Widkin
Member
Hi there!
If you are interested in building and flying this plane, please keep on reading.
Intro
Inspired by the original Viggen made by David, I have made my own foamboard Gripen. I posted an article about it earlier this year:
I have modeled this plane completely in 3D, so the plans are already available in the article. However, as I started building the plane, I continually made changes and improvements. For example, I originally had the idea of making the nose out of bluecore foam, but I later felt that it might scare some away from building the plane - including myself - so I changed it into foamboard too.
Rather than mess up my original article with too many updates, I will follow up my build in this thread here, where it's OK to make updates and changes as the project goes along. I'd also be thrilled to hear what the more experienced pilots have to say about it, because I am far from good enough to tune this bird properly. If anyone cares to build one too, that would totally make my day.
The 3D model and plans, in their current state, will be attached to this post. They differ a bit from the ones in the article.
Specs version 1
Version 1 of the Gripen, as seen in the picture above, is finished.
Weigh: ~1050g without battery. I use a 3300mAh battery, weighing in at 337g, so total weight is about 1400g. Thats a tad bit on the heavy side, because the foamboard I have is heavier (and stronger) than Dollartree foamboard. If you have access to Dollatree, you can subtract 200-300g from the weight.
List of electronics:
EDF unit: Alloy DPS 70mm 5 Blade - Light Weight Version 4000kv
ESC: TURNIGY K-Force 100A
Motor extension leads: Turnigy Pure-Silicone Wire 18AWG
Battery: Turnigy nano-tech 3300mah 4S 25~50C
Canard servo: Turnigy TG9 9g / 1.7kg / 0.12sec Eco Micro Servo
Elevon servos: Turnigy TSS-10HM Digital Micro Servo 2.2kg
Controls
I have three control modes, mapped to the three-position switch, which deals with different ways of elevator control. I can control elevator with only elevons; with elevons and canards for extreme control; or with just canards, like the real plane. Roll is always done with the elevons - the canards are not split.
Durability
I had my first flight today, in pretty heavy winds, which probably was not very smart. It did give me the chance to test the durability of the plane, though.
My first attempt ended in an immediate crash, since the wind caught under one wing and made me tip-stall. Results of the damage are below. Nose and one wingtip hardpoint broke off, but otherwise she was fine save some scuff marks. I designed the nose to break off, like the FT Viggen's. Hats off to David for the great idea!
The nose was easily put back on with a piece of tape on top and bottom. I removed the hardpoint, but those are also easily attachable with tape.
The second flight ended in a controlled landing, but the leading edge flaps caught in the long grass and broke. That too was easily fixed with some tape on top of the wing. I recommend to strengthen the leading edge flaps with some extreme packing tape from the start, just like the elevon hinges.
See you in post two for build pictures.
If you are interested in building and flying this plane, please keep on reading.
Intro
Inspired by the original Viggen made by David, I have made my own foamboard Gripen. I posted an article about it earlier this year:
Ever since I saw the awesome JA-37 Viggen made by David Windestål, I've been thinking about making an EDF-jet of my own. However, I did not want to mess around with all those formers and hot-wire cutters, since it seemed so time-consuming and seemed to be more a work of art than easily replicable. I therefore wanted to see if it would be possible to make a good-looking scale jet out of regular Dollartree foamboard instead.
Since I am a Swede too, I wanted it to be a Swedish jet. Since the Viggen was already done, it felt natural to make the JAS-39 Gripen. I also really wanted it to have fully articulating canards, something that the Gripen has but the Viggen does not.
I have modeled this plane completely in 3D, so the plans are already available in the article. However, as I started building the plane, I continually made changes and improvements. For example, I originally had the idea of making the nose out of bluecore foam, but I later felt that it might scare some away from building the plane - including myself - so I changed it into foamboard too.
Rather than mess up my original article with too many updates, I will follow up my build in this thread here, where it's OK to make updates and changes as the project goes along. I'd also be thrilled to hear what the more experienced pilots have to say about it, because I am far from good enough to tune this bird properly. If anyone cares to build one too, that would totally make my day.
The 3D model and plans, in their current state, will be attached to this post. They differ a bit from the ones in the article.
Specs version 1
Version 1 of the Gripen, as seen in the picture above, is finished.
Weigh: ~1050g without battery. I use a 3300mAh battery, weighing in at 337g, so total weight is about 1400g. Thats a tad bit on the heavy side, because the foamboard I have is heavier (and stronger) than Dollartree foamboard. If you have access to Dollatree, you can subtract 200-300g from the weight.
List of electronics:
EDF unit: Alloy DPS 70mm 5 Blade - Light Weight Version 4000kv
ESC: TURNIGY K-Force 100A
Motor extension leads: Turnigy Pure-Silicone Wire 18AWG
Battery: Turnigy nano-tech 3300mah 4S 25~50C
Canard servo: Turnigy TG9 9g / 1.7kg / 0.12sec Eco Micro Servo
Elevon servos: Turnigy TSS-10HM Digital Micro Servo 2.2kg
Controls
I have three control modes, mapped to the three-position switch, which deals with different ways of elevator control. I can control elevator with only elevons; with elevons and canards for extreme control; or with just canards, like the real plane. Roll is always done with the elevons - the canards are not split.
Durability
I had my first flight today, in pretty heavy winds, which probably was not very smart. It did give me the chance to test the durability of the plane, though.
My first attempt ended in an immediate crash, since the wind caught under one wing and made me tip-stall. Results of the damage are below. Nose and one wingtip hardpoint broke off, but otherwise she was fine save some scuff marks. I designed the nose to break off, like the FT Viggen's. Hats off to David for the great idea!
The nose was easily put back on with a piece of tape on top and bottom. I removed the hardpoint, but those are also easily attachable with tape.
The second flight ended in a controlled landing, but the leading edge flaps caught in the long grass and broke. That too was easily fixed with some tape on top of the wing. I recommend to strengthen the leading edge flaps with some extreme packing tape from the start, just like the elevon hinges.
See you in post two for build pictures.
Attachments
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