AKROMASTER QUESTION

[raby fink]

I am building an Akromaster for someone who has never flown before. I want it to be strong. My question is... if I were to use 1/8 balsa to cover the wing instead of monocote, would this work? I realize it will make it heavier. I am not worried about a little extra weight. My goal is for strength here, because she has never flown before. She will not be doing any stunts at all, just flying circles without crashing. So I just thought that balsa covered wings may give added strength. Please let me know if you think this is a good idea. I have the wing finished now and am pretty close to finishing it out. Thanks for your advice
Raby

[Serge_Krauss]

Raby-

I doubt if even that would prevent damage in a "normal" crash, and it would, IMO, be more difficult to fix than normal covering. Most sheeted wings use 1/16" or 3/32", and I doubt that the 1/8" stuff would fare better...but wait for a few other opinions.

SK

[Dennis Moritz]

Do a flat wing trainer. Guess the wing could be 3/16" or 1/4 " for a .15 size plane. Sig makes a few flat wing planes in that size category. A tired .15 should do it. On the other hand Monokote is tough and easy to fix. Doubt you get 1/8" balsa to curve enough and sheet the ribs. Not without soaking in hot water or amonia. Sheeting is usually punky 1/16", flexi and light, a waste for a trainer.

[afml]

Sig kits the Buster and Shoestring for 15 eng and a profile fuse with a solid wing.
Just build it like you would for yourself, but when it comes time to help some learn to fly, put the prop on backwards.
Instant trainer!   
The kits are also easy to mass produce yourself and have races with.

"Tight lines!"

Wes

[Phil Hawkins]

I taught my son to fly with a Estes Ringmaster Jr. (basically the same construction as your Akromaster) with Monokoted wings and Rustolium painted fuse/tail... Bring extra props, CYA, and 2" clear packing tape.

Go with a low pitch prop for the first few flights and if/when the plane goes in, CYA it back together, patch the wing with tape, install new prop and try again...

Of Course, this only really works flying over grass or other very soft ground.

We (he and I) crashed that Ring probably 10+ times before retiring it.

The problem with the extra weight is that when it hits ground, it hits harder than a lighter plane, thereby more damage and as already mentioned, a more difficult fix.

The field repair kit i.e., Props, CYA, and tape is just that, field repair. You can do complete repairs in the shop later.

[Terry Bolin]

The Acromaster flys well built the way the plans show so it would be a good plane to move up to, but one of the solid wing Sig planes mentioned would be a pretty good bet for a Trainer plane and using the tips mentioned above, you would be able to escape damage a few times when hitting the ground. (Unless it was straight in) Make sure and put a fillet on the wing to fus joint. I read in one of our magizines this last month that a thin sheet of plywood (1/64X3) on the bottom side of the wing really helps its crash survial on the Sig solid wing planes.

[Bill Heher]

Brodak has the Flite Streak Trainer kit. It has a bit more wing and larger tail surfaces than the Sig Buster/Shoestring profile wing planes. The Sig lkits were designed for entry level racing- so they tend to be on the smaller  / faster end of the scale.

The Flite Streak Trainer has a solid plank wing with an airfoil sanded into it, and was designed as a trainer so it flies a little slower and has a bit longer tail moment to make it stable.

here is the link to the kit on Brodaks site- you local Hobby Shop ( if there is one that knows what C/L is) can order it for you also.
http://www.brodak.com/shop_productdetail.php?ProductID=2559

Or you can make one from sheet balsa instaed of buying the kit, but after buying enough balsa, hardwood/ply, and hardware you would only save about 20 bucks- and pre-cut parts make assembly a snap. You could build the kit in a day, and paint it with spay cans, be flying in no time.

[Ward Van Duzer]

If I learned anything while rebuilding a seawall on a lake that used to freeze over in the winter it was "Don't make it impregnable (Because you can't! Mother nature WILL win!), make it REPAIRABLE!

Ward-O

[George]

...I have the wing finished now and am pretty close to finishing it out. Thanks for your advice
Raby

Raby,
If you do have the wing built, it is a moot point except to know that noone seems to like the idea, including me...for all the reasons previously pointed out.

If per chance you have not yet covered the wing, I would chime in along with other folks that suggest building to plans.

Now, with that said, I would also suggest you build another plane from scratch using the outline of the fuselage and tail section. For the wing, piece together some "C" grain 1/4" balsa to the wing outline. The reason for the new fuselage is so you can notch it for the new sheet wing.

This will yield you both a beginner plane and a more maneuverable plane for later. Noone wants to just go round-and-round once you learn to fly unless you are racing or something. She will quickly tire of flying such a limited plane.

George

[Chris McMillin]

Make the controls slow, that will keep her from overcontrolling the model and crashing it in the first place. Use a 3 inch bellcrank instead of two, and use a large horn with the outer hole for the pushrod.

If you use the kit supplied wood for the center planking, it should be sufficiently hard for the strength you require!

Chris...

[Andrew Hathaway]

Covering the wing with Sig Koverall would make the wing virtually indestructible.  I had three Akromasters covered with Koverall, and all three wings survived many crashes, several straight in from the top at full power.  I destroyed crankcases and fuselages, but the wings came out with hardly a scratch. 

[john e. holliday]

I probably shouldn't throw my two cents in here, but,  I had the Streak Trainer and it seemed the kids had more trouble flying it then the planes they finally soloed on.  Emmy soloed on my Flying Clown and went to my ARF Flite Streak.  James and Willow soloed on the original Magician after trying the Streak Trainer.  Seems the trainer keeps wanting to climb and dive if there is any breeze.  With the symetrical airfoils they did better.  They just needed enough help to get thru the first few flights with only enough fuel for about 20 to 25 laps.  My way of doing training as I now think trainers are not trainers without a lot of help.  DOC Holliday

[raby fink]

Thanks for the info guys. Wes had mentioned to place the prop on backwards to make an instant trainer. I am not sure what this does so can someone explain what this will do to the plane as far as speed, performance, etc. Thanks for the halp
Raby

[Serge_Krauss]

Reversing the prop runs its airfoil through the air backwards. It's inefficient that way - wastes lots of energy - and will fly the plane slower.

I agree with many above that you should build for repairability, since crashing WILL most often damage your wing. Also note that a rigid wing will be damaged as soon as the impact stresses it past its elastic limit. More flexible wings can give some and reduce or sometimes even avoid damage to the structure. Covering tears first. That's a much easier repair. But, if the "covering" is thick balsa, it too will have to be removed and replaced - much more difficult.