DICKEYBIRD

OK boys'a, an'a one, an'a two....oops, this ain't the Lawrence Welk Show!

My contest entry this year is going to be MUCH simpler than last year's 'cuz I wanted to do something FUN!

It's supposed to be a "hoverbatics" style profile plane that looks sorta like a Bearcat; hence the name "BareCat." It is made mostly from 6mm Depron foam sheet from Depron USA with a little balsa, ply and carbon fiber thrown in for good measure. The flaperons are made from Walmart 3/16" "Sturdy Board" with the paper soaked & stripped off. It has a 325 sq. in. wing (incl. flaperons) and should weigh under 10 oz. dry. With all the fuselage side area, it should have great knife-edge qualities. Honestly, I have to say that many of the construction techniques were borrowed from a couple of guys over on Ezone by the name of Ron Good and Darren Brooks. They posted a video of their plane over there that absolutely blew me away and I decided that I had to try one for (you guessed it) Cox power!

Hopefully, it will somewhat approximate the hovering and harriering characteristics of the brilliant high-tech electric machine that inspired it. It's hard to say, considering the differences in the prop disc area of the geared brushless electric motor's prop (12 to 13"!) vs. the Cox's 5 to 6" prop.

Here's a few shots of the plan and the early stages of construction, CNC cut Depron ribs & rudder. Seems like overkill to use a computer to cut parts out of foam but I have to keep using the thing or I'll forget how!

DICKEYBIRD

This shows: (1) More CNC'd ribs (2) CNC cutting fuse doublers (3) The 1/4" x 5/16" x 3" engine bearers installed with cross-grain balsa filler (4) The front of the fuse with CNC cut front section and wing cutout so the incidence (0 deg.) would be right. I can cut only 12" in any direction so the rest of the fuse had to be cut the old fashioned way.

DICKEYBIRD

This shows: (1) The almost perfect fit of the wing to fuse joint available with CNC cutting. (2) The wing framed up (3) A look at the spar/rib Spar is full depth with 1/16 x 1/4" balsa caps and .007" x 1/4' across the root, ribs in 2 pieces (4) CNC cutting 1/32" ply control horns

DICKEYBIRD

This shows finished horns....length is added to stiffen the foam control surface and to add gluing surface. More to come....just got home from work and hope to get something done tomorrow. Can't wait to fly this thing....good or bad! That's half the excitement....the anticipation!

matchlessaero

Of course you know--- This means WAR!!!!!!!!!!!!![>:]

Beautiful as always Milton!!! You know I will be your cameraman when the test flight comes!!!

ajcoholic

My Feedback: (10)

Dang DB, you are going to be test flying tomorrow if you keep moving like that!!!

I allways wanted to have a 1/2A fun fly profile, but never got around to building one. Maybe you will offer some kits if (oh yeah, "IF" like anything you build isnt going to fly well... ) you get the performance you expect? (Im sure I wouldnt be the only one interested)

What exactly is depron foam? Heard that name a lot, no idea what it is though.

Nice pics, keep em' coming...

AJC

DICKEYBIRD

Don't worry, I've got a ways to go yet AJ!

Depron is from Europe and is used as an underlayment for wall coverings....at least that's what I've been told. It's about 2 lbs/cu. ft. and is extruded so it's surface is a little harder and it's stiffer than a sheet of 6mm standard foam would be. I got mine from depronusa.com Usually I hate foamies because of durability issues but I decided to go ahead with this project anyway.

More pics tomorrow I hope!

2fast4u

My Feedback: (5)

As always, I am sitting here speechless in the presence of another West Tennessee Master.

You boys better step up. This will fire up MATCHLESSAERO and there is no telling what he will come up with next.

It looks GREAT as always DICKEYBIRD. The two of you are why bums like me don't even bother.

combatpigg

My Feedback: (3)

HI DICKEYBIRD! Thanks for sharing! If a space alien abducted me and showed me how to do 1/2A RC, what you show is what I would expect! It looks like UFO is your glue of choice? Is there a flexible glue[like GOOP] that works on that stuff? I've got to put this DEPRON on my shopping list, it looks like a great alternative to balsa.The day has come when small E power projects make this sport look almost too easy, and a day is coming when the "gooey glow boys" will be looked upon as NEANDERTHALS, but at least we can GO DOWN SWINGING! PS,, You guys from TENNESSEE have really "got it going"!

