Gryphon

Hi all,

I just recently put together a brushless Stryker setup. I've been doing a lot of testing on it using a Tach, Wattsup AMP meter, an accurate 5.5 LB electronic scale +/- 1 gram and a Radar gun bought from Radio Shack +/- 1 MPH(on clearance now for $75).

Soon I will post my various setups with 3 cell and 4 cell Lipoly using various props.

I like to hear about your measured setups.
Every one, NO OFFENSE but measured numbers only, PLEASE.
I can not count the number of times that many people on this site have talked about their combinations and they have been right out of MOTO calc. That makes me ill.
I am a proud/paid owner of a copy of MOTO calc, Its APC Prop constants are meaningless with my combo.
But lets have some exact real life, repeatable test, DATA for others to be able to copy, O.K.?

Motor is a MEGA 16/25/3 (The motor spec is 1700 RPM/volt, needs big Prop or 4S to wake up.)
Batteries are all Thunder Power, 3S 2100, 3S2P 4200, 4S 2100. Future test: 5 cell, or even 6S.
Castle creations 80 AMP Phoenix ESC (over sized for future use, I know 1 o.z. TOOOOO heavy).
JR micro 6 Ch receiver.
Medusa Research Universal BEC.
2 Hitec 81MG servos, with 2 JR sport 3" extensions, deans ultra plug connectors everywhere.
APC props tested from 5X5(too Small for 3-4 cells) all the way up to 8X8(too many Amps on 3S).
I built the plane on the heavy side. reinforcements every where because my friend and I try to smash each other out of the sky. 24 o.z. with 3S2100 TP.
First flight was with a 7X5 prop on 3S (not enough pitch, a light tail wind, radared 84 MPH, too slow) I need to find a 7X7 prop and radar it again should be in the 90's with 3S2P. But lets stick to facts not guesses.
Last week my friend and I both had glitches at our usual field, will try another field.
I will keep you posted.

What are your exact setups down to the motor, ESC, battery and prop, measured amps, RPMs, thrust, Radared plane speed?

No prop speeds please, seen too many of those right out of MOTO calc.

Lets make this link full of interesting real-life measured, repeatable data.

Thanks all

Gryphon

Let the good times begin

Gryphon

I found out what caused the glitches, I had the same problem at the new field. So I removed the only thing that was added to the plane since the last good flight.
It was the medusa research BEC. I removed it and then twisted the red wire of the ESC which plugs in to the receiver back together.
It was snipped earlier per instructions, because the new BEC was now feeding the receiver,6V.

So with every thing back to normal, and not much juice left in the 3S1P 2100 battery, with no wind, I radared the plane at 78 MPH. The plane was a little too high and it was flying a bit of an angle.
I have no doubt that it was flying faster, and a fresh battery would have helped too, especially a fresh 3S2P.

My 4S1P met the end of its life last week, with a nice huge bend. All I can say was that it was not done by me or even in my plane.

I have (2) Thunder Power 5S1P 2100 batteries on the way. Goal is 110 MPH with both batteries in parallel on the plane. It'll go fast and climb hard, but will do bad things to the stall speed. I will limit the static amps to 49-50. Will see what a 6X6 prop pulls amp wise.

I will have to put the Medusa BEC back on, but will mount it externally this time, so it can be as far away from the Receiver, antenna and ESC as possible. Its going back on because my castle creations ESC has a limit just bellow 4 cell Li-poly as far as feeding the Receiver and servo's, I flew with 4 cells and 2 servos just fine. But I am sure that 5 cells will fry it's BEC circuits. So Medusa BEC needs to go back on.

Also I got more comfortable flying wide open 4-6 feet above the grass field.

*** For any one interested the motor I mentioned above fits inside the stock motor mount. ***
All I did was remove the most minute amount of plastic from inside of the two motor mount loops, using the dremel and a round sandpaper attachment. dremel on half speed I spun the head inside of the loop for 6 revolutions. extended the sandpaper atachment so far out that it almost fell out of the tool and I was able to reach the inside of the second loop (where the motor mount screws go). The job takes just a few seconds.

Since I may not have a 4 cell to fly with for a long time, I will post all data in the next post within the next few minutes.

Hope to have many radared numbers in the near future (1-3 weeks). They wil be 3 cells and 5 cells

Enjoy

Gryphon

These are my measured numbers for the Thunder Power 4S1P 2100 battery using my motor above.

Prop Brand___Prop size____Amp____RPM_____Thrust____Plane Speed____Starting voltage of the battery

APC__________8X4________53____17,000__4 LB 7 OZ______XXX________Fresh charge 16.55
APC__________7X5________50____18,400__3 LB 3 OZ______XXX________-280mah___16.05
Graupner CAM_7X6________51.7___18,200__3 LB 2 OZ_____XXX________-430mah___15.85
Aeronaut______6X5________31.5___22,000__2 Lb 0 OZ_____XXX________-550mah___15.59
APC__________6X4________26.5___22,600__2 LB 1.5 OZ____XXX________-675mah___15.54
APC__________6X5.5______32.5___19,600___1 LB 15 OZ____XXX________-835mah___15.24
APC__________5X5________21.0___23,000__1 LB 1.5 OZ____XXX________-1110mah__15.12

I hope you will find these useful, I tried to be accurate, I did wait till these numbers some what stabilized, but you know they are always diminishing slightly especially at the higher amps settings.

*** The ESC was set at the default lowest power setting and no extra timing was added to get more power. The thrust reading were taken after the weight of plane had been zeroed out. I did my best to balance the plane, see a zero number on the dial before going full throttle with the nose down on the scale. Basically I just made sure to prevent the plane from rotation, so I had my hand on the sides of the body, loosely.***

LOOK at the amazing thrust number for the 8X4 Prop, the stock motor mount was leaning way too far over and YES I was very much scared. But that is not a prop for my high speed needs, other wise I would have strapped the motor down to the other side.

Let me now what you think.

Come on guys lets share some data.