since i have just bought my kangaroo, i have been doing alot of searching and reading what everyone has to say, i did notice alot of the planes alike, such as the bobcat xl -- top cat-- and i am sure not just these but others to, am i understanding it right, that the gyro is used for just the nose wheel??? or is it used on other control surfaces to??

mark

Mark,
I can't speak for or about any of the airplanes you mentioned except for the BobCat. My XL has 336 flights on it, and has outlived two different gyros. I have flown it numerous times when I was between gyros, and found it to be totally controllable at any speed.

All swept wing airplanes exhibit what is called "Dutch Roll'. The landing gear door/speedbrake configuration of the BobCats produces a force moment on the yaw axis when the airplane is slowed down to landing pattern speed. When the gyro gain is set properly, the rudders are active enough to really smooth it out on a windy day. The nose gear does not need the gyro, and as a result, isn't hooked to it. My nosegear steering servo is on Aux. 4,mixed to the rudder channel and therefor is "taxi-adjustable" independent of the rudders.

The gyro gain can be set up to be all but, or totally inactive when the gear is up. Simply program a mixer to set the gain to about 40% when the gear is down and no gain at all with the gear up. The final gain setting for your airplane can only be established by flight testing it.

Harley Condra
BVM REP
Team Jetcat

Having flown two Roo's with Gyros and attempting one flight on a roo without a gyro, I highly recommend the gyro on the nosewheel. I consider myself a conservative competant RC Turbine pilot, but once on preflight my gyro failed ground check and I took it out of the equation. Lined up on the runway, punched the throttle and that thing went left right left right and about 3 seconds later I was shutting the engine down as I was in the orange fence.

For $90.00 or so, very cheap insurance.

Mark,

Others may disagree, but I "highly" recommend a gyro on the nose gear of a Roo. A cheap single rate one will do such as the Century PG2000.

a heading hold gyro, i guess is NOT WHAT YOU WANT???

just a standard gyro like the csm 180

i have them and i also have a jrg410t gryo with both rates

if you are using this on nose wheel only, heading hold would be fine right?
but do not use a heading hold on rudder??

again thanks for the help

mark

You do NOT want a heading hold gyro. But....most heading hold gyros can be switched to rate mode as well as heading hold.

We're flying a Roo here in New Mexico and it does not have a gyro. Take offs, landings and ground handling in general are ok PROVIDED THAT you hold full up elevator for the entire take off roll and until it climbs out. If it is traveling at any speed at all then elevator must be applied to help keep the weight off the nose gear or it will become uncontrollable on the ground. This also holds true for landing and roll out - don't release the elevator until almost all of the speed is bled off.

Len

Don't use a heading hold gyro at all. If your gyro is a newer JR gyro with both heading hold and rate mode, just switch it to rate mode. I'd bet there isn't a single airplane on the market that absolutely requires a gyro. They do however require better use of your brain, and your left thumb.

Don't slam the throttle open. Start the takeoff roll smoothly and don't use full power until your flying surfaces are functional (around 20-25mph). Learn to use the rudder. I know there is great resistance by some people to even putting a rudder on our jet models, but I can't imagine flying an airplane without it. I guess that comes from my aerobatics background. Len's comments about holding up elevator through the takeoff roll ring true on a number of jets out there due to the landing gear geometry not being optimal (especially those with heavily loaded nose gears, high thrust lines, etc).

Try to fly the airplane like a jet, not a toy airplane. SMOOOOOTH FLYING..