BaldEagel

Rainman
Have you any experience with Spring Air retracts, I'v been looking on various Threads but cannot find any advise on the various retracts available, any feed back would be appreciated from anyone.
Mike J

Rainman-ACRF

Mike,

I've got a set of Spring-Air 700 series in my Graupner Harpoon. I put them in to keep the weight of this jet below 15lbs and powered it with a P60. They work pretty well but I've bent the frames a couple of times due to some less-than-graceful arrivals on grass. They bend back easy enough and are quite easy to maintain, and they are quite cheap.

Give Dave Wilshere at Motors and Rotors a call as he stocks most Springair stuff these days.

Phil

BaldEagel

Rainman
Thanks for the head up will contact Dave soon as.
Mike

iiiat

I've jsu tfinished building a Graupner 300L Leki. I've wanted one of these for a long time because they look veeeery good to me. I also have the Seagul 300S which is identical to the Graupner 300S. My impressions are as follows...
1. For very little more money, the Leki is FAR superior in looks, construction, and hardware to the less expensive 300S by Graupner/Seagul. Leki ha spre-installed pull-pull system, much bigger ailerons, nice but not neccessary split wings with aluminum tube, far superior scale appearance, airfoiled control surfaces etc.
2. The cowl, fuse, and tail section of the Graupner/Seagul 300S are very toylike. Not scale at all. this always bothered me.
3. I had a OS 91 Surpass 4-stroke in the Seagul 300S. That plane was WAY too heavy and flew/landed liek a brick with wings.
4. I haven't flown the Leki as of yet, but I went for super light on this build. I stuck in an old K&B 61 pump with Perry carb that I've had laying around forever (20 years) brand new. Hope it works! With the engine mounted as far forward as possible on the supplied motor mounts, and with 6V (5 cell) battery strapped on top of the engine, and with a 2Oz. prop weight, the CG balances at 102.5mm. Oh yes.. and I have the throttle servo mounted forward of the firewall as well. Because I knew I would need the weight up front, I used an old, full size Hitec 422 standard servo for throttle. Receiver mounted beside tank. Stock tank. Stock harware on tail with all excess screw threads removed. All other servos are JR ball bearing (can't remember model just now).
4. tank installation is funky as described in previous posts. I've used stock install in this build.
5. The supplied spinner is JUNK. I couldn't even tighten the prop nut with that pos. I've purchased a replacement GP with metal backplate. A nice aluminum spinner would be a good idea.
6. besides the spinner, I'm using all kit supplied hardware. The supplied linkages are thicker and nicer than normal, but a bit heavy. Clevis on servo end of elevator linkage is at a slight angel. Elevator servos would benefit from ball links and titanium pushrods.
7. They used their standard tailwheel assy. I prefer to use a lighter Sullivan model.
8. With all supplied hdwr etc. the kit finished/dry weight is 7lbs. Should fly great at that weight. I'll post my reactions if I get that old motor to work. I've never used a Perry carb nor a pump motor before. My 3-line fuel system is setup correctly for a pump motor.

iiiat

Maiden flight! The old K&B .61 pump started and ran very well. I was suprised. After running a couple tanks through for break-in, I decided to make the rest of break-in airborn. Trim after take off was required only 2 clicks rt aileron. I'm tenetive during 1st flights, so the flight plan was pretty boring. A few laps around the field on low rates only checking out control response etc. All good. Low rates are set to exact specs including expo. Plane was very nimble yet still easily controllable. I had a landing config programmed so I wanted to try that out. I had the elevator control way off so 1st landing was without flaps. No prob whatsoever. This planes lands sooo much lighter than the 300S. Anyway, the program for landign tuned out to be 100% flaps and onyl 5% down elevator. Slows down well, remains stable and controllable, very slow speed at touchdown, greased on landings. 2nd flight included a bit of aerobatics. The .61 pump with a 13 x 4 prop was still set rich and did NOT have unlimited vertical even at full throttle. There was plenty power to fly pattern, but not 3D. When this motor is leaned out and possibly even more prop (the .61 had not trouble with the 13 x 4), the .61 might be strong enough. Well, the weather is closing in on us here. Don't know when will be the next good flying day. Will post more as I go.

iiiat

A couple flights later and the satisfaction with this model is only increasing. Still want to try different props. The old K&B 61 runs very darn well. Idle is so slow that the plane is too slow at landing. The plane isn't trying to tip stall but flying so slowly that the elevator becomes ineffective. Landing with full up elevator. Increasing elevator throws.
Weather too cold to fly now. Thumbs shivering. Seeya in the spring.