I might get the + and - reversed from memory here (and I use Futaba too but it ain't here at work) but that is easy to check if you play with it; + is reverse exponential which hightens sensitivity around neutral versus what is typically used, - which is reduced response around neutral for less twitchyness.

MJD

That sums it up so nicely !!!

thanks


RICH

The Viper is a very good plane and with some strength and incidence mods it can become fabulous. I'm on my third ship. the first two died spectacular deaths due to structural and on board control failure. let me pass on some of what I have learned. Throw the stock wheels far away. All three planes needed the V tail shimmed up at the rear, I start with .040". You'll know when it's good when the tail's control surfaces are about flush when trimmed for level flight. Failure to fix this incidence problem could lead to servo failure or shorten battery's run time due to the constant load in flight. Just like a stalled throttle servo can do to a battery. Use a plastic push rod (like Goldenrod)and plastic ends on the throttle control, this will reduce the servo killing vibration. Before installing servos, drip in thin CA into all the little gaps around the wing mounts, formers and bulkheads(do this outside in the sunlight and fresh air). Add a 1/16" x 1/2" piece of plywood to both sides of the upper edge inside of the rear servo/batt compartment. You won't like this part, I remove a strip of covering material on both sides of the fuse to allow me to CA a strip of .014"X 1/2" carbon fiber 4 1/2" long that starts 1 1/4 ahead of the leading edge of the wing and running just under it. And again a 7" strip that starts 2" ahead of the leading edge of the V tail and running just under it. Then recover with Monocoat. I use BLUE Locktite (removable) on all steel screws. I use Locktite each time I put the wing back on. And no, I won't go to plastic wing screws! Use a timer on your flights,( I use 4 minutes) this lets you dictate engine shut off to set up for planed landings. Run the fuel out of the engine and use after run oil when done.

I use nylon wing screws on all the racing planes. Always have. Never had one come loose of fail on me.

If you're unlucky enough to do an autopsy on a Viper wing, you may find that to go larger hole for a 1/4-20 or an M6 may not be wise to do on that narrow piece of hard wood inside the wing. If the plane comes that way....Fine, use them. Just remember replace them after a hard/crash landing with good quality replacements. (I just had some winners that came with my Ultra stick)I've found a lot of junk nylon hardware that where under or over size, heads split or pop clean off with ease. Bob, if you have a good source chime In. Never use thread locking compound (i.e red blue or green Locktite) on plastic unless it is meant for plastic.

I maidened my viper with a 46 ax two days ago. Both wheels came off on landing and gear was ripped out form underneath the fueslage with mounting plate. Geez wheels didnt even last one flight. Called GP today rep stated this is the first time he has heard of problems with the wheels separating from the brass bushings but would be happy to send out some wheels and landing gear whenever they get some more in stock. Wonder why they are out of stock? Plane flew great though had to put in quite a bit of up trim though. Also when just running out of fuel the plane starts to climb. Is this normal? Also where can I get a decent set of racing wheels?

First time they hear of that. Mine kept coming out. I had ordered the $2.00 Hayes racing wheels when I bought my first viper and I had enough of the GP wheels. I just used some washers and #4 screws as axles with a wheel collar and the Hayes wheels and it works fine.


Marty

You can get the good wheels from Jett, SuperTRc, or Darrol Cady... They are about $12 for wheels and axels, you won't have any issues after that..

As far as your Viper climbing after the engine is shut down, that is most likely due to the fire wall having a negative incidence.. That could also explain the up trim you are carrying..

I use 10-24 nylon bolts to hold on Q40 wings.. No problems there and those hit upwards of 20G's on a full pull around #1..