By Mark Richardson, EAA 367635
From the January 2021 issue of EAA’s Canadian newsletter, Bits and Pieces.
Back in the 80’s and 90’s, my Saturday morning routine included This Old House and The New Yankee Workshop on PBS. I really enjoyed watching people build/reconstruct things, especially Norm Abram. On his show he made tons of great furniture and everything always fit perfectly. His mantra is “Measure twice, cut once.” Words to live by. I actually built quite a bit of the furniture he had in his books and even bought his DVD series on how to build kitchen cabinets so I could build my own for our new house, which I did.
Fast forward a bunch of years and I have built and flown my RV-8 from a Van’s kit. Just about everything is cut out and measured for you, but if you do screw something up, you get on the phone or Van’s web store and order the part … again. Admittedly I did have to reorder a couple of minor parts (can you say trim tab?) but nothing that broke the bank or made me cry.
Fast forward another few years (2012) and Linda and I have finished building our house with, as most of you in our chapter know by now, a grass strip in the back field. The RV-8 is a bit hot to get in and out of there so I decided to build a four-place Bearhawk.
For those of you unfamiliar with it, picture an upsized Maule with better performance. But this time I didn’t want to build a kit, I wanted to scratch build. (What’s that sound? A warning bell?) So I purchased the plans, bought a couple of builder manuals/CDs off the internet because there is no official build manual, and studied everything like crazy.
Now, when I say scratch build, I do mean the majority of the airplane comes from the plans and I build all the parts, but I had NO desire to snip wing rib blanks out of sheet aluminum and pound them into shape over a form block for a year or two, so I did buy the ribs and spars from Bearhawk Aircraft. While I was at it, I bought the landing gear legs as well. Since this was going to be my first foray into welding I figured something like the gear should probably be done by a pro.
So now I get started. I buy a pile of 4130 Chrome-Moly steel tube and sheet, and an oxy-acetylene welding rig and get to work. With the Bearhawk you build an 18 foot long table and mark out where all of the steel tubes go, put the steel over these marks and hold them in place with bits of wood or something so they don’t move, and tack weld every joint. What could be easier? (Wait, I definitely hear warning bells now.)
Remember my buddy Norm from New Yankee Workshop? Well, believe it or not I actually followed his advice and every mark on that jig table was measured twice before I cut the metal. I mean, this is an AIRPLANE and you want to be sure everything is just right otherwise it will not fly right (or at all).
Somehow, on the first day of measuring and marking where all of the 4130 tubes go on the fuselage top, and for ONLY ONE tube, I somehow forgot that the measurements on the plans are measured centre to centre. So, this means, for this particular 3/4-inch tube, it was 3/8 inch too far forward. I didn’t notice for eight years. Because I had been so attentive and measured twice before I cut, obviously this cross tube was in the right place when I jigged the top and bottom of the fuselage and inserted all of the other vertical and diagonal tubes in the fuselage. I finished welding the fuselage and spent the next couple of years making and welding in all of the mount tabs for floors, seat latches and rails, stringer stand offs, engine mount, floors, boot cowl, cowl, etc.
Now, why is this one cross tube a problem you ask? Because in September of this year I was preparing to mount the wings for the first time and this cross tube was where the rear spar of the wing attaches. You got it, the wings do not fit my fuselage — and there is nothing I can do about it. It is scrap. As you can imagine, I was gutted, embarrassed, annoyed, humiliated, and angry. However, believe it or not, all those feelings passed in a few minutes just leaving me embarrassed. Why? Because there were enough things that were, while not wrong, not satisfactory with that fuselage that I was kind of glad I wouldn’t have to live with them. In addition, in the intervening years I had seen a lot of improvements and ideas that would make the airplane so much better that I decided on the spot to start again.
My welding was mediocre at best so I decided to learn to TIG weld and do the new fuselage that way as I could eliminate a lot of the heat warps that I had put into the original fuselage with the oxy torch. And I also decided that rather than spend hundreds of hours cutting tube and then fitting/fish-mouthing every piece, I would get a pre-cut tubing kit from VR3 Engineering in Stratford. I have since received the kit, and in less than a couple hundred hours, I have a new, straight Bearhawk fuselage almost fully welded and the inter-spar distance is EXACTLY correct. I’m really enjoying this second go at it and am super impressed with the quality of the kit from VR3. When you jig the parts, if they don’t fit perfectly, you are doing something wrong.
So, why am I opening up? Well, first, eventually everyone will hear about it and this saves me embarrassing myself over and over telling the story — I’m just doing it once, like ripping off a Band-Aid. But more importantly, I really just want to say that we all make mistakes in our builds, and it can get very frustrating, but you can always find a way to carry on. Even if you are stupid people.