Tell us what you did today on your Bearhawk Project

[Bcone1381]

You will get very god drilling out rivets. It's easy to get the drill bit back centered on the rivet. Its a quickly achieved skill set. soon you'll remove 100 out of 100 without a problem.

I see a rivet's shop head as smashed aluminum. We are smashing the tail of the rivet. We want the proper smash. Use some scrap stock....use it to experiment and have some fun..... try bucking rivets wrong. Using rivets that are too long and too short is educational. Experiment with Rivet tape. That stuff is a big time saver.

It is almost impossible to properly drive a rivet that is long....even slightly long is tough. The smash will drift off-center or the tail will tip over. Data suggest that a "slightly" poorly driven rivet still has almost all of its strength. I found that cutting rivets to length work hardens them and makes forming a good shop head far more difficult. So you need to get the Dash 3.5 and 4.5 length rivets that are available....and rivets are very cheep....drilling them out is consuming.

I have a copy in my workshop of Mil Spec Rivet Installation pdf. The generalities that are well published are fine. (like 0.5D thick x 1.5D diameter). But real specs are published and give you more lee way. Meaning a shop head that is not 0.5d x 1.5d may still comply with the engineering standards.
https://www.vansaircraft.com/wp-cont...-47196A_MI.pdf

[RobinDeMarco]

Thank you for the insight, Brooks!

[Chewie]

The rivets that are hardest to access are the most likely to get messed up in my experience. And if course it's those that are hardest to drill out... go figure!

[spinningwrench]

Wings on and drilled. An unexpected revelation is how inaccurate digital levels are. I have three pretty good ones and the water level did a much more accurate job of setting angle of attack and dihedral.
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[Mark Goldberg]

Bob has told me a good quality bubble level is way more accurate than a digital level. Sometimes you have to do some math. Mark

[alaskabearhawk]

Painting with a pretty broad brush. I have two quality digital levels (not Horror Freight) and they are very accurate. I'll calibrate them every so often, but they seem to hold their accuracy. But, that having been said, congratulations!

"The M-D Building Products SmartTool family is one of the pioneers in 360 degree angle measurement. Beginning in 1987, Wedge Innovations, invented, developed, manufactured, and marketed the custom liquid inclinometer used in the SmartLevel electronic digital level, sold through professional tool retailers worldwide. In 1992, Wedge was purchased by M-D Building Products, then Macklanburg-Duncan, a leader in contractor grade levels. For the last 25 years M-D has continued to grow the market for electronic angle measurement and is the market leader in this technology. Still the most accurate, affordable, inclinometer sensor in digital levels today, it is made in the M-D Building Products Headquarters in Oklahoma City, Oklahoma."

[Dpearson]

I used a water level for leveling the fuselage on the roll axis (referenced main spar mounting brackets) and for dihedral ( with 2.9” offset at the wing tip per the build manual). Bubble level on lower longeron to level the fuselage on the pitch axis. Worked great!

[Nev]

Today I installed these bad boys in place of the Goodyears. They're ABW 29's.
I then flew a bunch of circuits with them.

They make a huge difference to the landings, it feels like the suspension has doubled in it's "plush-ness". Also on landings I was able to hold the tailwheel off easier. One thing I did notice was a slight "grab" as the weight settled fully onto the wheels during landing. It felt like I was going through a puddle of standing water at about 30 kts. Not an issue, just an observation.

Take-off's, the immediate effect was that I can lift the tail off earlier and with less forward stick.
I haven't really checked the cruise speed out properly yet. I did briefly set 2200RPM, 22", and 37 LPH. It initially sat at 110 KIAS. I'll report further once I've flown a bit more with them.

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[robcaldwell]

I love my 26" ABW's. Like you said, major improvement to the dampening affects of the landing gear system.

[rodsmith]

Those look great, what size were your prior tires? I'm starting out with Aero Classic 8.50s but plan on 29"BWs on another set of wheels for easy change over.

[Nev]

Previously I was on Goodyear 26" tires. These add 10lbs and move the CG from 8.3" to 8.2", negligible really. The improvement in handling is outstanding.

[Bcone1381]

Yesterday I stopped working on the airframe, and I'm shifting to paint. Thats a big step for me, its all new and I'm apprehensive....That is common for me when starting a new task. My goal is to shoot paint before it gets too cold to paint here in Michigan (About 43 degrees north latitude)

Windshield, windshield fairing, left side window latch (which interacts with my throttle quadrant in my installation), and the Sky Light have all been nut plated and installed. Today I removed everything in preparation for paint.

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[Mark Dickens]

Looks good! My experience on things like this is when you're done with them and even if they're not perfect, hey you're done with them! I wasted more time worrying about all kinds of things when I was building my RV-8 only to figure out later that all I had done was waste time worrying. I've finished priming the tail feathers and they will be the first thing I top coat.

[svyolo]

My build is sitting on two of those HF dolly's as well. Cheap cheerful and easy to move around.

[Chewie]

That's exciting Brooks!

[SpruceForest]

All these airplanes on wheels, etc. very impressive and inspirational. Just wrapped up all 160 ribs for the Patrol and starting to get stuff done on stiffeners/moving on the wing spars. Did a quick jig to get the nose rib stiffeners laid out and a bushed phenolic drill jig to do the stiffeners. Delrin Bob sticks in the shot... def hold up better than any other material I've tried.

