# Project Bush Demon

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#### rv7charlie

Changing your goal to 2 seat cross country opens up a whole universe of existing designs, that while don't meet your mental exercise goal, would allow you to get in the air for less money than building just about anything. Tailwind, Thorp T18, the occasional Mustang II, and on the lower end of the speed spectrum but still faster than your wished for xc speed, the Sonex series. Sonex & Tailwind examples can be found in good flying condition for under $20K, the T18 for$20K-$30K, & the M-II for a bit more. No way to build any of them for those prices. Don't get too wrapped up in that 1000 lb useful load; a lot of T18s, Tailwinds, RV4s & RV6s do just fine with ~600 lb useful load, and would likely knock 2 as much as hours off your travel time estimate. I used to do the 12-14 hr drive from MS to NC in ~4.5 hrs, in a dirt simple RV4 with 160HP, including an extended fuel/food/bathroom stop. BTW, if you pass on that Stinson fuselage, let me know. Charlie #### blane.c ##### Well-Known Member HBA Supporter I think airplane design in general is a trade-off. I look through everything I can get my hands on. I found a site with a lot of downloadable PDF's Plans for Everything - Aircraft Plans I look through these, and others I find. Taking ideas from one, adding them to others. I watch probably every build video I can find on YouTube (honestly some of these guys should not be making videos, they either have no personality, no clue or no real information. I love Mike Patey's videos but if your like me, you don't have access to a million dollar precision water jet cutting table. Also I can draft all day long on paper. I have not a clue on how to enter that into a computer. I think the problem is the programs are written by programmers, who have not a clue on how to draft. Lol. So far it has been a long process to figure out. On another note, it is hard to focus on which way to go in the design right now, got some medical test coming up next week and my Son coming to visit for the next month. He wants to help me with the plans for the plane. He thinks designing a plane is cool and thinks I am brave for taking steps to learn to fly. (He is scared of heights). Honestly, I am trying to find a new balance in my head as well. I my change the bush plane idea to something I can fly to see my kid. He is 750 miles away by road. So maybe something that I can fly down with one stop for fuel, it doesn't have to be super fast. Say 800lb to 1000lb payload two seat airplane. Say it cruises at 120 or so, I could get down there in 6 hours or so plus time for fueling in route. Don't know, this would be a more practical direction. I figured my cub at 75mph for trip planning. That way was safe on gas. 120mph was out of the question. That is a reason I would go with a Bearhawk among others, I doubt you would beat the price of the kit with your own build and certainly not by enough to justify the "mystery" portion. #### Arkan ##### Well-Known Member Changing your goal to 2 seat cross country opens up a whole universe of existing designs, that while don't meet your mental exercise goal, would allow you to get in the air for less money than building just about anything. Tailwind, Thorp T18, the occasional Mustang II, and on the lower end of the speed spectrum but still faster than your wished for xc speed, the Sonex series. Sonex & Tailwind examples can be found in good flying condition for under$20K, the T18 for $20K-$30K, & the M-II for a bit more. No way to build any of them for those prices. Don't get too wrapped up in that 1000 lb useful load; a lot of T18s, Tailwinds, RV4s & RV6s do just fine with ~600 lb useful load, and would likely knock 2 as much as hours off your travel time estimate. I used to do the 12-14 hr drive from MS to NC in ~4.5 hrs, in a dirt simple RV4 with 160HP, including an extended fuel/food/bathroom stop.

BTW, if you pass on that Stinson fuselage, let me know.

Charlie
All good info, and yes I am passing on the Stinson, right now I am not in a position to do anything. I can PM you with the guys number. He has two of them. Although, the point is, design and build my own. I know it costs more in the long run, but it is not all out on the front end. As Jonny Cash once said, build it one piece at a time. As for the I known a in my design... I am not going to build anything with out it at least being test either small scale as an RC, or on a computer model. Where air flows are calculated and lift.

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#### TFF

##### Well-Known Member
Big scale RC. Everything small flys from power.

#### blane.c

##### Well-Known Member
HBA Supporter
If you are going hunting this year you need friends with airplanes because you ain't going to build one fast enough. Make friends. Considerations for making friends include watching for the guys that are going to bring two cases of beer under one arm and two cases of Stagg chili under the other arm and the associated sleeping arrangements.

