A little bit of reality here and an antidote for marketing hype.:-) You do not have a "1125 oz-in servo". You have at best a 200 oz-in servomotor. The 1125 oz-in rating is the peak stall torque of the motor. You use that number and you will burn down the motor and the drive attached to it in 5 minutes.
Look at the motor's "Continuous Stall Torque" rating. Its value will be 0.2 or less of the "Peak Stall Torque" rating. The continuous stall torque rating is the maximum you can use continuously without burning the motor up. Anything above the continuous rating can only be used for very short periods of time (accel, decel, etc).
Motor vendors tout the peak stall torque as if it had practical value. It doesn't (I can't blame Keling, they do it because everyone else does). The only "real" torque you have is the continuous rating. No one touts that because it doesn't look nearly as impressive.:-)
A Z-axis is usually heavy and holds a considerable weight up against gravity. It is a sure-fire and tailor-made axis to destroy a sevomotor unless great care has been taken to insure proper gearing. Use a step motor for the Z-axis. It doesn't care and won't be hurt if it's overloaded. It's smart enough to shed a load it can't carry. People call it stalling like it's a bad thing.:-)
Mariss  |