Re: Stepper-Driven Power Drawbar
Hey John.
I'm using 30# of air on my small cylinder. The socket is a 6 point mounted to the 100:1 planetary gear box. I don't use a stepper motor just a simple dc motor (750) series powered by a independent 12 volt supply (started with a inexpensive 12 volt battery). When the PDB is called, the spindle rotates less than 1 360° rotation to the hall effect sensor which then fires into position, the pin locks the spindle and the dc motor rotates the required direction for function. The unlock function is just a timed event (arduino control) and the lock event is a function of the current draw through the motor controller. Once the predetermined current is met, the drawbar has reached the required torque then the system disengages. Thus the magic!! Oh yeah, I also had a problem with the drawbar sticking and corrected it by bumping the torqueing motor in the opposite direction (just a bump) at the end of the cycle to help release the socket/drawbar interface. Thanks for the pictures of your system. Looks impressive. Hope this helps.
Bill
billyjack
Helicopter def. = Bunch of spare parts flying in close formation! USAF 1974 ;>)