[Azriel]

This is a poorly cut piece that I wanted to work with before I used the actual rear end plate. I'm actually going to use 2 90 degree barbs when I do the real one. I have a straight one in the second hole atm, because they were too close together to install both angled barbs. One of those reasons for a test piece.

Drilling large dia holes in acrylic is not easy. First, you have a choice. grind a zero rake onto the bit and deal with heat, or leave it stock and deal with the chance of cracking. I chose to leave the bit alone, and only drill to 1/8" depth under power. At that point I shut off the drill press and turned the spindle by hand while holding the quill down to the part. It takes about 5 min to finish out the hole this way. After that, i just put the tap in a vise and cranked the panel onto it. When using a NPT tap (pipe tap) you need to remember not to crank it all the way to the end of it's threads. You want to stop about 3 threads shy, or you will have a loose hole, and it will leak.

When the final piece goes together, the pump will connect to the output barb with a 3/8 NPT male threaded 1/2" hose barb screwed into the ID of the 1/2 NPT, which just happens to measure exactly .562. (which is the tap drill size for a 3/8 NPT. Convenient, no?) For anyone who doesn't understand, the through hole on a 1/2" barb with a male 3/8" NPT thread will still be over .400" which is about the ID of the output of my pump, so this will not constrict the flow at all.