Servo moves very unreliably
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Good evening (or whatever time it is at your place)!
Some days ago I finished my dual printhead with one retractable nozzle which is lifted by a servo.
The problem is that neither the tool change macro nor a manual command moves the servo reliably.
I do have a delay after the M280 command and all the axes are homed. I can't really reproduce when and if the error occurs and apart from the servo not moving, nothing seems wrong.
My board is a Duet WiFi 1.04c. The servo is connected to 5V and heater pin 7 on the expansion header (not the expansion board).When I tried the mechanism out of the printer I used one of these simple servo tester devices and there wasn't a single time when the servo didn't respond so it has to be something within the Duet.
Anyone ever experienced something like this? Which places should I look at next?Thanks in advance!
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I guess it's just possible that your servo doesn't work properly on 3.3V signal levels when powered with 5V, although most RC servos are OK on 3V signals or lower. Can you provide a link to the datasheet for the servo?
Another possibility is that you have a bad crimp connection in the cable between the servo and the Duet.
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I'm not sure why it could be powered by 3.3V.. The servo is connected to plus and minus (pin 1 and 2) on the expansion header (which are +5V according to the wiring diagram) and pin 31 which corresponds to heater7 PWM.
The servo is a XLD-9HMB from New Power for which I could not find an useful datasheet. Maybe the servo is just garbage, I don't really know... -
@Eumldeuml said in Servo moves very unreliably:
pin 31 which corresponds to heater7 PWM
this is a 3.3V signal
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Alright, now I understand. Are there any 5V PWM pins that I can use?
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@Eumldeuml not directly, you can level shift the PWM signal. however it would be easier to try another servo first, there are many people who have hobby servos working with 3.3V PWM
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I'll try that! Thanks so much for your support!
