attaching heatsinks or fans, which may help protect nearby heat-sensitive components. But the motor is perfectly happy being hot. It’s designed to be hot.
Heat production comes from the square of motor current. So if you cut your drive current in half, you cut heat production by a factor of 4. Whereas torque production is proportional to current. So it’s very common in the 3DP community to under-drive steppers by around 10-20% current to give up 10-20% torque in exchange for 20-45% lower heat production and much less heating of plastic mounting brackets.
What does this mean for people tuning drivers without a multimeter? If your motor is hot but touchable, you’re near the rated current. If it’s warm, you’re under-driving it by perhaps 25% below the rated current. That’s probably fine. But if your motor is cool, you’re under-driving it by perhaps 50% below the rated current. This may or may not work for your printer. It WILL decrease your attainable accelerations, increase the probability of lost steps (and ruined prints), and slightly increase corner-ringing.
So yes, you CAN tune motor current entirely by feeling the motors. That approximates the same thing the manufacturer does to determine the rated current. Just start low, make very small adjustments, and make sure you leave the motors running for a significant length of time (30+ minutes) before checking them. They take quite a while to heat up. And if you smell the insulation cooking, you went way too far.