Is it junk, or do I just have it set wrong? - RC Groups
Thread Tools
Jul 13, 2012, 08:20 PM
Too many numbers

Is it junk, or do I just have it set wrong?

I have a bone stock Chinese 70mm EDF F-18. I love it. Yes, it's cheap and doesn't fly as rock steady as my Horizion Hobby stuff, but she's fast and is the biggest attention getter at the field.

But there's one thing about it that has always bothered me, and today nearly caused a crash. When I am flying and turn the throttle off, when I push the throttle back up again it often takes a second or so for the fan to come back on. I was landing today and a sudden gust of wind caused my F-18 to slow abruptly, and it stalled about 20 feet off the ground on final approach. I hammered the throttle but the fan didn't come back on until it was about 3 feet above the ground. I barely got it back up before it crashed.

So, do I have the ESC set wrong, or is it just cheap junk? The airplane flies great and is very fast for a stock setup, but it just has that one glitch.

Sign up now
to remove ads between posts
Jul 13, 2012, 10:56 PM
Registered User
yorkiepap's Avatar
Hey Dave,
You have to remember that an EDF takes a few seconds to spool up to thrust rpm. It is not instantaneous. The EDF pilots I've seen "never" turn "off" their EDF's to "0" throttle.

Jul 13, 2012, 11:20 PM
Space Coast USA
hoppy's Avatar
Some ESC'S also have a setting for how fast the ESC responds to throttle changes. Check your instructions.
The Turnigy Plush ESC'S have a Start Up mode adjustment. Normal, slow and super slow.
Jul 14, 2012, 09:42 AM
Too many numbers
Ok thanks. There's no build up of thrust. What I mean is the electric motor is off completely. When I hit the throttle, it stays off for a second or so before it comes on. If I keep the motor on but at very low RPM, it will spool up normally.

It just seems weird because on my prop planes I turn the motor off all the time for stalls and what not, and the motor comes back on immediately when I push the throttle with no hesitation. My other EDF models do the same. But this one hesitates. The instructions don't have anything in them about this, so I'm not sure what to do.
Jul 14, 2012, 09:43 AM
Too many numbers
Oh yeah, if the motor is on, RPM changes are immediate. If I go from, say 10% throttle to 50% throttle, it changes instantly. But 0% throttle to any% throttle takes a second or so.
Jul 14, 2012, 09:56 AM
Space Coast USA
hoppy's Avatar
Check your ESC for the Start Up setting.
Jul 14, 2012, 11:14 AM
Too many numbers
How do I do that? Thanks!
Jul 15, 2012, 06:05 PM
Space Coast USA
hoppy's Avatar
What is the brand and model of your ESC?
Jul 15, 2012, 07:23 PM
Registered User
seeingeyegod's Avatar
Or just don't ever go to 0 throttle
Jul 15, 2012, 07:46 PM
Wake up, feel pulse, be happy!
Piece's Avatar
Sounds like the ESC is just dumb. You may be able to program out the problem, but maybe not. I had an ESC that would occasionally spool the motor up from zero very very very slowly, like so slowly you could barely tell it was spooling up. This seemed to be quite random; very often it would just crank right up.

I'd say just replace the ESC before it actually causes a crash. A new ESC is cheaper than a new plane.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Video Boys just have to do that ..... specyfick Sailplane Talk 1 Jul 15, 2012 02:57 AM
Question Do all RC planes have power switches? Or can I do without? kenzietech Power Systems 6 Apr 21, 2012 03:44 AM
Discussion Wrong Prop or do I have to Reverse the Motor rotation? CnadianFF Electric Plane Talk 2 Apr 01, 2012 08:25 AM
Discussion Screaming Thunderbird!? DOA or am I just doing something wrong? ziomatrixacs Castle Creations 9 Jul 07, 2008 09:26 PM
Question Do I have the wrong idea about setting throttle curves? T.J. Kong Mini Helis 6 Feb 16, 2006 01:55 PM