Pulley Setup and Fabrication

Here are notes ont the pulley config and fabrication. As the the Rotrex is so new I will have t build the pulleys myself :)

Configuration

Below are two targets - low boost and high boost.

From the above the plan is to build 3 - 70mm, 80mm and 95mm.

These will have the ability to also be flexible in size (so I can make them smaller later if need be. So 95mm will have a inside diameter of 70mm, 80mm - ID 60mm, 70mm - ID 50mm.

Fabrication

Holding Tool

First step was to create a tool that mimics the Rotrex pulley adapter. This is so that I can have the pulleys I am making mounted in the lathe in the same way it would be mounted on the supercharger. The idea being that I can set up the pulley perfectly aligned in the chuck and the resulting poly-v grooves should be perfectly aligned also.

I made this with a combination of the CNC mill (for holes) and the lathe.

Step 1

Turn pulley blanks so that we have a flat surface and a centre hole for reference. Then set up the pulley in the CNC machine for drilling the 6  mounting holes (including counter sinks).

Note: The small one mounted is a test one

Step 2 & 3

Use g-code to drill out 6 holes.

Mount counterbore without moving blank and use more g-code to bore out the cap screw holes.

Step 4

Turn out the inside.

Note: I am finding issues with the pulley dimensions not matching what can fit on the C8-8. I will need to make the pulley thinner that what is specified in the technical manual (however I am only making it 6 rib instead of 8 so it should not be an issue).

Also note: I need to step the inside hole where the pulley nut goes. If I push it through 19.6mm all the way it takes the edges of the counter bores.

Warning!!!! The g-code files below are random uploads of g-code in various states of work in progress. Some are known to have serious errors (e.g. drill a hole and then try and move to another position while still in the hole - crunch!!!). As with everything on Vespa Labs if you you use anything, use it at your own risk! This is an extra warning as some of these will break your machine!