Stepping Update

Today I got the stepper motor connected to the rotary table input shaft for a preliminary test. The mechanical link between the stepper shaft and table shaft was made with a bellows type aluminium coupling. The stepper drive shaft is 12mm diameter, whilst that of the motor is 6.35mm. i.e. 1/4 inch. I managed to find an off the shelf bellows coupling with these bore dimensions.

Due to the relatively high gear ratio of 90:1, I took the decision to dispense with micro-stepping of the motor, and I altered the appropriate line in the software to reflect this, as well as setting the dip switches on the driver circuit.

Here is a picture of the set up. As can be seen, the motor was supported by a machine table clamp during the test:-

The motor ran the table with no trouble at all. I ran the table in Step, Angle, Jog and Run modes. I am not sure if the motor will be able to drive the table for actual machining, as opposed to just positioning, but it certainly did not seem to lack torque.

I didn't attempt any accurate measurement of the angle the table turned through in this test. That said, going by the graduations on the side of the table, everything seemed to be in order.

The metal has now arrived to fabricate the mounting bracket, so look out for another update in the next few days.