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Jun 02, 2018, 08:00 PM
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Quote:
Originally Posted by BSquared18
Do you read tea leaves too?
Bill
Only if the tea bag splits, otherwise stick to coffee....
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Jun 13, 2018, 12:17 PM
Nu2RC
BSquared18's Avatar

Building’s Done; Flying’s to Come


The final build step was to add a canopy and interior features (pilot, etc.) to the model. As with many other steps, this one required a lot of research (and some failures) along the way. The process and discussion are detailed in my thread, “Feedback Wanted on a Canopy-Building Project.”

You can read about the whole process in that thread, so I’ll focus here on what worked. First, I have to give credit to the YouTube video that finally showed me the path that accomplished my goals: “How I do it - Vacuform Canopy for my CL-41 Tutor Paper Model.” Thanks to davescardcreations.

After Thought: After researching several canopy approaches, I posted an "Idea" thread in the Builders Workshop forum titled "Making Canopies Using Clay and Page Protectors." It details the step-by-step process, with illustrations, that I used to build canopies.


Step by Step

Fig. 2 shows the main components of the process.

The Plug. As you may know, a plug is the male counterpart to a (female) mold. I didn’t know that before starting my research. If you press a plug into soft material, you create a mold. Conversely, if you pour a substance into a mold and harden it, you can have a plug.

After considering a variety of materials for the plug, I settled on clay—specifically, Super Sculpey 50/50 regular and firm polymer bake-in-the-oven clay. I hadn’t worked with clay since a teenager, but after watching a few YouTube tutorials, I got the hang of it.

Using polymer clay has several advantages: after being softened by rolling, etc., it becomes very pliable; it can have a very smooth surface, eliminating sanding; it bakes rock hard, so it can withstand pressure; it doesn’t shrink while baking; and it doesn’t dry out when stored.

I decided to fashion something that resembles the canopy of an F-16. It won’t be to scale, of course, because to do so would have required a much larger version.

I won’t go into the details of how I fashioned the plug, except to mention one trick that worked well. After creating a rectangular block of clay the same height as the canopy, I plunged into the clay a stiff cardboard cutout of the canopy’s profile (Fig. 1). Then, it was just a matter of shaving away clay until I reached the end of the indention made by the cutout. That gave me an accurate profile to start working with. (As shown in the image, I often use arrows to help avoid getting things wrong.)


The Plastic. I learned from the Tutor-Paper-Model video that the heavier version of page protectors works well for making light-weight canopies. And, needless to say, they are much less expensive than the specialized plastic you find online and in hobby stores. I happen to have a lot of those protectors lying around, so I can practice and experiment to my heart’s content at no additional cost. (Would anyone like to buy the eight-dollar-and-change piece of SIG plastic that I bought right before I discovered the cheaper alternative?)


The Former. For lack of a better name, the former (Fig. 2) is the cutout, usually made from hard wood, that is pressed down over the heated plastic and plug to simulate the pressing process done by a vacuum. Mine has very little space between the plastic and the former’s edge. It worked well.


The Process. Again as shown in the Tutor-Paper-Model video (minus the vacuuming part), the steps are: stretch the plastic tight in a wooden frame (I used an empty picture frame and metal thumbtacks); lay the stretched, framed plastic on top of the plug; start softening the plastic with a heat gun; after the plastic begins to sag over the plug, press the former down over the plug to stretch the plastic against the plug; allow the plastic to cool before removing the former.


The Canopy Support. The canopy support consists of two pieces—a U-shaped brace and a strip that goes around the canopy’s base. Both are made from polymer clay. Fig. 3 shows the two parts. The base strip clearly shows how irregular the canopy is shaped. I’m sure additional practice will improve that outcome.

These parts provide support to the thin plastic canopy and enhance its appearance.

The U-brace is glued to the inside, not outside, of the canopy, nestled in the bulge created during the pressing process. I think it looks much better than it would have on the outside of the canopy.

To make the base frame, I created a thin strip of clay and formed it around the canopy in the glass dish used for baking. Then, I removed the canopy, careful not to change the shape of the frame. Finally, I baked the frame.


The Pilot and Instrument Panel. The pilot, pilot’s back rest, and instrument panel are made from—you guessed it, clay. I was even able to include an oxygen hose coming from the pilot’s face mask (Fig. 4). The image shows an F-16 canopy/cockpit I used for size and positioning reference.


