Motor Shaft: Grind Yes or No?
 

I'd like opinions on whether it's better to grind a flat (or divit) for the setscrew, or leave it round?

Also do most of you use Loctite on the pinion setscrew? If so, then do you use blue or red?

Blue is temporary, red is semi-permanent and green is permanent, so I assume green is a no-no.

Appreciate your input.

If my motors don't have a flat spot, I grind one on. I use blue loctite on my set screws. With red loctite, you will have to always heat it up to get you set screw loose to remove your pinion. If you do have a solid set up and don't plan on changing anything then red might be ok, but I don't really recommend it as blue is strong enough.

Agree
 

Like Lutach stated the flat spot is a must. It is an improvement that will not hurt the motor. I also agree with the blue loctite as you never know weather or not you will be switching pinion gears or not.

I left a few things out of my first post.

I am running a 9XL with an RCM pinion, setscrew out. To get full mesh the setscrew is out as far as I can go. In other words I can't grind it, the setscrew will be on the edge of forcing the pinion off, so in my case I'm hoping there is enough bite without grinding it, only using Loctite.

It makes sense for balance reasons to do it, usually there is extra setscrew length that will be compensated for by removing some shaft material.

And what are your methods?

I'm pretty good with a dremel, but for some reason I can never do it cleanly on a motor shaft, even with the shaft held steady.

The cleanest way is using a surface grinder, but most people don't have access.

So what are your various tricks for doing it- cutoff wheel, round stone, etc.?

I didnt extend my flat spot on my Neu 2.5d and did use blue loctite and it has been running fine hasnt slipped on me

I've got several Neu motors with no flat spots at all and the all work for me.. Blue loctite is a must though..

Rather than grind a whole flat edge on your shaft tighten down your set screw then undo remove pinion and do a small grind right on the mark you just made.
If you are not going to grind here is a trick I use use blue locktight tighten down setsrew loosen a turn then retighten the first tightening makes a mark the second tighten lets it bite into the make and then it wont slip.

???
 

Of course without seeing your setup it is hard to figure, but is there room for you to flip the pinion the other way, and will it still mesh with the spur gear?? I have seen that on some setups.

My S600 motors on my Emaxx are in same situation, caused by motor shaft being shorter than the Titans they are replacing. I was concerned like you that pinion would come off after running a while. I am barely on the edge of the shaft and use a flat spot and blue loctite. About 2 dozen runs later, nothing has come off and I've stopped worrying about it.

I use motor spray to clean both set screw and the set screw hole before applying blue loctite. Any trace of oil on either - loctite will either not set at all or only develop part of its full strength. Also have to give it some time to set.

I always grind the shaft, and never use loctite. I have never had a pinion come off...so far!

My Neu 2.5D come with a little flat spot in the middle of the shaft. I ended up using a dremel and made the rest of the shaft flat (didn't take long at all). I then mounted the motor and realised that the spot that come with a flat spot is where the set screw went anyway :rofl:

I have only had one come off which is when there was no flat shaft. If you got a dremel it takes all of 3 minutes to do.

I locktite "everything", my wife thinks I have stock in loctite.....:lol:

Here is a homemade jig for making factory quality flatspots

thats a nice idea...are the square pice of metal you have wielded to each piece of angle iron used to keep the shaft straight?