RCfred_68

Pete - the pics and vids came out great! Next time out I am going to try the infamous "corkscrew" maneuver!

ETpilot

For my next airplane build I am looking at low wing models. I, too, found the 80" Corkscrew and have it downloaded. I've been studying the model. Still not sure which model I will build. Post your build as you progress.

optech

My Feedback: (9)

If you downloaded the 80" from Outerzone your welcome (my handle on RCGroups is Cryhavoc..... Long story.) I am so glad others are looking to build this as I really enjoyed it when I bought the plans back in the "day".

Jeff, If your scaling up to a 92 incher you might want to consider going to a 30cc to get the performance out of it. Remember that when scaling up an object like this its going to be a volumetric scale. It looks 2D on paper but the mass is 3D as well as the associated weight. A 20cc gasser is roughly the same power as a 1.20 Four-Stroke which the 80" was designed around. Going up to 92" might be a little much for the 20cc for all but general flying around.

Food for thought,
Mike

ETpilot

I did find the plans on Outerzone. Thanks for taking the time to submit them to Outerzone. That helps lots of modelers looking for a plane to build. Outerzone has so many plans that the hard part is deciding which to build. I am in that delemma now. Which Oh Which to build. Thanks again.

IronButterfly

Hi all! Just reminiscing my early days in RC, Corkscrew came to mind and I jumped on this thread. My bird is long gone but so exciting to fly, like no other plane I had before or since. Never knew what a flat spin was until I yanked the stick hard one day with WOT. Fortunately she had enough altitude and I learned real quick how to recover, just wouldn't pull out on its own! I was just shocked at what this plane would do. I fly electrics now and thought I'd give it a try with foamboard. Yeah I know, kinda sounds wimpy but never tried foamboard before but wood and Monokote are expensive and ARF's have dulled my creative skills. Thought I would use my Rimfire .10 motor and scale the Corkscrew down a bit. One thing I never understood about this bird is why the swept-back LG?

optech

My Feedback: (9)

Sucks to hear you lost your Corkscrew .... But glad to hear your gonna build another. The smaller E size sounds interesting. I've been think of doing sorta the same thing only the other direction. Everytime I look for something to build I keep seeing the Corkscrew but the .25 is just too small for what I want and the 80" 1.20size is too large so I've been pondering a .60 size. Something in the 65-70" range I guess that can also use the new crop of .10-15cc gas engines that seem to be popular these days. I'll have to think and run some numbers but too much life stuff getting in the way right now.

The swept back landing gear is because the generally accepted wheel axle position for a tail dragger is at, or just slightly forward, of the wings leading edge. This position is a compromise as the closer to the CG you are the better. However, the leading edge position will aid ground loop prevention but still be far enough ahead of the CG to prevent nose tip overs. Of course if you fly from a rough field you can move the axle position forward and vice-versa if you have a nice smooth paved runway to fly from.
Farther from CG = will make the plane easier to ground loop and take away from tracking under power.
Closer to CG = better ground handling but easier to tip the plane on its nose and break a prop.

Also be sure to take into account that this is for a straight wing. If the Wing is a swept back design then the wheel position to go farther back as well. The relationship to the CG doesn't change.

Mike

br549-2

I saw the prototype in 82' at the Goldenrod Fl field, man that thing was doing things I can't pronounce . Stu was getting a good work out . and co did the corkscrew. He put it away and took the old quaker out and would put up till it was just a dot, set the tx by his chair and would light a cigar watching it make large circles. ahh the memories.

IronButterfly

Nice story br, wish I could go back and do it all over again.
I finished my 36" version made out of Dollar Tree foamboard. Put a Rimfire .10 in the nose with 3s 2200mah lipo and getting 8-minute flights easily. Wing has no dihedral. I'm still trimming it out, need more down-thrust so haven't tried anything radical yet. Just wondering how lack of dihedral will affect agility.

Zep

br549-2

IB, nice looking build. I too like the foam board, and have a few projects that turned out nice. looking at the photos the corkscrew reminds me of a design by Randy Randolf called chips , with a cox 074 if memory is correct. again thanks for the photos.

optech

My Feedback: (9)

Wow.... Nice job on the foam board version Zep!
Did you do a build thread?

