Attn: Dr. H. Jack, P.Eng.

Date: 3/12/97

Memo on what I found interesting

on our tour of Michigan Wheel.

The sand casting at Michigan Wheel was very interesting to see. Their process seemed to be run by people who have had many years experience at sand casting. The systems for their processes looked like an area where there was some opportunity to improve the efficiency and quality of their products.

Their use of CNC mills and CNC lathes was also interesting. I was surprised to see that many of their smaller propellers were finished by hand after the sand casting. I thought that all propellers would be produced using computer controlled machines due to the complexity of their shapes and dimensions.

The use of the rubber "coupler" to join the drive shaft to the propeller was another surprise to me. I did not think that rubber under high pressure would be able to handle the large amount of torque that is transferred from the drive shaft to the propeller. I can see where the rubber would be a nice material to use as a "shear pin" to protect the propeller when the propeller contacts rocks or the ground when spinning.

One of their bottlenecks that I would not have thought of was when they have to wait for approval on the test bars of metal that they pour when they pour the larger propellers. This bottleneck seems like a problem that can not be avoided because it is required by the companies purchasing the propeller.

The fact that Michigan Wheel is a global company suggests that they have quality products and the skills to serve a large range of customers.