Wing Stand Build #4: Spar Towers

Build Crew:



Tonight Jack and I worked to get the “Spar Towers” installed. This is my name for the vertical 8020 pieces that will hold up the spars. I had been waiting for the parts from Amazon to come (I was waiting for the M8 screws to be able to continue the build). With everything I need to complete this build (or so I hope!), and Giacomo ready to help out, it was going to be a good night.

Since I was going to be adding a stiffening plate to the outside corner, I needed to drill and tap the end holes in the 8020 to accept M8 bolts. Mr Google helped me figure out that for a M8-1.25, I needed to drill 6.7mm, which was equivalent to about 0.264″. The closest bit I had was a 17/64″ drill bit, which was approximately 0.265″ …close enough for my tolerances. After drilling all eight holes, I proceeded to tap them. Thank goodness I splurged and bought the full tap & die set from amazon which included the right tap. I’m starting to feel like I have a lot of the tools I need for this job. Sweet! To clean out the tapped threads, brake part cleaner works really well the subsequent test fit of the M8 bolt was perfect.

As usual, the first corner assembly took the longest. Order of operations is really important here, otherwise you can’t get everything to assemble properly. In this case, Jack and I started by installing the corner braces, and pre-threading the vertical nutplates in those braces. Before sliding on the tower, I needed to pre-install the stiffening plate. Then, after getting the tower into the corner braces, I could slide down the stiffener, align the tapped holes, and tighten everything down. Jack stayed ahead of me, and did all the brace pre-install work on the corners. With all the bracing in place, this thing is as solid as a rock!

Once we knocked out one tower, we were grooving, and the rest of the work was simple rinse and repeat. After a few hours we were done installing all the spar towers, and the results were impressive. Next up, I need to install the “Spar bracing” and some miscellaneous additional components. The spar bracing is essentially some aluminum brackets I can hang and clamp the main spars to. It’ll be nice to see the spars hanging of there soon. Happy Building!!


  1. Curious: how do you know what kind of stands you need and when you need them? Do the plans call that out?

    1. Hi There,
      The plans do call out a specific way to build a “wing jig”, but from what I’ve heard, it’s a bit overkill with the pre-punched kits. The stand I built was just a variation of others I’ve seen built, but out of 8020, instead of wood.

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