Here's how I make my pivot points in aluminum round bar:
This super nifty JIG helps me drill the parallel holes in my round bar. It would be near impossible to get them perfectly aligned without this tool. I’ll show you in the next few pictures how I use this indispensable too. I sometimes use a piece of tubing for my pivots – but this type of pivot gives me the ability to adjust its position when I need to fine tune the fulcrum point location.
This is a blank cutoff aluminum plug. It’s already been faced with my lathe, so it has nice flat ends.
Once faced, I take this part and put it into my Milling Machine to cut a flat into it. The flat is very important as it keeps the round part from spinning in the JIG so the holes are perfectly aligned. Also, if it moves while I’m drilling the holes the drill bit will bind, and it becomes hard to get a good hole through it.
The bolt on the side of the JIG – sticking out the left side – holds the piece in place on the flat so it will not spin while drilling.
Here it is under the drill press getting the first hole drilled. The two black nubs in the top are “drill guides” they are made from tool steel and keep the drill bit straight while drilling. If it was just an aluminum hole, the hole would wear away after repeated uses and become sloppy and unusable.
Here’s the finished part. The holes are drilled through it, they are parallel and straight. The only thing left to do is press the bronze bearing into the center. I won’t on this part as I have to do some welding on it, and I don’t want the bearing to heat up too much and lose its impregnated oil.
At the top is a finished part used in a tipping arm. If you’ve ever tried to drill into a round surface, it’s very difficult. This JIG makes it easy to do.