DICKEYBIRD

Thanks C/pigg and 2fast! Ask my wife, she thinks I AM an alien and there's somethin' wrong with me. She just looks at this stuff and shakes her head! Fortunately, she still loves my wierd ol' self.

I used "Flash" brand medium foam-safe CA and their "Flashtac" foam friendly accelerator. I bought some UHU brand "por" foam-safe glue as well and it's great because it stays flexible to sorta match the flexibility of the depron but it's used like contact cement and wasn't fast enough for my schedule.

2fast: You're right; matchless has a house now with a real live workshop and there ain't no tellin' what he'll come up with now!

DICKEYBIRD

(1) Lotsa soldering fumes this morning. Couldn't sleep past 4:30 so I got up and put together the switch harness, mounted the Hitec Electron 6 rcvr. and 130 mah NiMH battery pack. I decided to take the light way out and forego a switch/charge setup and go with the single female Futaba G plug for the charge port and on/off switch via plug-in male shorting plug as detailed in a post here a while back. The antenna is wound around a 1/16" balsa "bobbin" and the entire antenna length is contained in the wing. Also note Depron stiffeners added between root rib and rib with flaperon servo to reduce flexing.

(2) Mounted the elev. & rudder servos way back in the tail to balance that long, heavy nose and rigged the .040" pushrods as well. Made up a junction plug for the extension leads from a single-row male header from Digi-Key.

(3) 1/32" ply rudder control horn installed

(4) Elevator horn was fabricated from nylon clevis with 1 side cut off, screwed to the bamboo joiner with a 2-56 nylon screw from other side and
locked with CA.

DICKEYBIRD

Close-up of the junction plug. The male header pins have the same spacing as Futaba/HiTec plugs so you cut off a piece with as many pins as you need (in this case 7 - center 1cut off for clearance) solder on the wires and insulate with 1/16" ID heat-shrink tubing.

Andrew

Hi DB --

The construction looks super -- makes me feel like 2fast4u -- the competition is so keen that any entry I would have would be embarrasing. Oh well !!!

Ive used the 0.10 headers a number of times in applications similar to yours. Obviously, they were designed to be used as thru-pin headers on PCBs and stabilized by soldering. With repeated plugging and unplugging, the pins will loosen in the plastic spacing strip and can sometimes be easily pushed back into the strip itself. My original intent was to use the strip as a lightweight and inexpensive male plug, but due to the pin movement, I have switched back to the standard pin housing found on our R/C equipment.

From your close-up, it looks like you may have avoided this problem by glueing the header and heatshrink together to a piece of balsa. If you have to plug and unplug very often, just be sure none of the pins back out and cause a bad connection.

Andrew

DICKEYBIRD

Not much to show so far this week but I did get started covering the wing. It's my 1st journey into the world of Solite covering. I dreaded getting started because I've read so many bad reports about it wanting to stick to itself and other issues. Turns out it handles very well and I didn't have any trouble with the sticking to itself problem. I DID HAVE TROUBLE getting the backing off! I always had to go to one of the edges to get it started....very difficult.

It goes on at a low temperature and sticks to balsa, Depron and itself (when you want it to on seams) very aggressively plus shrinks up very nicely. NO PROBLEM getting the wrinkles out! I did have trouble with heat-gunning it: I got a little too close just for an instant and a huge hole opened up. It did patch easily though!

DICKEYBIRD

Here's the finished wing with the stripped Walmart Sturdyboard flaperons stuck on. I spent way too much time figuring where & how to mount most of the radio gear inside the wing to keep it out of the oil-spray yet still be able to slide the covered wing through the fuse slot. After all that head scratching, I still screwed up and left stuff sticking out of the wing on both sides of the fuselage (Ya big dummy!) I guess I'll cut off the rear servo junction plug, tie a thread to the wire ends, stuff them back through the exit hole, slide the wing in, pull the wires back out and then solder the plug back on. Sometimes these "simple" planes give me FITS! [sm=spinnyeyes.gif]

combatpigg

My Feedback: (3)

HI DB! I'll bet you're pretty anxious for the roll out date to come! That SOLITE looks great, did it tend to collapse any of the framework? Does the wing seem pretty locked in? Would you use that SOLITE on larger, more powerfull stuff? Keep up the good work!

ajcoholic

My Feedback: (10)

Nice color too!

