Source of Maxon/Faulhaber 4:1 Gearheads

[SkipGear]

A little more motor hacking. 0816 motor on a 8mm 4:1 box.

Original motor with encoder on the top, modified motor with encoder removed on the bottom with 8mm 4:1 planetary. Amazingly enough the gear that came on the motor was the correct one for the planetary but was configured wrong. Had to cut down the shaft, which removed the weld so I had to reattach the gear with some sleeve sealer. Seems to be holding. Not bad for a $12 ebay special and a donated gearbox.....thanks @carlso . Now to decide what to put it in to test it.

[Chris333]

Damn, wanna sell any? 

[mike_lawyer]

If anyone needs gearheads to practice cutting down, I have plenty of them to use if anyone wants to try!

[mmagliaro]

Tony, I ran into that exact same issue with those 8mm Faulhabers from eBay (the long shaft sticking out of the gear).  What you did is pretty much the same as I've done.  A Dremel will grind the spot weld off and then the gear just slips off.  And no way am I going to spot weld the gear back on, so LocTite it is.  I have never had one break loose after putting it back on that way.

It's nice that those 8mm motors have been so available for the past (year?  maybe more).   The gearhead is still the hard thing to
find.

[SandyEggoJake]

Tony, so your mate doesn't seem to be a cutdown gearhead, is that correct?  If so, what is the part number from where @carlso found this M8 OD 4:1 gem? 

Like Max mentioned, I'm struggling to find 8mm 4:1 gearheads at a reasonable price point. 

And ideally seeking 6V 816 (0816P006S) rather than the more common 3V 10.7kRPM. 

Tempted by Mike's generous offer, but would rather avoid the gearhead slide and dice fun if I can.

[SkipGear]

@SandyEggoJake  - here you go...

[SkipGear]

All the info you need on 0816 motors and possible combinations.

https://www.faulhaber.com/en/products/series/0816sr/

[carlso]

 You are very welcome Tony. My hands/eyes do not work well for small stuff anymore and I knew that you could/would be able to use the gearhead.

As far as where I got it, this combo came from "The Motorman", Weldon(?) 6+ years ago.



I, for one, sure miss his knowledge and customer service.

Be well,
Carl

[SandyEggoJake]

Thanks guys.  Apparently, that little gearhead has had a very active social life! 

[metalworkertom]

Something I thought about is these motors and gearheads are designed for medical equipment and similar . Would modifying the gearhead down in length be feasible ? How much over kill is the output insert and bearing it alone is 4.8 mm long. The input insert is 3 mm long , now this one is matched to the pinion depth , so altering it would involve moving the pinon as well . How much can we take off each end and still meet the demands of our use . Only 1.9  mm is used for gear reduction . Just a thought.

[narrowminded]

I received the tap that I ordered and will try to get at this in the next few days.  I've got six fairly involved projects going right now so I'm juggling like a madman.   And Tom, I suspect that the output could be modified for a shorter length but I really want to get one apart and see what's there before to say much about that.  Max has probably already had some thoughts about this.

[mmagliaro]

I like Tom's idea about trying to cut down the ends to save some space.  We could get rid of some of the length of
that nose and bearing and still have plenty of support for our purposes.  But it's not the support/load I worry about, but keeping the shaft running true with wobble.  That front 4mm is the only thing keeping that shaft running straight with no play in it.  If we were to trim that to 2mm (.078"), that isn't much and even with the precision of these things, I'd expect that output shaft to start wobbling.

On the input side, I think the support would be okay, but I don't know how to physically make this work.  The gearhead screws on to the motor via that threaded insert.  I think we could cut the gearhead and insert 2mm shorter, but you cannot cut the motor nipplie much shorter.  The bearing that carries the front of the armature will fall apart.   We might be able to get the pinion to push in closer on the motor by some of that distance, and trim off, maybe, 1mm from the threaded nipple, and it all might still hold together and go on.  But all that to save 2mm of length? 

I see your point, believe me.  Getting rid of half from the front and half from the back, for example, would reduce the overall length by about 4mm.  A 1016 + gearhead is 25.7 mm.  So getting that down to 21 or 22 would be nice.  But it seems like a tricky thing to pull off that is more work than the potential benefit.

[SandyEggoJake]

Yes Tom's idea is interesting... though finding low cost thinner sealed bearings might be the limiting factor. 

but let's take this one to 11....
if going the next step to cut into the coreless motors, my nutty thought was could one stuff the planetary gear INSIDE the motor core? 
Starting thinking along this line when Tony showed his 8mm gearhead on the end of a 12mm.
 
Obviously, lot of issues, but looking at some drawings and it seems these gearheads could be turned down a tick if it didn't need to be protected.  Not sure you could get a 8mm into a 10, but it seems you could stuff it into an 13mm.  Maybe a 6mm into a 10mm? Some of the gear materials could be changed to retain / optimize desired properties. 

Might not be a huge space saver for us using a 4:1, but the higher ratio gears could get a lot smaller length that way. 

[peteski]

Yes Tom's idea is interesting... though finding low cost thinner sealed bearings might be the limiting factor. 

I thought these uses simple bronze sleeve bearings at the output shaft.  That is why the wobble with a thinner bearing is a concern.

As far as integrating a planetary gearset into the motor, that also seems thought to do because the magnet and bearings are occupying most of the space in the center of the motor.

[metalworkertom]

Yes Tom's idea is interesting... though finding low cost thinner sealed bearings might be the limiting factor. 

but let's take this one to 11....
if going the next step to cut into the coreless motors, my nutty thought was could one stuff the planetary gear INSIDE the motor core? 
Starting thinking along this line when Tony showed his 8mm gearhead on the end of a 12mm.
 
Obviously, lot of issues, but looking at some drawings and it seems these gearheads could be turned down a tick if it didn't need to be protected.  Not sure you could get a 8mm into a 10, but it seems you could stuff it into an 13mm.  Maybe a 6mm into a 10mm? Some of the gear materials could be changed to retain / optimize desired properties. 

Might not be a huge space saver for us using a 4:1, but the higher ratio gears could get a lot smaller length that way.

Edited my original post to better reflect Im talking of modifying the gearhead.
The motors have bushings as Pete stated however the gearhead out out shaft is in bearings 2 I think. .