FT-Viggen Build

frogs84ss

Junior Member
Frogs84ss, That is a very clean build- good work! FYI, you may have seen this in David's light set up video, but for the rear mount motor, its imperative to put as much weight as forward as possible (servos, esc, etc) so that you can obtain proper cg with a decent size battery. Especially if you plan on using the prop drive power system which weighs much more than this one. With this set up, I'm sure you would need a 2200 3s way up front to get balance. As Bolvon72 mentions, with his Suppo, he needs to have his 1800 way up in the nose which means you have no room to move battery for experimentation. If you move servos and esc forward close to the cg area, you'll be able to use an 1800 a little further back and have some flexibility for experimentation. Of course, this would require esc extension wires. The other option is to use a 2200 3s or better up front, but the your build weight skyrockets! :eek:
As an outside experiment, you could also add a KF2 airfoil which would creat extra lift at the rear to help shift CG in flight. I'll be experimenting with the proper KF configuration once I see how it flies with no KF.

yeah I figured I'd put it together and see how it goes. it balances with a 300 3s pack. putting me at 25 oz. I'll build another one when I get my edf next month. I'll most likely never get the prop drive set up in this plane. thanks for the advice though.
 

F1wanabe

Member
yeah I figured I'd put it together and see how it goes. it balances with a 300 3s pack. putting me at 25 oz. I'll build another one when I get my edf next month. I'll most likely never get the prop drive set up in this plane. thanks for the advice though.
Yeah, that's the thing about rear mount set ups. You have to plan from the start to build way light and mount everything up front knowing that it'll take a lot of weight to balance that motor. The more components you can mount up front, the less weight you need from the battery, and that will lower the overall weight. I'm building mine from MPF, using foam tac glue (and doing the reverse scores) which will save at least 4 oz ounces over DT foam and hot glue. Even if I do need to counter with a 2200 battery, the overall weight will still be under 20 oz. That's key to get performance from the 2212-6 rctimer I'm using.
A couple years ago I made up some esc extention wires for my rear mount planes. It takes about 20 minutes to do, But I always have it ready for my next rear mount project. This will put the Servos, ESC, RX and battery all up front to counter the Motor on back without needing to add excessive weight.
20140217_204807.jpg

If I can get under 20 oz with a rctimer 2212-6 and 30 amp esc, then this would put me in the ballpark for the Grayson MJV3. This motor is much lighter, only requires a 20 amp esc, and will probably balance with an 1800 3s pretty well. If all this comes together, then this plane could drop to 18 oz with unlimited performance from the super efficient MJv3 that'll give plenty of thrust and have an amazing flight time from an 1800 battery.
 

willsonman

Builder Extraordinare
Mentor
My Viggen is built! My schmancy new-to-me plotter made printing the plans a snap ;) Got it all assembled now and just need to connect the servos to the elevons. I'm using a 64mm EDF I had on a starmax model. I'm not a big jet fan but I wanted to give this one a go. Its a 4300Kv 5-blade EDF unit. Plan on using a 3-cell. If it does not have the oomph I'll go for a prop version. Thanks David!
 

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willsonman

Builder Extraordinare
Mentor
So, as a suggestion... I have been experimenting with printing on my large format plotter. I have been able to successfully print onto tissue paper... $store tissue paper. I use a piece of scrap paper as a backing and use a VERY light coat of spray tacking adhesive... stuff. Just enough to tack the tissue in place. BEFORE I put the tissue on the paper backing I iron out all the creases with my household iron. Make sure you use a bit of steam to help relax the paper. Then you can apply the tissue to the paper backing. Then load the sheet into the plotter and print from there. Once you pull it out you can gently peel off the tissue and you have your printed pattern! Now the application has to be done BEFORE you assemble anything. I've done experiments with this and it works. Use oil-based polyurethane to adhere it. It will not smear the ink and will also make it water resistant. The drawback is that this will not work over top of hot glue. There is a thread in the toolbox are that has discussed re-purposed old large-format plotters for our uses.
http://forum.flitetest.com/showthread.php?6796-No-more-taping-plans-together-for-me!
I got mine off a guy on craigslist for $20. All it needed was new ink. Ive discussed the printing on tissue there a bit more extensively so this may be a more viable option to supply people with patterns to apply to their planes.
 

Timgfoley

Member
You might want to call them. They had a flood a while back it may have interrupted that order.


Hmm, now I'm getting peeved... it's been a week and no update. I've opened a service ticket on their site and called. When you call you get an answering machine not a human... so I've left a message.

Has anyone here recevied their package from Grayson?


Thanks
Tim
 

Michael9865

Elite member
I like the look of the Viggen in black. Nice builds by peddiparth and ReDeYe makes me think that the black dollar tree foam is the way to go.
 

F1wanabe

Member
Werner, that does look amazing! Store bought, in fact. That is 44 oz you are looking at with a power system that would push 40 oz (?) ideally. What size lipo are you using? More than a 1:1 thrust to weight is important on a parkjet. I hope the delta canard design pulls through for you! Beautiful plane!
 

Jonob61

Junior Member
I have my maiden flight on my Viggen today. Incredeble stabil plane. Build with 6 mm depron, 3-cell 2200mh battery, 2200kv motor and 6x4 prop. With all electronics and battery it's 600 grams.
 

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ReDeYe

Member
Coming in at 26.93 oz with a 2200mah 4cell she is done and ready for flight. Cant wait till this weather clears up

image_zps3afff6ad.jpg image_zps9fc02eae.jpg image_zpsaf08882f.jpg
 

Timgfoley

Member
And the saga continues... just called Grayson Hobbies again, once again got voice mail. But this time the voice mail states that the showroom is closed for 3 days in November for the Thanksgiving holidays... umm, it's February?

Another day goes buy, no answers, no emails but still an advertisement on the Flitetest homepage.

*sigh*

EDIT: Just placed an order with EDF Hobbies and filed dispute with Paypal for Grayson. Hopefully have a happy ending and get this plane in the air!
 
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F1wanabe

Member
I have my maiden flight on my Viggen today. Incredeble stabil plane. Build with 6 mm depron, 3-cell 2200mh battery, 2200kv motor and 6x4 prop. With all electronics and battery it's 600 grams.

Thats a very good weight and this thing will have amazing performance with super low wing loading. Can't wait to see it fly, Jpnpb61!
 

tomstanton

Junior Member
I've got to say that this plane is simply awesome! I've gone with a prop setup with thrust vectoring because I had the parts laying around. I'm running a 2200kv motor with 3s 3000mah lipo.
Here is the video of my maiden flight, it started out a little dodgy due to it being tail heavy, but is now flying perfectly!

I liked this plane so much that I've decided to build a 50mm EDF version which is 70% scale of the normal version! Maiden flight coming soon :)
20140220_001933.jpg
 

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F1wanabe

Member
Tomstanton, I saw your video and loved the way you fine tuned it. Delta canard planes can get tail heavy very easily since there is not much forgiveness there, but you could see it come to life after your adjustment. Good work! I am still amazed it flares out like that on landing with a 3000 3s in the front.