PId Tuning tool not displayng graph correctly about dcservo HOT 20 CLOSED

Hi Robert, it seems you have given a lot of thought and work on your machine.

I can see that the encoder being on the output shaft can compensate gearbox backslash but that may also introduce instabilities in the system.

If the motor does not stop once reaching the final location can be a sign that proportional gain is too high. You can try lowering that.

Also, for manual adjustment remember you can use the Arduino IDE serial monitor to send various commands like a new proportional gain value. While you do that the system will also respond to step and direction pins. Initially set D0, I0 and P0.1 to see how it goes. Try manually adjusting them to get a good response (if possible, as I mentioned backslash on the gearset might give you hell).

If when lifting Z everything goes bad that might be caused by the power supply not delivering enough current. Just a guess.

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OMG! that was a unexpected fast response:)

I am powering my milling machine from my Off grid Photovoltaic system, from the batteries more exact, that s 600amp hours on 24v.
I am gonna give it a try with P0.1,I0,D0 see what happens.(everything slowed down:-) )
I can see what u mean with the encoder after the gearbox, backlash is what I had in mind:) and I made sure that the gearbox from each motor diddnt have any noticable play on it

I uploaded 2 videos to google drive with videos of the pid tuning tool and z axis erratic behaviour
https://drive.google.com/open?id=1jRwQhsOKyt0WeZdFfnS9Pzzm7uZ7SPew
What are your toughts on z going down smooth and when lifting z all axes going crazy?
Thank you.

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Well, if powered from batteries I guess juice is plenty (only if a too thin cable is used lack of power might be an issue).

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calbe is 4mm(diameter) silver coated they are rated at 70 amps, but the machine goes crazy only when i lift z:))) when i move x or y everything works well, check the video out when i lower z everything is smooth, when i lift z movement is not linear at all

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I saw the videos, Z axis up is surely creating some noise that seems to affect the rest, I do not see why noise and activation seems quite different than when going down. It may well be the motor's dead zone. Something I have not yet addressed in my project.

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coud it be encoder related( i have 2 adjustable resistors i think that s what they are called in english)

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hmm, gonna try to change the motor see what happens:)

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gonna try that too

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Thank you very much for taking the time to help me out, i really diddnt expect such a fast and helpful response:D

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It is the least I could do considering the love you have put to the project

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Thank you 4 the kind words Misan:)

I have removed the z axis letting the motor run freely, and the erratic behaviour stops but starts as soon as i apply a little bit of force on the motor (bad brushes maybe) taking into account that these motors are from a salvage yard:) gonna put a new motor in, see what happens would ceramic capacitors on the motor leads help in filtering the ripple that is going on there?

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also tried switching polarity to the motor, same result, diffrent direction lmao

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actually the z motor wich has screw and nut for movement requires the least torque, the other axes require 5 nm just to start moving

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Hello misan, i managed to get everything working, the noise was coming from a motor winding wich was tied to ground, fixed it, now I am still stuch at the PID tuning tool not displayng graph correctly:(( How can I fix that?

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Thank you very much, i am gonna try that, i l let u know how it works.

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what step time and step pulse time do u recommend in ns?

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@PaulRobert1 I expect step pulse time longer than 1uS. Not sure about the minimum acceptable time though.

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