Drilling Right Wing Rib Conduit Holes

Yesterday I drilled the large conduit holes in the right wing ribs. I basically got lazy and determined the "center" of each hole by eye, without specifically measuring for the center. I think this worked out OK but time will tell.

I marked the center with a center punch, then used a #30 drill bit to drill the pilot hole:

Then I up-sized the hole to 1/4 inch.

Then, just as I did with the left wing ribs, I used a unibit with a 3/4 inch final step to drill the holes to their final size for the conduit. The last step was to take a deburring tool and clean the edges of each hole on both sides of the rib web.

I now have the holes drilled in all but 2 of the main ribs. Those are the end ribs with the attachment bracket mounted so I could test fit the spars on each of the Wing stands. The next step is to remove the spars from the wing stands, remove each of the end ribs, and then mark and drill the same holes in each of them.

Today I contacted Vans for the first time in a long time, to verify how many holes and what size I can drill them to for the forward part of each main rib. All of the W711 ribs have 2 additional tooling holes in addition to a third one that has been enlarged to 7/16 of an inch to allow for the pitot tube routing. I plan to use 2 of these 3 holes for routing the SafeAir1 air lines from the pitot tube to the avionics, which will require a bushing with a 1/4 inch ID hole, and I will possibly open the third hole for an additional pass through for any other wires that may be required in the future. The rear tooling hole will be opened up to allow for a similar bushing for the RG400 coax antenna cable. Long story short, I still have more holes to drill before I can move on to other things. It just never ends.

I also spent some time researching the Grand Rapids HXr AHRS, and the correct plumbing kit to puchase from SafeAir1. I also researched the Dynon Heated Pitot tube and realized I will also need to determine where to locate the heating element. I also recall some information about locating the pitot tube at least one full bay further outboard than Vans plans call for, I just cannot recall the reason for this off hand. this becomes important because the most outboard access plate only provides easy access to the bay where the aileron belcrank is located. Will have to look into that one again I guess.

This is all part of building the airplane from the inside out. The more you are able to plan for and install the internal components of a structure before you close it up, the better. Now if I only knew what exterior light system and autopilot I was going to use I would be all set!

When all the routing holes are drilled and deburred, then I can attach and match drill the holes for the rear spar, and scuff, clean, and prime the main ribs.