Holmes BL overheating??

[Turtlejon]

I'm getting up to 180 pretty quickly with my wraith. It has a 3s, MMP, Holmes brushless sensored 3100 kv motor, 10t pinion, 56 t spur, all metal trans gears, mip shafts, od/hd diffs, 2.2 slw wheels, swamper xl. The bearings all feel smooth, everything is well greased or oiled. Its a pretty heavy truck. It's a very rough, steep, rocky climb. Pretty sunny, 83* out. After about 20 minutes, I have to stop for 15 or so to let it cool.

Is this normal? I've already reduced pinion from 14 to 12 to 10. I don't even think 8 will fit, nor will a 58 fit under the spur cover. I was hoping to go for hours and hours on long walks through the desert...

[maslin]

My brand new BL Pro geared 60/13 got hot today too, only the second time I've run it. Hot enough that I could smell it from 10 feet away.

Around 50* outside, crawling around for 45 minutes or so.

[new2rocks]

I haven't run a BL in my Wraith yet, but I'm not shocked given the rest of your setup. My ROC 412 3100 on 3s overheated running 12/56 when I switched from RB XORs to RB 2s, which aren't quite as tall as the XLs. I now run the RB 2s at 9-10t with no problems. Since you're running a slightly taller tire, I'd suggest dropping down to 9t to see if that helps. Also, if you're running OD ring/pinion in the front axle, try switching to HD stock ratio in front and UD in rear. As a last resort, you could try a shorter tire. The RB XORs are excellent (I switched them to a different rig and still love them). I hope that helps. Good luck!

[maslin]

Seems like most people throw around 56/12 56/14 ish on the roc412 and pro4. I wish I had known you can't actually run them at that gearing.

I had a 4600kv geared 64/11, pulled 20mph and never got hot.

Doing some math... 4600kv at 5.8:1 runs 20mph. 3100kv at 4.6:1 should run 17mph? GPS has it at about 9.

It crawls great, but I don't seem to be getting half the rpm's? And running hot. Something is up.

[new2rocks]

Are you guys running 2s or 3s?

[maslin]

3s.

[new2rocks]

If you were topping out at 7 mph with that setup before the motor got very hot, I would think something is wrong. (If you didn't notice the top end issue until after the motor got hot, there may be damage from overheating.) For reference, I'm probably somewhere in the mid-teens with 9t or 10t, a 56t spur on 3s, stock front and UD rear, and RB 2s. If it's not one of the usual suspects (re-binding the ESC, checking ESC settings, checking radio endpoints, etc.), I'd suggest reaching out to Jonathan at Holmes for his thoughts. I've found him to be very helpful.

(That's a long way of saying I'm out of ideas...sorry...)





Good luck and let us know what you guys are able to figure out. I'm curious to hear before I install my BL in a rig.

[Turtlejon]

Anyone know specifically what is the smallest pinion that will fit?
Maybe I'll switch to UD in the rear, and try smaller tires... I was really hoping the trailmaster BL would be stout enough not to overheat so quickly...

[Eric0424]

You've got something binding, you're getting too hot way too fast and the XL tires (5.8") are not that much bigger than the stock 5.5" Ripsaw. Double check your spur/pinion gear mesh and make sure everything in the transmission is spinning freely. Some of the trans cases have been known to bind with the screws tightened too much.

RC How To | Set Your Gear Mesh for Spur and Pinion | RCCOH

Maybe remove some of the grease as too much can be a problem.

Check the wheels to see if they're hitting or rubbing on something/anything.

[Turtlejon]

Thanks for the advice! It all "seems" to run very easily and smooth, but I'll go check all those things. I did hear some squeakines, maybe I'll try some new bearings too.