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M2 Worn pinion gear - flip it over?

Posted: Fri Aug 15, 2014 11:19 pm
by Spotopolis
My extruder motor had been making some clicks lately, but last night half way into a 14 hour print, the extruder stopped working and just clicked horribly. I took apart the gearbox on the stepper motor, and it looks like the pinion gear is worn. The planetary gears look just fine.

So, a couple of questions: the pinion gear appears to have three teeth areas - one at the outermost tip, a thin band of larger teeth around the middle, and another band at the innermost area. The inner tooth area appears to engage the planetary gears nicely, so I'm wondering if it would work to just flip the pinion gear over so the nice sharp teeth are outermost. It seems like it would work, but I can't seem to remove the gear. Is there a trick to it without damaging the motor?

The second question is if I can't fix the pinion gear - if I order a new motor from MakerGear, does it come with the planetary gearbox attached? It appears that all the motors on the MakerGear website are out of stock, so has anyone found a suitable replacement? There are no markings on the motor, so I'm not even sure which one to get. I have the 19V/12V dual power supply machine from June 2013.

Thanks,
Steve
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Re: M2 Worn pinion gear - flip it over?

Posted: Sat Aug 16, 2014 2:48 am
by Spotopolis
I think I found the answer to my question. I came across a photo of the pinion gear on the old MG Google group, and I see that it should have much sharper teeth than the inner teeth on my gear. The inner teeth on mine are kind of squared off. See photo below.

Flipping the gear will probably not work even if I could get it off the motor.

So, it's time for new motor. Can anyone confirm the proper gear ratio for my 6/2013 printer? It seems to be 5:1 but I want to be sure it's not 13.6.1.

Is there any difference between a 5:1, a 5.2:1 or a 5.18:1 ratio? I don't understand the extra numbers.

This is what mine SHOULD look like:
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Re: M2 Worn pinion gear - flip it over?

Posted: Sat Aug 16, 2014 5:14 am
by jimc
Yes its a 5:1 ratio. Its always listed as out of stock. Just send an email to karen, rick or support. They will help you out

Re: M2 Worn pinion gear - flip it over?

Posted: Sat Aug 16, 2014 9:25 pm
by Spotopolis
Thanks jimc,

I'll contact MakerGear and get a new motor. Any clue on what the ratios mean?

Re: M2 Worn pinion gear - flip it over?

Posted: Sun Aug 17, 2014 12:49 am
by jimc
its just the gear ratio. 5 to 1. i believe to be exact its 5.18:1

Re: M2 Worn pinion gear - flip it over?

Posted: Sun Aug 17, 2014 12:56 am
by Spotopolis
That's what I thought. So is a 5.2:1 just rounded up? Is it the same?

I appreciate the help. I love this forum!

Re: M2 Worn pinion gear - flip it over?

Posted: Sun Aug 17, 2014 12:57 am
by jimc
honestly, you dont need to worry about the details. the m2 has always had the same extruder motor and ratio so just email them and you'll get the right thing.

Re: M2 Worn pinion gear - flip it over?

Posted: Sun Aug 17, 2014 1:35 am
by Spotopolis
I will be ordering a new motor from Karen, but the engineering part of my brain is still curious about the 5.2:1 vs 5.18:1 question and if they are the same. Short of car differentials and motorcycle sprockets, I don't know much about gear ratios and would like to learn.

Re: M2 Worn pinion gear - flip it over?

Posted: Sun Aug 17, 2014 2:06 am
by jimc
Not sure where you saw 5.2:1 maybe someone is rounding the numbers i dont know.

Re: M2 Worn pinion gear - flip it over?

Posted: Sun Aug 17, 2014 2:44 am
by Spotopolis
It was an ebay thing after searching for a replacement motor. Here's the link: http://www.ebay.com/itm/Kysan-5-2-1-Pla ... 2a3e5f325d

Since I have no idea if this is the same thing that MakerGear uses, I'll just order a replacement from them. Hopefully they have one in stock since the website has listed them as "sold out" for a long time. I was just getting desperate to fix my printer ASAP so I could try out my new transparent red filament to print a custom tail light for the cafe racer I'm building. Patience is not a strong-point for me!