Hello
I want to have a stepper/servo motor turning on the tailstock (TS) synchronized with rotation of the lathe headstock (HS).
rpm - 50-100
accuracy - not precision, but shouldn't drift over time
force - nil
What I've looked at so far:
1. optical encoder on HS emits pulses to drive a stepper in TS. An intermediary mcu-driver. The cheapie optical encoders do 96 ppr, whereas the steppers need 200 ppr. But there are $50 optical encoders with 200 ppr.
See #2.
2. A stepper direct drives the HS, or turns passively on the HS. This is synchronized with a stepper on the TS via two driver boards and one set of control signals to drive both, but in opposite sense. (cw-ccw). The attraction of this over a passive optical encoder is to be able to drive the HS precisely at will...In this application, no appreciable power is needed. It would be useful, in general, to have a stepper rotating passively (no voltage in), and then cut the power to the HS main motor to enable the stepper to take over. Is this possible from a stepper perspective? The HS would be turning at up to 2000 rpm when the stepper is in "passive" mode. Though, for the application here, we are at very low rpm - 50-100.
3. a servo arrangement. Not my favorite, but I'm keeping open mind.
Any help or opinions appreciated. JB
I want to have a stepper/servo motor turning on the tailstock (TS) synchronized with rotation of the lathe headstock (HS).
rpm - 50-100
accuracy - not precision, but shouldn't drift over time
force - nil
What I've looked at so far:
1. optical encoder on HS emits pulses to drive a stepper in TS. An intermediary mcu-driver. The cheapie optical encoders do 96 ppr, whereas the steppers need 200 ppr. But there are $50 optical encoders with 200 ppr.
See #2.
2. A stepper direct drives the HS, or turns passively on the HS. This is synchronized with a stepper on the TS via two driver boards and one set of control signals to drive both, but in opposite sense. (cw-ccw). The attraction of this over a passive optical encoder is to be able to drive the HS precisely at will...In this application, no appreciable power is needed. It would be useful, in general, to have a stepper rotating passively (no voltage in), and then cut the power to the HS main motor to enable the stepper to take over. Is this possible from a stepper perspective? The HS would be turning at up to 2000 rpm when the stepper is in "passive" mode. Though, for the application here, we are at very low rpm - 50-100.
3. a servo arrangement. Not my favorite, but I'm keeping open mind.
Any help or opinions appreciated. JB