Replacing Bent Shafts

by Mike_spain | December 21, 2012 | (17) Posted in Tips

How many motors do you have laying around that can't be used because of a bent shaft?

I had a couple of motors, and I searched on the internet and didn't find a lot of information about it, so decided to share this photo-tutorial with you :

Replacing Bent Shafts





I have chosen the NTM Propdrive 35-36 1400 kv, as its shaft was bent, and also because it is a very popular motor, like the one in the EPP FPV, check it out if you haven't yet:

http://flitetest.com/articles/epp_fpv


Ok, so lets start with the build.

First of all, you need to get a spare shaft. I got mine from an Industrial hardware provider as a "machined carbon steel" 4mm shaft (they had 100mm long) for 0.80$ As it was too long I had to cut it but you can get the exact same shaft from hobbyking or anywhere else.

In my case, I had to cut the shaft, so I measured mine, wich was like 2.4 inches (61 mm). 


I decided to cut a bit shorter, as longer shafts get bent easily, so time for cutting. It was actually easier to cut than what I thought it would be...


Once you have finished cutting, you need to sand a bit the edge


Now we need to separate the bell and shaft from the motor, to do that, we need to get rid of the little metal lock in the saft, this one


Now both parts simply come appart.


Now we need to unscrew the little allen screw on the bell just like this:


Once removed, we need to separate the shaft from the bell. I would suggest to hold the shaft really tight on your workbench, and simply grab the bell with your fingers, and twist the bell as if you were unscrewing it, while pulling up. Just like this:


When you have separated the shaft, you can notice that the part of the shaft where the screw goes, is like this


So you just sand the same little bit for the screw to fit, like this


Now you need to introduce the new shaft in the bell, paying attention to the shaft position so that the little part that we sanded, matches the screw. To get the shaft in, you can use a little hammer and CAREFULY push it in



Now just screw the little allen screw in



You can now join the two motor parts 


Now, if you are going to mount a normal prop adapter, you are fine. BUT, IF YOU ARE GOING TO USE THE MOTOR WITH  SOMETHING LIKE THIS:


YOU MUST KEEP THE EDGE FROM GOING BACKWARDS WITH A LOCK OR ANYTHING ELSE (like in this HIMAX):



And thats it ! we have finished replacing the shaft !




Thanks for reading ! Hope you enjoyed it

Please rate ! :)


Mike












COMMENTS

Jake Wells on December 23, 2012
Cool man! What camera do you use? My tutorials always suck and I blame my camera. lol
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Mike_spain on December 23, 2012

Hi Jake Wells,
Thanks for your comment !

It turns out photography is my second hobby haha...
For that reason, my camera is a DSLR Camera... The Canon 500D
You need a bit of work to reduce the size of the pics to upload them,
but I think its worhty.
The camera is not that important haha
I have watched your articles and I have enjoyed them very much !
Thank you very much !
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Zach Robinson on December 22, 2012
know what im doing tomorrow with my bent motors
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Crouchy on December 26, 2012
Might seem like a simple process ......and it is, but it takes someone to point out how to do it. Thanks. A very informative tutorial.
Crouchy
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sailorJohn on January 5, 2013
I keep ordering shafts from hobby king but they are never the right size. A digital caliper from harborfreight ( on sale ) is a good investment and you can convert mm to in with the flick of a button.
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Beerpig on December 22, 2012
Interesting.Thanks
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lonewolf7717 on December 22, 2012
Thanks for taking the time to lay out a nice step by step. Just to add one thing cause I sure people will ask, the collar pictured in the HiMax image is made by both Dubro as Dura-Collars and Great Planes as Wheel Collars....can be found in various sizes at LHS and online. If using these especially on a motor, please use a small drop of MEDIUM strength loctite (typically blue depending on brand) on allen set screw. Thanks mike-spain!
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Mike_spain on December 22, 2012
I really appreciate your advice lonewolf7717 !
I agree. It will definately be safer to add a collar, however if you are using a standard collet type prop adapter, it simply works. I have replaced another shaft on one of my planes and works great
Thanks !

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Replacing Bent Shafts