Today, I drilled the holes for the Safe T Air Firewall Pass Thru's I purchased from Bob Avery. They require a 1 1.8 inch hole. The plans recommended a unibit so I made a trip to Harbor Freight. Unfortunately, their unibits have two cut aways where my DeWalt ones only have one cut away. Consequently, they don't work as well and don't really drill a nice hole. In addition, They curved the edges of the hole inward, and I had to use the dremel tool to grind some away. First, I used a ball peen hammer and bucking bar to flatten them. In the end they worked out ok, but I probably would have been better off using a hole saw bit. Just go slow and use lots of oil. The pictures below show the finished pass throughs. My plan is for the one on the left to handle the primary electrical and the one on the right to handle sensors etc. If I need another, I'll install it just above the controls at the top of the V.
