Since I still have at least 6 more weeks until my checkout I decided to go ahead and change the cyclic mixer to the upgraded, unitized version which has fewer parts and lower maintenance.
I wanted to re-use the two mounting holes in the cyclic control tube rather than drill two additional holes with a hand drill while laying under the helicopter. I removed the original mixer and came up with a plan to duplicate the holes in the old mixer into the new mixer by turning an aluminum sleeve to use as a jig for locating the first hole's orientation to the vertical flats on the old mixer then placing the sleeve on the new mixer as a drill guide.
First I drilled a 3/16" hole through just one side of the sleeve using the old mixer to locate the distance from the end. Then I inserted the mixer into the sleeve and aligned the holes then drilled through the other side of the sleeve letting the hole in the mixer guide the bit so the sleeve is now match drilled to the old mixer.
Next, I installed a bolt through the hole and clamped the flats of the old mixer in the mill vice and milled a flat across the top of the sleeve which became the reference for aligning the new mixer in the sleeve and transferring the hole to it.
Last, I clamped the old mixer in the mill again with the second hole lined up then installed the collar and drilled the hole from both sides so it would be sure to match up.
Positioning the first hole in the sleeve
Milling a flat for orientation to the new mixer
New mixer drilled with matching holes and radial orientation
