Tell us what you did today on your Bearhawk Project

[svyolo]

Fuselage on the gear for good today. Hanging the engine tomorrow or the next day.

[Nev]

I finished the fuselage this morning, more or less. So I rented a trailer and brought the wings up. I’ve decided to leave one wing crated, then I put the flap and aileron back inside the top crate until I’m ready to work on them. Hats off to the scratch builders out there !

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[Utah-Jay]

Nev, are your tanks installed? Wings set to the fuselage from the factory?

I think my tanks are set, but not the wing to fuselage.

[Nev]

Nev, are your tanks installed? Wings set to the fuselage from the factory?

I think my tanks are set, but not the wing to fuselage.

Yes my wings are set, so are the wing struts. Bolt holes all ready to go.

The tanks are only temporary installed and need to be removed and unwrapped (which I did this evening). I’m thinking of using an adhesive backed foam on the tank straps, if anyone has done this before feel free to comment. I seem to recall reading that some are using strips of carpet.

[Utah-Jay]

Yes my wings are set, so are the wing struts. Bolt holes all ready to go..

I’m Jealous

[Mark Dickens]

Congrats on reaching that milestone and in a pretty snappy time frame too!

[geraldmorrissey]

Got 50 each -5 forward spar capstrip rivets squeezed today. This is my last spar, so glad to see the end coming. Should finish all the spar work next week. Then I plan to carefully wrap them up and store them. I need a break from aluminum, got an urge to work with steel. So I'm going to build the empennage, then go back and finish the wings. Looking forward to cutting, grinding, bending and welding.
Gerry
Patrol #30

[davzLSA]

That sounds like great progress Gerry, be careful of the steel splinters, they will drive you crazy!!!

[Sir Newton]

Completely understandable!

[svyolo]

I did a test hang of the engine yesterday to locate, exactly, a very tight fit of the Vans oil cooler mount. And check everything else i mounted. Then I removed it. Worked good. Today I reinforced the oil cooler mount on the firewall, and 1/2 the battery box. Holiday weekend I need another piece of angle. The oil cooler mount is rock solid. I used some 1/2x1/2 x1/16 angle for the oil cooler. The angle overlaps the tubing under the firewall, and is clamped in place with unpadded Adel clamps with #8 clip nuts on the clamps (thank Colin, I love the clip nuts on Adel clamps. The Earthx battery box reinforcement is not yet done.

Everything else was good. I have had the engine mounted on its mount, and mounted onto an automotive engine stand with a firewall/instrument panel mockup to do wiring, systems, etc. So far so good. FWF finishing should be a couple of days, then build the cowling.

[AKKen07]

SV - I doubt this is new info for you but my A&P friend advised me not to put unpadded clamps on steel tubes. He says they will slowly wear through them. I've padded mine with thin teflon tape etc., although it doesn't help the fit of the clamps I haven't found anything better.

[rv8bldr]

I have found the rudder trim in my Maule (such as it is) really useful, especially on long climbs. In addition, depending upon speed, I have had to fiddle with the setting to get things where I like it. If you aren't familiar with the Maule rudder trim, it is essentially a handle you tug on that just pulls on your right rudder pedal with a spring. Dead simple. Also, right trim only :-)

Since I am putting an electric elevator trim in my 4pl (actually, a G3X system with AP and YD), I had the trim wheel left over. Not wanting to have a rudder trim tab sticking out the back of the airplane and only being trimmed for one speed (unless I have built everything perfectly straight...not likely since this is a scratch build) I thought I would try and design and build a rudder trim system that is completely adjustable.

Here it is.

Rudder Trim 1.jpg

I have put a red arrow pointing to the trim wheel under the throttle mount.. The wheel is snugged up using an AN310 nut using the right combination of washers to get the right friction so that it can be moved by hand but not by the rudder return springs. NOTE: I know there is an AN365 there right now. It was what I had handy doing the fit-up. It will be replaced after covering...


Rudder Trim 2.jpg

Here the arrows point to the trim wheel and the rudder return spring(s).


