I would never run a vented motor can. Doesn't make sense for offroad, as the dirt has lots of magnetic particles in it, once they enter the motor, they will never leave on their own. Even in the brushed days I would seal off my motor holes with heat sinks and put a dust filter over the end.

If you don't vent , you can get condensation inside the motor and the water short's the sensor....
The rotor spinning inside causes a vortex like you see coming off a wing on a aircraft ...
That's where the water comes from ....



The Old lrp x11 motors were really bad with this problem ..

Personally I can not recommend to anyone buying a brushless that does not have a vented can ...

I agree, vented cans have no place in offroad :nod:

I have quite a few brushless motors, and have yet to have an issue from condensation inside the can.

This mystery Contrail leaving rotor phenomenon would be a lot more believable if it was a jet engine leaving water vapor for exhaust, which is why those appear, lmao.

A bullet flying through the air doesn't leave a contrail behind, and neither does a rotor going far slower :rolleyes:

Jet engines leave jet exhaust, which may or may not cause condensation trails, depending on atmospheric conditions. It's usually vortices cause by the passage of the airframe that they're attached to! Click here to learn about contrails.

Supersonic rilfe bullets shot through high humidity air will also leave a contrail! 20+ years of competative military shooting, seen it on the 600+yard rifle line thousands of times! Very cool. If you're positioned above and behind the shooter and the sun is just right and know where to look, out past about 400yards you can see a flash of copper as the bullet reaches the top of the arc of it's flight, too! :nod:

Back on topic, wether vented or not, pretty much everyone is making vented cans, now, wether it's engineering necessity or to simply save materials. Sooner or later, they're all going to be vented. Those that aren't have lasted just fine, as well.

Bottom line, vented or not, open it up and clean it!

you gotta back up those principles with real world evidence.

the rotor does not have fins on it, it is a smooth shaft. you will not get any amount of appreciable condensation build up in the motor as even sealed non vented motors are not air tight. the heat from the motor running would evaporate any moisture build up. higher pressure caused by expanding air would release through the many opens in the can such as the motor mount holes.

and what's up with the ellipsis? cant finish your sentence?

Enough nonsense from everyone trying to prove they know science better!

Bottom line is:

Brushless has made us all lazy...some racers may remember the days of replacing brushes and truing your comm after every race day (and some of the crazy nuts were replacing brushes after every RACE)

Cleaning your motor once every month or so will go a long way to making it last just that much longer. They make them pretty easy to take apart for a reason....no odd Torx or Roberson screw heads....just standard hexes that you already use everywhere else in the hobby...

i dont know how much more or less a ball diff slips vs this slipper, but looking at how it's laid out, the slipper assembly can be easily converted into a center ball diff.

all one would need to do is drill the spur for diff balls.

I can run a X-11 for you even with the low humidity of the summer , open the cover for the sensor and show you drops of water....;)


The problem is much worst in the winter or rainy season in my parts...

Just sharing years of experience ....

Just look at most designs now , they are all vented , Orion , LrpX12, Trinity, ect .....

yes ,your right I can't finish a sentence ever ....:p

Sorry, I was assuming that you would have meant a centre gear diff....since the center diff needs to hold up to more abuse than the front or rear....and both other diffs here are gear....so I would have assumed that would be what you meant....sorry...made and "Ass" out of "u" and "me" (Assume)

That's an interesting thought. Though for it to ACT like a dif, it'd probably have to be run as a two belt system.

Not for sure , but I believe the rotor spin compresses the air inside thus the condensation or water ...

Just like a air compressor....

Eli would like to know how just one trackstar o-ring works out for ya. Eli has been running 2 trackstar o-rings with great success. Eli thanks you in advance:sneaky:.

:weird: The rotor tops out at ~25-30,000 rpm, spinning in place. The surface of the rotor is moving a whopping ~50 mph. It isn't sailing through saturated air at near sonic speeds. All that small amount of air does is expand from heat, but the bearings and opening for the wire connections are not air tight.

You explain how the water gets inside then , O please ....:nod:


think the issue is mostly when running indoors with a wet clay track , the humidity usually is very high indoors on those tracks ...

My main point is when you guys say
a unventilated can
is preferred , I would not agree & I gave my reasons why ....

2 ways. One, he said the wire connectors are not air tight...thus they are not Water Vapor tight either. Air contains water vapor. Second, the motor, if it was completely air tight, is not made in a vacuum. Thus there is already air, with water vapor, inside when it's built/rebuilt.

Not making an argument for either style, just answering your question.

As for how it condenses inside the can...I'm willing to bet that it has more to do with the cooling of the motor after a run then while it is actually operating. If you're running in a high humidity environment there will be more water vapor in the air. As you run your motor the temperature of the motor increases until it is (hopefully) in the mid 150 range. When you're done running, the motor will cool off as now the ambiant air temp is only 70-90 degrees. The water vapor inside may condense on the inside of the can just like it does on the outside of a glass with a cold beverage in it. Since no electricity is moving through the motor the water won't bother it.

Like I told my son, water and electronic devices are fine together, its water and ELECTRICITY that don't play well. Remove either from the electronic device in question and you don't have an issue.