It is good to have a long weekend with lots of time to work on my airplane. I got almost all of my custom front seat track supports for my Bede BD-4C airplane tack welded together.
The trickiest part was figuring out how to notch the square tubing so that the round tube would fit into it. Here are a couple of photos showing what I ended up with (click on any photo to see it larger).
The “right” way to notch the tubing would have been to use something like Medford Tools’ Notch Master Tube Notcher but I couldn’t justify buying one to notch just eight pieces of 4130 steel tubing. Instead, I made due with a hole saw mounted on my drill press and a spindle sander. I used the hole saw to do a rough cut, a little bit shallower than I needed.
Then I used the spindle sander to carefully get all of the notches to their final depths.
I ran a plumb line across the fuselage and used it to line up the two halves of the round tubing as I clamped four, of the eight, square tubes in place. This was one of the most finicky parts of the whole process. I spent lots of time with squares and calipers assuring that everything was “just right.” Here is a photo with the pilot’s side clamped and ready for tack welding.
Once the first two tubes were tacked in place, the next two were easy to position.
And the result:
I repeated the whole process on the copilot’s side and then added the tube which runs horizontally across the tunnel. This is what the seat track support looks like now.
I also tacked up the brackets (outside of this photo) which will attach the round tube to the fuselage walls, and the tube-ends (middle of this photo). The tube-ends will get welded into the open ends of the round tubes at the front of the seat track supports.
They go together like this:
I still have some work to do (of course). One of the pieces which bolts to the top of the landing gear box popped off of the square tubing. I goofed and bumped the power switch on my welder so I was working at low power instead of max power. Tomorrow, I will have to grind stuff down and reweld it. Then I can weld the tube ends into the round tubing. With that done, I will take the whole thing off to S S Welding where they will do the real welding.
In case you are curious, there are 33 pieces of steel in these seat track supports. But who’s counting?
Very detailed work! I hate 4130 work. Really nice work Art.
Thanks, John 🙂
Looking good! I really admire your creativity (and patience of a saint!) in devising this support system. Simple & elegant… Occam’s razor comes to mind.
I do feel like I applied a lot of creativity to this project. There has been lots of fabrication up to this point but this is the first big thing on the plane that I designed and built.
Very cool, Art! Isn’t it wonderful how you can get wrapped up in something so fiddly and intricate, and then you will be nearly the only person who appreciates it after the plane is done. You will remember every fastener and every bead of sweat (yeah, and blood and tears) that went into your creation.
I think that you are 100% correct, Jim!
Looking good Art!
Hi there,
I’ve quietly browsed your site for a long time now and am always drawn to it as I get closer to the time to start a build. You’re level of detail and progress is inspiring.
I’m curious about the amount of fabrication you are doing (door frames, seat structures, etc…is this required to build the 4C or are you doing this because you have the ability and skill? I’m wondering because I would have figured the kits would come with those pieces already constructed (minus covering and what not to achieve 51%).
If it is required, are the materials supplied in the kits or are you needing to source the parts and material?
Thanks in advance and keep up the amazing work.
As a side note…the other kit I’m considering is the 4 place Bearhawk but the strong wing and the honey comb ribs seem to make a lot of sense to me. So we’ll see.
Cheers,
Morgan,
I appreciate your kind words and encouragement! 🙂
The BD-4C does require a lot more fabrication than planes like the RV-10. BedeCorp provides all of the materials, though. Virtually all of the steel weldments were provided ready-to-use and painted with primer. Of the steel parts, the only things that I have had to do myself are the firewall support bracket (which is a custom fit for each plane) and the seats.
Cheers,
— Art Z.