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The cable then goes through an upper pulley, travels down the tube, and through a second pulley (just out of view).


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And finally the lower pulley and the shackle attachment to the rudder cable assembly.

Probably overkill, but it was fun to make and I am sure that I will use it.

[AKKen07]

Looks pretty clever to me! Looking forward to the flight report already

[rodsmith]

Clever, I like it.

[svyolo]

The closest thing to a BH I ever flew was a T-34C in Navy flight school. It was a bit better, or worse, depending on how you look at too much power. It had 3 axis trim. But, it was meant to train people. It was supposed to be hard. Going from 100 to 200 kts was still one of the hardest maneuvers I can remember doing. Continuously triming in all three axis.

The purpose of a BH is different. I am pretty sure I won't fly it the same way. But I like the idea of rudder trim. But having not flown anything like a BH I will keep it simple for now. But I have thought about it.

[svyolo]

I hung the engine again just to make sure everything is playing well together. I finished up making a few fuel lines, and the oil cooler and filter lines. Made a wood disk to start on the cowling,
Last week I made a bunch of reinforcements for things mount on the firewall. For lighter weight stuff I just made a .032 or .025 doubler of larger area, and broke the edges for stiffness. Heavier stuff I used mostly .025 or .032 angles to carry the load to a tube behind the firewall, either mounting tab or Adel clamp with a clip nut. Battery, fuel pumps, and oil cooler. They feel pretty solid. I don't know how anybody else did stuff like this, but my Ti firewall is pretty flexible.

I did screw up and my throttle cable is 1" too short. I went on ACS and typed "throttle cable extension". Sure enough, I wasn't the first person to do this.

[Nev]

On my installation the throttle cable was also too short (IO540). Vans sell a cable for their O360 that is longer and fits well in my case.

[Bcone1381]

I'm using Stewart's for my fabric interior. I work alone at my home workshop. I have no fabric experience. I've never painted anything before. Last march I set a goal of having my fabric/paint completed for the entire aircraft about now. (meaning my schedule has been scrapped.)

I took a Stewarts class in March with AKKen07 (see post 615...He's done!!) And yesterday I ended up with a shiny orange peel surface. The second photo makes the orange peel really stand out, but now it seems to be either flowing out and getting better, or I took a photo that magnifies the surface texture. I do not desire a finish like a new refrigerator. It's got some texture, but absent are any even minor foundational flaws like fish eyes or drips. The interior has so many obstacles for the paint gun to bump into its hard to paint with material flowing good out of the gun. I expected an orange peel look because I kept the flow out of the paint gun low due to obstacles.

I fabricated my own paint booth using 1" diameter thin wall metal conduit. Its 10 x 20' and has two 20" box fans in the ceiling. Filtered air enters from furnace fitters that I taped to the box fans. Air exits out of the booth at the opposite end through more filters. I had no overspray contaminate my workshop. The "booth" pressurizes and enlarges with the fans turned on. Now that I'm done, I'll just keep the sides clamped to the upper frame until I am ready to paint the fuselage.

So I'm thinking maybe I'll get the fuselage and everything else covered this winter, and paint in the spring. I will cover, and rib stitch, and install all inspection covers, and all else I can think of, stopping before I need to do my first coating....which is sealing the fabric. If that gets accomplished before Michigan's spring time warm up, then I'll ro-do the boot cowl, install windshield, and mate up the wings/windhield and fabricate the wing root fairings.
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[Nev]

I always preferred to photograph my painting results from 5 ft away.

[Bcone1381]

Watch Sir Newton Folks. His talent is amazing and he will improve it with simplicity that will beg me to ask the question "Now why didn't I think of that?"

[rodsmith]

For the interior I used Stewarts non metallic silver and flattener. I used the full amount recommended, still a very shiny satin finish. Your surface finish is not bad, might try a little more air pressure or thinning slightly more. It does flow out for a few days so will be smoother than when first sprayed.

[spinningwrench]

Looks glossy and nice. Confidence for the outside of the fuselage.

