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

3 comments:

Vencon said...

Nice blog.
My Skydancer striped it's HiTec HS81 aileron servo while in the air and landed far away on a rock. The floats and wing got damaged. I'm replacing the 1" ailerons with 1.25" ones and of course new hinges, either pin or CA.
Marc Venis

Tommy D said...

Hey Marc thanks for the comments!

It's possible you and I are the only one's left flying the Sky Dancer. That said converting it to electric is relative to any size .30 model.

The ailerons I added were 1 1/2"s and the cord is just wider then the stock plastic wing tips. When I tell you my model rolls like a drill I'm dead serious. If you go to the trouble of adding the ailerons you might consider adding individual servos to operate them. Mine are installed in the underside of the wing as there is not enough room inside the fuse to double them up in the center of the wing. Also the model likes a more rearward C of G with a longer overall cord. I like a tail-heavy model so before you adjust yours I would suggest flying it first.

My Club president had one of these models a good 10-15 years ago. Apparently it got stuck up in a tree. The RC Gods were shining on him as they fired an arrow with a length of cord over the tree / and model to try and shake it free. The shaking motion caused the model to drop out of the tree BUT one of the trike gears grabbed the line and the model slid all the way down the robe undamaged! Pretty good story huh?

Anyways mine is loaded and will fly tomorrow for the first time with the Axi. For sure I'm excited!

Take care!

Tommy D

lalo said...

I crashed my four star agaist a tree, and waiting a wing replacement that looks like it will take a while... so I went to my local store for something cheap to throw on the air and I got this plane.. just realize how old it is.. is pretty good shape.. I hope flies well has an enya 30 on it.