Why YOU should build a Viggen

Brett_N

Well-known member
....And what I learned with 2 builds.

First off, a HUGE thank you to everyone's favorite Swede for the design, and of course Sponz for making the freebie build plans.

My experience as a "5 month in flying 2 or 3 days a week..."

BUILD IT - BUILD IT NOW! I've buddy boxed a couple of Avanti's and Hawker EDF's, but hands down, the Viggen made out of $5 in DTFB out fly's both (for a newbie.) On a 4S, this is the only EDF at our flying field that will hover!!

Now, what I learned after building 2 of them.

1 - SKIP THE 64mm and go right for the 80mm EDF. HUGE difference in flight performance. Self hand launching is a breeze (hold the upper fuselage, firewall the throttle, and it's gone) with the 80, but difficult with the smaller one.

2 - I stole the covering idea from Experimental Airlines site (youtube it) - basically start with DTFB but strip the paper and re-cover with packing tape.
- it's tedious, but after building 2 identical models, one with regular FT build and one with the EX, I can un-scientifically say there is a major difference in structural stiffness, and neglible impact on weight.

3 - Spend extra time and tack with hot glue, but seam-seal with Gorilla Glue WHITE. I shaved almost 75g off the AUW based on the plans, with the big powerplant. My 80mm EDF with a 60A ESC came in 25g lighter (with gorilla glue white) as the 64mm EDF with a 40A ESC built with hot glue. I didn't pre-weight the EDF powerplant, but I'd say that's pretty good.

4 - Diff & Expo - on a spektrum setup, I had 100%/25% and 80%/25% D&R - both worked well, low rate for takeoff and landing, high rate for high speed passes, etc.

Flying impressions:
Now, to be honest, my hangar is 99% high wing Cubs, A Bushwacker, The new Maule, and all sorts of assorted stuff. I've never flown a low wing. Ever. I've flown the foam off my FT Delta, assorted Nutballs, and some wings that are all RET based, like the Viggen.

Flight 1 - Wheeled Runway Flight - I used CHEAP (banggood) EDF landing gear. Itty bitty little wheels, and our flaying runway is dirt / clay. It worked OK to takeoff, but on landing I ben t ALL 3 of the landing gear wires. No big deal, everything survived.

Fying - UNBELIEVABLE - rock steady in 10mph crosswind. Big banking turns and high speed, no frills, screaming by passes on low D&R like I was flying a Timber at 1/4 the speed. 100% throws? An EDF that will hover, with some work :) totally controllable, ALTHOUGH, like any EDF, give yourself plenty of vertical height. With this design you can recover from just about anything, but, still, give yourself some height.

Flight 2 - new battery, wheeled takeoff - No Bueno. Couldn't get the wheels straight enough and she wandered all over the runway.

Flight 2.5 - took the wheels off and my buddy hand launched. He gave it a good toss and back in the air (and he lost his hat)

Flight 3 - Hand Launch - and when I mean hand launch, I mean SELF hand launch. Hold the jet by the "spine" behind the battery hatch, peg the throttle, and off she goes. Now - again I built 2 of these. The 80mm will go like a .......... the 64, well, I can't self launch it..... it needs another person.

Flights 4, 5, 6 7 were all un-assuming.

As far as the EDF units - I'm using the cheap-o Amazon Primer one for like $28 and a 60A ESC. My small unit is the cheapo Amazon 64mm for like $20 or whatever. Go big, or stay home.

At the end of the day, I'm just like 99% of us and love building, flying, fixing, repeat. But - you gotta build a Viggen. Don't be afraid of an EDF - this thing is as docile as...well I dunno....it's pretty close to flying a Versa Wing. And I encourage you to try the packing tape (Dave Brothers on Amazon? 10 rolls for $28) covering and GG White.
 

Brett_N

Well-known member
Oh - I forgot to add - (And Peter if you read this!) - Mine BOTH seem to fly a little nose high happy, even with the CG per the plans. I'm guessing this is because the forward canards have some (negative?) instance - whatever the angle is called, causes the nose to come up. I'm going to cut out another one this week and change the canards to neutral and see what happens.