Source of Maxon/Faulhaber 4:1 Gearheads

[narrowminded]

For general reference, all of the gear boring, sleeving, etc with good tolerance and concentricity are things I can do fairly easily.  It is best to have the sample parts to assure tolerance, at least for parts where no experience exists to be sure of the manufacturers' dimensions, as 10ths of thousandths will matter.  In general I would try to make slip fits or very light presses, final assembling with loctite (weak) so that pressing on shafts of assembled motors and such is not required.  The potential to damage a motor when doing this is very real.

[mmagliaro]

For general reference, all of the gear boring, sleeving, etc with good tolerance and concentricity are things I can do fairly easily.  It is best to have the sample parts to assure tolerance, at least for parts where no experience exists to be sure of the manufacturers' dimensions, as 10ths of thousandths will matter.  In general I would try to make slip fits or very light presses, final assembling with loctite (weak) so that pressing on shafts of assembled motors and such is not required.  The potential to damage a motor when doing this is very real.

0.8mm is .031".   What are you using to bore holes like this in stainless steel?
I usually use cobalt bits to drill stainless, but will that work in sizes this small without breaking?

[narrowminded]

0.8mm is .031".   What are you using to bore holes like this in stainless steel?
I usually use cobalt bits to drill stainless, but will that work in sizes this small without breaking?

Small carbide drills.  I've fitted as small as .6mm shafts (.0236") with machined flywheels and necessary attachments for my small chassis.  Running really true, both chuck and tailstock, is important but otherwise normal duty.  Indicate your part OR, especially for a one off and using a less than perfect 3 jaw chuck (over .001" runout?), make a "collet" that isn't really a collet but a sleeve, by inserting a piece of material like brass that's just slightly oversized, maybe leaving 1/16" wall or so, then drilling it on size of the gear OD.  That part is now centered to the spindle perfectly as long as you don't let it move/ rotate (small hex bar can be helpful if you have it).  Now insert the gear into that collet/ sleeve and tighten the chuck.  If the fit to the gear OD is good the very slight collapse needed from the new "collet"/ sleeve will afford the very small amount needed to grip the gear and it will all be on center as dictated by the sleeve being machined to the machine's center.

This is where a nice/ true running collet setup can be most useful.  Now, if the gear's bore is off center, unlikely as it was most likely machined in one setup so should be good by default, but possible, then it's time to find another gear unless you're really a glutton for punishment and want to try to bore a sub 1/8" off centered bore.  Another possibility if it's a worm or another machinable piece would be to machine a new one and to make it easy on yourself, in brass.    

And while we're at it, if you had a round part with a misaligned bore that you're trying to "fix" or open up but the drill will want to follow the misaligned hole, you can plug it and redrill at a size over the plug size so you don't wind up with a sliver breaking loose in the hole and jamming.  That could then be sleeved back down or if the choice is there, a new oversized shaft could be used.

"Where there's a will there's a way"... usually.

[mmagliaro]

Very helpful trick, Mark!  (about putting a sleeve in the chuck to make a "collet" squeezer).
I do have a 4-jaw chuck also, so I can dial something in really precisely with that if I have to.  My main concern was even being
able to drill into stainless steel with a bit that small and not have it break off.  But I guess it's possible.  Good to know.
One day, I'd like to save up my pennies for a super chuck, like a Bison.  My current 3-jaw, with a 1/2" ground steel drill rod in it, measures .0015" runout on a dial indicator.  I think that's pretty darn good for a 3-jaw on a "consumer" lathe like this Grizzly.  I was shocked when I tested it.  But that's not quite good enough, I don't think, if you are trying to bore .031" holes in a little gear.
So your collet idea is a great one.

[narrowminded]

Very helpful trick, Mark!  (about putting a sleeve in the chuck to make a "collet" squeezer).
I do have a 4-jaw chuck also, so I can dial something in really precisely with that if I have to.  My main concern was even being
able to drill into stainless steel with a bit that small and not have it break off.  But I guess it's possible.  Good to know.
One day, I'd like to save up my pennies for a super chuck, like a Bison.  My current 3-jaw, with a 1/2" ground steel drill rod in it, measures .0015" runout on a dial indicator.  I think that's pretty darn good for a 3-jaw on a "consumer" lathe like this Grizzly.  I was shocked when I tested it.  But that's not quite good enough, I don't think, if you are trying to bore .031" holes in a little gear.
So your collet idea is a great one.

