To: Larry (EVCC Adapter Plate Machnist)
From: Jon Pullen (Sheer)
RE: Hub adapter for siemans motor
Return contact info:

Fax 949-916-1149
Phone 949-357-5701
email sheer@sheer.org

Housten, we have a problem. It's not the size of the notches - which as far as the naked eye can tell is perfect - or the size of the center bore, which as you said is just a titch bigger than the shaft. 

The problem is the placement of the notches with respect to each other.

As far as I can tell, the keys are exactly 180 degrees out of phase with respect to each other on the actual motor. However, on the adapter hub you have sent me, they are not - one is approximately one degree off.

If you will reference the second page of this fax, figure A, you can see a tracing of your part. As you can see, line A, when drawn straight off one notch, has the second notch offset by about a degree.

When I tried to place the part on the motor, this did not match the motor shaft at all.

If you will reference figure B, you will see a rough attempt at what I think the actual hub should look like. As you will note (aside from some drawing sloppiness, sorry, I've got to catch a plane so I'm in kind of a hurry) the second notch is the same width as the first and exactly 180 degrees out of phase with the first. As far as I can tell, one should place the notches by drawing a centerline across the circular hub, then creating a notch that is one-half on one side of the centerline and one-half on the other, on each side of the centerline.

If you will reference the enclosed photo (page 3 of this fax) you will see the shaft with nothing on it. Page 4 shows me attempting to fit the slug you sent to the shaft.