Turning down motor shaft
 

I need to turn down a Neu brushless motor shaft from 8mm to 5mm. I thought it was going to be easy to remove the rotor and do it in a lathe but I can not find out how to remove the rotor. Can has no screws holding end bells. Neu suggested sending motor to them and get rotor changed out. Cost and shipping it from Australia and back is not cheap.

I have thought about running motor up on ESC and using dremmel/file/cutting bit to turn it down but can't find an easy way to do it without using the radio to control the esc.

I have seen brushless motor checkers and speed passion has a system to do it without the radio but both are expensive.

Any ideas out there?

Thanks
Brow

Use the radio, just turn up the throttle trim to run the motor "hands free".

Best advice I've heard on the subject is to put the motor in a sandwich bag and poke the shaft through. Work slowly and measure often.

Thanks Dr, thats a really simple but good idea. I was thinking about it too hard to come up with using trim to free up my hands. The best ideas are most often the simplest.
Now I just need to make up some motor wire extenders so I can do it with a ESC in a car as I don't have any spares and it is too hard to pull a setup out of my cars.
Thanks again
Brow
PS I feel like a doofus not thinking of this.

:-) know where your coming from, just had to be reminded that I could shim up a center diff to help clear a larger motor from the chassis LOL every now and then I find I'm a total noob again. At least the guys here on RCM don't rub it in long :-)

Yeah, we get to know you a bit better before we really let it go on ya!!!

Well, I have been around here a while just not posting much. I don't know nearly as much as some of you on here and normally can't add much but am glad I can get answers every now and then to my problems.
I also keep up with all the friendly comments thrown around.
It is actually the motor I got off you, Linc, that needs turning down. Part of one of my long term projects.

From what I have seen around here, I think I can hold my own when you do "really let it go on ya!!!" lol

Thanks guys and girls.

You could use a servo tester connected to the ESC to control the speed of the motor. But if you can get it working with the throttle trim on the radio, that's free!

Along with the plastic bag over the motor, maybe cut a piece of cardboard into a circle, and poke the shaft through it. It will spin with the shaft and be an extra shield for keeping metal filings out of the rotor bearing. And after you are done turning it down, don't forget to grind a flat on the shaft for the pinion set screw.

Just looked and servo testers are a bit much so I now have a plan to get it done and hopefully get no crap in the motor or bearings.
Not sure when this will happen but thanks for all the tips.
I might even remember to take pictures to show how I end up doing it.

They have a few models of servo tester at HobbyCity for $5-10, but if you don't think you'd ever use it again probably better off just using throttle trim. The shipping would cost more than the servo tester. Maybe if you planned on placing an order there for some lipos it would be worth throwing one in.

I did a writeup somewhere on her of how I tured a 6mm 1717 motor shaft down to 5mm.

Bacially I clamped the motor in a vise, and then used a drill press with a larger grinding stone (think dremel bit but bigger). I used an esc and radio to spin the motor, then turned on the drill press and manually fed the stone into the shaft.

My reasoning was that the shafts may be hard material, and grinding stone would work better than a file. Plus having everything setup parallel/perpendicular would hopefully produce a better result.

Linc turned down my shaft once:cry: And he claims to have turned down a 1717, but other than that
LINCPIMP NEVER TURNS DOWN A SHAFT.

DESPITE STATING OTHERWISE:tongue:

:rofl:

So what does that say about you Harold? I turned yours down but otherwise never? Yours is that bad huh...

Just for the record I have never seen Harold's shaft, but there is a chance as I have just had an eye test and have a new pair of glasses, so it may be visible now.

Now the truth comes out.

Fixed that for ya. No need for thanks, just what I do.