My 6-71 Blower rebuild, Part 11: Flycutting ends of case to set end clearance.

Sorry everyone. This is a new version of video 11. I forgot to add my final video clip into the project, the part where I actually double checked the measurements to make sure that my machining was accurate. I deleted the video that I put up last Thursday, and replaced it with this one.
Getting my end clearance at the back of the blower down to the Detroit Diesel manuals minimum clearance of .014 required flycutting the case. The SA designs book shows that they set their end clearance at the back to .016, and I have heard that some blower builders go even tighter than .014 that I set mine at. In any event, I don't think that I will ever have a problem with things expanding enough to cause the back faces of the rotors to gall against the rear plate of the blower.
Both ends of the case were not flat, so I actually took a cut off of both sides to clean up and flatten both sides of the case. Because of the height limitations of my Bridgeport, I ended up making up a special 9” diameter flycutter plate that threaded right onto one of my existing tool holders. To be honest, I almost made up this flycutter about half a dozen times in the past, mostly when performing surfacing operations where I wanted to make as few passes as possible. The only difference this time, is that I made the cutter plate as low profile as possible, to clear very tall parts. =================================================== Disclaimer: This video series is not intended to be an exhaustive “How to do it” tutorial on how to rebuild a 6-71 blower for Gasoline use. Rather, it is meant to be a “How I did it” journal of one of many projects that I undertake in my home workshop, using hobbyist equipment and methods. If you attempt to duplicate any of these methods, you do so at your own risk. Therefore, I will not be held liable for any incidental or consequential damages as a result of trying to duplicate these methods. Sources for clearances and tear down/assembly details referenced the Detroit Diesel assembly manual, with additional details referenced from the SA Design book “A Do-it-yourself guide to: Street Supercharging” by Pat Ganahl, ISBN 0-931472-17-2. If you are not an experienced mechanic/machinist, do not attempt to replicate this work. Take your Blower to a professional Blower builder.