Tell us what you did today on your Bearhawk Project

My Stewarts "practise" pieces before starting fuselage interior. Decided they were keepers.
 

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Seeing those trim tabs reminded me of something. Do your best to keep the hinge line interface (front of trim tab and the tab pocket on elevator) as thin as possible. I don't know if mine were fatter than normal, but I struggled a bit to get the tabs in place when everything was covered and painted.

Bill
 
Beautiful work Rob! You are a craftsman! But no. My issue was the hinge barrels to tab and elevator. Sorry, I don’t have pics. I had a hard time pushing the pieces together enough to get the hinge pins in.
I guess the take away is that there are gremlins lurking back there...

Bill
 
Oh no Jared!

Today, I decided to Debt-Avalanche by moving over to Flap Nose Ribs. Made me feel good to get something fully done (for now)

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You should hear what I did with a 12" drill bit about a year ago. I still haven't gotten over it completely, emotionally. LOL
 
Did some work on the Van's baffle kit. I mounted the engine on its mount, and then onto a big engine stand and added a thin plywood firewall mockup. I didn't want to spend 3 or 4 months at the end of the project figuring out one detail at a time. I should have a whole FWF mocked up and ready to transfer to the fuselage when the fuselage is ready.
 
Gerry

I am working away at the moment. I'll take some more photos and put something in the "Building Tips" section later in the month.

It's not difficult. If you have quickbuild wings, you have to de-rivet the last rib. Then you insert a 1 1/8" piece of 025 (1/2" on the rib, 5/8" exposed). Match drill and rivet. Fitting the tip requires that you trim out 1/2" ahead of the tip rib so you have a recess. Then match drill the tip to the support and tip rib at about 3" spacing for #6 nutplates. The photo above pretty much shows how it's done. Not difficult - just takes a few hours.

Good Luck!
 
Rob,
Love your videos. You are a bit ahead of me on the fuselage. I have the space, and didn't want to wait till the end for the FWF so I mounted my engine to the mount, and then to an engine stand.
 
Got my avionics this week. I had my instrument panel cut to outline, and some CF panels laminated. I cut them today. Used a 2 inch hole saw to round the corners in the aluminum. I used an abrasive jigsaw blade to cut the curved parts of the CF. The abrasive blade worked awesome. instrumet.jpg
 
Paul, I haven't done that yet. But it has crossed my mind. I am religious about disconnecting air before changing anything on the squeezer.

Imagine a 12 inch drill bit, catching your jeans, close to your nether regions. Don't imagine it for long, it will give you nightmares.
 
I finished installing the engine side baffles and created a plenum made from carbon fiber. The expectation is for the plenum and coved (rounded) inlets to increase the high pressure side to help keep the CHT’s down. I used SkyBolts on the side panels for quick access to the cylinders and spark plugs. I still need to make a door to access the oil filler tube. I will set the C channels before making the door. This was my first experience working with carbon fiber. Overall, I am pleased with the results.
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@BravoGulf I used a thick sheet of poster board and cast the carbon fiber in place.
 

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I trashed oil cooler plenum version 4.0 with the rivet gun. The good news is I am getting faster making oil cooler plenums.
Also closing avionics harness connectors. I hope it all works!
 
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Very nice Rob. I’ve recently been watching Mike Patey’s YouTube videos on how to do this.
Will you make the cowl from Carbon Fiber as well ?
 
Finished the initial cover of the rudder with Oratex. Probably a lot more time consuming than regular fabric, but no painting when you are done. I like it. I should finish the gear legs tomorrow and start on the elevators and horizontal stab.
 
Nice! I covered my Rans S7 in Oratex and thoroughly enjoyed the process. Like you mention, it’s more time consuming regarding the attaching of the fabric but it’s airworthy a heck of a lot sooner. The most laborious job was attaching Oratex scrap as anti chafe vs. the standard adhesive tape used on conventional fabric processes.
 
I will probably do that to the horizontal stab tomorrow. That and the vertical stab ribs look sharp enough to need them.
 
I haven't posted many progress reports, but I figured this milestone was worth mentioning considering I hammered out the first rib nearly nine years ago. Yesterday--after four kids, three pets, six moves, and cumulative years of work-related travel--the scratch-built wings met the VR3-built fuselage right in my back yard. Ambient temperature started at 10F, but most importantly there was zero wind or precipitation. I will add a complete description of the day's events on my new EAA build log and add the link to this post at a later date.

Fun facts: my Bearhawk is already an avid traveler. Ribs were flanged in the DC area, stiffener angles were drilled in New Mexico, attach angles were deburred in northern Africa, and other odds and ends found their way to Europe and S. Korea.

