Author Topic: Another cooling thread (Read 886 times)

Paul Taylor · « **on:** May 12, 2014, 09:38:07 PM »

Ok guys
Help me understand. I only have two E-planes. Both are profiles. First is my old Tutor2 converted. Small collet spinner. Dont think I have cooling issues. As with my other plane the Force seems to had issues with getting air into the front of the motor. Cut a hole in the cheek cowl and will run it with the small collet spinner. Problem should be solved.

I went looking for pictures of other profiles to see if I could see what others did. Did not find any with 2in spinners.

I did find a lot of full fuse planes with full spinners. Question: no air flowing thru the motor, but thru the compartment. Is there cooling issues on full fuse planes too?

I want to be a sponge.
Thanks

Ron Heckler · « **Reply #1 on:** May 12, 2014, 10:32:56 PM »

Hi Paul,

I've had 4 electric profiles planes and never a problem of overheating electronics because everything is on the outside of the plane.

I now fly full body planes and have 2 that I fly constantly. I've learned from other electric flyers that if the opening in the front of the cowl is big enough, and if you put a baffle in it to direct the air coming in to the motor on top and the electronics on the bottom, there are no issues of overheating. The most important thing to remember is that you must have exit holes in the fuselage to let the hot air out. I have a hole in the bottom of the fuse behind the wing and an internal deflector to direct the hot air out that hole. The other thing I do is build the planes without full formers. I use 1/4 square pieces on top and bottom to hold sides together, which means the fuselage is practically hollow. Then I epoxy three pieces of scrap balsa to the top, middle, and bottom where the fuse comes together at the back. When the plane is completed and the rudder is glued on to these pieces, I cut away the center piece. This leaves another open area top and bottom for the hot air to escape flowing through the fuse.
Periodically I check the motor by putting my finger through the baffle, and the motor always feels cool (no pun intended).

I hope this is helpful.

Ron

Dennis Adamisin · « **Reply #2 on:** May 15, 2014, 03:14:02 PM »

For motor cooling there are a couple things in play. Front mounting versus rear mounting gives you different options for cooling air.

If front mounted (good for the motor bearings) you pretty much have to find a way to choke some air through or around the spinner and into a well ventilated motor mount. You can also get secondary air to the outside of the motor by various means, the deflector Ron mentioned is always a good thing.

A rear mounted motor generally allows a somewhat better cooling path from a chin scoop than front mount does. Of course spinner flow is still a good idea.

What does an electric airplane look like? Forget the chin scoop. When designed for motor cooling a radial cowl or Mig-21 style cone within a ring is likley the best motor cooling solution.

I think ESC cooling is more critical, it needs continuous airflow. Pretty easy on a profile, but we need to pay attention when the ESC is internal. I have had 4 installs where I mounted the ESC poking through the fuselage to expose the heat sink through the surface of the fuselage. Three of those also used finned CPU heat sinks thermal-epoxied to the FET array. Those ESCs run REAL cool!

Air outlets are a challenge. My favorite is my Swinger with all open bulkheads so air can flow through the fuselage and out the fake jet exhaust pipes! I have a couple new birds that will use Brodak plastic engine exhoust pipe simiulations, opened up to ventilate from the upper battery box location.

Author Topic: Another cooling thread (Read 886 times)

Paul Taylor

Another cooling thread

Ron Heckler

Re: Another cooling thread

Dennis Adamisin

Re: Another cooling thread