Feb 12, 2023     Finish match drilling nose rib stiffeners and start center ribs - (4 hours) Category: Wings

Now that I had the stiffener process down for the nose ribs, I was able to progress through the last few relatively quickly. As I was drilling these stiffeners I was also checking for flatness of the ribs and straightness of the flanges, making adjustments as necessary.

I started the process on the center ribs this afternoon, this time focusing more on uniformity. Again, my stiffeners were made to plan specs which were slightly longer than the actual formed rib, so I had some trimming to do for the front stiffeners. This was completed on my table saw, then I rounded the edges with my belt sander. Again, 1/4" edge distance was marked lengthwise.

  Feb 12, 2023     Studying and Pondering - (8 hours) Category: Research

I've been doing a lot of thinking lately. Is it worth it to continue this project financially, or better to just save up for a complete certificated aircraft? Would I be better off stopping and focusing on progressing with my flying skills? Is this airplane even what my mission is now? Will my mission be the same in the future? Will there even be general aviation aircraft in the future? If general aviation, specifically recreational aviation is still around, will we be running Lycoming internal combustion engines? Electric motors? Hydrogen powered combustion? Autogas? New AvGas? Will aviation become so expensive that the only people who can afford to fly recreationally be the well to do and rich?

These are haunting questions when spending hours and hours literally making parts to be assembled. I can't answer it I suppose. Realistically, I spent more than 8 hours pondering these things. It's hard to put a time stamp on it, because whenever I had a minute away from work or stuff around the house, I was dreaming of these things, probably more like obsessing over it.

So let's start with this. How did I end up here back in 2019:
-Obviously I am a pilot and looking for an aircraft for pleasure flying. To my knowledge, without a fancy letter of agreement from the FAA, an Experimental aircraft cannot be used for hire. I considered instructing out of my own airplane once upon a time but this wouldn't really be feasible out of this plane. So this is for fun.
- I love operating out of grass strips, and adventuring with the airplane. I have often not gone places because the airstrip was outside my comfort envelope of the cessna 172 I fly, mostly in takeoff performance. So I want not necessarily a tried and true bush plane but one that operates out of unimproved surfaces. I love the idea of landing in fields, exploring, etc. In my flying career so far, I can count on one hand the number of times I have ventured into Class C airports, due mostly to the cost (landing fees?) and also to the hassle of clearances, etc.
- I am a airplane mechanic, a tinkerer, and a builder. I like the philosophy of "Built Not Bought". I work everyday other people's fancy Cirrus'; that's not me. I don't think I will ever have the money or permission from my other half to purchase a 500k+ composite machine like that. Right now, a 5 way split on a 172 is comfortable. Depending on engine choice, I think I can make at lease a Lycoming 360 powered version of this plane run about around my operating costs for the Bearhawk, hopefully a 540.
- I am an airplane mechanic - labor can be cheap. My time is getting less and less cheap, but at least if I want to do maintenance, I don't have to fork over $150 an hour for someone else to do it. I also have seen how planes are put together in my years as a mechanic and see how I would do things differently. Along the same line, certificated parts can be very expensive. Within reason, I plan to cut those costs. Don't get me wrong, I'm not doing anything unsafe like using non-aircraft grade bolts. But I'm welding up my own bellcrank, not paying Cessna $1500 for new old stock, or something crazy for avionics, or swtiches, or whatever else.
-I am a relatively big guy. Thankfully right now that mostly means the height way and not the width way, but a 150 just isn't going to cut it. I fell into a Citabria a few times, but felt somewhat cramped, although more in tune with the airplane (it felt like I became a part of it. A few friends of mine had a Maule M5 side by side, also cramped feeling. My best flying experiences (comfort wise) were in a 182. I felt like I had a very acceptable amount of head room, and elbow room. I also loved it's performance, just not the airframe's price tag. Or the stories of collapsing nose gear off (and on) airstrips.
- I have often wanted to take friends flying but couldn't because more than 2 people in a tired 1963 skyhawk would require takeoff with minimal fuel to be comfortable. 4 souls aboard seems unobtainable, at least in today's world . A true 4 place would be nice, and the added benefit that things could be opened up for gear (camping, bikes, whatever).
- While I want to get my instrument rating, IMC in a single engine airplane sounds like something to avoid. In fact, the more I poke around and quiz pilots, the more I find that without an autopilot system and a plane designed for it, once you get your rating, you spend the rest of your flying career trying to avoid using it. Use it to punch through stratus layers on a scuddy day, sure. Options to get home when the clouds are low, sure. Go takeoff in the dead of winter in a snowstorm or go dancing around thunderstorms, probably not. Let's not forget maintaining proficiency, hard to do on 40 hours of flying a year.
- Knowing what I know about the industry, seeing where things are going, general aviation is about to have some big changes. Fuel sources, among other things, will be hot topics. Certificated aircraft will take forever to retrofit when that day comes - shoot, the FAA is still stuck in the 90s. Experimental offers a bit more freedom, albeit a lot more mental gymnastics to do it yourself.