We had a run-in with Physics along the way, as water levels are commonly used to set dihedral, and most water levels are inop in sub-freezing temperatures. We used a solution containing water, blue food coloring, dish soap, and loads of salt. As we set the dihedral of the second wing, we dropped an end and lost some fluid, so I just topped it off with fresh water as the temp had risen to the mid 20's F. We then completed the dihedral measurement and stepped back to admire the work. We immediately noticed the dihedral of the second wing was substantially off. After double checking all measurements and scratching our heads (and breaking for breakfast), we held both ends of the water level together and discovered one side was several inches higher than the other. No freezing had occurred and there were no bubbles. As a guy who does physics for a living, I was stumped. Finally, I realized the saltwater had not really mixed with the fresh water that I added to one side, and the very salty water was significantly more dense than the fresh water, causing a noticeable error. We cleaned out the tube and used only fresh water and finally had a working water level again. We rechecked all measurements and always held the tubing ends together to check functionality prior to making every measurement thenceforth. We also backed up all measurements with a digital level.

Much thanks to my father-in-law for his help (wearing the "cousin Eddy" hat in the photos), and to my wife for providing a constant stream of hot drinks served up in my brand new Bearhawk cup (thanks Jared!). Now it's time to pack up the project for safekeeping as I have another ~6 months of work travel coming up in January =(.


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Congratulations on a major milestone. Your persistance through so many life events is inspiring. You have made great progress.
 
robcaldwell said:
I have completed the installation of my engine cowling. And posted an update on my YouTube Channel:
Click to expand...

loved the video Rob! I definitely appreciated the talk about the lower lip you had to do it fiberglass. Slowly learning more and more about aluminum (or in this case, metalwork in general) and figuring out how to spot complex curves is definitely something I’m learning, and this was a great example of some great troubleshooting. Thanks for sharing!
 
Great video as always Rob! My air induction is nearly identical to your, I also used the James Aircraft inlet filter housing. I don't know if this would work for you, I bought a connection piece from K&N. It is a rubber like material and smooth inside and out unlike scat tube. It is about 3" long. The gap from my filter housing to the inlet on the cowling is about an inch. its not easy to clamp in place but doable and provides a flexible connection.
 
Rob, did you find a good source for the Piper latches? "Good" being the code word for cheap.
Nice video, again.
 
#svyolo No. The Piper latches I purchased are not inexpensive, but they are very good quality. Occasionally they become available on eBay. As of today, I could not find any current listings for them. Use this search term: "Piper Cowling Latch Kit Complete with Lock Part# 6502-05/ New# 6502-800"
 
Great video, Rob. It is clear that you will have a fine Bearhawk when you are finished. Your craftsmanship is tops.

Regarding your air inlet, I could be all wrong, but you may want to explore Rodsmith’s flexible union between the air box and lower cowl. My 360 with an 80” aluminum prop really rocks on starting. Perhaps your prop, which looks like it may be carbon fiber, may not have so much inertia. I think there is a video on Vetterman’s website which shows how much an engine can rock on starting...beyond what one might expect. Perhaps some other builder/flyers have additional insight.

I look forward to seeing your bird fly. Best wishes.
 
I'm equally concerned, Ray. And understand the importance of a flexible connection, as I discuss in the video. I will continue to seek an improved design. I appreciate the feedback and fully expect to receive some challenges on my build, and welcome any and all. Thanks!
 
Silicone hose is sold by a lot of speedshops. It comes in lots of shapes and sizes. It might make a really good flexible connection.
 
Rod, do you remember what the part # is for the piece you picked up from K&N? I did get some sceet tube (smoother version of scat tubing) from Aircraftspruce, but it has that wire coil running through it.
 
I'm still in the prep stage. Getting a couple walls built in my shop, gotta get a car out of there, etc... today is building walls to separate my gym from my shop and right now I'm getting all my plans into an art portfolio to protect and organize them.
 
Finished up my extended floor-level baggage compartment... Pretty close to how I pictured it but not perfect. Being floor level keeps allows me to put longer things on the floor and away from head height in case they become missiles. It goes about as far back as it can, while avoiding cables etc., which allows me to store a 6 foot longbow back there with the rear seat installed (4’ in the extension, 2’ on the floor.)
 

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I thought about putting it down low, but how many times would I have to empty out the whole plane to get something out? Or how many times would I load up and then realize I forgot to load the long stuff, and have to empty it all out again.

As long as I remember to duck when I hit the brakes I should be OK.........
 
