Adding vents to your motor

[paulwes83]

Hey gang,

Just wondering if some of the more experienced techs or those who know electric motors know can offer some sagely wisdom on adding vents to your motor to help it cool.

I saw this,

http://www.brillarmory.com/index.php...roducts_id=427

and figured I might try it with my SHS motor. I'm trying to keep costs down on my builds and SHS motors are a nice price, but heat up more than I would like.

If one WAS to do this to their motor can, would it cause significant problems? I assume it might attract a bit more dirt inside the can, but since it's housed in the pistol grip and the air would be pushing out of the holes, I imagine it wouldn't be too bad. Also, do think it would affect the integrity of the motor structure and it's interface with the bevel gear?

Thoughts? Comments? Anicdotes about whacky modds?

[RainyEyes]

I'm no expert, but I don't think this would make too much difference in terms of heating. Unless you're running a ridiculous spring, the heat built up is tolerable, even then, the issue lies with the stress and strain put on the motor. If the motor is unusually warm, check for proper shimming or shorts in the gearbox/wiring. Heat generation is contributed more to increased strain on the motor.

As for heat vents, they CAN work, but not so much if you don't have a heat sink base plate that has open vents. For example, standard M4 pistol grips have a base plate that might be fully sealed, causing positive pressure inside (because hot air expands, the air would push out from the motor and stay inside the pistol grip which results in stale air). You want NEGATIVE pressure (air going out) to alleviate the heat. Since there's very little air moving in and out of the pistol grip, there's unfortunately very little you can do other than adding a ventilated base plate to let in fresh air.

[EOD Steve]

It's been done but without as RainyEyes has stated - no benefit without supporting mods.

[paulwes83]

Thanks as always guys. Since gaming ridiculous springs aren't allowed, I guess I'll leave the SHS can as is and work on my shim and soldering game.

TY again

[iKliiu]

The vents on the motor-can shown on BrillArmory aren't even in the right place, the magnets would block those vents. You would want to cut vents on the curved side of the motor can.

[lurkingknight]

tienly motors are vented from factory... to cut the vents you'd have to know where the magnets are, so you'd likely need to take the armature out to see where and how much you can take material from.

It's been stated on other forums (asm) that venting the grip plate with the motor will introduce some nice airflow but some believe that the increased flow will introduce lots of crap/debris into the motor can.

[ThunderCactus]

The magnets rest on the curved part, the vents are in the right spot
Doubt it'll make much difference unless you have a nice fat MOE grip where air can actually flow around.
Couple points though; on a really high end motor, cooling isn't even that critical. The vented grip plate and open end bell should be more than you need on any rifle.
On an LMG you obviously need more cooling, BUT, high end motors can run at very high temperatures without breaking.
I've run my EF1300 on my 249 up to max temp just about every time I take it out. Grip gets right to that heat threshold between hot and burning while wearing gloves.
Motor went 4 years of doing that until the comm got covered in carbon, skimmed the comm, still running fine.
Mind you, motors with stronger magnets will draw more current and generate more heat. High torque (as in 18-24tpa) motors tend to be pretty efficient and not draw a lot. My EF1300 is a ferrite motor with what looks like a 13-14tpa armature, so a bit quick with low torque, and therefore doesn't generate heat very quickly.

FYI you absolutely do not need a lot of torque on an LMG when you're running 26:1 gears.