Saturday, October 27, 2007

Axi 2820/12 maiden report in the Altec Skydancer

What a nice Sunday. It was unseasonably warm with winds in the 5-10MPH range, perfect to remaiden the model at the SEFLI Wingnuts field in Calverton NY. Recently the field “bugged-out” and resituated it’s runway. With winds out of the West it was perfect for flying.

In a nutshell the repowered model fly’s great. Moving to the outrunner did not sacrifice as much airspeed as one might think. As one expected rate of climb has increased dramatically. Take off and landings are a non-issue despite the larger prop. Some of this I attribute to the fact this model floats in for a landing. Flight times are also longer as I no longer find myself flying the model with the throttle at or near the firewall. I did not time them but I would say I’m in the 7-minute range right now. That’s not bad considering I was hitting the ESC’s cutoff at about 4 minutes before!

One area that needs to be improved is the thrust line. I have added 2 shims in an effort to add some down thrust. Also I have shimmed slightly the models leading edge of the wing down to help it stop ballooning.

With just enough time for one last flight I announced that “just one more flight” was in order. Anyone who knows that slogan knows it’s the biggest jinx in the RC world! Having flown the Skydance 3 times before what could possibly go wrong?

As a lesson learned not to challenge the RC Gods about 2 seconds after liftoff the Axi motor and firewall departed the model! The motor had given no indication of trouble up to that point and it was quiet as a mouse. So at about an altitude of 10 feet and little airspeed I had but one choice. There was no going around for sure. I pushed the elevator all the way down to try and get the model some speed and landed HARD at the end of the grass runway!

Being the balsa outhouse that is this ARF she survived without a scratch, and without a motor for that matter.

The motor and firewall has been re-installed and pinned this time for safe keeping. Live and learn for sure.

Wish me luck on upcoming flights!

Tommy D

Saturday, October 13, 2007

Repowering the Altec Sky Dancer .25

Some time ago I built the Altec/Super Flying Models .25 Sky Dancer. Using what I had on hand I flew the model with a Mega 22/20/4 .

The model flew well and has become a plane to take to the field to just clunk around with. In it’s latest incarnation though it was starting to loose some of its attraction though.

To Recap the Sky Dancer was made by Altec/Super Flying models a good 10 years ago and sold by MRC in New Jersey. It was intended to be powered by a .25 glow motor.

It has a wing span of 50 inches and a all up advertised weight of 3.6 lbs. Even converting mine to electric, adding 1 aileron servo per side and larger ailerons I came in at 3lbs 6 ounces!

Upgrading to an Axi 2820/12 and running it on 4S has allowed me to go from an 8x6E from to a 10x7E prop. 525W for a cost of 38A will give me 145W per pound. More importantly moving up to a 10” prop should fly the model a lot better then the tiny 8 inch. With the 8” you felt much like flying a glow model you were mostly at full throttle. Now I would well imagine the rate of climb should be excellent with little sacrafice of top end speed.

To use the Axi outrunner instead of the Mega inrunner I removed the glow rails I had used on the Mega. A simple 1/4” plywood firewall with some triangle stock was glued in for support. Air holes were then drilled to help the Axi breath. I doubt surrounded by all that air it will have a problem with overheating though.

The photos also show the intake scoop for the ESC and battery pack. The scoop doubles as a hatch so I don’t have to remove the wing to access the battery pack.
Ill report back as soon as I fly the model but I expect only good things from the Mega vs the Axi.

The original build thread for the Sky dancer is here

Monday, October 8, 2007

Sunday, October 7, 2007

Multiplex Gemini Sport Bi-Plane Review

Multiplex Gemini Sport Bi-Plane

I recently assembled the New Multiplex Gemini Sport Bi-Plane. Having been a Bi-Plane fan from way back when, selecting this model is a natural for me. There are many small park flying bipes on the market. From what I have found they fly fairly decent at best. Most suffer from their light weight and will weathervane into the wind something awful. The Gemini breaks out of those inadequacy’s as far as I’m concerned.

The Gemini Specs are as follows:

AUW including a Thunder Power 3 cell 2100 battery 32 ounces

36” Wingspan and 36” in Length.

The Gemini is the latest in Multiplex’s line of kits for 2007. The Elaptor foam parts fit very well, but I did take the time to sand the entire model with 400 grit wet paper. It removed the mould marks that otherwise take away Multiplex’s smooth surface. A nice touch is Multiplex’s simulated ribbing on the wings.

Like all Elaptor kits the use of Medium CA is used with a shot of kicker here and there. This was the first kit I used Mercury Adhesives brand of CA and found it to be good stuff. No more clogged CA tips for me! Keep in mind when you use CA setup time to join parts is limited. Use your head to know its best to add CA to the female part and fit the male part into it, not the other way around!

The only change I made was to use the Himax 3516-1130 motor. You do have to drill the mount to use this motor but with the aid of a drill press its very easy. Fitting an APC 10x5E prop and some old thunder power 3 cell 2100s gave me 240W for about 24A draw. I can live with the 120W per lb for now. With new packs next year I hope to prop the model closer to 150W per lb. As is even with these 3 year old packs I’m getting 10 minutes of spirited flight as I rarely fly the model at WOT.

Flying the model I have found pushing the pack to the rear of the bay gives me a nice C of G. Actually I’m flying just rearward of Multiplex’s recommended setting.

So far I really like this model a lot. It tolerates 10 MPH winds very well as that’s about the AVG wind speed I have been flying it in. It truly is a better aerobatic model then I am pilot. Hopefully this model will teach me a thing or two on the warmer days this fall and winter.

While I have talked a bit about how good of an aerobatic model this plane is I cant say enough about how easy it is to fly. Slow or fast, low or high, inverted or straight and level you just feel confident flying this model. If you have flown an aileron trainer this would be a great step up for you. Make sure you set your throws per Multiplex’s recommendations and you will be fine on low rates .

To follow the on-line discussion of the Multiplex Gemini please click here.

Thanks for reading and feel free to leave comments! Tommy D

What matters most, Family

Much of this RC addiction I attribute to my girl Adriana. A gift of an RC airplane one valentines day re-kindled my love for flying. Adriana had seen some photos of me as a kid flying and thought they were cute. I have to wonder how cute it is when your man is running out the door every chance he can get to go flying!

I’m likely one of the few men in this world who after all this time is still at bliss with his girl. Men will rarely admit it however we love to gripe about our women! That’s said, I can’t think of one thing I would change with Adriana if I had the power. Well that’s not completely true, I wish if I had the power I could have one of her children’s books published. That would mean a lot to her.

A little about me.

My First attempt at creating a webpage / blog is here. I did that a lot of years ago and honestly don’t update that page at all now. It does have some old photos on it of people who are close to me or model airplanes I don’t even own anymore. That page will tell you a little about me and my life.


Tommy D's Blog

Created 10-7-07

Life aside this Blog will be ramblings of posts dedicated to RC Model Aircraft.

I would hope this site will help me remember the changes made to a model in it's lifetime.

For giggles Ill toss in some stories from life to keep it from getting too boring!