Rob, when building my LSA I also used hinges that pulled or sucked the cowling down . I purchased my hinges from Spruce about 10 bucks each. February will be two years and all is well . Great looking build . Stinger
 
I flew to New Orleans with my brother then rented a car to drive to Mobile, Alabama where the Continental/Titan engine factory is. There the sales rep, JB, took us on a GREAT tour of the facility. It was worth the trip. Due to some security and proprietary process secrecy needs we weren’t able to film the tour, but I was allowed to take some pictures and I incorporated them into a little post-tour video where my brother and I talk about what we saw. It would have been better if we could have captured more on film but I thought it might be somewhat interesting regardless... The takeaway for me was that these are very high quality American engines made by American workers - even if they are now owned by China. Funny enough there is a little plaque in the lobby that says something to the effect of this company being in the top 5 “business units” of China! Such is life. Still, After learning about how things are done and who does them I feel great about ordering my Titan engine - and Mark got me a great deal on it too.
Here is the vid: https://m.youtube.com/watch?v=CDTFdj1o6KE
 
I was planning to put in the LH main tank today, but I discovered that one of the upper straps has been made too short, and my tank cover won't sit flush :-/
Luckily I inherited a lot of spare strap material, so it's time to make my first tank strap woo hoo!

It's been raining pretty hard here, so during showers I've been stuck inside planning the cockpit fit-out. Today I was researching the ICS wiring - I think I'll just make up 4 drop leads with TP-120 type plugs, and cable tie the leads to the fuselage. Easy to install, no panel-mounted sockets to vibrate loose, and saves me from having to manage two different headset jacks...

James
 
You could also just cut the two verticals and extend them. It took me several tries to make a good strap.
 
I’m very new to building. I got my rotisserie made out of two engine stands, a couple of u-joints and some steel. It’s way overbuilt and cost way too much since I used a recommended welder who went overboard. (I can’t weld) I learned that cost control is an important element of home building and will keep things under my direct control from here on in.

The good news is that the rig works and I’m able to start installing components inside the wing now. 1AAA1897-454F-4BF1-B99B-488205355F54.jpeg
 
Fabricating stuff like a rotisserie is a great way to learn or get better at welding. I cut my wing crates up and have used the metal for all kinds of fixtures, a wing rotiserrie made mostly out of the wing crates, and a fuselage rotisserie made out of two engine stands like you did.

I did quite a bit of Mig welding on exhausts years ago but always wanted to get better at welding. I wouldn't claim the title of "Welder" yet but I am a lot better than when I started.
 
With nice weather this week, I took two days off work to prep and prime the aluminum flap and aileron parts. I used Stewarts ekoprime with a touch-up Finex spray gun and was very pleased with the results; they make a fine product. The finish is smooth and solid except for a few spots (mostly flanges that are hard to hit) that I need to touch up today. I ran out of room to lay out the spars and skins, they're next.

Hats off to you guys who can work on your build for 6-8 hours a day... I'm not used to this, it's exhausting!
 

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I'm on this step too and faced a question... what density Dacron or poly-fiber are you going to cover flaps/ailerons?
 
Olm ,
Great question. I'm not entirely sure. The numbers I've seen are:
Stewart Systems: 0.8 oz/sf = 7.2 oz/sq yd
Bob: 0.1 lb/sf = 14.4 oz/sq yd
Realistic numbers from this forum: 10-20 oz/sq yd
Oratex...?

Obviously the finish and my skill level will play into it! I'm holding off balancing the ailerons as long as I can, maybe even after covering. What's your approach?

Edit: If you're asking just about the bare fabric... I'm not sure on that either. Need to research.
 
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I wonder what the limiting factor on the weight rating is... since we're not using it to cover the wings, could we get away with it on the fuselage, since the stresses on the fabric there would be no different regardless of weight?
 
When I was buying Oratex for my LSA, I did the calculation of how much more weight the 6000 was compared to the 600. I don't remember but thought the difference was small enough that I went with the heavier fabric. Mark
 
Nice to see mere experienced guys are taking part in the discussion! I balanced my ailerons and without covering the weight is about 1,4 kg.(3,08 p) and thinking of leaving the hole in covering to be able to add some more weight into the balancing tube. We have in Russia Dacron poly for reasonable price it is 250 gr per m2(0,46 lb/yd2) and another 125 gr/m2 (0,23 lb/yd2). And to the theme, at the summer country-house begun assembling the flaps.
 

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Looking great! I had a question, I see that you are using attach angles on the nose ribs. My plan show flanges instead. Was that a change since your plans perhaps?
 
It was my decision on using angles. The plan is also telling to use flanges. I don't remember why it was done this way, because my nose ribs were done about 3 years ago.
 
