Keep losing gear mesh!

[Biomedchad]

Hey guys got a question. I'm running a puller pro 4 3300. Robinson racing slipper and 12t pinion on my bomber. I also am using an strc aluminum motor mount. I keep losing me mesh. The motor keeps pulling away from the slipper. I've loctited and re loctited and it still is happening. Could the strc plate be off just a hair and allowing this to happen? I have the screws tight as I can. I'm in the process of cleaning the screws and trying again but I'm at a loss besides ordering the axial plate and getting a little better machining maybe?

[mikebecher]

I don't think it would have anything to do with the plate itself but you're on the right track cleaning the screws. I would also suggest:

• Clean the screw holes on the motor with a q-tip and some rubbing alcohol
• Run your screws down without the plate to make sure they are going in far enough
• Let your loctite cure overnight
• Add some internal tooth lock washers to help bite into the plate

[Natedog]

X2, but I've always used just some good quality thick (preferably hardened) steel flat washers under the motor screws. Even on my Slash with Mamba Monster 2200kv and 3S or 4S motor always stayed put with a touch of Blue Loctite.

[Soldat Vaillant]

Lunsford has titanium motor screws with large heads for more contact/clamping surface area. but also look for pitting on the motor plate around where the screw make contact, if the plate is damaged a new one would probably help more than new screws or washers. so far I haven't needed a drop of thread locker on any of my brushless cars and trucks, but it's cheap insurance so I recommend using it anyway

Lunsford Racing: Short Fat Boy Titanium Motor Screws

Lunsford Racing: 3 x 7mm Titanium Brushless Motor Screws

[GLHS592]

I had this same issue the other day. I am also running the STRC motor plate and a Holmes brushless motor. I expected to see loose screws when I took things apart. My screws were still very tight. I'm thinking maybe the round part, that the motor is screwed to, is a tad too small and vibration caused it to rotate. Do you think a thin metal shim would help this issue?

[rcmaineiac]

I also had trouble keeping a good mesh in my Yeti rtr (stock motor) after installing the strc motor mount. It looked like the motor torque rotated the motor making my mesh very tight. I loctited the screws and alternately tighten them, so far this seems to be working. If I do have any more trouble with it I'll try a shim next.
My issue with the mesh now is that my spur gear doesn't seem to be running true. I back the motor off so that the pinion lightly touches the spur, then turning the rear axle by hand I watch the spur turn. The pinion lightly touching the spur at one point, then missing each other by about 1mm as the spur rotates about halfway around. Not sure if my spur is out of round or the bushing it rides on, so I ordered the RRP Gen 3 unit with a steel spur and an actual bearing for it to ride on. Hope this will solve the issue, will post when I get it installed.

[Soldat Vaillant]

You'll have to disregard my previous recommendation, the Bomber has a cam-adjust clamping motor mount and I'm guessing the motor plate is turning in the mount. The STRC motor mount set may be part of the problem, some of their parts are not made from the strongest aluminum.

Yes, a shim between the clamp and motor plate might help. You could also try a couple of drops of thread locker on the plate where it makes contact with the upper camp and lower mount. Make sure to give the thread locker time to dry before driving. Or you could try filing the lower mount right where the screw holes are a little so the upper clamp can clamp the motor plate a little tighter.

Axial has an upgraded motor mount set (AX31156) that may be better at holding the motor still.

[rcmaineiac]

Got the Gen3 unit installed, really liking it so far. Runs a lot quieter than I thought a steel spur gear would.

[High Angle Five]

I've found out the hard way that more speed equals more loose screws

[meatmonkey]

I'm running the strc mount in a bomber with holmes budget 330p on 3s without issue. That said, I'd heard of people having issues maintaining mesh with the strc mount before I bought mine, so I proactively filed the coating off of the underside of one side (only the little square section where the bolt goes through, not half of the semi-circle) of the upper piece that holds the motor cam in place. This allows a smidge more clamping force. Seems to work for me. It's been almost a year and I've broken lots of parts, smashed into plenty of immovable objects, and never had the mesh change. I was paranoid when I first put it together, so I paint-marked the cam to the plate. It hasn't budged.

I'm curious as to if this technique solves others issues? Figure its worth a try.

[Scttduk]

meatmonkey - your idea of filing part of the motor mount to get better clamping force sounds like something worth trying.
I run a 1/18 and just upsized the motor but was having issues keeping the pinion mesh correct. It would start out ok, but with just a few minutes of running I'd get a grinding sound (teeth slipping I'm guessing).
Thanks for the idea.

[JatoTheRipper]

I don't think you're the first to have issues like this with the STRC motor mount. This is why I bought the OEM Axial motor mount despite the price. When things are critical, the OEM parts have better tolerances.

[mikemcE]

Originally Posted by meatmonkey

I'm running the strc mount in a bomber with holmes budget 330p on 3s without issue. That said, I'd heard of people having issues maintaining mesh with the strc mount before I bought mine, so I proactively filed the coating off of the underside of one side (only the little square section where the bolt goes through, not half of the semi-circle) of the upper piece that holds the motor cam in place. This allows a smidge more clamping force. Seems to work for me. It's been almost a year and I've broken lots of parts, smashed into plenty of immovable objects, and never had the mesh change. I was paranoid when I first put it together, so I paint-marked the cam to the plate. It hasn't budged.

I'm curious as to if this technique solves others issues? Figure its worth a try.

I had the issue, when I dropped in the Tekin 4x4HD, but my pinion mesh got tighter..... every time, I took a tool stone to the flats on mine and never had the issue again. These are cnc'd and then anodized. I think the tolerance was lost.


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