Mike

IronButterfly

Thank you Mike. Yeah it does look nice...from a distance, but I'm not doing a build thread. This is my first foamboard attempt and the build time, mistakes I made and the frustration are more than I care to admit. I am not a master builder, in fact I think my last scratch build was the original Corkscrew back in '83. Anyway I followed the videos in the Foamboard Scratchbuild University thread on RCgroups. Main wing spar is 3/16 full-length dowel, two shorter spars of 1/4 x 1/8 basswood and 1/8 dowel on the leading edge. The wing is too flexible. Since the foam is 3/16 thick there's not much room to make a built-up spar. Today I did some pretty violent snaps and loops and noticed a crease in the wing covering near end of spars. If there's a next time I will use stiffer spars. Foam is very light but gains weight when you reinforce it. Fuse sides, top and bottom are foam stiffened with triangle stock and 1/32 plywood. Formers are 1/8 balsa and firewall 1/8 ply. AUW with 173g lipo is 745g. Wing area is 200 sq in. Seems to have unlimited vertical with Rimfire .10. BTW I put a servo in each wing. IMO driving ailerons with torque rods is just plain nuts.

Zep

RCfred_68

Hey Iron Butterfly, that electric version looks great, how does it fly?

Tee Bee

It's awesome to see activity on this thread again. Nice one, Iron Butterfly! I just did a little revival work to my Corkscrew featured earlier in this thread. A little covering repair and a new servo got her going again. Here's to lots of Corkscrew flights in 2017!

RCfred_68

Check out the "focal point" in November 2016 Model Aviation - my corkscrew got in there ! I only flew it a few times last year, I will fly it more in 2017!

Avaiojet

WOW!

Outstanding! I like it!

Charles

IronButterfly

Flies very well, maybe not quite as snappy as the original. Mine does have a crease in the wing, shoulda added a wood trailing edge spar. I think all said that foam is cheap and easy to use but no weight saving after adding wood reinforcement.

Tee Bee

Just giving this old goodie a bump. I've had my old Corkscrew out a couple of times so far this season and she's still flying great. I've seen a scaled down electric one recently on the boards, so Stu's design is living on.

RCfred_68

Tee Bee I am happy to see you dusted it off! I have about 5-6 flights on mine, I hope to get more airtime on it this year! Right now, sitting inside watching the blizzard!!

Lifer

My Feedback: (1)

I just received plans for the 80" version. Has anyone built this and used a DLE 20? I have built a lot of NotForSales of various sizes because I like planes that do radical maneuvers. The Corkscrew seems like a natural for me.

Tee Bee

Something tells me you'd probably be covering new ground with that setup. Seems like a perfect match of engine and airframe to me. Go for it and keep us posted! Good to see this thread alive again. Some of my favorite planes are NotForSales. My Corkscrew is still going strong.

RCfred_68

Hi - I have never seen the 80" version. Mine also is flying quite well, although I don't fly it that much. It spins and snaps like crazy -

[email protected]

Stu Richmond is now sitting on some cloud up there in modeler's heaven, looking down and smiling at everyone of you building his airplane. And blessing you for staying away from ARFs, foamies and *^$)8 drones.
A friend for many years, always lived far apart, but often found each other, like at the Tropical FunFly in Costa Rica. RIP Stu! Eloy

optech

My Feedback: (9)

Lifer,
Glad to see this thread still has some life. To answer your question... Sort of. The reason I built my Corkscrew 80 way back when was because I needed a simple airframe for a John Deer weedeater that I had absconded with the engine from. I'd converted it to airplane use and wanted to fly it in something. Unfortunately, this was way back before light weight electronic ignitions so it had the heavy magneto style ign. Also, the engine was well used and only like 13 or 16cc or something like that. So it worked but was heavy and not very powerful. But it flew the plane okay. Not a barn burner for sure but enough to do some aerobatics. The new modern, light 20cc with electronic ign would be perfect for it.

Mike

Lifer

My Feedback: (1)

After long consideration, both space and finance concerns have shelved the 80" version til I sell some of my older equipment. I did purchase a short kit for the original version and will power it with an MVVS .26.I'll start on it when the weather is too cold to fly.

Tee Bee

Good choice! Keep us posted.