  Feb 11, 2023     Nose rib vertical stiffeners - (8 hours) Category: Wings

I picked up all 30 of my nose ribs and decided that this weekend I would drill and cleco my nose rib stiffeners in place. I got all the stiffeners I had bent up out, and checked their fits to the ribs. They were a bit too long. This was not concerning to me because I have seen going forward that my form blocks did not exactly match the plans drawings, however they were directly derived from the mylar sheet provided. So I'm building to the mylar. I decided that I would trim the stiffeners with aviation snips to match the airfoil shape of the rib flange. So I took all 30 of the stiffeners and started lopping off corners. As I was going, I realized about half way through that I had very little uniformity with this method, and then my mind took off. I checked the fit of a few stiffeners to the nose ribs and was not happy with the asthetics. My perfectionism kicked in and my heart sank. I hate redoing work. What followed was about an hour of trying to decide if I should break out the .025 rolled sheet again and cut a strip out or try to salvage what was left. Ultimately, with a lot of fidgeting with the stiffeners, I determined to press on, and do things more repeatably. I proceeded to cut angles on the stiffeners I had already adjusted with the snips on my table saw with miter sled. This cleaned up one side. Then I cleaned up the other edge on the table saw at the other airfoil angle. This worked out to make acceptable edges on the stiffeners that I rounded over with my makeshift belt sander. Next, to keep the stiffeners aligned with the vertical spar line formed by the aft edge of the nose rib, I clamped a straight stick of wood to the edge of my bench that was slightly higher than the overall height of the rib flat on the bench. I aligned the stiffener where it needed to rest between lightening holes and measured the distance to the aft edge. Then I cut a 1/8" plate of plywood to rest on top of the aft edge of the aft lightening hole which would act as a jig to align the stiffener vertically. With my new overall length of stiffener, I laid out 1/4" edge distance lengthwise, and made an initial 1/2" inch inset from the lengthwise end. The plans call for 4 AD3 rivets, so I set up rivet spacing around 1.75", marked, and center punched the stiffeners. Then, I match drilled the stiffeners to the nose ribs, held in place with clecos.

As I started this process, I quickly realized that my supply of about 20 of each cleco size would not be convenient. So, I ordered enough cleco's from Yardstore to meet the number called out for in Bob's build book: 300 -3s, 200- 4s, 100-5s. Worst case scenario, I can use these at work, or they appear to hold resale value on ebay well.

  Feb 01, 2023     Parts Inventory and Material Ordering Research, Finish Bending Attach/Stiffening Angles - (6 hours) Category: Research

Because it has been so long since I've really studied my plans, I had to go back a few steps and determine where I am in this project. I also need an accurate idea of what I need to order for my next steps. As things sit right now, I have pretty much just scratched the surface of building the wings. I still need .020 2024 to make my flap nose ribs and aileron pocket ribs, as well as some of the flap and aileron hinge support brackets. I have one cracked flap trailing edge rib that I need to remake on the formblock. I lack (4) Aileron Pocket rib attach angles, otherwise I have all of those bent. Before riveting stiffener angles, I will likely have to trim some for clearance. Everything will likely need a good deburring and cleanup from forming.

Ideally I would go through and finish my ribs as far as possible. I don't think I intend to paint my aileron parts, I may Alodine everything prior to assembly and then I plan to be judicious in my application of Corrosion-X in the wings after the wings are completed. As I sit right now, my next logical step would be to determine the feasibility and process of alodining on large scale, then fitment and riveting of stiffener angles on ribs. At the same time I need to place an order for additional material to finally say I am done with the ribs.

