cut a flat spot in shaft for the pinion set screw?
 

i didnt make a flat spot on my neu 1515 and seems to be working. am I supposed to ?

No, but I would.

i see some of the NEU NEU motors have a flat on them? makes me think it is needed.
running on a dirt track so not much traction .

It's not completely necessary, and usually some locktite on the grubscrew will suffice. If it ever starts to slip, use a dremel or file to make a flat spot for the grub screw.

J.

I agree - I would start with no but be prepared to...

That was my route...

I agree with all the above. :mdr:

If works fine, good, you don't have to yet. But as others said, you may need to later. Me personally, I start with the flat spot

My Neu came with a flat on the shaft but I usually make one anyways. Some say it isn't necessary but I'd rather just do it and KNOW I wont have a problem down the road.

I must be doing something wrong then because even with blue lock-tite on the screw and torqueing it down (and I'm not a weak guy), the pinion started to slip in about 10 minutes. This was on a steel spur/hardened pinion setup so that may have something to do with it.

I would just grind the flat spot. It won't hurt anything to do it, and will prevent you from having to unmount it again later if you decide you need it.

If you're planning on racing, I would do it. You would hate to lose a race because of the pinion slipping or coming loose. I just put one on my new NEU last night. It had a flat spot already but wan't where I needed it.

I like it when the motors don't come with a flat spot so i can make on myself. That way i know it is not to big and is exactly where i need it. The more flat spots the weaker the shaft.

I agree. I like a nice quaint little flat spot. When the manufacturers do it, it seems they lop of 20% of the shaft.

With my 9L on a rustler I have the opposite problem, I can't get the pinion off, but unless I fry the motor I don't see a need to remove it, if anybody has any secrets I am all ears.....

pinion puller...

Heat just the pinion up a bit, it'll come off. Either that, or use a small gear puller :whistle: