RCM Plans Corkscrew
 

Hello all! I'm getting tired of assembling ARFs so I have dusted off a set of plans that I bought a couple of decades ago and I had a blast cutting out the parts! I forgot how fun building could actually be!!

The plane I'm building is a RCM Plans Corkscrew designed by Stu Richmond from the 1982 issue of RCM. It's a .25 sized plane. I put some stipulations on my scratch building experience! Before I ran off to the hobby store to buy ANYTHING I had to exhaust my workshop stockpiles to see if I had the parts. Much to my amazement I've only had to spend about $6.00 on this airplane! I had almost all of the wood and if it wasn't for a warped 5/16" dowel rod I probably could have kept it under $5!

I've finished cutting out all of the parts and have assembled the left wing. In the magazine they said they built the plane in under 2 weeks. I'm trying to chip at it everyday and I've made pretty good progress over the last 4 days.

If any of you have flown this plane, remember it or just want to keep my motivation up I'd love to hear from you! Here's a couple of pics!

Jerry

RE: RCM Plans Corkscrew
 

Really isn't all that difficult once you get going with a piece of knowledge behind you. Is it?

Presume that even before you fly it that you have now been thumbing other catalogues for A/C of a different type.

Gee, that was't so hard. Cost me only a few dollars to have something completely different than those Shake in the Box types.

Hang on to those skills and knowledge, for they will pay off later on.

Wm.

RE: RCM Plans Corkscrew
 

Jerry
Looks like you’ve got a great build started there! Looks to be a real fun flyer! Might have to build one of these myself. I too, love to build. There’s a deep satisfaction when something you built takes to the air. Keep up the good work, and keep us posted!
Bob J.

RE: RCM Plans Corkscrew
 

Hello Jerry

This bird is looking GOOOOD!!! , and keep us posted!

Saludos Enrique

RE: RCM Plans Corkscrew
 

Left wing is complete. Ready to join the two halfs.

RE: RCM Plans Corkscrew
 

Any updates on the Corkscrew project? I just ordered a set of plans for myself. Can't find much online about this one. What mag issue was it featured in? Thanks.

RE: RCM Plans Corkscrew
 

I just started building mine and would love to get feedback from any experienced Corkscrew builders/pilots. I'm going to use an OS .25FX. A few minor mods are planned but I think it'll be mostly stock. Thanks.

RE: RCM Plans Corkscrew
 

Hello Corkscrew Drivers,
I'm surprised there is any interest in this design. I've built 3 of them and am currently on my fourth. After the first 25 sized I upscaled it by 1.0812% to get me to appx 53" wingspan and I could put my ThunderTiger .36 on it. I also built a 60" span model. Now I am back to the 1.08% size, but am going with a trailing edge tapered wing, bolted on, and some sort of modified turtle deck. It is all in the works, but I work slow and it could be months while the summer flying season is in process.

The great thing about this design is its ability to upright flat spin like a top. And as designed it is a very simple build; great for first timer scratch builders.
I may post some results later.:)

RE: RCM Plans Corkscrew
 

Thought I'd bring this thread back to life with some pics of my Corkscrew project. After a long dormant period, it's underway again. I've been enjoying this build a lot.

I've deviated from the plans in a few places including the wingtip design. Once I traced a shape I liked on paper, I transferred it to some light balsa blocks. I then traced the aerodynamic profile on the sides. Cut out the top shape on the scroll saw, then taped the pieces back together, turned the block on it's side, and cut out the aerodynamic profile. Then I rounded the corners by handsanding until I liked the shape. Very fun and satisfying work!

RE: RCM Plans Corkscrew
 

I joined the wing panels in a more traditional manner than that called for on the plans with center ribs epoxied together. The center section was sheeted with 1/16" balsa. The aileron servo hole was cut out so that the servo could stand upright instead of laying on it's side as on the drawings. The torque rods were bent with 5 degrees of offset to provide aileron differential(more up than down) per the plans. The trailing edge pieces were channeled so that the torque rod sleeves would fit flush for mounting.

GarySS, I would love to see more of your Corkscrew pics and updates.

RE: RCM Plans Corkscrew
 

Hi Tee Bee, I'm slower than you are in this project! I'll finish up a 3D Primo first before progressing on the Corkscrew so it will be a couple of months.

I do have the wing basically framed except for the center sheeting. Like you I am sheeting more of the center in order to set up a bolt on modification. My wing is also modified to have a trailing edge taper like an Edge 540 with less dihedral. I thought about a radical redesign, but that is not what the Corkscrew is all about........it's about simplicity turned into a fun flying model. I wish we could correspond with the designer, Stu Richmond, but I don't think he travels the internet. His input would be valuable, etc.

