A perfect club project from kit or scratch, this aircraft is a winner
Greg Gimlick | firstname.lastname@example.org | Photos by Greg Gimlick
As seen in the Fall 2023 issue of Park Pilot.
If you’ve been involved with a club or group for any length of time, you know it can be hard to keep interest up and generate new things to engage the membership. My park fl yer club is the Holly Springs Skyhawks, and membership ranges from young people to seniors. The most common thread is a great appreciation for new things that everyone else is doing and learning.
Before the pandemic, our most prolific foam builder and mentor, Raymond Lefrançois (former AMA District IV associate vice president), held annual “Buildalooza” classes that were extremely popular. They began with basic foam-cutting and building techniques and grew from there. Everything from scratch- builds to Flite Test kits were brought and worked on in a classroom setting. The pandemic’s ugliness put an end to that.
Now it’s back! Raymond has pestered me—I mean, encouraged me—to help him find a project that would be both cheap and interesting but ensure success. He arrived for one of our flying sessions with a printed plan for the Quasar, a fl at-foam delta design that he found on RCGroups. He had one cut out and I was sold.
The Quasar Story:
The delta design with rudder that can be cut from a single sheet of DTFB (Dollar Tree foam board) or FTFB (Flite Test foam board) sprung from the fertile mind of Mike “r/cdawg,” an experienced pilot and designer who has had several designs kitted. This one is no exception, and it’s available as a kit from WMPF (West Michigan Park Flyers).
There is a very long build thread showing all sorts of modifications done by others on RCGroups under the foamie scratch-built section. I looked it over and told Raymond that I’d build one, but I also wanted to build the kit version for comparison. More on that in a bit.
This is Raymond Lefrançois’ scratch-built Quasar, cut from FTFB without wingtips or spars.
It takes tough skin to put a design online and make plans available for free, because it seems like everyone thinks they can do something just a bit better, wants to change things, or the internet is just being the internet … well, you get it. We were determined to build them as Mike intended without making any changes. Here is a bit from his notes on the design:
“The setup that I am currently using is as follows:
- Sunny Sky 2204-1480 Kv motor
- APC 9 x 3.7SF 3D [propeller] (I have some APC 9 x 4.6SF 3D [propellers] on order to try)
- Hobbywing 10-amp ESC
- Hitec HS-40 servos for elevons and a Hitec HS-45 on rudder
- Spektrum AR6115e receiver
- Thunder Power 2S/325 [mAh] 55C batteries
As you can see, this is a very light setup as I plan to use the Quasar primarily to be an indoor fl yer. One flight characteristic that delta’s lack is knife-edge capability. I enjoy flying knife-edge, and the Quasar will definitely perform the maneuver. There is still a bit of roll coupling but it is easily overcome by a little cross controlling. I do not use any mixes for knife-edge but I’m sure one could be used to overcome the coupling.”
I stuck with the recommended gear, with the exception of using a similar receiver and similar servos. I’ve also used 2S and 3S 450 to 550 mAh LiPo packs.
The Scratch Build:
Mike’s prototype was built from 8mm EPP (expanded polypropylene foam), but many online have been built from DTFB and FTFB. The difference we’ve found is that, in the final weight, the EPP versions all ended up being as much as 2 ounces lighter when complete. Raymond and I each cut one from single sheets of foam. I used DTFB and he used FTFB, but we both ended up at the same weight of 7.5 ounces without a flight battery. Mike advises to shoot for 5 to 5.5 ounces.
Greg’s scratch-built Quasar from DTFB has a special paint job.
Greg Gimlick’s granddaughter stepped in to paint Grandpa G’s scratch-built version.
Equipment to build these airplanes is minimal. You need a straightedge and something to cut with. Those cheapie snap-off razor cutters work well, as do box cutters, as long as the blades are new. The snap-off types are good because, as they dull, you can snap them off for a new edge. Do not try to push these too far or you’ll end up with ragged edges unfit for gluing. We printed the plans out as a tiled PDF downloaded from the RCGroups thread.
All sorts of glues work well for this project, so choose according to your own preference. Be sure to use something that is foam friendly! I have a lot of allergies to hobby products, so I tend to use hot glue on these projects. My preferred glue is Foam-Tac, but that requires a respirator for me, so I restrict it to outside repairs. For painting, anything from markers to water-based hobby paints will do fine; just remember that weight counts. A bit too much paint on the paper-covered foam will cause it to warp, as my granddaughter found out when she did mine, and EPP absorbs paint like a sponge.
Lay out your plans as templates and transfer them to the sheet of foam. From there, you simply cut them out and begin gluing them together. I suggest that you practice cutting some scrap pieces to get the hang of cutting them squarely and cleanly. Don’t try to cut all the way through the foam on the first pass. Multiple passes will ensure a cleaner cut. Hinges are done by cutting one straight cut with an adjoining 45° cut. Don’t cut all the way through if you can avoid it; this leaves the paper on one side to help with the hinge. If you cut through, just tape the hinge with some Blenderm tape. I also open the hinge and spread some Foam-Tac lightly along the edges. This gives a really good, strong hinge surface.
Greg treated himself to one of these Foam Werks foam cutters from Logan Graphics Products to ensure accurate, straight, 45° cuts.
Greg set the cutter for 45° cutting. Two intersecting slots were cut for the spars.
This is a sample hinge cut with the cutter. Greg practiced on scraps to get the hang of it.