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[svyolo]

Cowl doors cut and fitted, hinged. Ordered Cam-locs from Skybolt. Starting on fitting the intake portion of the baffling. Similar to Battson/Nev with an aluminum extension up to the inlet.

[Bcone1381]

The first round of Fabric Coating application is completed. I built a temporary, functionally ugly paint booth uses 1" conduit, 4mil plastic sheeting, stapling to corners together. Filtered air is pulled through filters in the booth ceiling by two Box fans that sit on the floor of the booths side wall.

I feel very safe using Stewarts. The air system it requires is significant, but the breathing supply that I need to stay alive is simple....a charcoal filter mask. I have no experience painting. I ended up with no drips or runs. Slight orange peel is acceptable for me at my skill and experience level.

These are the Boulder Gray elevator, rudder, and gear legs.

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The color is Insignia white with Boulder Gray trim on the tail feathers, tips and nose. The scheme is unimaginative. I want clean, simple and achievable. I designed about 60 schemes on a template from the plans and kept coming back to this one.

I hope the Boulder Gray will match the smoke gray windshield and side windows. A checkerboard or triangle rudder pattern for some zip and pizazz is not out of the question. I'm not sure N number size or location yet. 2 inch on the tail? Not sure if I have room for 12" behind the window. 12" on the stripe looks good.

[jaredyates]

Looking good Brooks, let me know of you need a vinyl paint mask for the numbers (or anything else). We can cut out squares for checkerboards too.

[rodsmith]

That looks great Brooks. One thing I found very important for getting a good paint job is lots and lots of lights. I twice ordered additional cheap led tubes to add additional light. I paint with the paint gun in one hand and an led trouble light in the other.

[Bcone1381]

Jared;

I just sent you an email on the vinyl.

Rod; It's interesting what you found. In the photo I have one side lite with three of my lights. So far I am using six Harbor Freight 5500 lumen LED shop lights and am not sure three on each side are enough. Light behind me created the reflection needed to help see the amount of paint being applied by the gun. Without reflection, its guess work. I ended up doing what you did with one of those shop lights to focus and boost the light reflection. Managing the cords and the air hose took some effort. More can be learned in this arena to form an EAB Industry Best Practice I think.

[rodsmith]

The fuselage is back out of the paint booth and on the gear again. I was all set to install the engine and discovered I had never ordered the engine mount bolts. The ones I had been using are too long and rather beat up after multiple installation/removals.

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[svyolo]

Engine cowl top done including oil door, ready for paint. I will start final assembly of the cowl bottom tomorrow.

[ElliotAbel]

Just stated the build and got the 5 fixed into the rotisserie today. I started a bit of the tail work too. Looking forward to the build!

[jaredyates]

Just did a little post-maintenance weighing. IMG_20220923_125125722_HDR.jpg
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[Nev]

Jared what engine have you got up front ?

[jaredyates]

It's the parallel valve 540. Its last weighing was 1511 and the difference reflects removing lots of things.

[spinningwrench]

Windshield done and all faired in.

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[svyolo]

I like the composite wing root fairing leading edge. Looks sharp. I may do the same.

[SpruceForest]

Wrapping up the wing bits and pieces over the last three days in prep for starting the spars. Just entered 9th month of project... looking back on the build log, I started cutting aluminum sheet stock for ribs and spars on the 10th of March.

I do a lot of jig building for instrument work, so more of the same for the wing attach, spar join plates, and the filler pieces under the wing strut attach straps. And before someone says it - absolutely not worth it for four of each, but someone down the road will get some awesome tooling when I'm done. Not fond of routing small pieces of relatively thick aluminum or much of anything else, so most jigs I build for that job have a reference surface or two as well as two alignment pins, and are two or sometimes three sided to bring both size and mass up to gain controllability and to Murphy-proof.

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Spar join plates were ripped to width and the jig uses those parallel sides as reference for alignment and to beef up the alignment pins.

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Alignment pins hold things while the bottom cover goes on and help steady things once clamped up.

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Really small stuff gets a big piece of ply to better manage control of the work. I have a lot of 1/2" and 3/4" scrap sheet stock left from all that form and body mold building, so one way of using up stuff too good to send to the dump but too small for use elsewhere.

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The plan pattern for the filler strips under the strut attach straps is a little rough, so just easier to take a 4" wide piece of stock and flip end-for end at every pass... temporary stop and alignment blocks tacked to the tapering sled make this a quick job with a 7-1/4" aluminum blade. The filler pieces are about 0.9" wide at one end, and the saw kerf is 0.096", so little waste.

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Ready for edge clean-up, but that can wait until the fittings start going on the spars.

Other progress:

- I have a nice 19" bandsaw in the shop, but wanted to segregate the aluminum and steel chips. Picked up an ancient 4 speed Reliant from 1996 for about $200 (it had a very nice US-made 1 hp TEFC 56 frame motor, so worth it just for that). After brazing a cracked lower guide casting and the usual overhaul on guides, alignment, tires, link belt install, and building up a mobility base, I was out about a week of evenings, but had a pretty decent metal saw. Lowest speed is still too high for blade life cutting steel, but I have a couple sheaves that should do the trick.

- Still destroying steel tubing and flat stock doing the self-taught stuff for OA welding. Hope to get lined up with one of the EAA chapter OA weld gurus over the next month so that I can get the wing weldments (drives, hinge, etc.) knocked out by the time the spars are ready to go into the wing assembly jig.