Author Topic: Training kids to fly CL...Trainer_Plane..? (Read 2653 times)

REX1945 · « **on:** July 28, 2015, 10:48:23 AM »

Last fall I started teaching kids in the local B&G Club how
to build balsa models, apply for AMA membership, and have
fun with Flying Clowns and gliders.

This summer, we are near completion of the clowns and going
out to the flying field to learn how to fly. After a comment from
Saul Williams (AMA 1066653) that he didn't want to fly his plane
and crash it, I started looking for a "Trainer Plane" they could learn
on that would be easy to build, cheap, and somewhat crash-proof.

The Osborne platter was my first idea, but I really think it's easier
to learn with a .15 due to line tension issues.

I made a couple of foam wings and attached power module and control surface
and we've been crashing one a week for the last month. The CG is a bit
too far forward and the chicken-hopper tank was vulnerable.

My second iteration was to make a longer chord profile (I used my Adams' Special templates).
This flies a bit slower and with dacron reinforcement is fairly indestructible.

Last week we KO'd the tank and I'm thinking of mounting a 1 Oz klunker sideways between
the motor and the BC.

Will a klunk work when mounted in this orientation, or will it go rich when we get up to speed ?

Looking for comments on the design and other options.

Tim Wescott · « **Reply #1 on:** July 28, 2015, 11:48:48 AM »

Hey Rex:

Give it a try the way you picture it, and see. I think your big problem isn't going to be going rich as it gets up to speed, but rather having it go lean as the flight progresses. I'm not sure if that's even an issue with a trainer plane but -- give it a try.

If it goes rich when it gets up to speed, or leans out too much during the flight, make it a uniflow.

The next bit only applies for the direction you're mounting your tank:

As long as there's no leaks all you have to do to make this happen is to run the uniflow vent all the way to the back of the tank -- that puts the uniflow vent on the outside of the circle, which is where you want it for uniflow nirvana.

Tim Wescott · « **Reply #2 on:** July 28, 2015, 11:53:42 AM »

And let us know how it comes out. This is my current solution to training, but it's smaller than what you're doing (it's roughly 1/2-A sized, but a bit heavy at 8 ounces). I think it could be scaled up, but then you may have to pay $2 to $5 for the airframe, instead of $1.

The key point of the design isn't that it's indestructible, but that the airframe is cheap and easy to assemble so you can show up at the field with a bunch of 'em. It's electric because I think that's easier to deal with for a beginner, and the particular beginner I'm training doesn't like the noise. It's a pusher because electric motors have smaller shafts than IC motors, and where you can bonk an 8-ounce IC plane nose-down on dirt and not break an engine, you'll bend a motor shaft every time unless it's not in the front of the plane. I hope that I haven't just replaced burning batteries for bent motors -- we'll see once I get a chance to have a training session with it.

REX1945 · « **Reply #3 on:** July 28, 2015, 01:24:35 PM »

Tim,

Good idea; I tend to forget making a klunk (clunk ?) tank uniflow because
I usually use Hayes tanks and they have no option for that.

My goal is to get the damage down to one prop per flight max.

On a lucky day in May, we got 3 flights out of a prop; but that doesn't
normally happen.

Rex

LARRY RICE · « **Reply #4 on:** July 28, 2015, 02:53:27 PM »

Black Hawk Models produces two basic trainers:
"Tenderfoot" is a .15 trainer made of solid balsa and very sturdy. It has the engine mounted up-right for easy starting. Cost $44.00.

"COX TRAINER" is based on the old Cox PT-19. It is made out of half plywood and half balsawood. The engine, tail and wing rubber band on. They will pop off in a hadr landing and rubber band back on in seconds. This plane was made for clubs that teach 25 to 50 kids at a time. Cost $60.00

You can look at the Tenderfoot on our web site under AC models and the COX TRAINER under new items of FS models
BLACKHAWKMODELS@AOL.COM

Larry aka Captain Blackhawk

Kim Doherty · « **Reply #5 on:** July 28, 2015, 03:02:33 PM »

The "ManWin Trainer" is by far the best trainer I have ever flown. Virtually indestructible, made from coroplast (lawn sign material) and some aluminum sheet for a motor mount. When all you are trying to do is to stop the world from spinning (no, not like Igor

but I digress ) but literally, the shape of the model is irrelevant.

http://www.balsabeavers.com/information/plans/manwin.pdf

Enjoy,

Kim.