In this order it would also make sense to obtain the metal necessary to form my spars as the next steps. Working on the spars means I will need to get material for the overlapping capstrips, which likely will have to ship freight since the .125 metal cannot be rolled. If I am paying freight shipping costs, then I may as well order some longer pieces of steel and other materials that require freight shipping costs. Because these plans do not include any kind of material list, I will have to research all the plans to try and get a feel for the remainder of the project and foresee any other freight parts I need shipped.

The moral of this long winded story is that I have a lot of material to order, and if I cannot find a local supplier of material, I will have a large fortune in the shipping industry. Top all this off with the fact that 4130 steel tubing prices are skyrocketing and availability of some of the more desirable structural sizes is scarce.

This may be the beginning of tabling this project for a better, more convenient (hahahah) time of life.

  May 01, 2022     Rib lightening holes, attach angles - (16 hours) Category: Wings

I've managed to make some big steps since the last entry. Most importantly, all of my nose ribs and center ribs have their lightening holes flanged. It's easy to write this, but it has been an ordeal to get to this stage. Initially, I tried using a hole flanging tool called the NOAH flanger 360. It did make flanges, but it also warped the ribs significantly along the longitudinal axis. Frustrating.

This resulted in a change of plan, where I then made new flanging form blocks from MDF, in the likeness of large dimple dies. I'm fairly pleased with the results. The ribs were loaded into the dies and pressed with a 12 ton hydraulic press, I have access to at my work. This method still deformed the ribs, but use of a "bob stick" slotted flanging tool allowed me to straighten the ribs longitudinally, as other builders have done and documented extensively in bearhawk forums and Youtube.

This was a time consuming process, and I honestly did not keep up with the time record. My 16 hours of labor is a rough estimate.

Spring and it's related chores took some priority around the house, and most recently I went through my scrap aluminum pile and sorted out some of the cutout discs from

  Feb 25, 2022     Clean aft center rib lightening holes - (1.5 hours) Category: Wings

Took all my center ribs into work and cut the triangular leftover tabs on the aft center ribs from where the two fly cutter holes intersected. Initially cut with aviation snips, then cleaned the edges up with the spindle sander at work.

  Feb 20, 2022     Cut rib lightening holes - (8 hours)       Category: Wings

Cut rib lightening holes in aileron trailing edge ribs, nose ribs, and center ribs. I had some discrepancy on my aileron ribs with hole sizes and location between the mylar sheet I used to make my form block and the plans. Turns out, Bearhawk Forums has some folks that have noted the same thing. Essentially my mylar sheet makes my aileron ribs about 1/4 shorter at the aileron spar than the plans show. This means if I stuck with the plan provided lightening hole diameters, I would not have room to flange my lightening holes. The consensus among scratch builders is that the mylar is gospel regarding the shape of the airfoil. Others with this issue contacted the designer, Bob Barrows, and he described that he would like to see, at a minimum, 3/8 of an inch between the edge of the diameter of the lightening hole and the beginning of the bend area for the rib edge flange. I sized my lightening holes accordingly to meet that minimum.

On the nose and center ribs, I was careful to check edge distance between the hole and the flange edge. For whatever reason, they seemed to match up pretty closely to the plans, so I made no modification. To cut the oval shaped lightening hole in the center ribs, I simply started with the smaller of the two holes with the fly cutter and then cut the larger, second hole very carefully using the predrilled center locating hole. This stressed the fly cutter, but as long as I made shallow cuts, I was able to get the rough radii of the oval hole. I will need to mark and cut out the points where the two holes intersect to make the oval shape. I expect to rough cut those holes with shears and then use an oscillating spindle sander to clean up the cuts.

The $30 purchase was for a set of toggle clamps to get my fingers away from the spinning fly cutter when cutting the larger ribs. Turns out, they were a very handy purchase from Harbor Freight, and I will use them again with the drill press in the future.

  Jan 30, 2022     Rib flanging - (8 hours) Category: Wings

It has been cold in the workshop, despite propane flame heat. Because of that I haven't taken many pictures of progress, or really kept up with progressCut out .032 center ribs, and initially edge flanged. All aileron trailing edge ribs were cut from .025 and also initially edge flanged.

  Dec 21, 2021     Aileron hinge plates - (.5 hour)       Category: Wings

Cut .025 aileron hinge plates from sheet stock. Drilled 3/16 radius holes in flange corners for stress relief.

  Dec 18, 2021     Aileron trailing edge ribs - (3 hours)       Category: Wings

Laid out and cut blanks in .025 sheet for aileron trailing edge ribs and 2 missing center ribs.