#### Arkan

##### Well-Known Member
If you are going hunting this year you need friends with airplanes because you ain't going to build one fast enough. Make friends. Considerations for making friends include watching for the guys that are going to bring two cases of beer under one arm and two cases of Stagg chili under the other arm and the associated sleeping arrangements.
Last thing in the world you want is me eating chili on a hunting trip. The gas smell will drive off all wild life within 75 miles.

I found some plans for different airplanes, STOL designs and some mid wing and low wing longer range planes... so here are my thoughts. I think I am going to buy the plans for the STOL high wing, with a mind to modify the design for better STOL performance. (ie... longer wing, lengthen the chord and up grade suspension, brakes, tires, and depending on cabin size, I may widen the cab area for room. Then I am going to look at plans for something like a Sling or Lanceair. I don't want to modify it, but a four seat fast plane with good range would work for visiting my Son... so, let's see where that gets me.

#### rv7charlie

##### Well-Known Member
I am passing on the Stinson, right now I am not in a position to do anything. I can PM you with the guys number. He has two of them.
If you don't mind, pm me the guy's number & location. Even if I don't bite, a friend might be interested.
Thanks!

#### Arkan

##### Well-Known Member
Okay I had a thought last night. Has anyone ever worked with fiberglass? Don't laugh, but I had an idea of using plywood and foam board to make an outer hull for the airplane, say two or three pieces. The use the hull as the outer skin of the aircraft. Strengthen the hull buy adding either aluminum or wood supports.... could form the wings I. The same manner, using say a carbon fiber wrapped wooden spar. Don't know, just an idea I had. Making the molds would not be difficult, and I know several homebuilt kits us fiberglass.

So what are the pros and cons of this method.

Is there an issue with weight?

Would reinforcing say the cabin area with steel or aluminum be a safe or good idea.

Looking for thoughts on this. Originally I was thinking carbon fiber, but costs of carbon fiber plus the facts that carbon fiber is electrically conductive and will block RF I think it would interfere with radio coms. Of course so is aluminum, so would would just say mounting antennas say atop the vertical stabilizer offset this concern?

I know I am throwing a lot out at once, really building with carbon fiber has a lot of merit, the material is super strong and light weight. But impractical if it prevents the coms from working effectively.

.

Granted this is a carbon fiber manufacturing company, so their article may be self serving. But discussion and exchanging ideas is what we are all about, so let's discuss it. What's your thoughts.

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#### TFF

##### Well-Known Member
Look up Carbon Dragon and Long EZ on how those are made. There are other ways but they are good thinking designs.

It is not usually good to mix materials as one will outshine the other and you end up with something heavy that would have been better pure in either direction. Composite stay composite. Wood stay wood.

You are pretty much on your own to figure out if it works, because most will not mix because it’s simpler that way.

You have built RC planes. I have built them all my life. Models ore very strong. Real airplanes are not near as strong. I’m old school and still fly glow, but a real airplane is closer to a rubber band powered tissue covered in strength. As long as it’s flying it’s as strong as it needs to be, but a hand can crush it mishandling it. Mixing makes figuring out how strong it is much harder.

#### patrickrio

##### Well-Known Member
I have been watching for news from BoKu on the CarbonMax...... I think you are gonna see some real innovation there. Read about it Here.

As far as coms are concerned: a solid aerodynamic solution is just to make the vertical tail with fiberglass reinforced plastic instead of CRP. Locate the antennas in the resulting tail.

#### Arkan

##### Well-Known Member
I have been giving thought into how to Insure even infusion through the mesh on my ideas, and came up with a couple ideas using a vacuum pump. But honestly I am still working on just how to make that work well. I don't have millions of dollars of equipment. So making my molds then laying wet carbon, or even laying it dry and then coating with the resign. I don't have ovens to bake it, so what ever process I use it will have to dry the old fashioned way of just sitting there.

One idea is a double sided mold. Use seal the edges and use a strong vac pump or even a few to vac the two pieces together. My resign will need to be slow setting, to give larger parts time to be laid and sealed.. so researching cure times needs to be on my list of to do items.

#### Arkan

##### Well-Known Member
, in case anyone wonders why I want Carbon fiber... lol

HBA Supporter

#### TFF

##### Well-Known Member
If you could get 1” square sections 30 feet long it would make a great spar cap, but carbon of fiberglass doesn’t usually come like that. You get a bolt of fabric and some glue and you layer specific ways and in three dimensions. Usually less than 1/8”.

