Saturday night I finished my Great Planes fabric covered ARF Cub. 81" span. Have not applied the decals since I like to see if the plane flies before finishing.

The kit went together well with just a few changes and gripes. First thing to change was the engine configuration. GP recommends a .48, .52 or a .70 in the four-stroke category. I installed the OS .52 in mine. Now the instructions suggest mounting the motor with the cylinder out the side of the cowling, and the picture in the manual was a real hack job! They must have removed at least a third of the side of the cowling to clear the cylinder head and header! Not this guy... I inverted the motor and had to cut a 3/4" X 1" hole in the bottom of the cowl to clear the rocker cover, and a bit to clear the muffler on the bottom left corner of the cowl. Still a lot less of a hack job on the cowl.

The second modification (I do this to most of my planes) was to install dual elevator pushrods, omitting the elevator tie rod altogether, which worked out well.

The covering of the windows with fabric, which is cut out to install the windows was not pleasing. Trimming the fabric out and leaving 1/4" excess to seal the window sills didn't work well for me, so I ended up trimming to the sills, then masking and spraying the sills and posts with jet black poly paint. It actually came out well, and worth the effort. The windows fit very tight, which are pressed into the frames and glued. Good job here, as they didn't need any tape to hold them in place while gluing.

Another mod was to replace most of the supplied sheet metal screws with cap (hex) style screws, increasing the size as well. Instead of #4 on the wing struts, I used #6 and #8, as an example. To get it flight ready took around 20 hours over 5 or 6 nights. Saturday was a cram session of about 5 hours to finish.

Sunday morning she took her maiden flight. I had my doubts about this 7-8 pound plane getting off the ground with the little .52, and after some taxiing to check the rudder/tailwheel trim I accelerated slowly, trying to maintain a relatively straight track, (Like my .25 size Cub, it's a bit of a squirrel on the ground, requiring gentle rudder input to maintain track) and at about 1/2" throttle and 60-70 feet, it lifted into the air. I was surprised.

Flying is gentle and scale-like, with the .52 pulling it is capable of well over scale top speed and a decent climb rate, but it just putts around very convincingly at little above idle. Although it will turn with ailerons only, like most high wing craft without dihedral it likes coordinated rudder input as well to get the tail out in the turn. Slow to respond to rolls (Go figure) but does decent loops.

It's really a relaxing flier, (grab a chair and sit down) and gets lots of positive comments from other fliers, and really sounds cool on those slow, low flybys with the four stroke. I'm thinking a Saito .60 Twin would be perfect for this plane... Perhaps after Christmas!

Any questions, feel free to ask.

Dave

Dam, I have the same plane and engine combo and I love it, especially in winter when the skis are on. A major problem that you will encounter is the CA hinges on the struts, they will fail. I cut mine and installed 1/2 A hinge points and so far the work great. This winter I plan on installing a wireless camera in the canopy.

rc, I had the same problem with the strut connectors on my .25 size GP Cub... The ones at the fuse failed, so I used 2 steel landing gear straps to fashion new connectors. The hinge idea sounds great for the larger model though.

Flew mine again today, wringing it out a little more. There's just something about a Cub flying around that is entrancing. I get pretty much the same responses flying the GP Tiger Moth too, but the Moth is a bit more aerobatic than the Cub. Reading the "flying instructions" in the manual, it says the Cub is as aerobatic as the full size Cub, but I'm wondering... "Where's the beef"? Do I need lots of surface movement to make this thing want to roll?

It will roll real slow but you need to add rudder also. This winter I'm going to build floats for it.

I just bought this kit. I am looking to have this plane for my lazy, scale, sunday afternoon plane.

Do you think it will be fine with a os 40fx?

I think you'd pushing it, better to go with a 46.

Damnathius:
Could you be a little more specific with your engine/cowl arrangement as far as air cooling. Did you open up any scale holes in the front of the cowl? How about a large hole in the bottom of the cowl for air exit, etc???

Has your OS 52 kept cool enough, say durring an aerobatic session with the throttle turned up some, etc?


Thanks.

