Spitfire

[GuyOReilly]

Source of power problem located: defective switch.   
I have another and will replace easily. 

[GuyOReilly]

Ready for Maiden Flight.
RTF weight: 3 pounds 14 ounces.
Design weight: was 3 pounds 6 ounces.
The additional 8 ounces, more glue, and one more servo and wiring and... 
Not perfect, many flaws, but happy with the end result.
It should still fly, hopefully land safely, and then repeat many times. 

Picture #7672 - Surgery on the bottom wings to add servos for ailerons.  I did not like the single servo seat-up.
Picture # 7675 - Servos installed and weights to keep plane light... err... to hold the pieces to cover the holes in place.
Picture # 7676 - Ready to fly, decals applied, Monokote stripes - what a $&@% to put down.

Looking forward to a calm, spring day for Maiden Flight @Frank v B . 

PS: Oh, yeah, I forgot one small thing remains to be done: figure out how to prevent the battery from sliding back, currently only velcro on bottom of battery. 

[Frank v B]

Guy,

The caption under photo 7675  should read "These bolts will keep the wing in place."  Joe Overkill or what?
Great weights.

re: "Not perfect, many flaws, but happy with the end result."  You over-delivered on the 50/50 rule*.


Frank

* if you can't see it at 50' and 50km/hr it is good enough.

[Andy Hoffer]

Guy,

The caption under photo 7675  should read "These bolts will keep the wing in place."  Joe Overkill or what?
Great weights.

re: "Not perfect, many flaws, but happy with the end result."  You over-delivered on the 50/50 rule*.


Frank

Darn!  @Frank v B beat me to it.  (Perfect bait monsieur!) Looks gorgeous @GuyOReilly .  And that wing is never coming off!! 

Andy

* if you can't see it at 50' and 50km/hr it is good enough.

[Michael]

PS: Oh, yeah, I forgot one small thing remains to be done: figure out how to prevent the battery from sliding back, currently only velcro on bottom of battery. 

Perhaps a block of Styrofoam?

[GuyOReilly]

PS: Oh, yeah, I forgot one small thing remains to be done: figure out how to prevent the battery from sliding back, currently only velcro on bottom of battery. 

Perhaps a block of Styrofoam?

Thank you Michael, a simple solution sometimes is the best option!!
Guy

[GuyOReilly]

@Frank v B should I reduce the movements?     This is low rates... 

https://www.youtube.com/watch?v=sQwmafNXuxY

[Frank v B]

Guy,

Great to be able to judge it via video.


If you were to ask me to maiden this airplane I would adjust the low rates as follows:
1) reduce elevator travel by about 60%.  A Spit is very short-coupled.
2) reduce aileron throw by 30%.
3) leave the rudder as is.  It is small relative to the plane so it may be required for take-off.

Two nits:
- the elevator halves are not lined up.  When the port half is neutral, the starboard half has about 3 degrees "down".  You had a joiner wire.  Grip the elevator halves with thumb and forefinger at both 90  degree bends and twist the elevator halves to neutral.  This easy to overcome with aileron trim but you would lose "neutral" when you change air speed.
- the starboard aileron has a lot more "down" than "up".  The port aileron is fine.

Remember that I have a different approach to maidening.  I set my throws at the minimum that would allow the plane to take off, fly circuits and land.  Once the first flight is complete, then add throws to your liking.  The reason...you can't do this on a second flight if you crashed on the first flight.

Also, I never switch rates on a maiden flight so the low rates and high rates are the same for me.*

FWIIW

Frank

* it is different for leaf blowers because they do not have prop/jet wash over the control surfaces.  They rely on pure air speed for control and may need dual rates.

[GuyOReilly]

Spitfire maiden flight did not go as planned.
The motor cut-off when attempting to takeoff as pe @Frank v B .
We suspected the ESC to be the culprit so I pulled it out.
Looks that it can handle the power based on the label on the ESC.
Any suggestion?
Guy

[Michael]

Do you know how many "amps" were being drawn?

I haven't read the entire thread, but, you mention you are using a "32" motor, I think with a 4-cell battery pack.

It is possible you are using too large a propeller.

It is also possible your motor is not adequate for the job. I have an OS 32 motor that is rated for only 3 cells. An E-Flite 32 can handle up to 5 cells, with a suitable (smaller) propeller.

What are the brand and ratings for your motor, and is the propeller size (you are using) appropriate for the motor on 4 cells?

[GuyOReilly]

The culprit was found! 
This switch has resistance where it should have none.
This results in the engine shutting down at full power.   
When bypassing the switch, no problem whatsoever.   
Need to figure out how to replace this switch with something more reliable; it was changed before and the same problem happened.   

[Frank v B]

For the record and to answer Michael's questions- we put a wattmeter to it. 
It drew 44.6 amps max.  The ESC was 60 amps.  It was well within range and a good reading.
When we put a voltmeter to the switch wires, one read fine.  The other one drew a blank when both "on" and "off" proving that the switch did not do its thing properly.

Frank

[GordPayne]

That's interesting. I have a similar switch and was having problems. I'll leave it out for a while. Thanks!