rc_skychief

My Feedback: (1)

I am looking fo any suggested modifications for the 4 star 120 I am building with a homelite 25 conversion for power. This is my first gas engine plane and have heard there are some modifications that should be done for gas engine use. firewall mods, tail,servo locations,wing structure, any advice on this combination would be greatly appreciated. Thanks, rc_skychief

Taildrager-inactive

My Feedback: (11)

Depending on the weight of the motor, the firewall might have to be moved back a inch or two. My RCS140 was installed in the stock location, although I did reinforce the firewall, and two servos I installed in the tail of the fuse 20" from the end of the fuse, using a lightening hole piece for a hach cover, and installing the servos upside down for easy access. Moving foward on the fuse, another lightening hole cut out was used for a hach cover for the recever & battery just aft of the cockpit for easy hook up of the ailerons servo wires. The gas tank was installed over the cg and acessed from a tank floor I made to come out with 4 screws where the wing goes on the fuse. I joined the wings flat on the board, then sheeted across the joint instead of sheeting the 2 wings seperate then joining, which gives a very strong wing joint with no glass tape needed. Some people cut down the wing one bay, but I wanted to stay IMMA legal. The canopy I turned around and installed, getting rid of the ugly looking bulge, and a more stream lined look. I also added 1" to the rudder. I will be ordering landing gear from TNT as the stock gear is too light and less than a perfect landing will result in the 4* bouncing like a ball, and on a rough grass field this happens 3 out of 4 times. My 4* weighs 12 pounds and the RCS handles her great. Good luck with your 4* she is a very nice flyer that is fun to fly as there is no surpirses and a very honest bird.

GeraldO

My Feedback: (2)

Taildragger, I've got an MVVS 160 gas engine in my fourstar. I've got the same bouncy landing problem with it. Of all my planes it is the hardest to land solely because of the bounce. It lands like a pogo stick! Even with our paved runway I really have to finesse the landing to keep it from bouncing and skipping down the runway.

Please let me know how your custom landing gear from TNT work out. I've been thinking of laying up a set from carbon fiber and glass myself.

jstanton

My Feedback: (14)

Rc Skychief

I just finished building a Balsa USA 120 with a Ryobi 31cc engine in it. And she flies great. You will have to install most of your radio gear as fare back as you can. I put both of my servo's for the elevator and rudder as far back as possible. You well need to do this becase of the added weight up front of your Homelite engine. I also cut off 2" from the nose and moved the firewall back another 2". This helped out most of all when it came to balancing the plane.

You will find these engines are great fun, but they do not have the over all power as compared to one of the good nitro 4 stokes.

Her is a pic on my Balsa USA Stingray 120. Good luck and have lots a fun.

curt2005

Are you guys using two servos for elevator and a pull-pull rudder?

jstanton

My Feedback: (14)

I am using one high torque servo on the rudder and elevator. I have two high torque servo's for the aileron's and a standard servo for the throttle. I hope this helps.

Taildrager-inactive

My Feedback: (11)

I'm using the old Hitec 602 servos, no pull pull on rudder. The TNT gear and a change to low bounce tires seemed to help on the landing, as she only bounces if I screw up.

SDM

My Feedback: (9)

Are you guys able to use the cheeks on the fuse with the gasser installation or are you going with another type of cowl?
I was thinking of going with a G23 or G38 on mine but mounting it with the standard engine mount on the G23 won't
allow this because of the limited firewall space.

Thanks
Sam

Taildrager-inactive

My Feedback: (11)

Had to cut off cheeks because of the the muffler. Am planing to build a cowel, although been flying her for 3 years, and no cowel built yet lol