I held off on gluing the bottom half of the fuselage on until the end so that I had a nice, flat surface to work on. Once the bottom was glued in place, I used two large foam blocks to support the airplane and allow the fuselage to go down between them. No control throws are given, so I just allowed for the maximum throw that the servos provided and set up a flight-mode switch for three levels of throw. I used some Du-Bro micro control rods supported along heir path, but carbon-fiber rods provide a stiffer setup. Raymond used bamboo barbecue skewers for rods.
I used 3mm carbon-fiber tubes for spars in the designated positions, along with the 1 x 3 fl at, carbon-fiber strips where designated. I’ll note here that Raymond used FTFB for his, and it was stiff enough that he didn’t use carbonfiber tubes for spars, etc. Our final weights were the same, but he didn’t have to take the time and effort to cut troughs for the spars.
The kit from WMPF is available painted or plain white. I opted for the plain white and downloaded the lightning bolt template that WMPF provides online. The kit is from 7.5mm hot-wire-cut EPP and includes all of the horns, control rods, and some extra foam for repairs. Even the hinges were all done for me. The quality of this kit is remarkable given the price, and the attention to detail is impressive. Service and shipping were fast, and emails were replied to promptly.
The Quasar kitted by WMPF in flight.
Everything—and I mean everything—came out of the box ready to be glued together, and each piece fit perfectly. I do mean perfectly! I can’t say enough about the quality here. Having the slots precut for the spars and the hinges being perfectly done saved a lot of time and effort, not to mention that they were done accurately. Within a couple of hours, I had it together and was almost ready to start painting. I used some water-based acrylic paint and brushed it on.
Kit contents from WMPF are shown upon arrival, with extra foam for repairs, if needed.
The spar slots are precut, and the CG location is marked on the WMPF kit.
The DTFB version parts are cut out and ready for assembly.
The kit contents are laid out and checked. Everything was perfect!
The kit in its finished form was a full 2 ounces lighter than the scratch-built versions, and its performance in the air was markedly better. I honestly don’t see how you can do better than the WMPF kit to ensure success, especially if this is your first build of this type. My background is in large, scale airplanes, so there was a learning curve when I first got into small airplanes such as this. Doing a kit will educate you in many aspects of building like this and will help you be successful right from the start. I highly recommend a kit for your first foray into small, foam airplanes.
Let’s face it: No matter how cool something looks, if it doesn’t fl y well, it’s just not fun. No worries here; whether you choose to scratch-build one or do the kit, they both fl y well. My first test flight was with the WMPF kit, and I set the controls to the lowest of three rate settings. It was also breezy for a 7-ounce airplane (with a 3S 450 mAh battery) at 8 to 10 mph. I did my test flights with the 3S pack, and then tried the 2S pack for comparison.
The WMPF kit in flight.
As soon as Raymond tossed the airplane and it started its path away from me, I could feel that it was solid. There were no roll-tendency, pitchiness, or CG (center of gravity) issues. By the way, the CG location on the kit is printed on the bottom of the wing and felt perfect to me. After a moment or two to get over my surprise at how well this thing flew, I went about exploring the envelope. All three control throws are perfectly manageable and suited to whatever comfort level you have. It can be very mild on low rates and all-out 3D-capable on high rates. I struggle with the knife-edge a bit, but it’s getting better.
Name it and do it. This airplane is just a hoot to fl y and explore areas you’ve never gone before. It’s instantly recoverable when you mess up, and if you do find the ground unexpectedly, there is minimal to no damage. I set my timer to 5 minutes and that seems to be about right for my 450 mAh packs.
The two scratch-built versions came in at the same weight and flew very similarly to each other. Neither is as spritely as the kit, but they also weigh 2 ounces more, which, at this level, is a significant amount of 20%. Raymond left the wingtips off of his version, and it does inverted fl at spins like it was designed to do them. Mine is more stable and not as capable of such maneuvers. Aside from that, they both perform the full spectrum of aerobatics, including hovering. My granddaughter’s paint job warped my elevons a little, so there was a bit of oddity as a result. I’ve since laminated some carbon-fiber strips on the trailing edge to keep them straight.
2S or 3S:
All three airplanes showed that they would fl y on either setup, but because we fl y primarily outside, we choose 3S most of the time. The kit version certainly does better on 2S than the others, given the weight difference. For indoor flying, 2S is just fine.
If you’ve never built an airplane such as this or experimented with extremely lightweight airframes, this is a perfect introduction with minimal output in terms of cash. It’s a perfect project for involving kids or groups, and it’s forgiving of errors in construction. The kit will eliminate those errors. After our club build session, the air over Holly Springs will be full of Quasars! This airplane puts a smile on my face every time I fly it. If you’re in the Raleigh, North Carolina, area, come see us and fly one yourself.
LENGTH: 27 inches
WINGSPAN: 21.5 inches
WING AREA: 325 sq. in.
WING LOADING: 3.15 ounces/sq. ft. WMPF with 3S; 4 ounces/sq. ft. DTFB with 3S
WEIGHT: 6.7 ounces WMPF with 2S; 7.1 ounces WMPF with 3S; 8.6 ounces DTFB with 2S; 9 ounces DTFB with 3S
EMPTY WEIGHT: 5.6 ounces WMPF; 7.5 ounces DTFB
>> Hovering ease
>> Smooth flight
>> 3D capability
IN THE BOX:
>> Laser-cut foam parts
>> Three 3mm carbon-fiber tubes
>> 1.5mm solid trussing
>> Four 3mm x .8 fl at
>> Control rods