I got my brackets and sticks back from the welder today. I forgot to take a picture of the bracket, but this is how I fitted and attached the aluminum "fingers" to the sticks for welding.
I cut a square wooden peg to match the OD of the aluminum tube, drilled a hole where the aileron cable connection will be, then chucked it up in my lathe and turned the other end down to the ID. I turned far enough along the peg to set the depth of my jig.
This is the jig inserted into the tube, with the fingers already welded on. A small C-clamp held the fingers to the tube for tack welding, and then was removed for the full passes.
I realized after I got these sticks back that I had forgotten to mark where I needed the other set of holes. The main problem I faced was getting the holes in the center of the tubing and lined up with the existing holes. My drill press vise is just far enough off of level and plumb that I didn't trust it, so instead I used a speed square to find the center on both sides, then drill and ream the holes.
This is the jig inserted into the tube, with the fingers already welded on. A small C-clamp held the fingers to the tube for tack welding, and then was removed for the full passes.
I realized after I got these sticks back that I had forgotten to mark where I needed the other set of holes. The main problem I faced was getting the holes in the center of the tubing and lined up with the existing holes. My drill press vise is just far enough off of level and plumb that I didn't trust it, so instead I used a speed square to find the center on both sides, then drill and ream the holes.
I drilled and tapped a length of ¼" 4130 tubing to connect my two control sticks along the horizontal axis, which turned out to be a little bit of a trick. I chucked the tubing in my lathe in order to drill it out so I could tap it, then locked the lathe up and tapped it by hand. I didn't drill quite far enough on one end, so I broke the tap... luckily, enough was sticking out that I could grab it with pliers and screw it right back out. Another trip to the hardware store for a new tap, and I was finished. I threaded in two AN42B "eye bolts," and it was ready to connect.
The last of the metalwork for the control sticks was to make the mounting brackets. I needed a set of brackets to hold the control sticks, and a set of brackets that will mount to the back of the rear spar where the pushrod will transition to cables. I did some adjusting to Mark Langford's drawings for the former, and did some math and drew up the latter on some graph paper. Here they are, attached to ⅛" 6061 T6 aluminum angles, but not cut out yet. I started by drilling all the holes, since that can be a difficult procedure once everything is cut out.
Tomorrow I hope to finish the mounting brackets and begin assembly in the fuselage.
Continued in Control Sticks (Part 6)
Continued in Control Sticks (Part 6)
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