World model chipmunk need help
 

Hi guys

took my new world model superchipmunk to the field today. It flew great had no bad tendencies, but it kept on tipping over during taxi and landings, i fly off a grass strip and the model is equipped with retracts, has any body else experienced the same problem and if so have you managed to solve the problem. Changing to fixed gear would be my last option if every thing fails as it looks great in the air with the wheels retracted.

Thanks
Zain

RE: World model chipmunk need help
 

This is a common problem with a model with a long nose, operating on grass, that has it's wheels too far back when measured from the wing L.E.
Solution?
Fit bigger wheels or bend the legs so that the centreline of the wheels are further forward. Either way it's going to give you a headache as far as the proper retraction of the gear goes and make fitting fixed gear look the simpler solution.
As for putting on fixed u/c, well, the original Chipmunk had fixed gear anyway.

RE: World model chipmunk need help
 

My only thought would be to use more elevator. I taxi with full elevator to keep my Ultimate from tipping forward and every landing is a harrier or darn close. My grass field is very rough. Many guys use 3" or bigger wheels on a .40 size plane to help deal with it.

RE: World model chipmunk need help
 

Zain
I had the same problem on landings until I started retracting flaps as soon as the plane touched down. This should help but I dont know if it will be enough on a grass runway.
BTW how does the WM Chipmunk compare to the Goldberg ?

RE: World model chipmunk need help
 

I heard that the WM Chippy is a clone of the Goldberg kit (??).

I had a WM Chippy for several years and eventually converted it to fixed gear with some Stan Fibertech pants and some of that airfoiled aluminum from my LHS. It turned out great and no more nose-overs.

I missed the retracts cause I changed the stock gear for some Robart Robo-Struts and loved the look.

I miss that plane and see that WM now offers a choice of fixed or retractable versions --- AWSOME !

CJ

RE: World model chipmunk need help
 

i have that plane with a os 91 fs and it did the some to me , quick fix just add strip of lead to back next to tail wheel its spot on

RE: World model chipmunk need help
 

Well
the first thing i did was i put a strip of 1/8 ply on the trailing side of the retract gear which has definately made a difference. I also moved the battery about three inches back, so now it sits right next to the throttle servo.

I have both the chipmunks one goldberg and one world models both are great flyers.

How much weight did you add at the tail gear. I dot want to mess up the CG as it flies great in the air.

Zain