This is a project that has been going on for the better part of several months. I read about the benefits of doing this a few years ago, and had been thinking of it since. I know you can buy a G bowl, or an American Turbine, but I like to do things myself and to save a few bucks! I am going to school to learn to be a machinist so I have access to the equipment and this was done in my spare time.
First off was to stick the bowl on the mill and take it down to just above the vanes. I made sure that this was perfectly square and perpendicular to the mill table. After milling, I chucked it up in a 14 inch engine lathe to take off the rest of the ears.
I also made a pair of consistant tapers for the adapter ring to snug up against. I didn't take much off here, as the bowl doesn't appear to be real thick. Just enough to get a nice smooth finish.
Next up was to purchase a piece of 6061 round stock that was 8 inch round, by 3 inch thick. This is what became the adapter ring. First a center drill, then a 1/2 inch bit. Then i took a 2 inch bit and went all the way through. Ever see a 2 inch bit flex? This thing must have weighed 8 pounds!
After going through with the 2 inch, I took a boring bar and took it out to the same inside diameter that the pump outlet was at the spot the vanes ended. Then I recreated the tapers I made on the outside of the bowl, on the inside of the adapter ring. I used a black felt pen to check for clearances and to check fit. This thing fits very snug and solid to the bowl. I was very happy with this!
I turned down the outside of the adapter ring to fit the inside of the steering flange. This also fits very snug. I ended up with the outlet side of the adapter, the same diameter as the steering flange.
Welding is part of my machinist training, and my instructor, Rick, offered to weld the adapter to the bowl. I used a DA sander to get off most of the powder coating in prep for welding. We clamped the whole thing together with a large C clamp and used two cutting torches turned all the way up to preheat the bowl and adapter. We kept moving, never stopping in one spot so we had a nice consistant heat. Rick used a 300 degree wax marker to make marks in several spot to check the temp. When he was happy, he set in to TIG it together. I'm pretty sure this is never coming apart! These instructors here also certify welders in all phases of welding. They also certify others, to do certifications to other welders.
I clamped my bowl to my workbench and used a level to get the steering flange perpendicular and then drilled and tapped holes to mount the flange. I upsized the holes to a 7/16 size and am going to run studs on it.
Next up is powdercoating at AHP's and then a trip to Skagens to get it ready to run! Maybe I'll have it done this year.........
We are having a motor done, and this is sucking up most of the funds.
Any questions, please feel free to ask away!