I would still try the .0015" runout if that's all it is before to dismiss it entirely but don't be surprised if it doesn't work perfectly.  It might work acceptably.  When you get down under .010" drill, certainly by .005", it would almost assuredly be no good.  And runout at .002" or certainly .003" or more, don't even try drills this small. 

For as short as most worms are consider carbides known as circuit board drills.  They are fairly inexpensive, very stubby for rigidity, and they have a second benefit for this which is a very shallow drill point when compared to standard drill points.   Spin it up pretty good and be gentle with the feed.  Not rubbing but not jamming it either.  You might be surprised how easy and how "on size" they cut.  You can often get a reamed hole quality straight from the drill and for any oversize that might happen will be easily in the range to be readily handled by loctite.  And for the loctite, consider the weak stuff.  I've found it to be adequate for the job in our trains and yet can be pulled apart with little force when needed.

[mike_lawyer]

Any idea if those made-to-order ones from China on top the previous page would work with the Faulhaber pinions?

[metalworkertom]

I managed to get 4 gearheads cut down today. My Sherline definitely has too much run out for those tiny drills. I need to remedy that. Lots of good tips here.

[mike_lawyer]

I managed to get 4 gearheads cut down today. My Sherline definitely has too much run out for those tiny drills. I need to remedy that. Lots of good tips here.

Wow, did you complete all of the gearheads, or just the initial cut?

[peteski]

I managed to get 4 gearheads cut down today. My Sherline definitely has too much run out for those tiny drills. I need to remedy that. Lots of good tips here.

Is it the chuck run out, or the tailstock is not centered?
If it is the latter, these might help: https://www.sherline.com/product/12021204-adjustable-tailstock-chuck-holders/

[metalworkertom]

Wow, did you complete all of the gearheads, or just the initial cut?
[/quote

Cut down and bored. Have to clean up the internal gear . And clean all the parts again. As Max said getting it clean enough is a chore. Need to improve in a couple of the operations . Thinking a ultrasonic cleaner is worth trying . I have so many to do potentially , streamlining operations will help.

[narrowminded]

I managed to get 4 gearheads cut down today. My Sherline definitely has too much run out for those tiny drills. I need to remedy that. Lots of good tips here.

The runout is trouble when trying to open up a small hole to little less small hole but it also surfaces in the counterbore that aligns the heads of the gear case which then aligns the planetary gear mesh.  Irregular whine in service would be the next logical potential issue and if it happened we would know why, wouldn't we?  

[narrowminded]

Any idea if those made-to-order ones from China on top the previous page would work with the Faulhaber pinions?

Hard to say from this distance but they would have a good chance if it's a worm as they have no special involute tooth profiles needed.  Straight cut to the theoretical pressure angle is all that a worm gets, much like a regular bolt thread or straight rack gear but at the gear pressure angle, not that of a bolt thread. It's probably 20 degrees but gears can be many other angles and special depths of cut that are service dictated.  It's the round gears that need the involute tooth profile that rolls smoothly in and out of that angle and can be suspect on molded plastic gears, especially inexpensive ones destined for light duty, relatively low load, and short service life.

Edit add:  I just realized from a later post that you were talking about whole assembled planetary units.  Sorry for this confusing answer.

[metalworkertom]

Is it the chuck run out, or the tailstock is not centered?
If it is the latter, these might help: https://www.sherline.com/product/12021204-adjustable-tailstock-chuck-holders/

I'm sure it's in the Chuck itself . I'm not using the tailstock in my operations , all tooling held in the tool post.

[SkipGear]

Any idea if those made-to-order ones from China on top the previous page would work with the Faulhaber pinions?

They have the same M5.5 thread as the nose of a Faulhaber motor. The gear ratio is different so pinion size is an unknown and the product sheet isn't much help. I'm sure if we ordered some, they would provide a matching pinion.

All this talk about planetary gears....have some fun with this.

http://www.thecatalystis.com/gears/

[metalworkertom]

The runout is trouble when trying to open up a small hole to little less small hole but it also surfaces in the counterbore that aligns the heads of the gear case which then aligns the planetary gear mesh.  Irregular whine in service would be the next logical potential issue and if it happened we would know why, wouldn't we?

Yes we will. Hopefully not . Need to tighten everything up on this lathe some more. So far I've spent as much time on repairs and adjustments . I'm going to get these assembled and see how they do.