editNot really sure what happened but I think it was the battery because when I charged it, it would not charge it said voltage error. 0 volts took off the 3700 pack and put it back on and it charged so maybe a bad connection in the pack it self. I was fying about 200- 250 and it just lost power and went straight down. when I get to crash site it was blown out everywhere did not you find the motor . in the picture motors missing
I got a total of 3 flights and the launch is pretty hairy little hard to control not really enough power. Once I got it up it flew really smooth like 2100 gram plane should. I have a gps data logger in the plane (witch was totaled ) and it's indicated. I flew over 50 miles an hour but the climb rate was really bad I really could not it get over 350 feet high maybe 2500-3000 foot park. and it would stall pretty easy. I flew for 12 minutes and use 2900 amp on a 9x6 prop . It landed a little fast

Originally Posted by Blaser

editNot really sure what happened but I think it was the battery because when I charged it, it would not charge it said voltage error. 0 volts took off the 3700 pack and put it back on and it charged so maybe a bad connection in the pack it self. I was fying about 200- 250 and it just lost power and went straight down. when I get to crash site it was blown out everywhere did not you find the motor . in the picture motors missing
I got a total of 3 flights and the launch is pretty hairy little hard to control not really enough power. Once I got it up it flew really smooth like 2100 gram plane should. I have a gps data logger in the plane (witch was totaled ) and it's indicated. I flew over 50 miles an hour but the climb rate was really bad I really could not it get over 350 feet high maybe 2500-3000 foot park. and it would stall pretty easy. I flew for 12 minutes and use 2900 amp on a 9x6 prop . It landed a little fast

FWIW, when my EZ* lost total power, due to a broken battery wire, it just continued to glide all the way down.

Perhaps your cg may have been a bit off (too far forward???). That behaviour sounds like a deep stall. Did you have a lot of back stick trimmed in?

Talking about not much power.It has happened before that the prop was installed backwards as it has happened many time with people on the EZ and other pusher threads.
I would also say nose heavy unless the input during loss of power caused a down attitude.
Sorry for your lose as I know there not fun.

Originally Posted by Blaser

editNot really sure what happened but I think it was the battery because when I charged it, it would not charge it said voltage error. 0 volts took off the 3700 pack and put it back on and it charged so maybe a bad connection in the pack it self. I was fying about 200- 250 and it just lost power and went straight down. when I get to crash site it was blown out everywhere did not you find the motor . in the picture motors missing
I got a total of 3 flights and the launch is pretty hairy little hard to control not really enough power. Once I got it up it flew really smooth like 2100 gram plane should. I have a gps data logger in the plane (witch was totaled ) and it's indicated. I flew over 50 miles an hour but the climb rate was really bad I really could not it get over 350 feet high maybe 2500-3000 foot park. and it would stall pretty easy. I flew for 12 minutes and use 2900 amp on a 9x6 prop . It landed a little fast

A battery running out of juice or a connection break would not cause any change of flight characteristics with this aircraft. It is, after all, a glider. You should be able to launch this plane without any power being applied at all. As an example, my Radian will glide 300 feet with a power off hand launch. In fact I do a couple of these power off glide tests every time I take it out to check trim before i commit to a flight.

It sounds like your CG was way off or that it shifted in flight if your battery moved.

9x6 prop produces 350 watts kinda on the weak side as I like 100w per lb and that would put it in the 450 watt category.
Might be suited for a 4s setup.

Originally Posted by cliffkot

Whoa, not so fast. If you collect all the pieces this airplane can fly again. Gorilla and CA glues plus a little hot water can fix this. Believe me I know. Off course you will have to bury the pilot. He looks dead.

What happened to the battery? Did it fall out of the plane? What were you doing when this happened?

Is this a picture of the crash scene, or a collection of the parts you collected after it hit the ground?

i totally agree- I could fix that and it wouldn't even be hard- I have crashed Radians and easystars into that many peices and they came off the operating table stronger and better than ever'''

By the way i ordered one on friday morning...and a 4000mh 3s battery...