My aileron servo on the latest version was also upright with a little housing protruding out the wing's bottom. I think it was a "male" corkscrew :D.

RE: RCM Plans Corkscrew
 

Was the protrusion to prevent possible interference with the pushrods?

RE: RCM Plans Corkscrew
 

I suppose you could say that, as I was insuring I had enough room for all of the radio gear. As it turned out I don't really think I needed to mount a corner of my servo outside the wing. But, remember my model was 8% larger on my last version. The first build was totally stock size and I mounted the servo on its side. I tried to upload some pictures last night, but RCU refused. Will try again, maybe with a high speed connection.

Picture of new version wing: Picture of rig stack with ply root 10 1/2 inches and tip about 7 1/2 inches....ready for final sanding:

RE: RCM Plans Corkscrew
 

Very nice!

RE: RCM Plans Corkscrew
 

Found a couple more pictures of my previous Corkscrew showing a different angle and closer shot of the engine/tank, etc.

RE: RCM Plans Corkscrew
 

Laminated the 1/32" ply doublers to the fuse sides. Then started working on the bulkheads and triplers. Moving right along, like an inchworm.

RE: RCM Plans Corkscrew
 

Looking good. What will be the choice for radio equip., engine, tank, and covering scheme????

RE: RCM Plans Corkscrew
 

Thanks, Gary. I'll be using a Futaba 2.4rx and servos, a new OS .25FX, and Sullivan 6oz slant tank. I plan to use Ultracote to cover it in a Navy theme, T-28-ish. I'll keep the posts and pics coming as it progresses. I wonder what became of RCPilot66's project.

Had a bad tooth extracted at the dentist today, so I'm resting on the couch. Hope to get back to building in the next couple of days if possible.

RE: RCM Plans Corkscrew
 

I was guessing an OS25FX would be nice before you posted!!!. I was wondering about the 35FX AX for mine, but it's 3 oz heavier than my Tiger 36. RCPilot66 hasn't checked in since 1/3/11 but a PM inquiry might eventually be seen by him. Ouch! about the tooth.[:@]

RE: RCM Plans Corkscrew
 

HELLO! It's been forever since I checked in on this thread! I'm glad to see there's other people who like the Corkscrew! I started building mine in November 2007 and it's been in storage since August 2008. Since my Corkscrew went in storage I have lived in Maryland, Tampa, FL and now Lakeland FL...home of Top Gun! I bought a house, got out of the military, am settled down and am now in the process of building my permanent shop! Once the shop is built this year, the Corkscrew is the first project to go on the board and get going just so I can limber up my building skills! Thanks for remembering me and keep up with those pictures of your new Corkscrews as they come off the assembly line!

Jerry

RE: RCM Plans Corkscrew
 

Great News, Jerry!! Welcome back. :) Hummm, a Corkscrew Brotherhood in the making.:D

RE: RCM Plans Corkscrew
 

Welcome back, Jerry!

RE: RCM Plans Corkscrew
 

Went to visit my parents this evening and found a nice piece of oak while rummaging thru my dad's workshop. I cut it up to use for the engine mount rails(the plans call for maple but this should suffice).

Came home and got the engine rails installed along with the firewall, landing gear ply, and wing saddle doublers.

Not too bad considering I spent 7 hours at the flying field today with several airplanes. :D

RE: RCM Plans Corkscrew
 

Spent a lot of time on the Corkscrew project today since the weather was too cruddy to fly. Sanded the bulkheads flush with the fuse top. Used the scroll saw to cut the forward fuse bottom, fuel tank compartment floor, and cockpit top cover from 1/32" plywood. Glued the fuse bottom sheet over the landing gear support plate and reinforced from the inside with epoxy and tri-stock. Then I epoxied the fuel compartment floor in place. This plane is built like a tank, very strong(and somewhat heavy) structure.

Next, I worked on the engine mount setup. Drilled the rails and made some angled downthrust shims from 1/16" plywood by sanding them to a sharp edge on one end, and match-drilling them to the engine. Used 4-40 hardware. The muffler fit with no issues but I had to notch the cowl cheek for the mixture knob. I made an extension for it from music wire.

Made a trip to the hardware store for some 1/8" music wire. Bending the gear was a challenge for me as there are 8 angles to bend and making it come out symmetrical was a tedious exercise. Used a vise and hammer for most of the bending. I had underestimated the time it would take to make the gear but it came out decent enough after a lot of headscratching. Luckily, I had the wheels, collars, and gear straps on hand so I could go ahead and mount them.

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More pics of today's work. The .25FX, with it's rear-mounted needle valve mounted all the way back at the firewall, still protrudes further forward than the engine shown on the plans. No biggie, just an observation.

I believe I'll install the servos and route the pushrods, throttle cable, etc. before installing any more fuse sheeting. That should make it easier to work in there.