HS Rear And Front Spar Assembly

5/30/20 – After waiting for about a week for additional Clecos, they arrived. I also receive a Scotch-Brite 6″ 7S wheel, which is supposed to be finer than the medium 7A wheel.

After some testing, the 7S definitely provides a much more polished finish than the 7A, which works fantastic for removing material. The 7S will now be my go-to for de-burring and smoothing.

Now back to the HS rear spar.

Today I finished clecoing the HS-412PP and HS-413PP brackets to the rear spar assembly, then matched drilled them to #30.

I then made my first (known) error of the build. I had clamped the HS-411APP and HS-411BPP brackets together to match drill, like this:

The setup of this is great, I was happy with that. It does differ from the plans a bit, but has been proven by others to work well. My mistake happened while match drilling. I ended up elongating a couple of the holes I was using as guides. (UPDATE: This was fixed and completed 6/8, including primer, riveting and match drilling with rear spar.)

The elongated holes are in the HS-411BPP bracket on the right. The left-most hole is the worst. Diameter is over 0.140″, which puts it out of spec. by at least 0.005″.

The rest of the rear spar was completed, so I decided to come back to the bearing assembly later and move onto the front spar assembly. I began by separating the two HS-00001 spar doublers per the plans, which involved cutting them in half with my band saw, then using the Scotch-Brite wheel to remove the excess edge material.

5/31/20 – Today involved a lot of staring the plans, trying to make sense of exactly what they wanted me to do. I found the pair of HS-702 spars on my shelf. I then measured for and drew the bend lines as depicted by the plans, then marked the #30 relief hole positions and drilled them. Somehow one of my holes wandered a bit, but that was OK. These get drilled up to 1/4″ diameter, so I was able to hand-file the hole to proper size. The others came out fine. I then made band saw cuts along the bend line at the flanges, into the relief holes. The remaining flange/tab gets bent flat, then trimmed flush with the edge of the spar.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.