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Darwin with Push-E and Manx

This page is dedicated to providing a preview of what is soon to be released from Garrison Aerodrome. As the past year or so has gone by, we've been trying to become better at working with and processing EPP foam so that we can design and manufacture better kits for our customers.

Cabin Foamie 4-Channel Electric

The geneology of the Cabin Foamie goes back to a one off balsa plane that Pat Mattes built, which he called "the Cessna". "The Cessna" was inspired by a Kyosho foam Cessna that Pat had salvaged from the local hobby shop's basement. I actually ended up with "the Cessna" and even generated some CAD work which culminated in about 5 sets of laser cut ribs. The intention was to eventually take this "sort-of-Cessna" forward as a Garrison Aerodrome kit, and we may still do it. However, the project got sidelined by the wonderful world of EPP and the charge to production for the Push-E Cat.

Time went by.

Last year, Pat made friends with a fellow at work who had built models since he was a kid, but had never actually had much luck flying them. Under Pat's wing, Sanjeev eventually started flying some models and even had a Blue Foamie going at one time. During this association, Pat scabbed together a high wing, three channel Blue Foamie for Sanjeev to try. It was way ugly, but it flew quite well. Eventually Sanjeev managed to bash the fuselage into styrene powder, and he came to me to try and fab up an EPP version of the plane.

With Pat's permission, I scammed some dimensions off the original "Cabin Foamie" and did some initial work. The similarity in shape between "the Cessna" and the Cabin Foamie is striking, but it is not direct. I did not end up measuring anything between the two aircraft, although I took clues between the two. In fact, the pictures on this page are actually of the second EPP Cabin Foamie prototype. The first had constant chord wings, and I got the corrugated plastic tail glued in the wrong place.

Anyway, the first Cabin Foamie flew OK, and actually had a VERY effective rudder. Unfortunately, I put too much dihedral in the wing, and the thing had a wicked Dutch Roll. The ailerons on that first CF actually did very little except get you into serious trouble. The pictures on this page are of the P2 Cabin Foamie. It features a tapered wing with tip plates, much better wing reinforcement, and a much stiffer fuselage. This plane is actually going to Sanjeev in Chicago as soon as I test fly it. One additional thing I've learned from the two prototypes is that the cabin needs to move about 1.25" back toward the tail so it will balance properly. Oh, well, on to P3, which I should have at the NEAT fair.

Other than modifying the tooling for the relocated cabin, the ground work for releasing the Cabin Foamie is complete. Once I am sure it is flying correctly and that the CG issue is resolved, we will be able to write the instructions and release the kit.


Send us your feedback on the Cabin Foamie!

Hand-Cat Hand Launch Glider

The concept for the Hand-Cat came out of a conversation between Pat Mattes, Will Sears and myself in which Pat wondered out loud about what kind of hand launch glider you could make out of a Push-E Cat wing. So we built one, and it flew pretty good!

The first pictures are of Hand-Cat Prototype 1. It was a pod and boom style fuselage mated to a regulation Push-E Cat wing sans motor pylon. It used two S-80 servos, a Hitec Focus 3 AM receiver, and a 270 mAh pack (courtesy of Radio Shack) for an all up weight of 13.3 ounces. The prototype wing had a span of 58 inches, and used an Eppler 205 airfoil which penetrated pretty well to cover lots of ground to look for thermals, but it would still slow down.

The Hand-Cat was the first plane with which we have pursued the concept of the composite construction EPP fuselage. The idea is to create hard points in the fuselage by using non-EPP materials to bear tensile loads, and to design in "bend points" for the fuselage to absorb damage without affecting the control systems. I won't go into any more detail than that, other than to say that it works, but it takes some experience to understand how to space out your gear and tape the thing up properly.

The Hand-Cat P1 had already proven itself to be a great small field flyer. It had a reasonably tight turn, launched fairly easily, hung well, and bounced off obstacles very well.

Well, there still appeared to be some room for improvement with the original concept. In particular, the general trend in handlaunch is to smaller, lighter models with more agressive airfoils for better penetration and launch height. Additionally, continued flying of the original P1 prototype pointed out some serious shortcomings in our original fuselage lay out.

The second set of pictures below show the newly completed P2 prototype Hand Cat. This prototype incorporates many of the changes that I wanted to get into a high performance EPP hand launch. However, the fuselage will be changed to use a different mounting technique so that the components are more easily accessible via a canopy.

