Fabricating the spacers for the tie down assembly's wasn't too difficult but sure created a lot of aluminum filings. The first lightening hole that I did I cut all the way through from one side. This was hard on the fly cutter since the material is so thick. I used some drilling oil but this still cut away a lot more than the way I did the other 3 holes. Basically I just cut halfway through each hole, flipped the bar over and then cut through the other half. Much easier on the fly cutter. Still got hot though. Once the lightening holes were cut, I deburred them and then sanded them using the Dremel. I then cut each spacer to size according to the plans and polished them on the Scotchbrite wheel.
Drilling lightening holes using a fly cutter in the drill press
