Scratch Building a Mercury Marlin

Good to see such a variety of building going on at the moment. Will be good to see all these projects finished in the next few months.

I'm wondering if trying to build the Mercury Marlin was a good idea after all. I'm now on the second "go" at building a wing. Taking for granted that the printed parts are accurate led to all sorts of problems with fitting things together. Half the trouble was that I'd cut narrow spar slots in the ribs. After easing them out, the rib lengths didn't match the wing plan. This, coupled with the fact that I'd got an error of 3mm (!/8" in 1950s measurements) in the profile of the trailing edge, made it a difficult job to get the parts aligned accurately. Looking back seventy years, I'm sure I never had this sort of problem. A tube of balsa cement and a handful of my Mum's dressmaking pins seemed to be all that was needed. Perhaps all this CNC and laser cutting has made me forget the basics. No pics of this stage, I'm too ashamed of the mess.

Oh dear! Never mind Brian. Weathers improving so get that MX out and flying.

I was going to make a start on the Phase 6 soon when the other half let's me have "MY" workspace back but no rush now, virtually no slopes to use.

Brian - What you had forgotten that many of the early plans were not really plans but a guide to help you build
something that looked similar.
I spent many happy hours on Mom's kitchen table recutting bits of balsa to fit .

Colin.

That's encouraging Colin. I've spent a while wondering whether to carry on or abandon the Marlin project. It was a case of making the right decision. I think I was being too technical in trying to use tapered packing for the trailing edge of the wing. The answer was fairly simple. I re-built the wing upside down, dropped the spar into the slots in the ribs. Seems to have worked alright. If I can manage to avoid shopping/gardening and assorted chores, perhaps I'll build the other wing. Finally, I remember the words of an old flying chum. He reckoned that all models looked OK from a distance of thirty feet. So I'm aiming for a "thirty foot" finish.

Several attempts later and the wings are ready to sand. Formers gluing to the longerons. While the glue dries, I'll saw the front bulkhead , dihedral brace and bellcrank mount.
There isn't a prize for spotting my stupid mistake on the left wing. I'm sure there's a way round it. The stunt tank is about as old as the design of the model.