Prospects for S.P.A.D. CL Models?

How about all you clever and resourceful folks who have experimented with S.P.A.D CL models sharing your thoughts and experience?

Thanks in Advance,

Andrew Tomasch

In my mind I don't think anyone has really designed the ultimate trainer and the SPAD idea could be an excellent way to get there. I would like to see something designed around the LA or FP 15 or 25 that would bounce like the 1/2A platter does. The 1/2A's are to hard to deal with and I don't feel they are as easy to fly as the bigger ships.

I have quite a bit of the coreplast material left over from a sign shop, wished I had time to play with it and see if I couldn't come up with something. Too many projects too little time.

Quick and easy coroplast CL plane plans

Thanks! I've drawn something similar myself for 1/2A. I think this one needs more engine offset .

Andrew;

Mike Ogren has been making and selling a line of combat and sport kits using this stuff for a couple of years. He even has one that supports an upright engine - sounds like a good choice for someone trying to get into the hobby and has a Fox 35.

Site is: http://personal.bellsouth.net/c/l/clflyer/www_protech_com.html

Those aren't 100% Coroplast. They've got foam wings and Coroplast tails.

I think he's quit using the upright engines. Had problems with those at the Nats last year (hit the ground at the bottom of an outside..). His new ones are sidewinders, like most other Combat planes.

I have built the plane from the Balsa Beavers site. I have one of my RR-1 clones on it. It flys GREAT, shame on people talking bad about Cox reedies! I see no reason why you can't size it up to take a bigger engine. My 1/2a jobs made from Coroplast just bounce if they hit the ground. I also have an Osbourne Platter made from coroplast. I made it tail heavy so I can do loops 18 inches off the ground in it's own length! Coroplast would be perfect for combat. It takes me 45 minutes to make a 1/2a Platter from coroplast.

I don't know about "perfect for Combat" - for 1/2-A, they're good for fooling around with friends, but they'd be heavy and flop around and in real competition the VA and Cyclon powered Lighthawks, Buzzards and Russian RTFs would eat them up. Not to mention they'd probably come in at you if you tried to fly them to the limit on 35 foot .012s, let alone 42 foot.

I'd make a point of getting one free each time I visited the lumber yard, too. I even put aside one of each type to hang on the wall (I have some rare ones from other towns..).

Maybe I should have just found out where they make 'em and gotten a box of unprinted ones, since I used a lot of them.

Barry Baxter

Kris

Kristopher Citrin

Yup. Finally tracked down the link:

http://clstunt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=1609&forum=DCForumID1

Andrew Tomasch

Hmm...I think I have an old SPAD plan somewhere. Now to locate some coroplast...

Where to start? Well, if we are just talking trainer here, I'd probably just build a flat bottomed 2 mil wing similar to the the new Hell On Rail wing and mount that straight to the top of the PVC fuse. We've been having more trouble finding the PVC fuse, so the new fuse is aluminum L or U channel from Lowes' That means you need to make an engine mount too which is just a piece of Walmart Cutting board. But you can mount your engine and screw on some landing gear to that piece as well. When I get around to it, I'll probably use the PVC for ease of operation. You can get really fancy and fold a fuse out of the 2 mil stuff, but it gets heavy quick, not that the PVC and Coro wing is particularly light.

In the end, durable is going to be the key word. The Coro takes a lot of abuse though the 2 mil isn't half as strong as the 4 mil. It'll still take a licking that would turn your balsa plane to pieces. In stunt though, we tend to build on the lighter side of durable. Built to fly not crash. In speed and race, exact control of aerodynamics is more of an issue and you simply cannot control the airfoil produced by Coro. Each sheet is just a wee bit different. No problem in the RC combat arena for the most part, but more critical in our domain. Carrier, maybe more durable again but all the pains you need to go through to produce an airplane that looked scale? Maybe a Carrier Trainer.

I think getting the plans or at least the stats on the Circle Jerk and going from there is a good place to start. Remember, the really fun thing about the SPAD concept is YOU are the ErrorNautghytcal Ignorear. Play with it, alter it a bit, roll your own. If it doesn't work, another couple bucks worth of Coro and half an hour and you can be ready with your NEW design.

Soon as I get to it, I'll post what I do, but as I started this response with, 2 years ago I was going to do something, haven't gotten there yet.
From somewhere near Parkville, Mo.
William Crane
AMA 6733

All we need is now is a fuselage...

Thanks,
George

The more I think about the Bipe thing the better I like it. Rubber band the wings on and it would be close to indestructible. If we could find the PVC drain pipe or maybe some other light round pipe you could cut a hardwood plug for the front and bolt on an RC motor mount.

The big engineering problem is getting the needed spacing between the wings and figuring out a way to hold them on with rubber bands. If my lathe was big enough why couldn't you take a piece of thick wall PVC pipe and taper it to a fairly thin wall towards the rear. This would get rid of quite a bit of the weight and leave the nose strong enough to hold the engine.

Bob,

One trick you'll find for fuselages if you root around on the SPAD site for a while is to use a blow molded plastic whiffle ball bat for a fuselage. Sounds pretty close to what you have in mind?

One of the more amusing/entertaining aspects of SPAD building is the endless scavenger hunt for materials that can be adapted to suit a given purpose. Makes wandering the aisles of the Home Depot a real hoot!