AJC

DICKEYBIRD

Hi c/pigg, I'm thinking about using Solite on all my .010-.020 models if the seams on this one hold up to the oil and repeated cleanings.

Being so thin & light, it doesn't add the torsional strength of MonoKote but it does pretty good. It shrinks up really tight and I yes, have a warp in the right panel to twist out. It didn't bow the 1/8" balsa L.E. in because of the .050" CF rod glued to the back side but it did crush the back of 2 ribs and pull in the 3/16" T.E. on 1 side. [] Next time I'll glue on a few gussets to strengthen the thin rear rib area. For lightweight structures, the instructions mention steaming the stuff over a boiling kettle (or teapot, it IS British after all!) till it expands, then it's supposed to shrink just a little as it cools.

combatpigg

My Feedback: (3)

HI DB! Thanks for the product review on SOLITE! You're the complete PIONEER by taking on this building technique, so it seems fitting that you went with the covering that your ALIEN ABDUCTORS told you to use! It's too bad you can't go back in time to when WALT GOODE and his brother were just getting set up to fly RC for the very first time[1939?], then have you show up with your BARECAT and put it through some 3D stuff for their eyes to see[X(]!![X(]!!

DICKEYBIRD

You're making me blush there c/pigg! I wish I could take credit for all the construction stuff but as I said in the beginning of the thread, a lot of this was worked out by Ron Good and Darren Brooks. I'm just altering it to fit my needs and hoping for the best!

Funny you should mention being able to go back in time with modern equip.; I was just talking to a flying bud about how things would've been if we'd had access to CAD & CNC tools way back when I 1st got into r/c and was still single! Like Jim Carrey in "The Mask": Somebody STOP me!!"

hotdogx

Hey DB! That's a dang cute aeroplane! And wow what a short tail arm! I'm very interested in hearing how it flies. Shoot, you might have already flown it by the time this gets posted! I can add a few comments about the Solite since I've been using it on electrics. First, the backing is dang near impossible to get off and you'll be there all night trying to get it started. However, an easy way to do it is to take two small pieces of masking tape and put one on the backing side and the other on the covering side located right at one of the corners. Then just pull and the backing will start peeling off easily (you probably already figured this out). Second, if you take one of those anti-static sheets used in the clothes dryer and lightly rub it on the covering as the backing is peeled off, it gets rid of a lot of the static cling. Third, if you have covered some thin open frameworks (like 1/8 thick tail surfaces) with transparent Solite, be careful whilst handling the parts not to squeeze them such that the top and bottom surfaces make contact - if you do, they will often stick together at that spot, and the only way to get them apert is to heat the spot a little - this then causes a blemish on the transparent surface. Fourth, the Solite has a lot of shrink and can get pretty tight. If you have a lightweight structure, set the iron at 240 degrees for shrinking and this will keep warps from developing. At higher temperatures the Solite will shrink more and get nice and tight, but the framework will pull in and warp. All this sounds bad, but it's just a matter of taking a bit of care and the Solite is really pretty easy to use.

Good luck on the test flight of the Barecat!

DICKEYBIRD

Thanks Al but nope, not ready to fly yet. Haven't done much in the past few days....I've been plum tuckered out from work and the shop's too dang cold! What little hobby time I've had I've spent working on another FM mag. article in the house where it's warm! Hope to get somethin' done on the 'Cat this weekend.

Thanks for the Solite tips; I tried the wrong kind of tape I guess 'cuz that didn't work for me either.

DICKEYBIRD

Still too much work-work goin' on to get a lot done on the 'Cat but I did build a fixture to repair the warped left T.E. The Depron doesn't have much compression strength and I under-estimated the shrinking power of Solite. Result, 2 crushed ribs at the joint with the T.E. and the T.E. bowed in about 1/8". [] I wrestled with the problem until I came up with this fixture to stretch the T.E. and rib back into place and I'll glue a couple bits of C/F onto the rear of the rib to hold it. Hopefully, the Solite patches well.

combatpigg

My Feedback: (3)

HI DB! That's a very clever device you got there, your plane will undoubtedly reward you with some very happy flights when you're done! I wonder how much thicker the ribs would have to be to avoid this, or else how tightly spaced they need to be? As it turns out, there is a DEPRON distributor practically in my own back yard, so it's high time to get some of this synthetic balsa and give it a try!

DICKEYBIRD

My next one will have a little Depron gusset at the rib/T.E. junction and I'll use less heat come shrinky time!