Mike James

Hi everybody,

I thought I'd start a new thread, since we're into assembly and getting ready for test flights now... ( Previous thread is at http://www.rcuniverse.com/forum/Who_..._482440/tm.htm )

Finally, I'm not sanding plugs and making molds for a while.

I won't finish the second vertical fin and second taileron for a couple of days, but thought you might enjoy a few photos that show the plane starting to look like it's supposed to. Just started basic painting yesterday, and it's getting exciting now.

MustangAce

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How much will it weigh and what is your engine selection?

Mike James

Target weight for a .60 to .90 is 10 pounds maximum. We expect to get that down to a little over 8 pounds in production. The prototype is heavy, because it's been through "prototype hell", but that's ok... Better for us to fly a heavy testbed than a light one. If this one flies as expected, the next one will be the "perfected" show plane... Better-looking cosmetically, and lighter. Wing area is 927 sq. inches, if you want to look at wing loading, although the simulation predicts a vertical lift vector from both the fuselage and canted vertical fins, at elevated angles of attack.

By the way... About the general philosophy of this design...
From the start, it was designed to be flyable with a stock 2-stroke .60, so that more people could afford it. I expect that a .60 will power it about like a .91 and Ramtec fan powers an Avonds F-15. That is, it should fly well, but of course you won't have turbine-like unlimited vertical, and you'll have to wait for the plane to accelerate.

We hope to test it with a Jett .90L, which should make it a LOT more aggressive.

One final option... Send us a few thousand dollars, and we'll make you one out of carbon. (!)

Razor-RCU

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Looks great Mike! Love that color scheme---

You have Rotties?

Mike James

Those (4) are my partner's, W.C. Fischer. Really meanacing at first glance, but great dogs, and very nice. (I have a cat.)

HaveBlue

Simply stunning, it looks fantastic, I bet your glad to be so close to the final stage here of the major work.. I cant wait for a video or just a flight report on this , even more so with the Jett 90.
looks like it's going to be everything you set out to achieve if not more..good luck hope it all goes well at the test flight!!!

combatpigg

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BEAUTIFUL WORK MIKE[X(]!!! You should get credit for coining the phrase,"prototype hell'! It's amazing how slight changes of direction have a way of adding ounces, it almost never seems to go the other way. Did you count all of your sanding strokes from day one? Maybe a pedometer would work on the old sanding arm?

Mike James

700,000,010,0030,041,894,023 strokes. ( I have no fingerprints left. )

"Prototype Hell", meaning a lot of test parts, helped us improve the plane...
In a rush to get the first few molded parts into flight testing, i overbuilt everything, thinking that with the fabrication time involved, it would be better to have flyable, albeit overweight parts, than to have unflyable, lightweight parts. So that's why the extra weight. (about a pound, overall) But now we know several things that we didn't know on the first parts. Maybe some of you will find this interesting...

I wanted to create lightweight, vacuum bagged parts, using companies like BVM as the quality model to aspire to. But, we wanted to do that somehow, without the CNC machining that goes with that, and without using extreme amounts of Kevlar and carbon, which would make the price much higher. So, a sandwich-core construction was chosen for the wings and tail parts (and certain parts of the fuselage, like the gear doors) using glass/balsa/glass. Without knowing the specific finished strength, I selected 2 oz. glass for both the interior and exterior, with 1/16" balsa as the core. Out of "structural fear", I also added some internal spars and ribs. What we ended up with is VERY strong, but heavy. These sandwich-core structures are so strong on their own that they don't need the internal structure, and are plenty strong enough for all flight loads, using only 1/32" balsa. This is similar to what Composite-ARF does, but we're using balsa instead of Herex foam, to keep costs down. You can't twist or bend the wing and tail parts without applying enough force to break them.

I believe we can get the wings down to about 12 oz. each, including paint. The tail parts have been tweaked through a few test parts now, and we're down to about 4 oz, for fully assembled tailerons, including the installed linkage and paint. The vertical fins also have less internal structure, and all of it is balsa, aside from the connecting spar. The fuselage is fine, overall, and the only changes will be in fabrication techniques. For example, the NACA inlets and auxillary ducts (which connect) are two separate parts. Combining the plugs into one piece, and then vacuum bagging one contnuous part saves a couple of ounces. A couple of the formers can be made from 1/8" AC ply, rather than the current 1/4" AC ply, which will save more ounces. When we go to laser-cut formers, we can make more elegant lightening holes, which will again, save a few ounces. I'm also looking at some laminates for some of the formers, which will be even lighter. Adding the lite ply frame to the canopy instead of molding the whole thing and using a lot of Cabosil saved a couple of ounces. It goes on, but you get the idea. We've learned a lot on this one, and are fine-tuning it all the time.