Black Decal. The decal is shown in Fig. 3. I wanted the area under the canopy to be black. Instead of painting the area, I created and applied a black decal, using the same process described in an earlier post. With a decal, I could exactly control the size and shape to fit the canopy. See fig. 5 for the result.

All the cementing was done with marine-grade, fast-cure epoxy cement. Very strong. No fumes, and, unlike hot glue, you have a few minutes to make adjustments before the cement begins to cure.

Fig. 5 shows that completed canopy/cockpit. I realize that the structure is fragile, and one flip-over during landing may mean starting over again. So be it.

That completes the build. The next time we meet, I should have a maiden-flight (and/or crash) video to show you. Keep fingers crossed.

Thanks all for your support and advice,
Bill
Last edited by BSquared18; Aug 05, 2018 at 10:56 AM.
Jun 13, 2018, 06:33 PM
Registered User
Ugly servos sticking up behind the cockpit. What about doing what they did to the Skyhawk to cover those? OK it was a fuel tank but looks OK.
Jun 14, 2018, 12:18 PM
Nu2RC
BSquared18's Avatar
Quote:
Ugly servos sticking up behind the cockpit. What about doing what they did to the Skyhawk ... .
Thanks for the input. We apparently share an interest in appearance, thus the decorative decals and canopy on my model.

But this plane is intended for slow, stable flying by low-time flyers like me. That's why I bought this particular kit. I have to balance looks with performance. The more weight, the faster the plane needs to fly.

I've been told this model is "disposable" and therefore extras aren't important. It also has been suggested that to reduce weight, every non-essential thing, even the landing gear, should be eliminated. Obviously, I haven't gone that far. Hopefully, I haven't gone too far the other direction. We'll see.

This isn't a scale model, so I can live with the exposed servos and control rods; and, by the way, the battery hung onto the bottom, which some would consider even more ugly that the servos.

Bill
Jun 14, 2018, 06:23 PM
Registered User
Quote:
Originally Posted by BSquared18
Thanks for the input. We apparently share an interest in appearance, thus the decorative decals and canopy on my model.
Bill
Quick and dirty has been the approach to that model so my canopy is all foam with black or blue felt tipped "windows". Used to cover the Rx. The Skyhawk hump I was told last night was avionics and not needed later as these got smaller. My servos stick out the sides under the wing.

U/C or no U/C - I should actually remove all of mine as the grass is too long unless I walk another 100 metres to a cricket pitch runway - which I usually miss. They can be used for take off OK.

Disposable - yes - except I've found I take home the load of foam "rubbish", glue a bit on here, a bit on there and it is back flying again, despite being right-off. Uglier but flying.
Jun 15, 2018, 10:57 AM
Nu2RC
BSquared18's Avatar
Quote:
I should actually remove all of mine as the grass is too long
That makes sense. One nice thing about the Flite-Test power pod is that the landing gear can be easily removed. Might have to change the position of the battery to bring the CG back where it should be. I have installed a long strip of velcro and can install more if necessary, so that adjustment should be no problem.

My current flying field has close-cut grass, but who knows what we might run into when traveling.

Bill
Jun 26, 2018, 11:16 AM
Nu2RC
BSquared18's Avatar

Canopy Footnote


Just a quick note to say that I posted an "Idea" thread in the Builders Workshop forum titled "Making Canopies Using Clay and Page Protectors." It details the step-by-step process, with illustrations, that I developed to build canopies.

Bill
Jun 26, 2018, 11:40 AM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Flying yet ?
Jun 26, 2018, 11:56 AM
Nu2RC
BSquared18's Avatar
The planets don't seem to be aligning right now. Will report back when they do.

Bill
Jul 27, 2018, 12:43 PM
Nu2RC
BSquared18's Avatar

Final Pre-Flight Work


Back again. No, Balsa or Carbon, due to “circumstances beyond my control,” I haven’t flown the model yet, but we’re getting close. My building/flying has been slowed down some by several unexpected events; for example, car totaled (no one hurt; other driver’s fault), so needed to buy a new one. And that was the least of the issues that arose.

Since my last post, I’ve made a few changes and pre-flight calculations. Please feel free to comment on my methods and conclusions.


Minor Tweaks

For one thing the small amount of propeller ground clearance that the landing gear provided and the gear’s relatively narrow stance kept bothering me, so I replaced the landing gear with a design more to my liking (Fig. 1).

