I don't feel like going into depth on every little aspect of work I've done over the last 10 months, so I'll hit the highlights and if anyone has questions, feel free to comment and I'll elaborate.
As the year started the garage was cold. With a propane heater it would get warm enough to work for a few hours, but because 4130 steel is an air-tempered alloy, it needs to be sufficiently warm out for welding. Long story short; I can't weld, so I make parts.
I plugged away making little bits so I can use them when it comes time to build a new assembly. The landing gear legs and spring struts have metal straps to reinforce the bushings in the ends. I knocked these out in a couple days after work. Likewise, the tabs that will become door hinges and the fittings for the tailwheel were cut, drilled, and deburred.
I also cut pieces for the rudder pedals again; the last ones were cut to the wrong size.
Tubing was cut for the spring struts, the ends were notched, heated, crushed, welded, ground to fit bushings, bushings welded in, and the reinforcement strap heated, bent, and welded in over the bushings. The bushings were left long for welding, so they will need to be reamed to size and the ends ground to length before they are done. When I was tidying up I slid the smaller tube into the larger and they sprung apart from the air-pressure of a tight telescopic fit. I was thrilled and took this video. The bounce you see in the video is just from the air trapped in the tubes.
I had to do a bunch of cutting and fitting to add the gear fittings to the fuselage. It would probably have been easier if I'd accounted for these fittings when I was laying in diagonals for the fuselage. The diagonals added for the door opening interfere with the wing-strut fittings. The lower fuselage diagonal also gets cut away to make way for the forward gear fitting. Looks weird, but it's in the plans. To help align all the landing gear fittings with one another I made up tubing spacers then threaded nuts and all-thread through the fittings. The tubing spacers locate the fittings relative to one another and the nuts let me adjust the distance between fittings along the all-thread.
The longerons and horizontal stabilizer were drilled for the eye-bolts that will mount them. Widening the fuselage changed the relationship of these bolts relative to the stab, so they needed some finessing.
The tubes for the seatback were another thing that needed to be tweaked due to the widened fuselage. There are a pair of diagonals at station 3 (behind the seat) which go from the upper longerons to the center of the fuselage bottom. With the wider fuselage these diagonals interfere with the seat back as drawn. I elected to push the bottom end of the seatback tubes forward slightly to give a just a little air between the tubes and prevent chafing. Picture one is looking from the center of the fuselage out at the left side (The front of the plane is to right side of the picture). Picture two shows the sliver of light between the seat back and the station 3 diagonals.
Towards the end of summer I began welding in the tailwheel fittings, strut fittings, seatbelt lugs, and the center mounting plate for the rudder pedals. I didn't feel great about the original fitting where the tailwheel spring mounts to the tailpost. It's just a flat plate in the plans, so I chose to mimic the way Piper did theirs on the Cub and added some diagonals that tie into the tailpost.
The rudder pedal mounting brackets also got cut, cleaned, and TIG welded.
Comments
Post a Comment