Hey gang,

I have a couple of questions for you.

I converted a Guillow's display model F-16 Fighting Falcon to EDF. I stretched the wingspan from 12 to 14 inches and balsa sheeted the topside and created internal ducting out of 1/32" balsa. It uses the GWS 40mm EDF unit. With a 2s 340mah li-po battery it weighs only 136 grams.

The guy at the hobby shop said it wouldn't fly. Nothing galvanizes my resolve like that kind of statement!

It does fly although it could use more power. Climb rate is poor and the best way to gain altitude is to build speed and climb in steps. Once at altitude it will do a loop after a dive and some simple aerobatics.

I haven't done any experimenting with the exhaust nozzle diameter so maybe some improvement could come from there.

I flew two packs out without much of a rest for the motor on a hot day and now the motor is going south which leads me to my questions.

Would the EDF40"H" model fan be better for this application (run cooler)?

Does the Astro Flight Firefly motor fit into this fan unit? Has anybody tried it? If so, is there a trick to removing the fan from the GWS motor?

The most amazing thing about this plane is how realistic it looks in the air when it's calm out. Even with a little wind it's very stable. The neighbor lady thought that a jet was practicing for the upcoming air show until she saw it land!

Lance

sorry that I can not help....but COOL! Idea I also wonder if firefly brushless would work?

got any pics?! (wipes drool from chin)

Gentlemen,

I would love to send some pics and video clips. I just can't get them to upload. It's telling me the file is too large. I'll try to figure it out next week.

Lance

Lance, these little motors don't seem to like to pull air from a long inlet. did you have a large cheeter hole on the bottom? and was the motor as far toward the rear as possible? What kind of radio gear were you using, mybe you could lighten the plane up a little by using two of the 4.4 gram servos that are out. I've built several planes for the 40's and they were both the low voltage version. Next plane that I'm building I"ll try the High voltage fans but I'm going to try 4 cells. According to the specs. from GWS the High voltage motors on 3 cells won't put out quite as much as the low voltage on 2 cells, but they only pull about half the amps. The best fix would be a CD brushless motor, but then the cost starts to climb. Also it sounds to me like you just got a bad motor like so many other people who have bought edf50's, some say they last hours and others fry in seconds.

Congratulations on your success so far.

Cheers --- Stacker

In regards to the firefly motors, I'm pretty sure it's a coreless motor, not brushless. Your very fortunate to have been as successful you are with that set-up, you almost need a glider type plane with single edf 40 or 50. Very neat.

the firefly is a coreless motor. In an edf 40 (low volt) it will draw .95 amps on 2 lipos giving you 7 watts. this is where to get one.
www.astroflight.com

Well, the GWS motor really went down on the last flight so I ordered a Firefly last Friday. We'll see. Anybody have any tips on how to remove the fan from the GWS motor?

Stacker,

I didn't put a cheater hole on the intake. I hate to cheat, but maybe it would be worth it. The motor is well back, about mid-way between the main wing and the stabilators. Any advice on a good cheater hole configuration?


I can't get a picture file smaller than 155 KB and it won't send. Frustrating! I want to send a video because I know I wouldn't believe it flies unless I saw it and I want you all to see it because it's so cool. How the heck do I send a video if I can't even get a picture to upload? I can make a little plane fly but I can't work this computer stuff. I'll keep at it.

Lance

okay... to post a pic ... first go to MS Paint (Start>Windows>accessories>Paint) open the picture file, click image, click strech/skew, in strech box type in 20% , for both fields, click save as , type in a name, then on the scroll down menu under the name select JPG.

Hey, thanks ssyed, I'm sending two shots. Now can you please hold my hand and tell me how to send video clips. I have three, the longest is 25MB and the shortest is 4MB. If I zip them they only get about 25% smaller. How do I upload them?

Stacker: The bottom view shows the fan unit hatch toward the rear. The intake duct has a larger cross section than the fan unit. I read somewhere that a boundary layer is set up in the intake tract and that the intake should be larger than the fan. There is a small step at the fan unit inlet because of this. The initial exhaust nozzle reduces the cross section to about 90%.

Are there any good rules of thumb for the size and shape of a cheater hole?


While I'm waiting for the Firefly motor I suppose I should paint the nose gray, add a pilot, and fake in the exhaust nozzle.

Oh, by the way, its sitting on its display landing gear dolly. Someday I would like to work up the nerve to try a ROG using this dolly.

Cool...the images are really small now.... try on the strech/skew box type in like 50% or 60% or maybe skip the whole strech/skew step and just click save as> and choose jpeg....

Now you can have bigger pics ..... (strech/skew just streches the image to 20% size or whatever you type in size)

Okay, now I've got the hang of it. Here's a couple more larger views. In the port view you can see the gun port that has a small tube inserted in it. It is now the intake for the battery cooling air.

Ssyed, help me with the video clips, please!

Lance, these little motors don't like to draw air from a long inlet so cheeter holes are the best way for getting the most out of them. I'm with you, I cringe at cutting a hole that should not be there. Also if you build another one you might want to consider putting the end of the fan back as far as possible. Here is where I positioned mine on my 262.

Cheers --- Stacker

Sorry... i've never uploaded video before... just pics