Here is my solution for the weakness in the Viper and Predator at the V-Tail leading edge. The design of both aircraft cause a weak spot right at the front of the V-Tail. An additional problem is the rigid rear tail skid which creates a long lever. This give leverage which will crack the fuselage sides during launch or tail 'smack-down' landing.

Since my first Predator broke it's tail off after a few heats in a race, I have been doing this on all Predators and they have taken abuse well.

This modification is especially important if Bill Vargas is going to launch your plane. They don't call him 'Rocket Launch Man' for nothing.

Step one - Remove the bottom sheet covering. I widened the antenna tube notch to move the tube to one side. Note that I do NOT have my antenna trailing out the rear. I have seen at least 3 antennas stepped on during launch, pulling them out. I saw one pulled out just picking the plane up to ID it.

Step two - Cut out carbon fiber or thin plywood doublers and saw alongside the fuselage sides with a Zona saw into the V-Tail mounting block at a 45 degree angle.

Step three - Epoxy the doublers in and mount a music sire skid.

May I add step four?.

Resheet the fuselage bottom.

Ed S

Nice job Paul. I was too chicken (or maybe too lazy) to open mine up.

Now I know how to do it the right way.

What do you do with the extra antenna on the inside?

If I may butt in here. I keep my antenna inside the fuselage. The reciever is usually placed in the middle of the wing saddle. There is about 6-7 inches of antenna going forward, in a piece of plastic tubing, to the firewall. The antenna then loops back to the rear of the fuselage, taped to the inside. There is about one inch sticking out the back which is taped to the rear outside fuselage.

Ed S

Thanks Ed.

I didn't even think of just taping the excess down. The provided tube ends at the servo bay. And I wasn't sure if going all the way to the firewall was a problem.

I do what Ed says, the old U-Turn tube.

Paul, you gonna be at the Champ Race?



BV

>>Paul, you gonna be at the Champ Race?

Yeh, I will be there as a pilot, photographer and worker.

Cool,,,

We'll have to test out your Tail modification




BV

Ed
If I try to lay my antenna anything forward, I get remote problems (flickering or what you call them in English) Have always been that problem. Have also seen many other with this problem. Do you think this could have anything to do with our big gap of freq.

Hahaha

Thus any one know where to find any videos from your racing over there.

I don't know about European freq issues, but I do the exact same thing with my antennas. I run them forward in a tube, and do a u-turn from the right side to the left side of the fuse. I adjust it so that about 2 inches will come out just under the tail. I tape this to the side of the fuze. Darrol Cady sells some clear tape that works perfect for this. It is very flexible and holds up well to fuel.

Some hardware stores sell the same tape in colors, so you can match your planes. The colors are not quite as flexible, but still work well. They have a very nice shade of Green.

Dav

Exactly the same way I have done but with no success. Got radio interference.
Probably something wrong with the TX.

Per

Here is what I do with the antenna wire just pull it through the tube and cut off the extra. Heck, I can only see about 200 feet anyhow who needs to fly further than that? As for the tail just drill a hole and fill it up with epoxy you need some weight back there to make up for the 91 surpass you need to mount on the front anyway right?[:-]

greetings, I cut out 2 - 1mm plywood discs the diameter being the full height of the underside of the veetail to the bottom of the fuselage- removed a portion of film and cyanoed them in place- of course one per side, centrally located around the former at the leading edge........I also glued the tailplane in place. now quite a strong unit.
Trevor henderson.

what i am doing with my new Viper regarding the strengthening of this weak rear section is; remove both sides and bottom of covered area at the tail as all are doing but i feel more strength is gained by using light fibreglass or carbon fibre mat and glass this in one piece to both sides and under, so its like a bottom wrap around. lightly sand all edges etc and re cover the section.