John Domville wrote: > Lawrence G > Ok, I finally got around to running the test you suggested. The first > couple moves (test #1) up and down > Are ok, but after that the tip gets lower and lower into the piece. Also > the motor makes a binding noise just > Before it starts screwing up. Sounds like the motor is trying to move two > opposite directions at the same time. > Never did get to test two. So where do we go now? This by the way is with > a config file that uses + as a Z axis up > And - as a Z axis down. Had a pencil stub loosely in the collet during the > test and it kept getting pushed further and further > Into the collet until I forced a stop to the program before the face of the > collet went in to the bed surface. > > John
You are losing steps (stalling the motor) when trying to lift the head. I assume that your machine doesn't have any kind of head counterweight, so it is a lot harder to lift it than to lower it - that is why you have problems going up only. Things to try: 1) make sure nothing is binding - is the screw lubricated? are the ways lubricated? 2) reduce the Z axis acceleration - starting more gently will help the motor lift the load 3) reduce the Z axis max velocity - steppers get weaker when you run them faster - keeping the speed down will give you more torque. 4) counterweight the head to reduce the load 5) get a stronger motor or drive for the Z axis Regards, John Kasunich ' ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
