turning down the motor shaft? - RC-Monster Forums

tashpop · **turning down the motor shaft? -** 10.08.2007, 02:25 PM

i have the kb xl brushless motor with the 6mm shaft. i have decided to just have it turned down instead of battling and searching for pinions. does anyone see a problem with getting it done to 3.2mm's so i can get all my gearing locally anytime? stock emaxx gearing is 3.2mm right? i could go with 5mm, but then i'm still ordering on line and i hate waiting, especially on such a small and simple part.

squeeforever · 10.08.2007, 04:47 PM

I would never turn one down to 3.2mm. Go to 5mm and get a small assortment.

10.08.2007, 05:08 PM

I'd agree with turning it down to 5mm. If you go with 3.2mm, it might snap on you.

jhautz · 10.08.2007, 05:24 PM

Quote:

Originally Posted by AAngel

I'd agree with turning it down to 5mm. If you go with 3.2mm, it might snap on you.

I agree. especially with a motor that big. It can put out some massive torque!

tashpop · 10.08.2007, 05:35 PM

i'm kind of thinking the same, but i was looking for convience so i figured i'd ask. i'll try to snap some pics of it pulled apart tonight for you guys. its the first brushless i've seen apart and i noticed there are some voids in the wire windings. i don't know if thats normal or what.

suicideneil · 10.08.2007, 08:07 PM

Get some pics of the rotor/magnet too- it would be nice to know whether it is slotted/segmented/one big magnet etc.

As for pinions- it is always the smallest parts that are the most critical it seems, but Mike is quick with his shipping so you wont be waiting long if you order from him.

MetalMan · 10.08.2007, 08:38 PM

Just out of curiosity, how'd you get the motor apart? Mine doesn't want to come apart, but I want it to (to throw the rotor into a lathe).

MetalMan · 10.08.2007, 11:54 PM

I just finished turning the shaft on my KB-45 10XL. Unfortunately it's a bit far from perfect, but it will work. Since I couldn't get my motor apart to chuck the rotor into a lathe, I tried something else. Bascially, all I did was duct tape the motor to my vice (the vice was open less than the diameter of the motor, so the motor was sitting in the vice). There was duct tape between the motor and the vice, to reduce vibration and keep the motor scratch-free.

Then I spooled up the motor to maybe 20% throttle, and took the Dremel to the shaft with a reinforced cutoff wheel. Once the diameter of the shaft got to the right size, I used 100 and then 400 grit sandpaper to smooth it out. The result is that there are a couple very minor dips in the diameter, but I don't think these will affect performance/strength. But now 5mm bore pinions fit, and now my Savage can hopefully break 70mph :).

tashpop · 08:48 AM

sorry guys, i never got to taking a pic. it is one large magnet. if i can't turn it down to 1/8th inch, i really don't see much of a need to turn down the motor at all. i can easily open the bor of a 5mm pinion to 6mm and just use those. my problem is finding anything 5mm or larger that matches 32p gearing. mike has a 16tooth, but all this work for 20mph doesn't set well for me. i'm still researching my options for changing over to mod 1 gearing which will allow me to find 5mm pinions with the correct gearing that i can drill out to match.

unless somebody on the boards has something around 20+ tooth 32p they can sell me?

tashpop · 10.09.2007, 08:42 AM

Quote:

Originally Posted by MetalMan

Just out of curiosity, how'd you get the motor apart? Mine doesn't want to come apart, but I want it to (to throw the rotor into a lathe).

i was messing around trying to get the motor bolted up to my motor plate and noticed the body turned easily. so i unscrewed it. lucky i guess that its not locked down like yours.