Gearbox failure - need replacement

Newbie question.

Stepper motors such as the nema 23 or 34 won’t work because they basically shift into neutral when they are not actively turning? And is the speed not controllable with out the gearing?

I’m sure someone else can answer better then I can. However there are options to use stepper motors but many good ones to not use them. Stepper motors are “ON” or “OFF” the behavior is the opposite of what we get with these motors. When power is lost the motors hold the sled, with a stepper loss of power would let the sled freefall. Steppers typically are “dumb” devices, it’s assumed they followed the signals given. Steppers with encoders are quite expensive. There is more to it but this covers the basic problems I believe.

Thank you

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I definitely know people that could cast this no problem. But how do we get it to metal from a silicone mold? We’re about to make a bunch of molds so if there is a way to make this happen I’m totally game.

I have the good motor and I just ordered 3 more last night. Thinking I might try to get a second Maslow on the go with the spare shield and mega you gave me.

Might try to get a sled laser cut too. I really like that idea for maximum percision

I’m gong to try a MDF sled on a precision CNC when I get a chance. I also want a Acrylic laser cut sled. I have made 2 sleds and feel making it by hand is by far the fastest solution.

Silicone can withstand some wicked heat so I think you could do aluminum casting or pot metal. Metal gears might make something else break but whatever.

I was / am getting a Maslow together for the UK office. I got 2 motors and Z kit from Maslow. A little disappointed that the motor cables were not included as I had ordered the same thing in the past and they were. It must have to do with shutting down. I was able to get 1 set of gears , a set of motor cables, and a UK power supply from the surplus site. I can fake everything else. I think my total cost to get it together was $320. Of course we don’t need shields - lol

Keep me in the loop on molds please. We can go PM on this too.

Thank you

The inside of my gearbox looks different than what is pictured here…

I wonder why that is?

please post pictures.

I already did. They are like 4 comments up

Wait a minute … I’m pretty sure this top sprocket doesn’t do anything …

They are posted above. I just realized that it looks the same if you remove the top sprocket from the double sprocket.

They must’ve ran out and used this in a pinch

EDIT : nevermind … that sprocket is def important … it transfers power to the axl hahah

i am surprised your metal gears were destroyed instead of the plastic gear. I thought the whole point of using the plastic gear was that it would self destruct first. basically acting as the weak link in the chain of gears.
I believe all the other gear box failures were with the plastic gear. the plastic gear is the first gear to rotate so it gets the direct power from the motor.

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Part of the problem (at least for me) is the stock lubrication (or lack there-of) in the gearboxes. It is woefully inadequate given the application. The picture of the gearbox shows very little if any grease remaining. A little smear of white lithium grease is not going to be enough given the hours of continuous use these motor/gearboxes are seeing. What is applied by the manufacturer will very quickly either evaporate or be slung off onto the inside walls of the gearbox. Once the gears are dry they will overheat and wear, fail, and the broken teeth will further damage the remaining gears.

Possible solution is to pack the gearboxes with a light weigt bearing grease. No more than 3/4 full. Not sure if this idea has been tested before. After seeing the photo, its something I am going to test on mine.


I’m 3D printing a petG one right now as a test. Going to a CNC machine shop at lunch to check out getting them to mill one

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Please do follow up with us!
I suspect you are right, at least in principle.

Do you think the gearbox is sealed? Maybe it is tight enough to use a lighter weight lube?

Well … haha … The petG printed sprocket worked beautifully … for like 30 seconds…
haha then it had the same failure as the real one.

When a load was applied we lost our teeth.


Judging from the picture of the flange, no I do not think its sealed well enough. I may have to cut a gasket or use RTV for this part. A lighter weight grease is more “slingable” by the gears so maybe filling up to th 1/3 mark is all that will be necessary. I am going to use a grease similar to what is used for the nose wheel of a chainsaw bar. Its more of a medium wieght. There doesn’t appear to be any seals around the output shaft either but I plan on using an exterior felt washer for this. It’s a bit old school but they work well for low speed applications.


IIRC, all but one of the original gears are metal

David Lang

Quick update. I pulled the covers off my motors last night. One had a single dollup of grease on one of the gears. The other gearbox was bone dry. Not a spot of lubrication. Gears were totaly dry. These motors have never been run, right out of the foam they were shipped in. I’ll post pictures when I take them. No matter, It looks like I’ll have to do something just to get started.


I suggest PTFE super lube -

Thank you


That’s a thing to watch out for if people start regreasing these things - make sure the grease you’re using wont damage the plastic gear. This means that graphite and moly greases should not be used, but that one that brandon posted (silicone with ptfe) looks pretty good, plain white lithium grease should work as well. Don’t use anything aerosolized, they tend to be designed to flash off and will make plastic brittle.


Thanks, I’ll check it out.