Gary, I opened up the bottom of the cowl for cooling and glow plug access. I had forgotten to install my remote glow adapter, and realized this when I got to the field. I was going to see how it ran without the bottom opened up, but ended up cutting it out in the field to access the glow plug. I opened up the two molded in slots in the front of the cowling during assembly, and just enough of the lower corner to clear the muffler which is very close to the lower left corner of the fuse front.

I've run this thing for several minutes doing "high speed" flybys without any overheating problems. The .52 runs very well in all flying conditions on this Cub from full speed to putting at just above idle. I first tried running a 12/6 APC prop, but found the motor likes an 11/7 Zinger on this plane as it doesn't have to work so hard. I want to try a 12/4 or 12/5 on it for a more scale look with lower load. The .52 is more than enough motor which provides quite a bit more than a scale top end speed.

The first change I made to the plane was install the second landing gear wire. When we get to the feild we fly! Some times the wind will challenge us with a crosswind landings which require approachs with the up wind wing low, having to set it down on a single wheel and hold it there until all the flying speed is gone. Having to do this, that one wheel needs to be rigid and its alignment must not change if it hits the runway alittle harder than perfered. That second wire insures that to be the case because it does not allow the main wire to bend back.
The second wire (1/8in dia. Cold roled steal) was bent to fit behind the hinges for the landing gear pants and then attached to the first main wire just infront of the wheel axle, rapped with copper wire then soldiered. Extra landing gear straps were used to hold the second wire in place right over the covering, the cabin floor is light ply so that is acceptable for bearing the loads this wire will see. And the screws where taped into the mounting block for the landing gear pants hinges and struts. The kit comes with rubberbands to hold the axile end of the landing gear pants to the landing gear wire. Having an inverted engine I had quite a bit of exhust hitting the landing gear pants and would go through rubber bands. Bill Tozer came up with the Idea to use tie raps (twist ties) there and the problem of having to replace those rubber bands regularly was solved.
When I had 22 flights on the model the EZ hinge that held the strut to the fuse. broke. I repaired it with another EZ hinge and the one on the other side later broke at 42 flights. At which point I decided to go with out them until I figured out how to fix this correctly. That ment I needed to glass the center section of the wing so I bought a role of century 21 Cub yellow and glassed the wing with 2inch wide 6oz. Glass and recovered the centersection. Then I read of using coke bottle peices to replace the EZ hinges so I pulled all of the EZ hinges and replaced them with plastic cut from a Dr. Pepper bottle (it was a bit flatter than coke)and put a bolt through it.
I have to work for a living so it is a common occurrence for planes to be left in the car while working and it did not take long before the seams pulled. At first I would pull them back and retack them but soon that was nolonger possible. After the last retack things were beginning to look pretty shabby so something had to be done. So I had that extra 21century film, and I picked up a pair of pinking shears at a garage sale years ago ( you can probably find a pair at the local fabric store). You guest it, I cut pinking strips and covered the edges of the models with pinking tape and it looks pritty good if I do say so my self. Mine has spent most of August in the van and non of the pinked seams have shown any signs of pulling or delaminating. There are some pictures of this on the in the photo gallery.

Good luck!
There are only tow types of models: Those that have and those that gonna, crash.

Thanks Damnathius
I'm building a Sig 1/5 Cub (bout the same size as the GP 60 Cub) with the OS 52 and was concerned with how to ensure adequate cooling.

I just finished my 2nd GP Cub ARF. Since I live half the year in the midwest and the other half in CA, I have 1 at each place!! It's a great flying plane as long as you realize it's never going to be a pattern flyer!!! As a lazy Saturday flyer is great!! I have a Saito .56 in the first one and it seem perfect. The only mods I did were to add Robart scale landing gear (the stock ones seem too bouncy) and used threaded insert in the wing and fuse for the struts. 6/32 allen heads hold everything in place just fine.
The second plane is constructed the same, but I installed a Saito .60 Twin! Those 2 cylinders sticking out of the cowl just look great. Both planes have a JR 460T gyro on the rudder and it seems to help alot. I hoping to fly the twin this weekend if I have time. I'll let you know how it flies.