Loose front bearing slot on Neu motor - RC-Monster Forums

The Dan · **Loose front bearing slot on Neu motor -** 10.14.2009, 03:05 AM

My Neu 1512/2.5D/Q had been running poorly and loudly in my RC8 for a little while. A few weeks ago, I took it out to have a look, and apparently there is a fraction of a gap between the outer edge of the front bearing and the motor can. Has anyone else experienced this happening to their Neu motor? If there's a way for me to fix it on my own, I want to know. I've become less interested in 1/8th scale lately, so I'm not entirely willing to send the motor back to Steve for some costly repairs, if they even exist.

What's_nitro? · 10.14.2009, 03:11 AM

Aluminum foil? Teflon tape? CA glue?

BP-Revo · 10.14.2009, 03:36 AM

Yeah, I'd say just do something like line the edges with some Silicone Sealant just to prevent the bearing from banging around (which would cause more problems beside enlarging the hole).

himalaya · 10.15.2009, 12:26 AM

Replace the bearing and apply threadlock when installing the new one. If the gap is larger than 0.1~0.2mm, you can eigher fill the gap with metal foil and glue, or machine the front endbell to make it suitable for a larger bearing like 5x14 or 5x16mm.

The Dan · 10.16.2009, 01:18 AM

I tested the motor again without doing anything to remedy the bearing problem, and holy crap did it sound bad. Far worse than before, even! It wasn't as fast, either. It's honestly baffling to me as to what may have caused this; I never recall the motor climbing over the 160dF mark. I'd always had the front screw holes sealed with electrical tape, and I'd never opened the motor.

Since I wasn't worried about salvaging it, I decided to glue both bearings into their slots to see if that would help at all. The glued made a strong bond and eliminated the play altogether. But the motor ran no better than before. This time, I opened it up from the back and took a look inside. Nothing seemed out of the ordinary, except a couple loose metal flakes from where the screws that hold the back on had been drilled out. The glued-in bearings were both as solidly anchored as before.

So I guess we can wrap this up by saying:
-Sorry the motor turned out bad, otherwise you would have gotten a good deal, superek4.
-Next motor I'm gunna get will be the MMM 2200.

othello · 06:59 AM

>It's honestly baffling to me as to what may have caused this

I had the same issue with my Neu 1515. Reason beeing a crappy motor mount. If you can push the rear of your motor somewhat to the side with your fingers while beeing mounted than chances are good that due to shocks while driving the motor shaft changes alignment to the spur and the pinion is pressed against the spur which over time results in a gap where the front bearing sits.

Did you have to change the spur and/or pinion oftenly due to wear? Did your pinion often came loose? Those are signs that the motor is able to flex when mounted.

A stronger motor mount remedies those issues. Maybe you are able to support the rear of your motor too.

I changed the front bearing, wrapped the new one with alu foil and glued it back into the can. Doesn't sound like a new one and i can feel some slight vibrations (rotor has some scratches from dust and is not perfectly balanced any more) but it still does its job.

The Dan · 10.16.2009, 02:28 PM

Quote:

Originally Posted by othello

I had the same issue with my Neu 1515. Reason beeing a crappy motor mount. If you can push the rear of your motor somewhat to the side with your fingers while beeing mounted than chances are good that due to shocks while driving the motor shaft changes alignment to the spur and the pinion is pressed against the spur which over time results in a gap where the front bearing sits.

Did you have to change the spur and/or pinion oftenly due to wear? Did your pinion often came loose? Those are signs that the motor is able to flex when mounted.

A stronger motor mount remedies those issues. Maybe you are able to support the rear of your motor too.

I changed the front bearing, wrapped the new one with alu foil and glued it back into the can. Doesn't sound like a new one and i can feel some slight vibrations (rotor has some scratches from dust and is not perfectly balanced any more) but it still does its job.

The motor is a Q-can design, with the mounts machined into the can to anchor it to the chassis. I always ran it in vehicles converted with Tekno kits, so it was always ran with the four screws holding it very solidly to the chassis plate. Those vehicles included a Losi 8ight, 8ight-T, and Associated RC8. But the thing is, Tekno thought of the chassis flex/motor mesh problem when they were designing the kits, because they all included very rigid center-diff braces that span the gap between the CD and the motor mounts. There is no flex whatsoever between that gap. Maybe it's just the nature of having to span the gap in the first place... it is a distance of about 2cm from the front of the motor to the spur, to allow the use of their clutch system. I always ran long-shank pinions though.

The Dan · 11.01.2009, 10:51 PM

Just for the record, I'd like to end this thread by saying that the motor was officially dead.

My friend took it apart and inspected the windings, and found a deep-rooted kink in a wire. He can't fix it, the motor's trash.

Time for a MMM!