Paul Taylor · « **Reply #6 on:** July 28, 2015, 05:38:45 PM »

The ToughBaby we used at KidVenture took a real beating. Power was a Norvel .061. I only went through 3 in about 3 hours of back to back flights.
The plane never broke, just had issues with the engines. NVA's mostly.

I know they have been posted here in the past. A quick search might bring results of some plans.

But basicly it was a platter cut in the shape of a plane.

Mark Weiss · « **Reply #7 on:** July 28, 2015, 06:26:25 PM »

Hi Rex

After four years of teaching at the Joe Nall, I can suggest the plane we have been using all along. It is the RingRat, manufactured by Stevens Models in Colorado. Bill Stevens is the owner and designer and this plane can take a hit and yet teach the fundementals. It is electric powered and flies with a 1350 2 cell battery and a timer. The kit is laser cut and a pleasure to build. I can do it in three days no including covering. It looks like a baby Ringmaster, flies very well and with the timer, you can set rpm's and fight time. We use 42 foot 010 lines.

We have over 1700 flights with hundreds of crashes and they keep on ticking. Bill can give you a rundown of the prices and suggested accessories. It has about a 26" wingspan and is very light. Handles the wind surprisingly well. With a larger three cell battery, it will do the entire pattern. His email is sales@stevensaero.com and tell Bill I sent you.

Call or email me with any questions: ama82824@yaho.com (302)547-4917

Hope this helps,
Mark Weiss

Tim Wescott · « **Reply #8 on:** July 28, 2015, 06:59:15 PM »

Quote from: Mark Weiss on July 28, 2015, 06:26:25 PM

Hi Rex

After four years of teaching at the Joe Nall, I can suggest the plane we have been using all along. It is the RingRat, manufactured by Stevens Models in Colorado. Bill Stevens is the owner and designer and this plane can take a hit and yet teach the fundementals. It is electric powered and flies with a 1350 2 cell battery and a timer. The kit is laser cut and a pleasure to build. I can do it in three days no including covering. It looks like a baby Ringmaster, flies very well and with the timer, you can set rpm's and fight time. We use 42 foot 010 lines.

We have over 1700 flights with hundreds of crashes and they keep on ticking. Bill can give you a rundown of the prices and suggested accessories. It has about a 26" wingspan and is very light. Handles the wind surprisingly well. With a larger three cell battery, it will do the entire pattern. His email is sales@stevensaero.com and tell Bill I sent you.

Call or email me with any questions: ama82824@yaho.com (302)547-4917

Hope this helps,
Mark Weiss

So, how come my electric thingie bends the shaft on every landing (granted, all the landings have been straight down) and yours doesn't?

Mark Weiss · « **Reply #9 on:** July 28, 2015, 08:27:42 PM »

Tim

Our props are held on by a prop saver hub. We use slices of surgical tubing to secure the prop instead of O rings. The plane is very well designed and with such light weight and mass, it has proven to be very durable. The LG is also shock mounted using O rings/rubber bands. We tried hard mounted props but could not afford all those replacement props and bent motor shafts.

Trust me, with 4 years under our belt, we have worked hard to develop the right package. 1700 flights provides a lot of important information. The last thing we need are airplanes that cannot take the
hits from new students.

Mark

Larry Renger · « **Reply #10 on:** July 29, 2015, 08:36:01 AM »

Do a search on the ET-1. The Knights of the Round Circle has been using it for training at the AMA Expo and two air shows for years. We are still flying the original 4 planes!

john gunn · « **Reply #11 on:** July 29, 2015, 11:56:03 AM »

The best combo I have found is the SIG buster and a FOX 19,been using this combo for years, it works There are is an easy start motor and a good motor for restarts. There are lots of them on ebay, Fox has needle packages for them, I just ordered 2 complete needle and spray bar packages.

Tim Wescott · « **Reply #12 on:** July 29, 2015, 12:22:11 PM »

Quote from: Mark Weiss on July 28, 2015, 08:27:42 PM

Our props are held on by a prop saver hub. We use slices of surgical tubing to secure the prop instead of O rings. The plane is very well designed and with such light weight and mass, it has proven to be very durable. The LG is also shock mounted using O rings/rubber bands. We tried hard mounted props but could not afford all those replacement props and bent motor shafts.