Today I machined a bezel for the pilots window out of .025" aluminum. I made it as a solid piece with some corner radiuses. I am going to pop rivet it to the window frame and sandwich a piece of .093" Plexiglas between the bezel and window frame. That will be my complete window system. I am not going to use bent up aluminum strips in the interior for backup as the window alone makes for a very rigid installation.

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I really like little plywood pieces that fabricated to support the window frame tubing, the plexiglass and the bezel.
 
The blocks have a 1/2 round slot to mate with the steel window frame and the edge of the jig gives the proper 1/2” bezel overlap on three sides and flush on the top. 2nd jig in the works for exactly drilling the tubes in dead center so the bezel will not be wonky when the rivers are put in
 
Today I test fit my exhaust system headers. I'm relieved that it fit perfectly. Clinton at Custom Aircraft Exhaust did a great job working from my hand sketched drawings to get it bang on!. There's not a lot of room in these cowlings for the IO-470! We managed to get 1" of clearance or more to every piece of structure, the cowling and the spark plug on the fwd left cylinder.

The tail pipes can wait until the engine is mounted in the airframe.

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I hate to be "That Guy", but I’m probably going to be. I don’t see slip joints between the cylinders. Without provisions for cylinder movement, I'm leery.

Bill
 
Don't worry about being that guy. That's why I posted here. I want opinions. There's seal-less slip joints at the connection to the tail pipe on both sides. Clint thinks that'll be enough. He's been building these for 40 years so I hope he's right. He definitely gave me some recommendations for how to secure the tailpipes to the airframe and to each other to avoid putting any torque back into the headers.

I'm not sure there would have been any room to have a typical slip joint in the header anyway.
 
Finally painted my floor boards with Stewarts acrylic metallic grey. Supposed to be pretty tough. I had made the floor boards a few years ago but was not happy with the fit of the most forward one, plus I had to move the fuel selector. So remade the front one and painted them. Weight of the .032 AL without paint was 12#-6oz. Paint added 8 oz. I may replace them with a carbon/kevlar laminate but not before I fly. Interior fabric paint is Stewarts Ekopoly, non metallic silver with flattener added to reduce the gloss, I like the way it turned out.
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I finally got around to starting the fuselage covering. I applied the fabric (Oratex) to the two upper sidewalls, and am almost done cutting the ceiling (aft of the skylight). Hopefully I will be done in 2-4 weeks, and hang the motor. A bunch of little super magnets really come in handyto hold the fabric in place
 
Great tip about the magnets! I would not have thought of that, but it's a really smart idea! I think I would avoid using them anywhere near the eventual compass mount location, however...
 
We heard there was going to be a demolition close by, so we flew over to watch it. Then we flew to the produce stand for a load of melons, cucumbers, peaches, icecream and slushies.
 

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Syvolo, what do you think about the Oratex? I'm seriously considering using it on mine (when I get to that point) in a constant quest to add lightness.

Jim, I would be quite surprised to find that those little magnets could impart enough, or any, magnetism to the steel to alter a compass reading. Though I've been wrong before...
 
I started up my Barrows O540 today and got the idle speed and mixture adjustment on the carb set. Even without a primer with the SureFly electronic ignition magneto the engine started right up which was a relief of course. The only issue was the Newton fuel selector valve was sticking and hard to switch to different positions. It was 104 degrees today in Southern Cal so that it’s hard to much done.
 
Hey everybody

I've been using up some left over vacation from last year working on the boot cowl and cowl for my 4pl. It has been STINKING hot and humid around here lately so not a lot of fun, but I have gotten quite a bit done. The pictures below show about 70 hours worth of work. I hung the engine, mounted the prop, got the nose bowl in place with spacers, then got to work on the metal.

I have a rather tall panel (I'm putting the portrait Garmin G3X GDU 370s in), and I wanted a straight line from the panel to the nose bowl so I started by making a sign board template of the firewall, then made the firewall from that.

Once that was done, I mounted the panel and got the boot cowl parts made (the side panels are removable). Then I got to work on the main cowl.

Once the cowl shape was done (just clecoed and screwed), I cut a hole in the bottom (scary) for the fuel servo. I am using a Van's Aircraft filter airbox and a massively hacked up RV-6 chin scoop for the air intake ala Michel Roy. I have attached before and after pics of the chin scoop. Canadians will recognize the clear hockey shin pad tape holding the scoop on :-)

It kinda has a C-170 vibe going with that long, straight top cowl.

Tomorrow the fiberglass work starts to make the chin scoop mountable, aerodynamic, and non-ugly. I hate fiberglass....
 

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That is great progress. It took me about the same amount of time to accomplish that. I still haven't completed the fiberglass work for my induction inlet, guess I have been avoiding it.
 
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