The tail skid also was replaced (Fig. 2). The previous one, made from a trimmed zip-tie, wasn’t strong enough. The new one is made from plastic shafts from two Q-tip-type wipes. They are bound together and to the foam tab with fish line saturated with epoxy adhesive. Some flex is still provided but with more stiffness.


Bird’s-Eye View

Using both Velcro and a rubber band, I installed my BrightTea Mini DVR 808 #16 V3 Lens D Micro Camera (Fig. 3) under the model’s nose. The green tag on the lens cover helps me remember to remove the lens cover before flying.

To access the camera’s control buttons, I had to install the camera upside down, which means the video image is inverted. However, I downloaded onto my computer one of the many free Windows programs available that can be used to flip a video image. I tested it, and it does the job.


Pre-flight Calculation 1: Wing Loading

Because I lightened the plane in some ways and made it heavier in others, I wanted to calculate the plane’s wing-loading factor before flying it.

I calculated the plane’s weight by using two digital bathroom scales (the model’s and my weight combined minus my weight = 9.6 ounces on both digital scales) and an analog postal scale. The latter gave a reading of 10 ounces. I decided to use 10 ounces in my calculations.

Next, I calculated the wing’s area, which came to 244 square inches.

Wing loading was estimated to be 5.9 ounces per square foot, and wing-cube loading came to 4.53 ounces per cubic foot. These numbers seemed to be within the ballpark for the type of slow, stable flying that I want the plane to do.


Pre-flight Calculation 2: Propeller Thrust

Next, I wanted to estimate the ounces of propeller thrust with the plane at all-up weight, and compare that number with the model’s weight. I was hoping for a thrust to weight ratio of at least 1:1.

The simple contraption that I built (Figs. 4 and 5) to measure thrust was inspired by a YouTube video titled Thrust Testing on AP03 Brushless Motor, Champ 1 cell LiPo power system. My version involves using a pivoting music-wire that, based on the model’s pull at full throttle, puts pressure on a postal meter. For more information, see my thread titled FT Flyer Bench-Test Thrust-Measuring Gauge. A video showing the device in action can be found at FT Flyer Thrust Test Meter.

The plane’s all-up weight is about 10 ounces; the thrust at full throttle was close to 14 ounces. That amount of thrust seems sufficient for my purposes. Comments are welcomed.


Range Test

Finally (I hope), I conducted a range test, following the directions for my DX5e TX. Everything worked as desired.

After a little more sim time, I’ll report back with photos and video of the maiden flight.

Bill
Last edited by BSquared18; Jul 27, 2018 at 01:18 PM.
Jul 29, 2018, 03:47 PM
Registered User
jimjim06's Avatar
Quote:
Originally Posted by gpw
HOLY S**T …They ripped off Everybody !!!!
I see what you are saying…

The Nutball is Goldguys design https://www.rcgroups.com/forums/show...-RET-foamy-yet , The AMA flyer is A Classic AMA design, and I saw the Power pod here on RC Groups a long time ago…
I don´t know the 3rd plane, who designed that one?

Shameless stealing is now not only for Chinese!


Tommy
Last edited by jimjim06; Jul 29, 2018 at 03:54 PM. Reason: The designer of nutball...
Jul 29, 2018, 09:56 PM
Crash,fly,crash again....
I wouldnt necessarily call it stealing, flitetest gave credits to both designs, they just put a little twist on it with the incorporation of the powerpod for easy swapping between airframes
Aug 05, 2018, 07:33 PM
Nu2RC
BSquared18's Avatar

Maiden Flight and After


A video of the maiden flight can be found on YouTube at: Maiden Flight of a Customized Flite-Test "Flyer" RC Airplane.

I’ve flown—and crashed—a couple of off-the-shelf, almost-ready-to-fly foam models before, but flying for the first time a plane you’ve spent hours building is a whole different matter. There’s a feeling in the pit of your stomach; if you’ve been there, you probably know what I mean. We’ve all seen videos where RC planes, some of them incredibly sophisticated, have met an unhappy ending on their maiden flights.

July 31 was the day. The weather was perfect. Sunny. Seventy degrees. Virtually no wind, which is rare here on the Northern Plains. So, if anything went wrong, I wouldn’t be able to blame it on the weather.

Would the plane have enough power to take off? Would it break apart in the air? Would the receiver, which I’d never used before, stop working?

As mentioned above, I’ve documented the short maiden flight and two subsequent flights on a YouTube video. It shows the good, the bad, and the ugly. If you view it, I’d love any feedback on the flight characteristics of the plane—and of me.