I'll have to try that. Could you post the exact motor, & prop you're using (battery too, if you want it all in one post). I've tried prop savers on high-RPM setups and the prop tends to come loose in turns, which can be more than annoying.

john e. holliday · « **Reply #13 on:** July 30, 2015, 12:44:14 PM »

For training you should only be worried about the student getting over the dizzies while learning to take off, fly level and land. The start doing climb and dives until they are doing wing overs.

Phillip Kenney · « **Reply #14 on:** July 30, 2015, 02:49:15 PM »

I did try a serech on Toughbaby but wasn't able to find any real information on it. If somebody has a link to an earlier post that might shows the plans I would appreciate it.

Chancey Chorney · « **Reply #15 on:** July 30, 2015, 03:04:17 PM »

Quote from: Phillip Kenney on July 30, 2015, 02:49:15 PM

I did try a serech on Toughbaby but wasn't able to find any real information on it. If somebody has a link to an earlier post that might shows the plans I would appreciate it.

I second that thought.

Tim Thompson · « **Reply #16 on:** August 03, 2015, 08:55:52 PM »

Since I'm partial to foam wings,I like the looks of your design! Could you please answer a bunch of questions? Like are there any spars in it ? How about the span and chord ? Any reinforcement for the pod and booms? Is that pink foam and if so is it covered? Looks like it would be pretty quick to build. Thanks in advance

Blue Skies. ......Tim

Tim Wescott · « **Reply #17 on:** August 03, 2015, 10:39:32 PM »

Quote from: Tim Thompson on August 03, 2015, 08:55:52 PM

Since I'm partial to foam wings,I like the looks of your design! Could you please answer a bunch of questions? Like are there any spars in it ? How about the span and chord ? Any reinforcement for the pod and booms? Is that pink foam and if so is it covered? Looks like it would be pretty quick to build. Thanks in advance

Hey Tim:

First, it still hasn't flown: I'm a one-man shop and I'm putting out customer fires. So I can't guarantee that it won't fall apart on the first landing. However, it follows a motor-front design that I did, so I have high confidence in it.

Second, it's made completely out of dollar-store foam. There's more than enough foam in a $1 sheet of foam for an airframe.

Third, there are no spars -- the wing is two pieces, with a tripler folded over the leading edge, to make three layers. It's pretty robust in a crash.

Span is 24". Chord is 5" on average (I think it's 5-3/4 at the root and 3-3/4 at the tip. Maybe).

Each airframe took me four hours -- but that was designing as I built. If I ever build the same thing twice in a row the second one will happen in about an hour.

This video is great for understanding how these dollar-store foam planes go together:

http://flitetest.com/articles/FT_Bloody_Wonder_Scratch_Build

Tim Thompson · « **Reply #18 on:** August 04, 2015, 02:27:38 PM »

Thanks Tim. My bad here, but I actually was asking Rex. Sorry. But DT Foam does crash pretty good, so I hope you have good luck with your design!

What I'm after is a foam wing that is quick and easy to build, fairly tough and easy to repair.

Blue Skies. ...Tim.

REX1945 · « **Reply #19 on:** August 04, 2015, 03:55:02 PM »

Quote from: Tim Thompson on August 03, 2015, 08:55:52 PM

Since I'm partial to foam wings,I like the looks of your design! Could you please answer a bunch of questions? Like are there any spars in it ? How about the span and chord ? Any reinforcement for the pod and booms? Is that pink foam and if so is it covered? Looks like it would be pretty quick to build. Thanks in advance

Blue Skies. ......Tim

Tim,

   It is made out of Home Depot 2" x 24" (pink) foam. Wing chord is 8". The airfoil profile is from an Adams' Special plan.
I started with a Flying Clown airfoil and it flew a bit too fast. White foam would be a lot lighter.

   The assembled wing( 2" motor mount foam blocks, Dacron fabric reinforcement, and 5/16 hardwood LE dowel) weighs
4.5 Oz. Engine pod and tank weighs 3.9 Oz w/o engine. Dacron strips help keep the trailing edge from separating when
the plane lands on it's nose. Strips are "painted on" with polyurethane. The hardwood dowel never has broken so far.
The only "spar" is the leading edge glued in with "TiteBond". If I added spars, they would probably be at the high point
in dado slots made of aluminum tube. Bend flex is not a problem, cracking on centerline when landing on the nose is.

