Are these geared reducers worth using?

[Apples]

I know the better reduction units to use are planetary gearboxes. But these are from what I gather, straight cut gears.

Are they worth considering for use on a CNC gantry plasma system. They state arc minutes down pretty low. 2.5, 4 etc This seems pretty tight.

http://anaheimautomation.com/manuals...ec%20Sheet.pdf

Any comments?

Peter
Australia

[holbieone]

the average back lash is 4 degree

even if you can adjust the backlash in the controller there will still be a dwell at the axis reversal

this would distort the geometry you are trying to create to some degree

if you need that much torque use servo motors

[Stepper Monkey]

To get 4 arc-min or less you need a VERY expensive planetary from what I can tell from trying to solve the same problem. As just mentioned above, these units are 4 >degrees< which is insanely sloppy.
Since so far I only have used reduction to get more resolution (increase in my steps per rotation), harmonic drive worked for me to get that, but obviously that doesn't work for gearing down to get greater torque. I don't know what you to do for that, especially for something that large, save getting a bigger drive (or multiple drives on that axis), or servos....
I am now running into the same problem you have right now, so if there are any bright solutions other than stupid money for planetary gearheads, Let me know!

[massajamesb]

Depends on the gear ratio you are looking for. I have seen a gentleman selling some nice 3:1 boxes on Ebay from SPD SI every so often.

[JerryFlyGuy]

Those gearbox's would work great for some non-critical function, but for NC machine control they will not be very usefull. You'd be better off using a belt reduction over those units.

If you guys are looking for cheap reducers I'd be looking on ebay. I've bought all new reducers for my machine [they were like $700 each] and then later bought three off ebay for $75. These are Nema34 10:1 reducers. I saw a 10:1 on there the other day that didn't even sell for like $20 or something. I'd have bought it, but I've got 9 of these things hanging around now and don't think I'll be needing more for a while.

Anyway, they do exist and can be bought cheaply off ebay. I waited for 1/2yr and never found them, so I bought new. A week after they arrived I got these cheap ones. [Just my luck ]. Also harmonic drives would be an option depending on what kind of reduction your looking for.

Jerry [giving my best, secret "bargain stops" away for free ]