We also did some testing on different epoxies and tooling resins in the process, and even made our first molds using a sand/epoxy technique, which was educational. We've come back to West Systems, but may use a different tooling resin for the mold surfaces, depending on some testing I'm doing now.

The only "exotic" material used in the plane at this time is a few 1-inch wide strips of Kevlar, for the aileron and flap skin hinges.

Of course, the only proof is in the flight testing, so that's what's next. When that's done, (probably in the next couple of weeks) I'll have both still images and video.

combatpigg

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Good luck with the flight tests! I'm sure you deserve at least to crack a little smile when you see her in the air. Now that your molds are done you could have some fun and see just how light you can make a "hot rod" version and get away with it. Have you looked over any F-1 or Q-40 models? Those fuselages[ the light ones] are about as pliant as a shampoo bottle!. The only extra fabric is in the engine and wing areas, and it's amazing how little there is of that. Those guys have, through the years managed to whittle away a little here and there and now those airframes look like they would only be 2 MPH away from exploding!

Mike James

Thank you, everybody.

It's a strange feeling, honestly. I've gotten so used to thinking of all of these projects as long-term, that it's only now sinking in that we're actually close to flying. Seeing a little paint on the plane somehow makes it seem more "final", and it is exciting. From the very first polls I did here on RCU, and the aerodynamic research, etc., this project is about 2 1/2 years old... Whew!

raston

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johntheroadie

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Excellent work Mike! [sm=thumbup.gif] For a prototype, it's turned out very well regardless of what it's been through. Isn't it a wonderful feeling when you can sit down the sanding blocks for awhile and look at what you've been working on has now taken the shape of an airplane? Good luck on the test flights!

btw, is Mitzi going to help you out with the test flights too?

smchale

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Looks great Mike! I'll be especially interested in seeing/hearing about the flight testing off of a grass runway! Keep up the good work and sharing the progress with us!!

Mike James

Thank you, everybody!

We'll be doing the test flights at Triple Tree. (Joe Nall event field) so it will be off grass. I'll get lots of photos and video.

Mike James

I did some of the pinstripes on the top of the "Eliminator 2" today. The second taileron and vertical fin (already painted white in the molds) are being joined, (second photo) and I'll be able to pull them tomorrow and start painting the red on them.

seanreit

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Lookin good, how soon to maiden? What engine you going with on maiden?

Mike James

Hi Sean,

Don't have a firm date yet, but we should be doing it "soon." I'll post something here when we're going.

We intend to test it first with a stock OS .61FX, which has been the plan all along...to prove that a plane like this can be somehwat affordable. I expect that a .60 2-stroke will power this plane about like a .91 and Ramtec powers an Avonds F-15. It should fly fine, but you'll have to wait for the airplane to accelerate.

Later, we hope to test it with a Jett .90L, which will probably become the engine of choice, for those interested in "hot" performance.

seanreit

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Sounds good, I look forward to reports on how it goes as I'm sure many other do. I can't remember, on this airplane are you doing leading edge slats? Or is that later versions?

Mike James

The prototype is already overweight, so it won't have those.

Actually, it won't ever have slats, but will have leading edge flaps, like the F-16, F-18, F-22 and F-35. I'm really interested to install them on a persoanl copy and try them out, because the simulation predicts greatly improved stall resistance in sharp turns. If they work as expected, we'll offer some additional parts and instructions, as an advanced builder's option.

seanreit

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email me at [email protected] let's talk details what it will take to get my hands on one of these. I may want to put one together simply due to the complexity of the creation process. I will want the leading edge flaps option.

Mike James

Thanks, Sean. It's on the way.

Mike James

Okiedokiethen...

All the radio gear is installed, basic painting is done, and we're nearly ready for flight testing. Right now, the forecast is calling for about a week of rain...

Oh well, that will give me a chance to double-check everything. We're overweight, due to the things mentioned in previous posts, but I'm still anxious to fly, though.

RC-Captain

WoW [X(] Man do you work fast.........I cant even finish a freaking SPAD for going on three weeks now LOL

Are you going to video tape the first flight......I hear your heart beating from here..lol

Good Luck , Nice plane.

Mike James

Thank you! (It's not really that beautiful, if you get up close, but this is the prototype "stand back and take photos from 10 feet or more" paint job.)

We'll get lots of still photos and video, and I'll post the video as soon as we get back, that day.

Rudeboy

Yo Mike,

Ship it over to me... over here the forecast says beautiful weather for this week
I'll do the testing for ya... lol... And I promise to send it back in one piece!