Impeller machining

[JayBee]

Ok, so I was just starting to look at cutting my A down to a B using the diagram in the Seloc manual. First thing I noticed is the Seloc manual shows the cut angle to be measured from a line parallel to the centerline of the shaft. When I looked at my impeller it was obvious that the actual machined angle was the compliment (90-the angle). So, I went to the Berkeley site (Berkeley Size Diagram) and sure enough they have the same angles only they show it from a line perpendicular to the shaft centerline. So, I guess the Seloc manual has a slight error!
Ok, next problem. Mine is an A, but the angle measures about 63 degrees as opposed to the 60 that Berkeley lists. The large and small diameters are right on, though... That made me start looking at the other sizes and I noticed something else that I cannot figure out. How can the angles change from A2 through C in the following sequence - A2=57.5, A=60, B=56.5, C=56.5 if the large diameter is the same and the small diameter is getting progressively smaller??? Am I missing something here?
Any info from people who have cut their own impellers would be appreciated!
Jason
PS - I am glad I tore the pump apart. When I bought the boat I was told it had just been blueprinted and rebuilt by an expert somewhere in LA. Well, the thrust bearing's front balls are all pitted heavily. I had an awful time getting the impeller off the shaft - probably because there was Loctite the whole way through the impeller bore. And there was obviously no blueprinting done, but there is a nice coat of paint on the impeller! Also, there were very visible polishing marks on the end of the shaft that goes into the bowl bearing, so it hadn't been run long.

[sidewound]

WOW,
That's heavy man. Had Duane do mine.
Peace man
CESAR

[miller19j]

JayBee:
Ok, next problem. Mine is an A, but the angle measures about 63 degrees as opposed to the 60 that Berkeley lists. The large and small diameters are right on, though... That made me start looking at the other sizes and I noticed something else that I cannot figure out. How can the angles change from A2 through C in the following sequence - A2=57.5, A=60, B=56.5, C=56.5 if the large diameter is the same and the small diameter is getting progressively smaller??? Am I missing something here?
Any info from people who have cut their own impellers would be appreciated!
Jason
PS - I am glad I tore the pump apart. When I bought the boat I was told it had just been blueprinted and rebuilt by an expert somewhere in LA. Well, the thrust bearing's front balls are all pitted heavily. I had an awful time getting the impeller off the shaft - probably because there was Loctite the whole way through the impeller bore. And there was obviously no blueprinting done, but there is a nice coat of paint on the impeller! Also, there were very visible polishing marks on the end of the shaft that goes into the bowl bearing, so it hadn't been run long.
I am not sure but this picture leads me to believe that both the large diameter and small diameter change. Look at the different angles and where they start and stop. In other words you start with the new small diameter and machine out at the angle given in the table. That would also cause the large diameter or where the blade stops to change.
I have never turned down an impeller so I am not really sure. Hopefully one of the experts will chime in.
[ June 02, 2003, 09:20 AM: Message edited by: miller19j ]

[Max_182]

Both diameters change. If you put an A and a B side by side, resting on the bench with the axis of rotation parallel to horizontal, the A is taller (larger OD) than the B. The A2 and A3 impellers have the fins extended. You can see that in the drawing posted earlier.
Rk