Need help keeping motor from moving...
 

Hi guys. I had major issues with my MBX6 conversion today. In two different heats, the motor moved away from the spur enough to not make contact and I had to abort the run. I managed to get one good run, then it moved during the warm up lap for the main and I had a DNF.

I am running a Medusa motor with Mike's Mugen mount. When I had my 777 with the RCPD mount, I never had a motor move. I have tried blue loctite on the screws and that didn't help much either. It is always my top screw working loose and then the motor pivots away. I am wondering if there is a screw with serrations or a lock washer I can get into the groove of Mike's mount. I actually liked the RCPD mount in that the whole face was flat and I could use different headed screws. It seems like Mike's is made for cap heads only.

Please help me as I want to finish a race!!!:tongue:

Use a star washer behind the head of the screw. With that you should never have an issue!

If not, you can also use a lock washer in addition to blue loctite.

Star washer? Never heard that term before.

Star washer:
http://www.circlipindia.com/star-washer.html
http://www.circlipindia.com/images/star_washer.gif

Lock washer:
http://img.alibaba.com/photo/5049974...ock_Washer.jpg

Thanks for the examples George, lot easier than explaining

Are you using cap-had screws now? :neutral: Honestly, you are #1 that I have heard of with this problem. Maybe the threads in that particular hole are worn out(?). Try rotating the motor to the next set and see if you still have a problem. I do find it hard to believe threadlock didn't help. Did you let it cure before the run?

Yes I let it cure and I am using cap heads. I bought brand new screws just becuase it was a new build. The problem with the Medusa cans is the holes are closer together if I rotate the can and they will not line up. I could do that with a Neu, but not a Medusa.

I may have to go back to my Neu to see if that does the same thing. I tried this Medusa just to see how it compared to my Neu plus it was more efficient than the 1512/2D I was running.

I never had problems with my screws loosening. But for added insurance, I use lockwasher with blue loctite to ensure they don't loosen up.

In the two 50mm Medusas I have, there are two sets of mounting holes; the typical 25mm spacing, and a set that are narrower-spaced.

Have you tried the RED threadlock??? :oh: Make sure the socket is in good shape on the screw or you might not get it out.

I would advice against using red locktite . It will stick very very well & make it tough if not impossible get the screw back out . If you do this & the screw wont come out . ?Take your soldering iron put it the highest setting & touch the screw for a minute or so . you should know be able to back the screw out .

You mean something like this? The block on the motor mount has a 4mm screw that is used to hold the motor from moving away from the spur. It worked great, but once I moved up to a better motor (Neu which allowed me to tighten the motor mount screws tight enough to prevent the motor from moving( I no longer needed it. The Feigao's use softer aluminum and you couldn't really tighten the screws to much without fear of stripping them out.

http://i142.photobucket.com/albums/r...3/DSC00338.jpg

out of 10 medusas ive seen run, 9 of them had thread problems. the aluminum/taps they use are crap. i usually just tap them to a bigger size right away, i have 6/32's in the motor im running now, and they loosen up after a race, not to bad tho

That's very interesting- that it could be a design flaw with the Medusa motors. :neutral: If so, I hope it's fixed soon because I have been looking into their motors.

Shark413, I can't see your picture here at work, stupid filters :cry:

big greg, I had thought about tapping the hole to a bigger size, but then I would have to modify the RC-M mount. It seems like Mike made the mount for the smaller size and Neu motors, especially since there is a channel for the cap head to sit in and the screw slots are not the right diameter. I'd hate to hack up the mount for one motor. Maybe I will buy another mount to play around with.

My 80mm Medusa was flopping around after a roll over the last time I had it out.
No stripped threads that I can tell?
Just hand threading the screw into the motor about three threads, I noticed that the screw would wobble a little in the the hole like it was too small of a screw?
My Medusa had a noob warning sticker on the box about using the right length and size screws. Something like no less than 3mm, no more than 5mm of screw into the motor.

Bruce,

That is exactly how mine feels.

Mr. Pumpkinfish
I read the box sticker again to day at lunch, It said to use a 3mm screws and a minimum diameter of 2.MM?
I'm going to look for better fitting screws tonight.
With my 80mm, I feel there is a lot of weight hanging on the top screw working itself loose with every bump. And a 36mm dia motor compared to a 43mm dia, the motor weight has more leverage working against the threads IMO at least.

Bruce750i

Ps I was using mine in the E-revo

if you go with a standard 6/32, you can shave the inside just a little and it will fit, i had to do this

Seems like Mike should be making a motor adapter plate about now... :whistle:

I hope that is a thinly veiled hint:wink:

I have always thought that these motors should have some sort of support opposite the mount side. Even my Neu in my Kyosho 777 always had me worried. It never moved, but I alwyas check it. Is there any place I can buy one of those "ring clamps" and drill a hole in my chassis to mount it?

The Neu motors have a much thicker front plate, something like 4-5mm. The Feigao motors do too. It seems like the Medusa motors are 3mm, or less, judging by the nature of the problem. My Lehner XLs also have a thin front plate, but they are smaller, lighter motors.

Those are 36mm motors, right? You can try these mounts. You would want the "05" size.