As you can see, the P2 is a radical departure from the P1. Gone is the modified Push-E Cat wing, replaced with a high performance single taper planform using a blended Selig 3000 series airfoil combination. The oversized tail of the P1 has been replaced with a more logically sized, swept forward V-tail. The fuselage in the P2, although not representative of the final version, shares the integrated finger pad for launching, and the inline component placement, which minimizes the need for nose weight. The bolt on wing reduces weight and drag.

So what was the point of these changes? The little experience I have had with the P2 indicates that we have made progress on a couple of key points: first off, the all up weight has been reduced from 13.3 ounces to 10.1 ounces. Second, the aircraft now launches much higher and has a much faster cruise speed. Third, the durability of the fuselage has been significantly improved. In short, the P2 Hand Cat is much closer in its wing loading, performance and handling to the current generation of competition hand launch gliders.

The intent for the Hand Cat is to be a glider that you can reach for not only to sport fly, but also one to reach for when all the high dollar planes have succumbed to battle damage during a contest. At our hand launch contest last year, I saw first hand how valuable a Hand Cat could have been. The weather was incredibly gusty and many, many high dollar birds got torn up pretty bad trying to compete for one little local contest. Even my Spectre blew its tail feathers completely off in a violent flutter on a bad gust.


Send us your feedback on the Hand-Cat!

Cyber Cat 2 Meter Glider

The Cyber Cat is a project born of desperation. Will needed a 2 meter glider for the LOFT Weekend contest. He had a choice of either repairing his smashed Spirit or trying to fabricate something from the EPP scraps we had laying around the shop. "I'll bet we could build something that quick," I remember myself saying.

Well, we did it, but not successfully on the first try. The pictures below are of the P1 Cyber Cat. It uses an Eppler 205 throughout, modified for thickness at the root only. The wing planform (and also the plane's name) came from Dennis Adamisin who suggested it so that we could use a straight spar joiner matrix. Dennis used the same concept on his one of a kind two meter that he calls the Cyber Crow.

Because of this, I guess you'd call the Cyber Cat a collaborative design. The fuselage is all mine (including the blame). The tips are Pat Mattes' from the Push-E Cat, and the planform, of course, is mostly Dennis' fault.

The P1 Cyber Cat had a short but miserable life. On its first winch launch, the fuselage broke in front of the wing. Also, in our hurry to try and get it ready for the LOFT contest, I allowed Will to use really lightweight Sullivan steel cables, instead of insisting that he use the heavier ones like we use with the Push-E Cat. The end result was that the plane had little real control at true flying speeds.

Another issue was that the extremely thin (for a foamie) fuselage at the tail allowed the control group to "wag". This was also unacceptable.

The result of all these lessons was the formation of the concept of composite EPP fuselage construction. I went back to the shop and built a second fuselage with carbon and wood reinforcements added to the tail boom and a central balsa "crutch" which ran from the wing TE to just behind the nose. I did a composite tail group which included a corrugated plastic fin and stab with lightening holes and balsa rudder and elevator flying surfaces. The fuselage length was constrained by the length of the EPP billets we use in production, which is about 34 inches usable.

The P2 Cyber Cat took to the air at the end of the 1999 season. It launched about the same as a Spirit and flew reasonably well. However, it was hampered by excessive weight due to the need for significant nose weight. I continued to fly the P2 until it suffered a catastrophic spar failure on launch after the season was officially ended.

P2 has been rebuilt to temporarily serve me as a 2 meter plane until I can get P3 or my DJ Aerotech Spectre built. The nose has been lengthened to reduce the need for nose weight, and the wing has been repaired and reinforced.

The P3 will be the final pre-production model. It will feature a revised airfoil (3021) and a more robust fabricated spar matrix. The fuselage will be stretched overall to allow the same fuselage to accept 2 meter and 100 inch wings, as well as standard servos and radio gear. The wing has been modified to use a basswood sub-trailing edge and balsa TE to allow for control surface variation.

The final production Cyber Cat kit will allow the builder to fabricate the model as a rudder/elevator, rudder/elevator/spoiler, rudder/elevator/flap, or as a full house glider. The wing will come pre-routed to accept micro servo driven spoilers.

The Cyber Cat is a slightly longer lead time project. I am sure that it will prove to be a great flyer and popular model once we finish development.

Send us your feedback on the CyberCat!

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