[4stripes]

Flying my 90mm Starmax F/A-18 on a hot day (34C) two flights consecutively caused my Cyclone power 85 ESC to cut out half way through the second flight. I assumed it was the thermal protection. First trouble I've had after at least 30 flights. My ESC is mounted stock under the belly with one side of the ESC exposed so I removed the surrounding plastic panel to give more airflow. Flew a few flights on a cooler day after that event and then lost all power including the SBEC on short final. Battery still had plenty of power so it was the ESC that quit. A little damage to the aircraft but repairable. The ESC had no visible signs of distress (unlike the ones that smoked in the MIG).
After disconnecting and reconnecting the battery it began working normally! I'm running similar ESC's in my other 90mm F-86 and L-39 but cooled inside the intake duct just ahead of the fan. Those planes have many more flights with no issues. I think from now on all my ESC's will be inside the intake air for better cooling. There are a few designs that show external mounted ESC's but I don't think it is adequate.
Cheers

[Bob Byrnes]

Eric: My Sabre has been fine with the ESC in the stock location, on the belly, with the heat sink exposed to the airstream. On the two new ones that are fibreglass I think the better idea is just as you say. A modification that allows at least the heat sink to "poke into" the intake is the wise course. The Super Sabre has it located in a recess just behind the fan at the top of the thrust area, I hope it will be OK too. I have used up two airplanes this year. I had a mid-air with the little Mig which collided with my pal's( the other Eric) little Panther. I also lost my RC Lander Panther the other day. I tore off the elevator due to flutter. I fixed it and first flight it was terribly badly out of trim. I think a cracked horizontal stab had gone undetected in the repair job. I am starting to think about moving away from the foamies, but,the example you set shows with the right amount of work they can be made to go and look really well. What about a Hobby Topgun L-39 done nicely like yours with a Stu-Max fan to get that turbine sound!!!!!! I was cosidering the HET L-39, but, judging them by this F-18 I have, I am not impressed. The other threads claim the quality is much better with their F-16 and L-39 offerings, but, overall I wish I had saved the money I spent on the F-18. A fellow at our field flew a foamie F-18 the other day and it looked just fine in the air and went like stink. Hope you, your Dad and Son are well and enjoying the summer.
Best Regards
Bob

[Cougar429]

Have to agree to increase cooling airflow over the ESC. Obviously outside air temp will have an effect on how much heat it can take away from the ESC.

My other point requires asking about your comment on losing the SBEC. Was that integral to the ESC? If so, seriously look to install a separate unit that will not thermal shutdown if the ESC overheats. If it is already separate then I would recommend investigating why that would shut down on short final, (likely the worst possible flight environment for it to happen).

[Guest]

How long are your Battery lead Eric?

It is recomended that the leads have a capcitor every 4" from the esc. Overtime, SPIKES will kill your Esc Capacitors.

Were are you BEC leads soldered too? They should be connected as close to the battery plug as possible. If your BEC is part of the esc and the caps blow, you will loose every thing.

[4stripes]

Hi Bob
midair is a shame, I suspect you might have been mock dog fighting too seriously! Too bad about the Panther as well. Think positive, 2 planes gone can mean 2 new planes on the horizon. The HTG L-39 would be a great choice. Did 7 or 8 flights on mine today and marvel at it's abilities. Puts along nicely at 40% power or goes like stink at full throttle. Handles X-winds very well with its wide gear and grass is no problem all on a cheap Freewing motor/fan. Flew the F-86 as well today without droptanks. The performance is noticeably better (almost L39 like). We are having a great summer and hope to see you come to the Burlington field someday!

Cougar429,
My SBEC is integral to the ESC. All my electrics have the same setup, but unfortunately this one failed. Hoping to cure with better ESC placement, similar to my other models which have performed well. I have considered a separate BEC but figure it is just another component that could fail...

Hi Trevor!
My leads to the ESC are just under 12" (shorter than most of my other planes). I've heard of using caps but figured my leads aren't that long. The SBEC was part of the ESC. would the caps on the ESC show any signs of damage? The ones on the ESC still look normal with no visible damage. I intend to replace the ESC with a Turnigy 85A ESC which internally is the same as the Cyclone power. I want to see if perhaps it was the RX that failed but I suspect it was the ESC.
Cheers Eric

[Guest]

All your questions will be answered here Eric
http://www.rcgroups.com/forums/showthread.php?t=952523

[4stripes]

Thanks for the link!
What type capacitors are you using and where did you buy them?
I might need a dozen or so...
cheers

[Guest]

I got them at Sayal. Just bring the ESC to the store and ask them for the same or slightlly bigger