Problem with setting current for Chinese stepper...

deckingman

@briskspirit said in Problem with setting current for Chinese stepper...:

@deckingman I know that you are a Master in building 3D printers ! So maybe you could throw me an idea how to convert my printer from integrated screw to stepper+coupler+screw? Replicator 2X clone, stepper is underneath and no space at all..

Show me a picture of what you have. Better still, send me a PM with your email address. Then we can see what can be done without cluttering up this forum with non-duet related things.

briskspirit

@deckingman I can't send you PM as you have restricted who can send.

briskspirit

@dc42 Rotor is misaligned and has black marks on teeth where it has contact with stator teeth.

deckingman

@briskspirit There is your problem then. If you can't fix it, TBH I can't think of a cheaper alternative than to replace the motor/shaft assembly. Being a cheap Chinese stepper, I don't suppose you can get your money back? It's obviously faulty.

briskspirit

@deckingman It will take too long... better imho is to convert to coupler or belt driven screw but I don't know how to do that the right way. Can you PM me your e-mail and I will send you photos of what I have got.

dc42

@briskspirit said in Problem with setting current for Chinese stepper...:

@dc42 Tried... Will try your idea to readjust with 4 screws! How long it will "leave" on Z axis with 2A current if rated for 1.5A(or 1.3A... )

100% of rated current is safe. A little more is safe, because rated current is specified with both phases energised, but microstepping drivers such as those on the Duet only drive one phase at a time with the full current. 141% of rated current is unlikely to be safe unless standstill current reduction is used, because then the power dissipation is the same as if both phases were energised at full current, but depending on the motor position all of that power may be dissipated in just one of the windings instead of shared between both.

deckingman

@briskspirit said in Problem with setting current for Chinese stepper...:

@deckingman It will take too long... better imho is to convert to coupler or belt driven screw but I don't know how to do that the right way. Can you PM me your e-mail and I will send you photos of what I have got.

PM sent.

briskspirit

@dc42 As I understand right I am already using current reduction to 30% with I30 argument , right?

dc42

@briskspirit said in Problem with setting current for Chinese stepper...:

@dc42 As I understand right I am already using current reduction to 30% with I30 argument , right?

Only when all motors have been idle for 30 seconds.

briskspirit

@dc42 Thank you ! Lapping stepper with oil - run for ~30min forward / ~30 min backward - towel and repeat . Noise is almost gone, turning better. Will see if I could reanimate it.