Skyray progress

[Larry Renger]

It is done, here is a photo.  It weighs 5.5 ounces.  First few flights are, well, not disappointing, but not what I am used to with my full zoot 1cc competition planes.  What a surprise!

I did manage to dump it in the grass once, overestimating its ability to complete a loop.  I was flying on 35' x .008 lines, and it is clear that the prop choice is not optimum.  I am trying to strike a balance between flight time and performance, and it is clear that there is a lot of testing to do to hit the best combination.

Engine is a dead stock Golden Bee.  First flight was with 10% nitro and a Master Airscrew 6x3.  Very poor line tension and speed.  2nd flight was with an old Tornado 5x3 and 25% fuel.  Better, but not there yet.  The engine is pretty new, so more flight time is in order.

I suspect that a stock Black Widow on 40' lines is going to be worth testing.  More power is easy to get, but I need to get about 35 laps out of the thing to meet my goals.  I also want to be able to "fake" all the PAMPA maneuvers (oversize, wide corners, etc., but recognizable).  So, there is a multi-function trade-off between power, line length and duration.  The variables are engine tune, fuel, prop, line length.

Once I get this plane dialed in as a basepoint, of course I have plans for my own design.....  

[Bill Adair]

Larry,

I've always liked the little Skyrays, and the kits are a bargain.

Hope you get it to meet your expectations!

Bill

[john e. holliday]

I  always flew the little SkyRays on Golden Bees with what ever 10% was in the pit pox.  Used 6-3 props, name your brand.  Also limited to 35 foot dacron lines.  Had to be careful because of the stretchy dacron.  Same planes on .008 X 35 ft lines was a world of difference.  DOC Holliday

[Larry Renger]

I shortened the nose about 3/8 inch, but left the tailweight on and moved the leadouts back.  What a difference.  The model now maneuvers very nicely.  I have a slight warp in the inboard wing, but think I can heat-gun that out.  The epoxy finish should control the wood and retain it wherever I set it.  I am flying on 35' of .008 wire lines.  Tension is adequate everywhere.  The prop is a 5.5x4 Master Airscrew cut down to 5".

[Bob Furr]

Larry,
The skyray is an honest little airplane.   The nose could be stronger for use as a trainer (we put 1/64 or 1/32 ply laminations on to help).   The Omaha club built about 12 of these 20 years ago to use as trainers and there are still a few flying.   
Bob Furr

[Larry Renger]

I am using mine as a benchmark for the proposed Kwikee Stunt fun fly event.  I am satisfied that the model meets the minimum requirements in performance, but so far am not getting reliable performance and duration out of the Golden Bee.  And that should be one of the most reliable engines in the Cox line.  Spoiled by AP Wasps, I guess.

In addition to my own troubles getting the good run reliably, grumbles from my friends about having to deal with Cox reedies, and the availability of the Sarpoulos designs kitted by Blackhawk caused me to revise my engine requirements.  I still want to keep the small size and slab wing to keep it simple.  Of course you could fly the Kwikee Stunt pattern with a piped 60 ship, and, hopefully, darn well!  But I want to encourage participation without major investment in time, fear, building skill, etc.  I figure the Skyray has about 3 hours invested, including finish.