My Bearhawk stratch build project.

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Pops

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Thought that I would post another Bearhawk project. Scratch built from plans. At this time everything is built except the wings. All the parts for the wings are made. Just need to start assembling. This project has been going slow because since I started on it, I built the single single seat Super Cub that I am flying and have my JMR Special at the same stage as the Bearhawk. Also at this time I am majoring the C-85 engine for the JMR. Plan on starting on the Bearhawk wings in a couple months.
I am trying to beat the empty weight of the prototype Bearhawk. Will have a Lyc-360 engine, fixed pitch prop, no electrical system. I do have seats that fold down to make a bed. Dan
 

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Pops

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Pictures of Fuselage jig. The big red thing, is the engine mount jig that bolts to the front of the fuselage jig. Also the jig for lining up the axles and jig for making the landing gear. Dan
 

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Pops

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Pictures when we were bending the Bearhawks spar webs for the wings with the 8' brake that Dallas and I built. I took the pictures. All 3 of us are building Bearhawks and also my neighbor across the runway. Dan
 

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Pops

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Put the .025 2024-T3 aluminum rear baggage bulkhead cover on today. Latter I will be making a small inspection door for inspecting the control cables,etc. Could made a box for storage behind the panel, but it'll just add weight and trying to get the empty weight lower than the Prototype, if that is possible . Starting to make cardboard patterns for the aluminum floor. Floor will be .032 2024-T3 by Bob Barrows Bearhawk plans.
Dan
 

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Pops

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In building the 4 Bearhawks in my hanger, an old friend of 40 years, (Dallas) has the fuselage that is the farthermost behind. So yesterday we were installing the windshield channel and the square tubing that outlines the cabin top to the top of the wing profile.
Dan
 

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Pops

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I built the ribs for the Bearhawk before I started on the fuselage and tails, so now is the time to put the wings together. Worked today on starting to rivet the angle stiffeners on the ribs. After this, I'll need to start putting the spars together. Dan
 

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Pops

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I have all the aluminum stiffing angles riveted on all the ribs except for the long tip ribs. I will finished those tomorrow. The two double back to back ribs are the wing root ribs. When I was making the ribs, I used the scrap aluminum and sheared and bent all of the stiffing angles. I have a small homemade 12" shear and a 30" bar folder that makes for quick work in making the hundreds of angles. These is all the wing ribs for the Bearhawk except for the ribs of the flaps and ailerons. Total of 72 ribs on the table.
The next thing that I will be doing on the Bearhawk project is bending the wing spar webs.
Dan
 

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Pops

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Dallas S. and I worked today bending the .032 aluminum spar webs for the two Bearhawks. Got the main spar webs bent for my Bearhawk and Dallas Bearhawk. There is a web splice at the wing strut attach fittings, so that requires 4 long spar webs for the main spar of each airplane. Next week we should complete the rear spar webs and flap, aileron spar webs. That's 12 spar webs per airplane. We are taking our time and measuring 3-4 times and bend once because we have no extra long material if we should make a mistake. If we make a mistake, It'll be his fault :) Who are those 2 old farts in the pictures? 40 years ago, we were young.
Dan
 

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Pops

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Finished the .032 aluminum floors with flush rivet stiffing angles and channels on the bottom side in the larger unsupported areas. Have to unbolt the stick assembly and rudder pedals and put the floor in from the seat front to the firewall. I make cardboard patterns first then cut the aluminum.
Dan
 

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Pops

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Back in the 80's there was an article in Sport Avition about building a tool to set the rivets in the main spar for the RV-4. A friend of mine built the tool to set the rivets on his scratch built Zenith 601 and it worked very good. Uses a bottle jack with a rivet set on one end and a machined anvil of different lengths on the other end . Lay the tool on its side and slide the spar to the correct location. Made from 1/2 cold roll steel plate and 1/2" all-thread rods. I left the all-threads long so the plates can be adjusted to any position needed. I have all the Bearhawk wing parts made, now need to start assembly of the main and rear spars.
Pictures

Dan
 

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Pops

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I mentioned earlier about the seats in the Bearhawk folding down to make a bed. Thought I would post some pictures so you can get a better Idea of how I did it. I had to reshape the back of the seats to clear the side walls when the seats are fold down. There is a link on each side of the seat that unhooks the seat back. The seat back has to be put in one position and unhook one side then the seat back has to be put in another position to unhook the other side of the seat and the link has to be sprung out to unlatch. The seat back can't be accidentally released. You have to crank the seats forward and release the seat backs and then the front seat backs rest on the tabs on the front of the rear seat bottom. I started to make legs that fold down for the rear seat back but to save weight just decided to rest the seat back on a piece of foam that stores under the rear seat.

Picture of the inspection panel in the sides of the boot cowl to access the rudder pedals and master cylinders. I have spent to many hrs under instrument panels installing radios with the resulting back pains. A Cessna 150 is the worse.

Also picture of the removable top panel above the center radio stack for the same reason.

In trying to save as much weight as possible, I drilled lighting holes in all the door sills . Saved a total of 8 lbs. Yes, I weighted all the slugs.

This last week Dallas and I installed his stabs, elevators and made the elevator trim tab pushrods and measured for the tail wires for his Bearhawk. Dallas keeps saying his Bearhawk will be lighter than my Bearhawk. He is buying carbon fiber doors and rear window frames. Don't think so. Tail post full of lead is heavy :)
 

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Pops

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We built 4 Bearhawk fuselages in my hanger. #1 Bearhawk is across the runway in Larry's hanger ( the 2 pictures of the white primered fuselage), #2 Bearhawk fuselage is still in my hanger but belongs to my building buddy Dallas that has a hanger two doors away. My Bearhawk is #3. Picture of Dan taking his #4 Bearhawk to his workshop to finish. At this time Dan is also working on his wings. All 4 Bearhawk's were made form the same heavy steel jigs, fuselage, landing gear, engine mounts, rudder pedal assembly, etc, etc. Any part of the 4 Bearhawk are interchangeable. Post #3 is Dallas, Dan and me bending up Dan's spar webs for his Bearhawk wings. Dan
 

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