View Full Version : E-Flite "Ascent" Motor Overheating

08-13-2005, 02:04 AM
I just test flew my new E-Flite Ascent motor glider this afternoon, and after landing I discovered the motor was hot... VERY hot! Bumped my finger against it and boy did it hurt! Could smell something like burning wiring also, but all else seems to be in order.

I broke the motor in last night, and all seemed fine. At the LHS owner's suggestion (based on about 4 other folks in my area doing exactly the same thing to reduce power consumption while increasing climb rate and run times) I switched to smaller Graupner 6-3 blades instead of the stock ones. Also I'm running a 3S 1800mAh Li-Po pack, just like everyone else locally is running, and they have all had excellent results with this setup.

The only thing I can personally think of is the stock spinner is a piece of crap. The outer cone actually flares out nearly 1/4" at full speed, which causes a good bit of vibration. I contacted my LHS and they are out of the good Graupner hubs/spinners until next week, and suggested I go ahead and fly it as-is (the other locals with this airplane are still flying the stock hub/spinner) until the Graupner units come in.

Has anyone else had an overheating problem with their Ascent motor? Can the vibration from that crappy spinner cause enough friction in the motor to make it overheat that bad? And yes, the cooling air ducts are all open and unobstructed...

Any thoughts, comments, suggestions, or casual observations are welcomed!

08-23-2005, 02:29 PM
There is very little incoming ventilation of the motor.

I took the spinner off to replace the stock blades with Graupner 6x3 folders and drilled 4 inlet holes in the "firewall" just outside the motor. They stick out a bit from the sides of the spinner to suck in air along the sides of the motor.

I do not have the expanding/wobbling problem with the spinner; perhaps yours was a bad QualityControl problem. Just replace it.

Also, 3S might be just too much for the motor (you're pushing 11volts into motor spec'ed for 8!!).... I'm running a 2S 1500mah lipo and it climbs just fine on 1/2 to 3/4 power with no lift flights of 1/2hour.

Jason T
08-23-2005, 05:46 PM

Welcome to Wattflyer!


08-26-2005, 03:27 AM
I just converted my Ascent to the BP12 outrunner with an 8-4 rigid prop and a 2cell 1200mah lipo battery. All from Balsa Products. I got to test it this weekend. I got three flying sessions and had battery left. I was also able to take an ounce of weight out of the tail by getting rid of the speed400 and nicads. Didn't need any more nose weight to balance. You are probably putting too much voltage on the motor and not enough air. If you are running it up and looking for lift, the motor shouldn't run long enough to get hot. I have to look for a folding prop to streamline it better. With a fresh battery I was able to get a really strong climb at full throttle and a good climb rate at half th. The Ascent stock prop has way too much pitch and will get the motor hot while it struggles to climb.

Jason T
08-26-2005, 03:45 AM

Welcome to Wattflyer!


08-29-2005, 09:12 PM
I have to agree with the earlier post- unless things have changed, the stock motor is a 6V speed 400 (at least that's what I got). It will get very hot on 3 li-po cells- that's almost twice rated voltage!

Jason T
08-30-2005, 12:41 AM
I used to run 3s lipo on a 7.2v sp400 brushed motor for a long time and it did not heat up much of all. So 2s is probably better.

09-09-2005, 01:42 PM
Well, I just took care of the overheating problem this week. I pulled the Speed 400 motor out (the second one that I had cooked from the inside out) and replaced it with an Ultrafly BC/06/15 brushless motor controlled by a Castle Creations "Thunderbird 18" with programmable prop brake. With a Graupner 8x4.5 folding prop on the front, this thing climbs straight up... and FAST! It doesn't slow down until I back off the throttle, and better yet, there's no sign of overheating! Naturally the motor, battery, and ESC all get warm with repeated vertical climb-outs, but definitely not HOT like the old Speed 400 setup was doing! It goes from the ground to "uncomfortably high" in about 20 seconds, and a shallower climb requires backing off the throttle so I don't tear the wings off of the airplane... COOL!

Jason T
09-10-2005, 02:43 AM
Good to hear. I think you are really going to enjoy that setup.


10-16-2005, 06:10 AM
Nice to hear others talking about the Ascent. I had tons of trouble with power for ages. But was told to go to a 6x3 prop, and still running 8-cell 800mAh Nimh. That setup gives what seems to me (only) hotliner performance. Yippie!!! As for overheating, never was in the air my first dozen attempts more than about 10 seconds, before changing props, and of course having someone else launch the puppy. Seems I couldn't chuck it hard enough. LOL!! It is a fun little glider. Has anyone had trouble with the control rod system? I had the glue the manufacturer uses to glue they guide tubes in place, gel up and that caused a bunch of problems. I got fed up and just attached they guide rods to the exterior of the fuse. Works far better. No binding. Much smoother response on the controls.

10-18-2005, 05:21 AM
My solution to the problem was to replace the entire prop assembly with the Graupner prop and spinner made for their TERRY airplane which is a 6.3 X 3 rather that 6 X 3. Also in my shop are several boxes of plastic spoons of various sizes. When cut in half and epoxied over a hole in the fuselage they make excellent air intakes. One on either side of the fuse near the nose works wonders. Mine cover 1/2 inch holes drilled into the fuse sides.


10-31-2005, 05:41 PM
What's this.......a glider with a motor? Did you slope it in SD?
Fred Sanford

12-09-2005, 03:34 AM
Sure enough, the Ascent will cook S400s since ALL the airflow THRU the motor is blocked by the solid firewall. I made a paper template and drilled holes to match the motor's vent holes. It weakened the firewall which required a layer of glass and epoxy and redrilling... sigh...

The stock prop literally SMOKED my first S400 after a modest test runup. 6x3 is max for a S400 direct- I prefer Graupner hubs with CAM folding props and ALWAYS use 7.2V motors with 3 lipos- but have a few extras on hand for changeouts thruout the season. I had previously drilled a 1" hole in the canopy forward- but it didnt help much with the critical thrumotor cooling air blocked.

The best S400 combo was a 6V S400 and a 2 cell 2100 TP lipo with vent holes drilled in the firewall. One of the Turbo Spinners from Hobby Lobby would help also since it has a hole in the nose of the spinner to feed air to the holes. It makes for a LIGHT ship despite the modest power output- and lighter always climbs better and stays up longer- proof follows:

After 3 yrs flying my trusty beloved Ascent I was scratch-soaring a small bowl shaped hillside a couple months ago and found a monster thermal, climbing beautifully with every turn. I was joined by a vulture- then 3 more- in a left hand turn, all going up at a great rate! I turned to my grand daughter for just a moment and said- "Look! I'm flying with the turkey vultures!" I returned my gaze skyward- and NEVER SAW IT AGAIN- altho it was directly overhead... somewhere, too high to see! Burial in the sky, with the best of company.

What else could I do but go home and cut the nose off my 2 meter Aspire highstart sweetiepie and put a motor in the nose? Life goes on. Have fun- and welcome to electric soaring!