32J's MKIV Build Thread, Project "Serpente"

[32J]

Whew! I thought installing the IRS was a challenge. Every single mounting IRS mounting bracket on the frame, or the spindle-end brackets, were too tight for the corresponding bushings. Even if the bushings are tight into the tubes, the metal pivot sleeves may be proud. In some instances the clearance in the brackets were up to 1/8" smaller than the width of the bushing/sleeve. Is this interference caused by the powder coating? Probably doesn't explain all of the interference. Maybe the distance between the mounting tabs shrunk after welding? Perhaps. Anyway, I'm not sure if there is an easier or smarter way, but I had to work with what I had.

With a machinists ruler or some locking calipers, measure the bushing/sleeve and then compare to the mounting bracket. Then use some 5/8" bolts and nuts, or some 1/2" threaded rod and some nuts, and thread them through the mounting brackets to create a power-screw to spread the tabs. If using 1/2" threaded rod you'll need a metal plate on one side of the bracket to keep the rod from going through the hole. Spread the tabs maybe a 1/16" to 1/8" to allow for spring-back after you remove the bolts or rod. You can then mount the arms to either the IRS frame or onto the spindles.

Does spreading the mounting brackets mess-up alignment long-term? I don't know. Everything looked pretty square and tight after I torqued the bolts to spec. I'm going to trust that alignment of the IRS arms can be adjusted and locked.

I admit that it took me a while to figure out the first one, and find the bolts, and cut some threaded rod to size, etc. This "nuance" (or "nuisance?" ) added about 10 minutes to each end of the bracket. Overall it probably added an hour to the IRS assembly. Should this be added as a note in the manual?

Some photos:

32JIMG_9566.jpgIMG_9561.JPGIMG_9567.jpgIMG_9566.jpgIMG_9561.JPGIMG_9567.jpgIMG_9566.jpgIMG_9561.JPGIMG_9567.jpg