[robcaldwell]

For me, I found that equipment made HUGE difference. Continuous high output compressor, (I went with a Eastwood scroll compressor), a quality air dryer, high flow lines and fittings, and the Devilbiss paint gun recommended by Stewarts. I swear that alone really made the difference for me. I only encountered orange peel when I tried painting aluminum when it was too cold outside.

[rodsmith]

I don't know if they still sell the Devilbiss Teckna Pro lite. It's more expensive but a very nice gun. I got a new one on Ebay for a substantial savings.

[Bcone1381]

The Devilbiss Tekna Pro Lite indeed is the smaller gun that Steweart's sold me. The Stewarts offering includes the right size tip to apply their products and the DeKups liquid reservoir setup. (DeKups is like a J&J baby bottle that allows an infant to suck milk out of a bottle without overcoming the effects of gravity by using a plastic baggy housed in a cylinder. It allows the paint gun reservoir to feed fluid with the gun upside down and nothing spills )

[Bcone1381]

FYI, This compressor will power a Devilbiss Finish Line Paint Gun. https://www.tractorsupply.com/tsc/pr...l?cm_vc=-10005

I waisted a day or so shopping for a used one. Know what to listen for if you go the Craigslist route. Don't settle for anything you think might knock just a little. When I'm done with my new compressor I think I can sell it & do OK. I might like painting though.

That compressor I listed is 70 Db in my shop when it runs as measured on an iPhone app. A scroll I looked up is "as low as 63 Db" and will never wear out. The traditional compressor is about 7000 hour life. If you see something less (like 1000hr life) keep shopping (DeWalt).

[Gerhard Rieger]

I decided to replace my aluminium tunnel with a stainless steel one, it makes perfect sense that the firewall and tunnel must be stainless steel. If you have a FWF fire, it will blow through the tunnel. I have my header tank at the back end under the tunnel, for me its very important and I will also add some heat shield between the tank and the heat shield. 757D8D69-0976-420B-8064-57E437F3C5F8.jpeg

[AKKen07]

Got the wings painted a few days ago. That’s all the painting for now since it’s getting pretty cold out and I rely on airflow from outside. Still need to paint a couple dozen small parts and need to cover and paint the flaps and ailerons in the spring.
I basically am using the same system as Rob to get the job done. One thing I struggle with is water in the air system. My filter catches it but needs replacement too often (at $65 a pop!) I resorted to putting them in the oven at 200 degrees for a couple hours to dry them out. Then I forgot it was in there and set the oven to 400 for dinner… :/ oops.
I’ve found that the topcoat goes on well with three real light fog coats then a heavy wet coat. I like how things are turning out but you have to lay the topcoats on REALLY heavy to get the nicest finish, hopefully I can polish a bit of orange peel out later if it still bothers me.

[TimTall]

I made a cheap air cooler/dryer and it works well. I took about 50' of copper tubing and coiled it up in a garbage can. I put a drain at the low point of the coil and a drain out of the garbage can. I run a garden hose with a light mist on the tubing while I'm painting. It catches a lot of water and the air leaving the coil is cooled to room temp or cooler. I have decent shop compressor but it's not quite enough volume so I tee'd in a smaller compressor. No problem holding 27psi at the gun indefinitely.

[Bcone1381]

Currently air leaves the pump of my compressor and flows through an 8 inch long small copper tube into the top of the tank. The short copper tube is too hot to touch when the compressor is running. Why cant the air can be cooled after it leaves the compressor pump prior to it entering the tank? Huge temperature differential exists and it ought to cool well. So, I maybe if the air left the compressor, then went through a 25'long coil of tubing that had air flowing over it from the fan associated with the compressor pump's fly wheel combined with a water trap prior to the tank, it could do a lot of good.

[AKKen07]

Thanks for the tips guys! If I get some slow time this winter I’ll try to incorporate a fix for my system.
Sir Newton, those are also the colors of the Denver Broncos I guess lots of good folks like ‘em!