Originally Posted by cliffkot

A battery running out of juice or a connection break would not cause any change of flight characteristics with this aircraft. It is, after all, a glider. You should be able to launch this plane without any power being applied at all. As an example, my Radian will glide 300 feet with a power off hand launch. In fact I do a couple of these power off glide tests every time I take it out to check trim before i commit to a flight.

It sounds like your CG was way off or that it shifted in flight if your battery moved.

I had the cg right at100mm as recommended I had to put 505 grams in the battery compartment the flight pack 3700 and an other 3000 not hooked up to get cg it was a tight fit it can not move so cg did not move.

And I think 4 cell might be better but my 5000 -4c would not fit

I went back to the crash sight and found my motor it looks like it's in good shape
I will mount it on my prop dyno and do a 3c and a 4c test and get the grams of thrust

Originally Posted by Blaser

I had the cg right at100mm as recommended I had to put 505 grams in the battery compartment the flight pack 3700 and an other 3000 not hooked up to get cg it was a tight fit it can not move so cg did not move.

And I think 4 cell might be better but my 5000 -4c would not fit

Not that I have this plane, but thats sounds like a lot of weight, I wouldn't doubt that it'd really struggle on a 3 cell setup.
That's have to be ~1kg of batteries, plus your 500g ballast.

Originally Posted by sammyc

Not that I have this plane, but thats sounds like a lot of weight, I wouldn't doubt that it'd really struggle on a 3 cell setup.
That's have to be ~1kg of batteries, plus your 500g ballast.

no I'm saying 505 gram total thats how much the two pack weighted

Super sky surfer mods (1 min 27 sec)

Ok here are the dyno #'s the stock motor 130 grams stock prop 8x7
stock set on 3c
1120 grams thrust
315 watts
26.1 amp
4c
1630g
583w
38.1a

4c 8x4 speed prop
1605g
453w
28.7

3c with a different type of 9x6 prop than what I was fling with
http://www.bevrc.com/bev-gemfan-96-p...1900_p315.html
1480g
470w
39.8a

so it looks like the 8x4 4c is the best setup by far

Mine's on the big, brown truck for delivery this afternoon.

If the supplied motor is indeed about a 35/36 1250kv; most motors this size are rated for about 350-400 watts max. It could be that pushing it beyond this could impact it's efficiency and life.

I'm also concerned that 500g (including the battery) is required to achieve recommended CG. Most 3600 3s weigh around 300-330g. I'd imagine the one supplied with the RTF is in this range, thus requiring nearly 200g dead weight to achieve CG?

It appears the chord of the wing is about 12" which would imply a CG of between 3" and 4" back from LE of wing (using the 25%-33% of MAC rule). If the recommended is 100mm, thats in the range of what would be predicted; but toward the rear of that range. Maybe the recommendation is a little nose heavy?

Maybe I'll be able to answer my own questions later today. In the meantime if anyone has some additional experience, please post your findings.

BTW, the big design deficiency of this monster foamy, is the fact that it uses the integrated linear BEC to drive the radio equipment including all 6 of those 17g servos, which is much too much current demand from any integrated linear BEC on 3S lipo power. Typically, most ESC with built-in linear BEC recommends use with no more than 3-4 micro servos on 3S. This huge model uses 6 mini size servos, and with huge control surfaces, it would be prudent to install a separate switch mode BEC, I'll be using a 5A switch mode BEC.

Originally Posted by Doubletap

BTW, the big design deficiency of this monster foamy, is the fact that it uses the integrated linear BEC to drive the radio equipment including all 6 of those 17g servos, which is much too much current demand from any integrated linear BEC on 3S lipo power. Typically, most ESC with built-in linear BEC recommends use with no more than 3-4 micro servos on 3S. This huge model uses 6 mini size servos, and with huge control surfaces, it would be prudent to install a separate switch mode BEC, I'll be using a 5A switch mode BEC.

Hi Al
Are you upgrading the power system or just the ESC?