This sounds like a great project. I'm looking forward to the results.

If memory serves, which most of the time it doesn't!
Allen Brickhaus designed a small trainer using Ace foam wings that were banded on the profille fuse.
Had landing gear too!
The larger 35 version was called "Grassroots".

"Tight Lines!"

Wes

CG Wizard Trainer redux might be just the ticket. The only downside is that it uses a machine shaped plank wing airfoil that would be more expensive to produce than a simple flat plank wing.

That's a really pretty little plane.  How big is it?

Hi Larry,

Shades of the Richland NATS, & boy that was fun!  This IS indeed an engineering challenge to design a decent flying model designed to survive crashes into concrete!
Due to a new home project, I can only offer an idea or too.

1. Definately use the L/H snap starter arrangement, with the black 4.5 X 4 prop. Of course the L/H rotation gives more line tension on take-off & everywhere else, plus that prop w/ the thick tips is really tough. With a L/H prop, a rudder on top will NOW be functional again to help keep the model out on the lines. Perhaps a supply of those larger cox red rubber spinners might be useful to reduce impact shock...but like I said 'a supply', you might go through them faster than normal...
2. The smallest circle radius ( ~26') is safest as a model diving from 26' has less momentum than a dive from 42', of course!
3. Sheet hard balsa wing & tail components will need full length spars.
4. Don't discount basswood either as it makes for really rugged mouse racers.
5. The fuse really needs some thought. Just as I thought 1/4" basswood was the
 end all...some junior broke one at the wing t/e joint....hmmm.
6. A flexable (in crash) motor mount is brilliant. Keep working on that!
7.A bit of tip weight will still be advisable.
8. Keep controls on top of the wing where they can anyways be seen.
9. A rubber band spring loaded 1-3/8" mono-wheel would be very good.
OR, a fixed  1/8" music wire LG which might hardly never bend...
That's all I can think of for now , Larry. 
I can't wait to see what design you come up with. I sure do know first hand what you're up against!
All the best,
Paul

Regarding structure, the group in North California, and the R/C combat boys have had great success with the coroplast material.  I scored 10 political signs so far, and it is just the primary 

   And it turns an evil purpose to a good one.

    Brett

Have you taken a good lok at the "Little Wizard".  Landing gear well forward to help save props.  Motor plate held on with rubber bands.  For got the landing gear is held in place with rubber band.  Solid sheet wood construction, so breaks are easy to fix.  Taught quite a few kids with one.  I think it fell apart from old age.  Also Babe Bee .049 with the stock small tank.  I also used 6-3 props to keep rpm down.   

For cost effective spars in coroplast use bamboo skewers... a bag of 100 can always be found for $2 and often for $1.   We built a lot of 1/2a flying wings with double tapered wings (leading and trailing edge) to use for teaching kids.   Found they almost never broke before you would wear out or break the surestart engines.
Bob Furr

That looks like some pretty Half-Fast design work to me!

Seriously, where do you find that many kids interested in getting away from their computers and i-Pods?

Actually we contacted a local school that had a summer program that lasted two weeks and offered to do something related to model planes....  It ended up costing each kid about $20 and they walked away with a ready to fly plane they "built" (really just assembled as coroplast flying wings are way easy to do).   Got some donations from 3 clubs and one hobby shop and that helped.    Problem was that once they finished we lost track of them... they had no way to get to the flying field.   I know that for about 2 years though some kept flying in their neighborhoods...not many but some.
Bob

Thanks for the input, everyone, I did solicit it.

John brought a Skybaby carcas to the meeting and gave it to me.  However, I'll stick with the concepts I am developing, as discussed (way) above.  For flying over asphalt, you either need flexibility or fall-apart or both.  Grass is a MUCH simpler problem.

My design will have the motor/tank mount pivot up, the landing gear pivot back and the wing rubber-banded on.  Should be OK for anything shy of a 90.00 degree figure 9.

