Bent electric motor shafts

Bricks

Master member
Merv noticed I had put up a post that on some of my cheaper electric outrunner motors I have bent the shaft and could not find replacements. In a PM Merv was going to tell me how to make my own but then he came up with the bright idea.. I would put up a post so the entire community would get a chance to learn how to make there own and get more input from the group.

So here it is Merv have at it as I have several motors from 3MM shafts to 5MM
 

DamoRC

Elite member
Mentor
Looking forward to this one. I saw a vid somewhere where a guy used a block of metal with a hole in it and the shaft mounted in a drill chuck to straighten a shaft.

DamoRC
 

Hai-Lee

Old and Bold RC PILOT
We have one club member who buys drill bits of the correct diameter and cuts and grinds them to suit the damaged motor. That works for him.

There are many other sources of suitable diameter round stock but the rigidity varies considerably. You can also modify an available spare motor shaft for a different motor to suit as long as you make sure that the new motor shaft is long enough and has a channel for the circlip if needed.

Just what works here!

Have fun!
 

Merv

Site Moderator
Staff member
Finding the correct size of stock materials is the most difficult part of the process. I have had success using music wire, nails and suitable stock from eBay. I have found these 3.17 mm shafts . I just received some today they’re look like they will work fine. All you will need to do is grind or file a flat spot for the motor bell to engage
.

I also used this stainless steel stock, it comes in 3, 4, 5, 6 & 8 mm. With this material, you will need to grind a slot for the clip. I chuck it in a drill and use a Dremel with the cheap cut off wheel to cut a slot. Don’t use the heavy duty wheel, it’s too thick. Be sure to wear safety glasses. Secure the drill, spin it up and with a steady hand cut the slot. On my first few attempts I cut the grove too deep. Just cut it off and try again. The Dremel also work great to grind the flat. The setup takes longer than the process, I will make several at one time.

For me this is a quick and easy way to breath new life into a motor. Like anything else it will be awkward at first but will become easier the more you do it You might want to order some extra E-Clips also.
 
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Merv

Site Moderator
Staff member
a guy used a block of metal with a hole in it and the shaft mounted in a drill chuck to straighten a shaft.
I have also successful used this technique to straighten a bent shaft. The straighted shaft will be weaker and bend easier. For me it is just quicker to make a new shaft.
 
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Merv

Site Moderator
Staff member
Great idea Merv chucking the shaft and us dremel disc to cut the E-clip groove
It works great, you do need to use the thinner 409 disk. Not the heavy duty 420. Be sure to wear safety glasses as the 409’s are very fragile.

I received my E-clips, the 3mm clip works on the 3.17mm shaft & 3.5mm works on the 4mm shaft.