   Tip weight is a 1/4-20 carriage bolt tightened across the foam between a pair of lite ply plates.

   Most often we've broken the stabilizer booms which were made of lite ply. I have added popsicle stick doublers
at the trailing edge to stiffen it up a bit; we'll see this week.

   Out of six "wings" I have rebuilt the engine pod assembly twice.

Rex

Tim Thompson · « **Reply #20 on:** August 05, 2015, 01:51:37 PM »

Thanks Rex !
So it appears the pink foam is holding up pretty well. Is it Formluar 150 or 250? We can't easily get it here but we can get Dow blue foam sometimes.
So is there any reinforcement for the engine pod? And when the wing cracks in this area how are you repairing it ?

I think you have a nice design here ,after I finish a couple of projects maybe I'll try one out!

BLUE SKIES. ...Tim

REX1945 · « **Reply #21 on:** August 05, 2015, 06:10:04 PM »

Quote from: Tim Thompson on August 05, 2015, 01:51:37 PM

.... Is it Formluar 150 or 250? We can't easily get it here but we can get Dow blue foam sometimes.
So is there any reinforcement for the engine pod? And when the wing cracks in this area how are you repairing it ?
BLUE SKIES. ...Tim

Tim,

   If I break a wing, I use another one; they are easy to cut out and all the other stuff bolts on.

   The foam is Formular 250.

   The engine pod is reinforced by wrapping it with Dacron cloth painted down with nitrate dope.
There are stub engine bearers between the two sheets of plywood.

   On my next iteration I plan to extend the Dacron for the full wingspan on LE and trailing edge.

   The CG is a lot improved with the clunk tank located behind the engine. It will do loops, reverse
wingovers and figure eights quite smoothly.

Tim Thompson · « **Reply #22 on:** August 05, 2015, 07:57:18 PM »

Cool!
I think that Dow square edge 40 would crash better than pink foam. But I really wonder about EPP. It tends to tear easier than even pink foam but it bounces great! Maybe an arrow shafts in the chord line and some dacron on the leading and trailing edge and the rest like you've made might be the hot ticket?

Blue Skies. ....Tim

Jack Pitcher · « **Reply #23 on:** August 05, 2015, 09:03:19 PM »

I have also been searching for ToughBaby plans. They're supposedly downloadable from Model Aviation/Plans but I haven't been able to find them. Any one know where they can be found?

REX1945 · « **Reply #24 on:** August 06, 2015, 10:35:34 AM »

Quote from: Tim Thompson on August 05, 2015, 07:57:18 PM

Cool!
.......Maybe an arrow shafts in the chord line and some dacron on the leading and trailing edge and the rest like you've made might be the hot ticket? ......

Blue Skies. ....Tim

Tim,

   If I want the wing to be indestructible, I would spend time to make it like my real Adams' Special wing. I used 1/4" aluminum tube spars, cap strips
and covered it with silk using butyrate dope. The hard part is making all the square windows to get the weight reasonable. It still is 2 oz
heavier that a conventional balsa stick-build C tube wing.

  But, that is labor-intensive and Murphy would probably find a way for kids to break it.

   I'm thinking of investing the spare time on a take-off dolly with big wheels. Most of the kids loose control on
the hand launch take-off. I'm hoping more than one of them will complete a lap in the near future.

   Do you think it's easier to learn taking off the ground or hand-launch ?

Rex

Rex

Tim Thompson · « **Reply #25 on:** August 06, 2015, 12:44:08 PM »

Actually I'm looking for a wing that is quick, simple and cheap to build. One that has a low emotional investment. When it gets destroyed replacing it will be fairly painless.

Our club trainer is an older combat design that uses Corehouse cores and a big chunk of popular wood for the fuselage. It's Fox 35 powered. Old Torpedo 10X3 props work best on it but are hard to come by. I've watched it go into the ground a dozen times without doing much to it. But what it does need attention it takes a few hours.

As far as hand launch /wheel launch beets me! Our club trainer can be launched both ways and some people have a hard time either way! All you can do is hope the plane will survive without hurting that persons feelings and let them know it's OK that the plane crashed.

Blue Skies. ....tim