The big bang of Mustangs

Hoomi

Master member
Thanks for your response. The first ridge is only 2.0 inches, not 2.75. Now I can get 2.0, or the first ridge. I've got my battery in the same place but waaaaay back, unreachable. I literally take a stick and shove it as far back as it will go. To remove, I pull the cable and strip free of the velcro. Now, I never fly ft planes at the spec cg, I find I have to fly the plane really slow if I do. On my maiden, I typically go about 1/2 of an inch forward of spec and then keep moving the cg back until I see a behavior I don't like. I'm using the same battery, 2200, btw.

The plane w/spinner, weighs 484 grams, which is great (Simple Scout weight). Should fly exceptionally well at this weight, less weight than the Spitfire. I'd like to put the spinner on but it weights 33 grams, and then I need to add another 25 grams to the tail, with the battery shoved back as far as I can get it (and still way short of 2.75).

The Spitfire and the P 40 with spinners attached are darn near perfect from a balance standpoint. The battery is located on both really close to the cg, so you can change battery sizes with minimal impact. I was hoping the P 51 would be the same, I hate to add dead weight. I guess I'll try and maiden tomorrow and figure out the cg, from there, I can decide on Spinner or no spinner.
I haven't weighed mine, and my spinner is probably smaller than what would be "scale" on the model. I posted a video from the second flight, with the CG at the first ridge, measured upside-down. I also have the landing gear on mine, with actual foam wheels, rather than the foam board that come with the SBK.
 

Wildthing

Legendary member
HELP! CG location, spec says 2.75. If I use this number,my bird is very nose heavy. The spinner arrived today, but I'm not using it for the maiden, as I can't balance this plane without adding 25 grams on the tail (just to get 2.25). So did I screw something up and are they all nose heavy? I've got the battery as far back as I can get it. I can fix this, but before I do so, I just curious if this is a nose heavy design. I'm talking about the full size Ft Mustang.
Also,
I got a new receiver today, so I calibrated it to the ESC. However, if I turn the transmitter off before disconnecting the battery, the prop will run slowly. I've had this happen once before with a set up and thought I fixed it be re-calibrating, but this time no luck.

Any ideas?

Thanks,

Not sure about the cg but you could try a smaller battery.

For the radio, you should never turn off the tx before unplugging the battery, battery always first on shut down. It could have done just the opposite and went hog wild slicing you apart.
 

Wildthing

Legendary member
Well I would rather have a plane that is unplugged sitting beside me then one that is plugged in and has no brain to speak of to tell it what to do. Even at the best of times we know technology will fail, if it fails with no juice it is much safer for everyone.
 

BATTLEAXE

Legendary member
Well I would rather have a plane that is unplugged sitting beside me then one that is plugged in and has no brain to speak of to tell it what to do. Even at the best of times we know technology will fail, if it fails with no juice it is much safer for everyone.
Yea but there is no other reason like it messes with your binding or something technical, its purely a physical safety thing?
 

Wildthing

Legendary member
I always heard the Bix talk of unplugging the battery first but he never said why, that's why i was surprised when you said bodily harm could be the result, just never thought of it that way. Never heard a reason before

By accident I have turned of the tx first and suddenly the motor goes full throttle , good thing I was hanging onto the plane. Also those props cut really good through flesh, ask me .

Just thought of this, why program in a kill switch? What is the reason for it? Especially if you turn the tx off. :D
 

BATTLEAXE

Legendary member
By accident I have turned of the tx first and suddenly the motor goes full throttle , good thing I was hanging onto the plane. Also those props cut really good through flesh, ask me .

Just thought of this, why program in a kill switch? What is the reason for it? Especially if you turn the tx off. :D
I have heard of being able to program an ESC into a safe mode of sorts that will run the throttle up to a certain setting say 30 or 40% if it losses signal. I have an ESC that does this at like 10% throttle if it losses signal or the Tx is turned off
 

Wildthing

Legendary member
I have heard of being able to program an ESC into a safe mode of sorts that will run the throttle up to a certain setting say 30 or 40% if it losses signal. I have an ESC that does this at like 10% throttle if it losses signal or the Tx is turned off
Just think if you have your face infront of the prop when you accidently turn off the tx and the motor powers up.
 
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BATTLEAXE

Legendary member
Just think if you have your face infront of the prop when you accidently turn off the tx and the motor powers up.
I get it, there is no confusion as to the damage that it could do. Even my dog understands it, the day she decided to eat a spooled up prop. All i have been told is to unplug the battery before the TX is turned off, just not why
 

Marty72

Elite member
I haven't weighed mine, and my spinner is probably smaller than what would be "scale" on the model. I posted a video from the second flight, with the CG at the first ridge, measured upside-down. I also have the landing gear on mine, with actual foam wheels, rather than the foam board that come with the SBK.

Thanks for the confirmation.
 

Marty72

Elite member
Well I would rather have a plane that is unplugged sitting beside me then one that is plugged in and has no brain to speak of to tell it what to do. Even at the best of times we know technology will fail, if it fails with no juice it is much safer for everyone.
Yes, very good point. I know the the proper procedure is to unplug the plane first, but I also like to have the prop not run just in case I forget or something else happens. I just like to cover all the bases when I can. I, like Battleaxe, had always heard the proper shut down procedure, but had never heard the reason. I would think they'd design the receiver to never do what your's did, run wide open without the TX turned on. Good to know, that could happen.
 

Marty72

Elite member
Ok, problem solved!!! First rule, when all else fails, read the instructions! So the failsafe was set wrong. To set the failsafe on a Spectrum RX, you bind the RX to the TX, when you do this, the default setting is where ever you have the joystick set. So in my case, the throttle must have been really close to the off position but not quite. So I rebound the TX to the RX with the throttle shut off (hard) and that solved it. You can now shut the TX off and the prop won't run. With that said, the shut off procedure for the plane is what it is and should be followed but if you screw up and shut the tx off first, the prop should not run (if you follow this procedure).

Rarely, if ever, do I solve a problem in the middle of the night, this is a rare occurrence.

Maiden is planned for this morning, will report back later.