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15cc EF 60" Edge 540T-EXP Gasser

Got the GT15 in. Pulled the evo. Here is the weight comparison.

15GX 603 grams with plug
GT15 630 grams with CM6 plug

The perry pump and hardware was 30 grams so we are almost dead even in the swap. Just that the OS will put more weight foreword.

Since the OS ignition does not have the RPM lead I pulled the TM1000 and that was 17 grams plus the sensor plus the wiring. I will just have to use the tach. The boxes are the same, just they did not add that third wire.

This will be an almost dead even swap in dimensions and arrangement so this should go quick.

I will make a platform to mount the gas tank aft to hopefully solve the balance issue.

ImageUploadedByTapatalk1389060956.290010.jpg
 
Parts finally came in to space muffler out enough for the throttle servo to work. Not ideal as the spacer had a little smaller port size than the engine. I will see if it runs hopefully tomorrow.

ImageUploadedByTapatalk1404582098.260824.jpg
 
Finally got to fly the new GT15 today. All I have to say is WOW. Once we figured out that a servo extension was backwards (a bad lot I got a tradeshow) and hooked up the hall sensor correct, it started right up. Little bit of tuning on the high speed needle like a glow motor and we were all set. I got 9900 RPM on a Xoar 14x7 PJA right off the bat. That works out to 11 pounds of thrust. It did not feel that strong in the air and I will verify with my better tach tomorrow I hope. Also got the go pro loaded up for a video attempt.

Eventually I hope to get a 15" prop on it and be able to directly compare it to the electric version. Once I get a little more pull on prop setup I think I will have achieved my goal. It is a honest alternative to the electric setup. It is equally as quick and flies very true. It still lacks the insane pitch authority I love, but it is not slouching. CG is just slightly nosey, but I have run out tricks to shift weight aft and this might just be a function of that mass sitting on the nose. I think it has more to do with a 10k spinning prop over the usual 7k light electric PJN.

One of the other members of club was watching the flights and was so impressed was asking about the setup. He was complaining about the battery cost for the electric setup. To be honest, this is a expensive setup, and for most the electric is the way to go. This saves you from having a 6s charging getup. We did 6-7 minute flights and did not use more a third of the tank (probably a quarter, but I will go conservative). This motor is brand brand new, so that fuel burn will go down even more!

As one can see I am gushing about the GT15. What a dream compared to the evolution. That built in pump made all the difference in the world.
 
Wind defeated us today. Even my 89 slick was sketchy. Flying tomorrow with [MENTION=769]dth7[/MENTION] so we shall see if we can get some footage.
 
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Got a video of the 4th flight with the GT15. This one I tried a Xoar 15x6 PJA. 9100 RPM on the initial run up. That works out to just short of 11 pounds of thrust. You can hear on the video Patrick and I talking about the 14x7. Looking at data I do think it is probably a better prop for energy stuff. It was too windy to get a feel for the low and slow stuff I can currently do. It is 13 minute flght and there was just a little less than a half tank left on the 8 ounce tank. afterwards I got the fish scale out. Adding back in the used fuel it worked out to 6 pounds 10 ounces. Probably a half pound heavier than my laser. Even with a 6s 5000, I would not get this type of flight time.

[video=youtube;dxrgdV7Vh5A]https://www.youtube.com/watch?v=dxrgdV7Vh5A[/video]
 
Got the props in and tested them today. I put them into my spreadsheet and it tells the story. All of these are Xoar PJA.

14x7 10200 RPM, 11.85# thrust, 67.6 mph pitch speed
15x6 9100 RPM, 10.84# thrust, 51.7 mph
15x7 8400 RPM, 10.15# thrust, 55.7 mph
16x6 8100 RPM, 11.44# thrust, 46 mph

The throttle response felt good on all the props and none of them felt like they bogged it down, unlike with the 10cc evolution. The engine is still breaking in as the 14x7 improved 300 RPMs over the initial day. Tyler McCormick flew it around on the 15x7 and 14x7 and he said hands down the 14x7 wins. Kind of weird flying a 3D plane around with that kind of Rs, but that is what it is.

The only negative thing I can say is that with the battery in the tail, there are some tricks it just does not like. Waterfalls are the most distinctive.

I will do some homework on the EF 60" Extra as I think if I can get the firewall to work, this will make a wonderful IMAC/XA platform as the plane will be able to use the speed better. It fits real well into a truck fully assembled and will make a great cold weather pull it out and go fly plane.
 
The 14x7 gave the best of both worlds. The edge is not the most precise platform so I think the Extra might be a better airplane in the power envelope of this engine. It flew pretty good on all the props and the 16x6 was probably the best for low and slow.

This plane will get a lot more use when it gets colder here. I guess it will depend on my mood for the day which prop I use.
 
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