Re: Silly 4th Axis Question
If you do direct drive then the holding torque on the stepper would limit the type of work you can do. The gearboxes multiply the holding torque so you can do machining away from the axis of rotation without fear of loosing steps. Most of the time the slow RPMs due to the gear reduction aren't a deterrent to this implementation. Backlash is always an issue with gear reduction on 4th axis.
doing a word search in these forums can yield a wealth of information quickly.
Re: Silly 4th Axis Question
Quote:
Originally Posted by
cncuser1
If you do direct drive then the holding torque on the stepper would limit the type of work you can do. The gearboxes multiply the holding torque so you can do machining away from the axis of rotation without fear of loosing steps. Most of the time the slow RPMs due to the gear reduction aren't a deterrent to this implementation. Backlash is always an issue with gear reduction on 4th axis.
doing a word search in these forums can yield a wealth of information quickly.
Thank you for your response. I was intending my question to be more focused towards using these index fixtures that I have laying around. It's a lot easier for me to get an oversized motor (1600+ oz in) with a holding power that is, and you'll have to take my word on this, more than sufficient for my purposes, than it is to do gear/belt.
Re: Silly 4th Axis Question
Used harmonic drives aren't that expensive, but if you are just doing engraving or something low force you probably don't need it.
Re: Silly 4th Axis Question
Do these units have bearings or bushings in the spindle? I'd prefer bearings if I knew my work had a lot of small back and forth movements.
The size of stock or workpiece would make me prefer a face type of work holding compared to a collet style work holding. How are these unit configured?