T8 motors and RCM motor mount
 

I read on the RCTech forums from user Jhautz that:

"Anyone else notice that the motor mount screw holes in the front of the motor seem to be farther apart than other motors. Not alot different, but enough that I cant get it to sit with the 2 screws aligned top to bottom in an RCM motor mount. It has to be cocked just a bit to fit in and it wont work with the keyholes that are on the motor mount. Not a big deal, just an observation."

He then goes on to measure the spacing between the mounting holes and it is 25.8mm center to center.

Has anyone else tried mounting a T8 motor on an RCM mount? Is this going to be a problem?

No because as jeff says you can just clock the motor - I estimate about 14 deg

We've had no fitment issues with the RCM mount.

Alright, sounds good. Just wanted to be sure. Thanks.

I'm with Randy - mine screwed right in with no fitment issues at all. :)

The screws on my T8 motor are farther apart than the slots in the motor mount. I have to kinda turn the motor a bit to get it to fit. It fits, its just that the screws cant be perfectly vertical. I'm not crazy. The motor screws are 25.8mm center to center on my motor. Most motors Ive seen are either 1inch(25.4mm) or 25mm.

Don't anyone freak out about this though. It works fine. Its just a bit off. An observation as I was installing it for the first time.

What made tekin decide to change the whole spacing away from standard?

I think they don't want. For me it is a production error.

The spacing is 25.4mm or 1 inch on my 1700Kv truggy motor. My motor mounts have 25mm spacing, but use 3.3mm slots to accomodate 25mm or 25.4mm spacing. I was able to insert and remove the motor (with screws attached) through the back of my RC8T motor mount with no trouble. I wonder if both m3 sets of screw holes on your motor have the same spacing Jeff? There are 3 sets of holes(both of my m3 holes have the same spacing, but I haven't measured the m4 spacing).

Yes. Both sets of 3mm holes are the same as far as I can tell. I didn't measure both sets, but neither set works well on the "keyholes" on the motor mount. I have to let the screws hang way out and force it thru to get it to work. I tried both sets of 3mm holes and both "fit" the same so I'm just assuming they measure the same.

If you want I can pull it out tonight and measure the other set, but I think its the same.

Not necessary, Jeff. Just curious is all. The truggy motor I have worked perfectly fine and I didn't bother to measure until this morning as I was posting. I was just curious to know if Tekin intentionally had 2 different hole spacings to accomodate other applications. 25.8mm spacing seems odd to me, so I was trying to work out an explanation in my own feeble mind. I would speculate that 1 inch is the intended hole spacing(most are 25mm, but 1 inch is close enough). :)

We are looking into this matter. The motor screws should be 1" or 25.4mm spaced which is the standard.

I just got my RCM mount and I'm running into this same problem.

I also have a RCM brake spacer that I can't use since the spacing is different. I'm taking pictures now and will post them up.

Ok, here are the pictures: (they are big so I thought I'd link them)

3mm Spacing

4mm Spacing

Brake Spacer

RCM Mount with 3mm holes

I'm thinking that a possible solution for me would be to take the RCM brake spacer out to the shop and drill out two of the holes to fit 4mm screws. The 4mm spacing looks a lot more promising on the motor than the 3mm spacing. If I can fit the 4mm modded brake spacer on the motor then I can use the tapped screws on the brake spacer to mount to the motor mount.

well i finally got my system (last time i preorder anything from impakt rc)

and the spacing on my motor is off too

can i just tap them to 4mm and be done with it or will that void my warrenty?

There should be 4mm holes already in the motors front endbell.