Mark is another Zenith builder. I got the idea from Mark after he mentioned it on Matronics back in October. His pics show where he opened the rudder bearing points to 5/16. I used the same approach. I first opened the holes for the bearings to slightly under 5/16 and then used a 5/16 reamer. (Note: Mark chose to use a slightly smaller reamer to make a press fit. I only had a 5/16 reamer on hand) I then installed the bearings, with grease holding them in place, one at the top mount of the fuse and the other at the bottom pivot point on the rudder. For each bearing, you install one bushing above and one below. This requires you also open up those holes to 1/4 inch .. see Mark's pic of this using the angle drill. The above bushings from McMaster Carr are probably slightly longer than needed, but you can adjust the vertical positioning of the bushings and bearings by using an appropriate number of AN3 and AN4 washers placed to keep the bearings from sliding out of their reamed holes. Plan on having on hand a few longer AN3 drilled bolts in varying lengths as the total assembly at each bearing point is slightly longer than the original Zenith bolt/bushing approach. Also the above bushings and bearings are exactly 3/16 id and will require you remove most of the cadmium plating from the AN3 bolts in order to fit them over the bolts. I chucked the bolts in my drill press and at low speed held up some scotchbrite to remove the finish.
I have yet to get a pic of the finished assembly, but the above and Mark's pics may help you get started.
Here are Mark's comments in a recent email to me: "Dave, I now have about 20 hours on it since the update and the rudder is very solid, this will probably far outlast the aircraft and all of us. I did use a reamer to make the hose in the brackets a press in fit. There are now more pictures at the bottom of photo.hubbles.com I have not put in comments, that will be coming."
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