RUNDUCK

I put the first fight on a new GP Viper with a Webra Q40 and performance specialties Q500 muffler. The plane was built according to the manual and balanced perfectly but just after take off when I turned to make my first down wind pass it dived rapidly at the ground!!! I had read all of the posts about the tail incidence and decided to fly it first before I changed it. This diving was only evident at 1/2 throttle up to full throttle. I landed the plane and unbolted the tail and shimed it with some 1/8" hard balsa at the trailing edge and flew it again and what a difference it made!!! The Viper tracked like it was on rails and is a very smooth racer. After the shimed flight I took it home and mixed up some micro ballons and epoxy, stripped off the
covering under the mounting area of the tail and installed the tail with the shims and glued it down with the micro ballons/epoxy mix and reinstalled the mounting screws. I took the Viper back out to the field today and put 5 flights on it. I have never had to change any trims [ just lucky ] and I am running a 3s 360 miliamp lipo with a voltage regulator from Castle Creations and it works great due to you can program the regulator for the voltage output to the receiver. Not to mention its very very light!!! Would I buy another Viper? Your damn right I would. You just have to do a little work on it and it rewards you with some very fast flying.

sahartman21

Do you think the Amarillo area is ready to try Q-500 racing?

I have a "Dawg Gone It" ready.

Are there other potential racers?

RUNDUCK

We would have to change the course due to its to short and to close to the pits for the Q500 speeds. I'm trying to get people interested in racing and I am willing to let them wiggle the sticks on my plane any time I'm at the field. I just hope we can get Q500 revived due to it's the most fun you can have with your clothes on.

sahartman21

I agree that the course should be lengthened. Possibly the Q-500 short course.

I have been building my racers to the AMA 424 Class.

1) Engines are limited to the Thunder Tiger Pro 40.

2) Props are limited to the 9 x 6 APC

Cost is minimal for the engine and performance is still very good.

freeair

glad you happy with your Viper [ RUNDUCK ] when there trimmed out they do fly very well indeed. i am running an OS46AX in mine and it does go very well, no problems doing full laps at knife edge attack.

jaka

Hi!
But beware of the tail coming lose! It will happen ...sooner or later if you don't do something about it.

tIANci

I have been running my Viper on a TT Pro 46 with a 9x8, 8.8 x 8.75 and the 9x7. She is nice. I love how she can change directions with ease. Would love more speed though but then its a TT46, just received my Jett Q500 and that will be bolted on soon, hope to see some gain in the speed department!

Anyways, I did not read about shimming the stab and mine is glued on. Guess will be getting another one for the Jett. What sort of mini servos can I go with? Would it be possible to use HS85MGs? I am thinking of going with those if possible and then to use a 2S 400 mAh pack. I am hoping all that can save me about 5-6 oz. Present AUW is about 4.1 lbs.

DMyer

My Feedback: (2)

You don 't need to get another Viper just because you glued the tail on. If the stab is set at zero, just shim the leading edge of the wing up slightly until you can get rid of all the elevator up trim... then pot the wing saddle.


dan

tIANci

Dan ... what I meant was to get another for the new engine that's all, I am literally 100% EP now but ended up back to glow because of friends who want to race. So I thought why not get another and try to get her as light as possible. Thanks for the advice, I will be shimming the wing soon to get rid of the up trip.

tIANci

Here's a video of my Viper with a Rossi 53 and a Scimitar 9x7.

[link=http://www.youtube.com/watch?v=BDGIrtdc3EM&feature=channel]Viper 500[/link]