#### blane.c

##### Well-Known Member
HBA Supporter
When a steel tube fuselage gets "wrinkled" in the bushes, you simply straighten it out best you can with some rocks and crude wooden clubs add some strengthening members garnered from the same bushes you got the clubs from and with the judicious application of our trusty friend "duct tape" you fly back to town. There is not likely to be much left to work with of a carbon fiber fuselage as it doesn't wrinkle it snaps.

Same analogy for propellers, many have straightened a bent metal prop enough to make it back to town but other types of props don't bend they break.

#### Arkan

##### Well-Known Member
When a steel tube fuselage gets "wrinkled" in the bushes, you simply straighten it out best you can with some rocks and crude wooden clubs add some strengthening members garnered from the same bushes you got the clubs from and with the judicious application of our trusty friend "duct tape" you fly back to town. There is not likely to be much left to work with of a carbon fiber fuselage as it doesn't wrinkle it snaps.

Same analogy for propellers, many have straightened a bent metal prop enough to make it back to town but other types of props don't bend they break.

So I spent a lot of time researching Carbon Fiber. I learned a lot, and I think it is very possible material for home built. Fact is there are a lot of home build kits in the past that have used fiber glass. Now Carbon Fiber is stronger, and lighter. Companies like Boeing are now building planes with carbon Fiber laminates. The fact is carbon fiber can be used in home built and experimental aircraft more than it is currently used.

So I researched weight, strength, the different cloth types, epoxy, and different ways to lay the carbon fiber.

Boeing is uses a three layer laminate for outer skins. Is it something like .033 of an inch, and lighter and stronger than the aluminum they used for the same job.

So the best way in my opinion for a home builder at first glance seems the hardest, but in reality would be best for even and smooth application. It works by laying the material dry in the mold, setting up the infusion tubing, vac sealing the dry cloth and opening the infusion vale's letting in the epoxy. You get an even application over all your material. The best part on this method is the ability to add bulk heads and structure instead of having to hand lay the material later, this creates a stronger, bond.

So I have three test beds in mind. One is making a kayak. This will give me a way to test my method of laying the material and infusion. Also will give me practice layering and working the material. Second actually building an air bike ultra light with the material, I can see how much lighter my Carbon fiber plane is vs. a traditional build of the same design. Third is a 1/3 scale model of my stol design. This will let me test wing design, and actual assembly method.

Everything is a trade off, to fit your own mission in aircraft design, I am shedding weight and adding strength in a STOL back country bush plane.

I am sure some will have positive and negative, I want to hear from both.... any problems you see that will have to be overcome, issues,. You don't have to agree, but let's look for the obstacles and find the solutions.

As for beating temporary repairs in a bent up bush plane in the bush, unless you just bust a whole section off a carbon plane, those same locally found materials your bracing broken frames with duct tape can be duct taped over a crack or hole you busted on carbon fiber. To get it home.... I only suggest finding both ends of the crack and drilling say a one inch hole, to head off the crack spreading... then use duct tape and bracing to hold the cracked piece in place and get to the nearest airport for proper repairs. I think the kind of bang up that would incapacitate a carbon fiber build like I am thinking, would do the same beyond repair to a traditional al build.

#### Arkan

##### Well-Known Member
Thought I would give an update on my health. Today colonoscopy, performed... all is good and healthy, problem is we still do not know why my blood count is low. So everything good is a great thing, but still facing the unknown as to where my problems is

#### Arkan

##### Well-Known Member
Starting to think I upset you guys... the silence is deafening. Lol.

I have bought plans for a J-3, and will be joining EAA next week. I am actually going to go with a traditional set up, only I am going to widen the cab slightly and move the front seat back to accommodate my larger frame. But I am going to make the back seat removable for added cargo space... (I like my creature comforts when camping).

As for the build, I am going to go the carbon fiber route. Use of honeycomb sandwiching, and adding supports such as bulk heads and longerons. I can make the fuselage in two pieces, and join them with rivets, and a adhesive to seal them solid.

I do have a few questions or issues I should say. One is on the firewall, connecting the engine mount to the firewall, I want to put a backing plate and some kind of insulating barrier to prevent issues with vibrations. My concern is busting the carbon fiber. Maybe a layer of Kevlar between the plates firewall? I don't know. Any ideas?

The other is the landing gear mounting. There I am thinking on making a pocket to bolt either steel or aluminum brackets to mount the landing gear. Same with the shocks. Any ideas would be helpful.

#### blane.c

##### Well-Known Member
HBA Supporter
Dude! Carefully reconsider.