My cnc spindex-trunion project is moving forward, by hook or by crook!
I need some help attaching a grearbox to the motor. This is a low power, low speed thing. It just needs to rotate to a series of angles.
The trunion has two pillow block bearings for the headstock end, with a 3/4" shaft. The tailstock is also 3/4", with a single pillowblock.
I have a brake coming from ebay. It's an always on, apply power to release unit. It will be getting installed on the 3/4" od tailshaft of the trunion. I think that bit will be easy - the brake has a split collar. I think I can just turn the 3/4" shaft to match the bore and tighten the collar. Hopefully the alignment of my mounting bits and the shaft will be sufficient.
But I am also going to order a gearbox, just in case. Though I hope I won't need it. I'm thinking around a 25 to 40:1 unit. The question is.. How to couple the gearbox to the stepper? The stepper shaft is approx 6mm. It has a small toothed pulley that I would press off.
Gearboxes are available either with keyed female shafts, or with male shafts. For a female motor shaft, I am thinking I would make an aluminum plug, with a light press fit and keyway to insert into the gearbox. On the motor side I would use a set screw to engage the motor shaft (and also cut a flat on the shaft). Is that a good plan? I worry about binding, etc. It is important that the motor is tightly coupled since the steps set the angle.
Here is an example:
I am thinking of a similar approach for the 3/4" headstock shaft, though misalignment is more of a concern there.
I could instead choose a gearbox with male shafts rather than female, but that seems more complicated and would be longer to package.
I need some help attaching a grearbox to the motor. This is a low power, low speed thing. It just needs to rotate to a series of angles.
The trunion has two pillow block bearings for the headstock end, with a 3/4" shaft. The tailstock is also 3/4", with a single pillowblock.
I have a brake coming from ebay. It's an always on, apply power to release unit. It will be getting installed on the 3/4" od tailshaft of the trunion. I think that bit will be easy - the brake has a split collar. I think I can just turn the 3/4" shaft to match the bore and tighten the collar. Hopefully the alignment of my mounting bits and the shaft will be sufficient.
But I am also going to order a gearbox, just in case. Though I hope I won't need it. I'm thinking around a 25 to 40:1 unit. The question is.. How to couple the gearbox to the stepper? The stepper shaft is approx 6mm. It has a small toothed pulley that I would press off.
Gearboxes are available either with keyed female shafts, or with male shafts. For a female motor shaft, I am thinking I would make an aluminum plug, with a light press fit and keyway to insert into the gearbox. On the motor side I would use a set screw to engage the motor shaft (and also cut a flat on the shaft). Is that a good plan? I worry about binding, etc. It is important that the motor is tightly coupled since the steps set the angle.
Here is an example:
I am thinking of a similar approach for the 3/4" headstock shaft, though misalignment is more of a concern there.
I could instead choose a gearbox with male shafts rather than female, but that seems more complicated and would be longer to package.
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