Just a couple of suggestions:

HI Larry,

I flew the modified 'Man-Win" coroplast trainer today, w/ the QZ engine. Although it IS very quiet & unbreakable when flown over grass, the major complaint is it has next to no line tension regardless of leadout sweep back when flown on 26' X .012" lines.
 
Cheers, Paul

I'm just guessing here but if you "modified" your Man-Win by taking out most of the engine offset, then this is your problem. My Man-Win built to plan and powered by a Cox Black Widow will do small overhead circles and overhead eights all day without the loss of line tension and this is on 35' lines. I also fly my model in winds higher than I would fly any other 1/2A model with no trouble. I also have a Babe Bee powered Man-Win trainer for teaching purposes and although it will not do the overheads the BW will do, it still stays out at the end of the lines quite nicely. This is a light model so it doesn't pull like a tractor, that's why it needs the radical engine offset.

Orv.

How about Rick Foch's "Student" From American Aircraft Modeler.
The plane can be built with
2 - sheets of 1/8" x 3" x 36"
1 - 1/4" square x 36"
1 - 1/2" square x 4"
plywood and various finishing hardware.

These planes are very sturdy because of the crutch that goes down all the way down the body.  They are not completely unbreakable but they hold up fairly well to practicing the figure 9.

I have the original article and plans if anyone is interested I could print them off and ship them at cost or try and scan them.  

The picture shows one of mine that is modified to have a 4" chord wing instead of a 3" and it has a slightly different motor mount.

I have built one for the "its only a half a contest" that is on the 19th at the aurora airport.  I hope to be there competing with it. 

cant say I have ever flown off concrete. Wouldn't the motor get damaged in a crash?

I can build a plane from coroplast that will survive... but even if the motor is held with rubber bands it is likely to be damaged.   Now fly over grass and you will wear out a motor before you break a coroplast model.
Bob

Consider a design with a removable LG for hand launching over grass.

Just thinking out loud here but has anybody done anything with an EPP foam wing with a pusher motor? Kind of like a Zagi?

Hi Dave,

I have a half sheet of Coroplast looking for a project, but haven't found plans that interest me. That Oshkosh trainer looks much better than anything else I've seen. Will the plans/drawings be available soon, and if so where?

Thanks,

Bill Adair

Nice looking trainer Dave. 

I am surprised that noone has mentioned (unless I missed it) the Osborne "Platter" from the Aeromaniacs site. They have trained lots of kids using that design. And the site has some step-up designs to follow the trainer.

I believe earlier versions were constructed of cardboard, or even balsa, but the current version uses coroplast.

Another thought...if I remember correctly, AMA had a design that was initially used as an unpowered swing-around, then later the nose could be replaced with an engine pod.

George

     Most of you may already know that I am very interested in teaching kids to fly control line.  The trouble with teaching them on a one off designed plane is that if the youngster is at all interested in the hobby is that you have to tell him/her that they can not get the plane that they just flew.  If the instructor is any good he will direct them to a low cost alternative, unfortunately this seldom happens. (I will stop here and not go into a rant)

That's a good point.  I should think that you'd not only want to have whatever model you're going to teach with, but a table with a display of what you can get at the LHS (if anything), what you can get as an ARF, what you can get as a kit, etc.

Yes it is better to train a beginner over grass,the whole world accepts that but the training area we have to work with is not grass and there is no other option.  I started my son at age 4 over grass with a Scientific hollow log but the use of these trainers is at an airport open house and they do not have any grass for us.  Larry has to try to design an updated PT 19.  Like the old Timex slogan "it takes a licking but keeps on ticking" we need to build for the site

I just build basic trainers with a piece of glider wing stock for the wing (one 36" plank makes two) and 1/2" balsa for the body.  The engine can be rubber-banded on.

Trainer with a Babe Bee.
Racer with a Black Widow.

My daughter liked the colorful film covering best.

We always give each kid a certificate after his flight.  Next year that certificate will have club, hobby shop, and website information on the back.  Don't know why we didn't think of this sooner!