Andy Tomasch

However, the newest of the SPADs the SPA3D uses essentially a flat wing. It designed for those annoying hovering over the runway and so called '3D' flying routines. They double the leading edge of the wing over and secure it backards a bit from the front with a piece of bent coat hanger. These perform at low airspeed and high AoA as well as the big fat balsa wings. In fact several reviews have just come out in a couple of the magazines talking about them as being THE 3D trainer. Not as pretty but everybit as functional.

There would be no problem with attaching two of these wings to a folded up fuselage of 2 mil coro, reinforced in areas with 4 mil. I'll throw a couple links up here in a second, one for the wing, the other for a fuse similar to what I'm thinking here. The fuse desing would follow either Krauts Spadet LC 40 or SpadStick.

http://www.spadtothebone.com/SPAD/SPA3D/Page2/page2.html
http://www.spadtothebone.com/SPAD/Spadet/index.html

Actually, the Spadet fuse construction comprise the first pages of instructions, so scroll through those pages for instructions how to. Our SPADSlob should be quite similar.

While the wing construction for the SPA3D involves the wing coming back down to the level and is also formed with the use of the aluminum channel. I don't see why it wouldn't work with just a flat upper surface, shouldn't be to hard to try one, then re-engineer another.

Glues and Flashing, that is a common question with SPADS. There is supposed to be a new formulated CA glue that makes surface prep unnecesary. I haven't boughten any of that yet though I here it's good. Instead, I find the glue line, flash that, a little light buffing with 400 grit paper to take the shine off and a quick wipe with denatured alcohol or acetone. Ok, in a hurry I just flash it and glue.

Flashing? This is passing a flame from a butane torch over the surface of the coroplast to burn off the release agents from the Coroplast. If you pass the torch over too slowely, the coro will warp a little and straighten back up as it cools. REAL slow and you'll melt your Coro. To keep things straight and level, I usually just lay an aluminum straight edge next to the area I'm going to flash. You can see the gasses of the release agent flow away from the flame along with the unspent butane fuel I'm sure, but there are more gasses on the first pass then the second. The glue really works best on piece that is warm from the flashing, maybe the pores of the coro are likewise expanded at this time.

Glue, fresh CA. As the CA goes stale, it glues the Coro less effeciently. You've noticed how your CA takes longer and longer and longer, especially if you opened a bottle, left the cap off, and returned to the buildling board several weeks later. Or, as is more likelyin my case, your beautiful, lovely daughter has obsconded with it to glue here nails back on and left the bottle open in her room for a couple of weeks. After prying the glued and once brand new bottle of glue off of the dresser that you likewise spent loving time finishing, painting and detailing, you'll notice that what glue is still in the bottle and didn't spill out, just doesn't fuse quite as well or fast.

Time to start buying smaller bottles of glue and keeping them in the spare refrigerator in the garage. The one everyone has right that holds the pop and any bulbs that you might be trying to force for Xmas blooming?

Only buy big bottles of CA if you are starting a big project. When you get around to it, glue is cheap, even if it is 13 bucks a bottle. Refinishing agents and time for the Dresser, well, lets not go there.

From somewhere near Parkville, Mo.
William Crane
AMA 6733

George,

The Bi-Slob idea has surfaced before. Mr. Clean built a Bi-Slob wing out of coroplast, but got concerned about the weight. You can build with it just like cardboard, but adhesives have got to be appropriate for plastic, mostly CA (as Mr. Clean has discussed here). I built a Cardboard Stick in the '70s, and BTW, cardboard is still a possible choice for material. The advantage of coroplast is that it is fuel proof and comes in nice colors. And you can get a smooth airfoil by simply wrapping the coroplast skin around the spar and taking whatever "polywog" shape you get (see the Circle Jerk). One other adhesive I've not heard much mention of, and would be curious to try, is hot melt glue. This might be just the ticket for assembling traditional type fuselages with sides and formers. The big issue with the coroplast is removing the mold release so the adhesives will stick. I don't much care for the torch technique which is the most popular, and plan to try wiping with rubbing alcohol instead. White or yellow glue absolutely will *not* work on slipery plastic like coroplast.

Andrew Tomasch

The problem with hot melt glue is that the coro gets pretty hot out in the sun and I have heard of seperations on days in the 90's and full sun. Otherwise I here it works really well. There are high temp glue sticks though, perhaps they would not be so likely to release.

Tim

The admonition about using too much glue is true - one glue dot per cm seems about right, coroplast to coroplast. But you need a lot more for wood to coroplast (because the wood really absorbs glue). I used thin CyA throughout.

Flashing - well, it turned out to be pretty easy to do, after all, no big deal at all. I just used a butane lighter. The easy way was to hold the piece just past vertical, ignite the lighter, and run the flame down the length of the part fairly quickly. To tell the truth, I didn't see any of the stuff coming off the plastic that people tell you about. I ran the flame across the piece very quickly - about one second to cover 10 inches of seam. I did repeat it 2 or 3 times just to be safe. The coroplast looked exactly the same before and after but the difference in gluing characteristics is dramatic. I wonder who discovered this technique - I wouldn't have guessed it in a million years.

I wonder what's actually happening. I seriously doubt it's got anything to do with molding residue (isn't this stuff extruded?). Spectra, which is essentially the same material (polyethylene, while coroplast is some sort of polyolefin), needs to have its surface "flashed" before it can be used for composite layups, because it repels resins otherwise. I think they use electron beams and vacuums or something of the sort, and in our case, it's similar because flame is basically ionized gas.