Nothing tragic. Just another day at the park. The first flight went very well. Fig. 1 shows the takeoff. The plane climbed like the proverbial homesick angel. This image was grabbed from a video made by a cellphone camera that I had positioned at ground level some distance from the launch site. I couldn’t have asked for a better framing.

The second flight was very short. The plane seemed to just fall out of the sky. I’m not sure what happened. One second it was flying, the next second it was on the ground. Still in one piece, though.

The third flight, not so good. The flight time was a bit longer, but, again, one second the plane’s flying and the next second, bang. This time there was damage; nothing fatal but enough to end the day’s flights. The two dowels that hold the wing/empennage and power pod together tore out of the wing (Fig. 2), and there was a small, easily-repairable crack in the power pod (Fig. 3). Thank you, Gorilla Glue.


Observations and Questions

Torque. As the video shows, there appeared to be a lot the torque on takeoff, pulling the plane sharply to the left. The Flite-Test company had provided me with two sizes of propellers, both having 4.5 pitch, but one ten inches in diameter and the others nine inches.
For the maiden flight, I chose to use the longer propeller. I’m wondering if a shorter propeller would be better to reduce the torque. Any thoughts?
Another question: The Horizon Zone Super Cub I own has the engine angled slightly to, I presume, offset the effects of torque. Would that be a good idea on this Flyer model.

Could the torque have caused the sudden loss of altitude on the second and third flights? Perhaps while banking to the left?


Model’s Weight. I’m aware of the need to keep foam planes as light as possible. Earlier in this thread, Balsa or Carbon says, “For best (flying) results, I recommend making your planes as lightweight as possible (light wing loading). Do not add anything that it doesn't need to fly, such as: swappable pod, landing gear, decorations that add weight, "crash-proofing" reinforcements.” That advice makes sense, but I resisted it because building a nice-looking model is, for me, as much a part of the hobby as flying.

As I mention in an earlier post to this thread, the plane’s wing loading was estimated to be 5.9 ounces per square foot, and wing-cube loading came to 4.53 ounces per cubic foot. The all-up weight of the plane is about 10 ounces, and the thrust of the plane during a bench test was calculated at close to 14 ounces. Are these stats not good enough to provide a stable flight? Do the flat wing and tail surfaces contribute to poor stability?

Is one lesson that this particular model should be stripped to the bone, and I should use fancier building techniques for other, more appropriate planes? After all, I’ve seen videos where the pilot was able to catch his Flyer in mid air. I’m not sure that feat could be done with my model, but perhaps it could by a more experienced flyer.


Wheel Size. The foam wheels on the plane are two inches in diameter and weigh 0.48 ounces each. Based on suggestions I had read, I replaced the two-inch wheels on my Horizon Zone Super Cub with 2-1/2-inch, spoked wheels (Fig. 4). They weigh a bit more, approximately 0.80 ounces each. They have worked very well on my Cub.

As the video shows, the plane took off fine from the grass the first time but had to be moved to a dirt track for the subsequent takeoffs. Any thoughts about the pros and cons of changing to larger wheels? I hate to add more weight, but I’d prefer to take off from and land on grass.


Why No Grass Takeoffs After First Flight? As seen in the video, the plane refused to take off from the grass after the first time. I’m stumped as to the cause. Perhaps something happened during the first flight’s landing, which, while not a crash, was not soft either. Perhaps moisture picked up from the dew? Any thoughts? The plane did take off okay from a dirt strip.

There’s a lot of stuff here. I could add more, but enough is enough.

Please don’t hesitate to respond with suggestions, questions, etc.

I don’t know when I’ll have the plane patched and ready to fly again. As with most of us hobbyists, sometimes other tasks finally catch up and need to be addressed.

Bill
Aug 05, 2018, 11:12 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
I'm going to stick with my original recommendation : build with the main goal/focus being slow stable flight . After achieving that goal , then add things such as decorations , etc . From what I could see in your video , I don't consider the flying speed of your plane to be "slow" . Also : for stability & making turns without ailerons , you need more dihedral .

If you suspect moisture may have affected your plane , I recommend making your next airframe out of a material unaffected by moisture .

Aug 06, 2018, 12:50 AM
flyin' fool
goldguy's Avatar
Light is might!!!!!!!!!!! Build to fly, not to crash.

Don't expect the Dart to be a good flyer if it's porky. That goes for small, big and bigger models, 1:1 scale too.
Last edited by goldguy; Aug 06, 2018 at 01:03 AM.


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