Just been printing the 2 parts of the J2 arm. Before fixing them together..permanently.. I noticed that there was a hole on the side of each part. Now if I had fitted them together as printed, ie bottom to bottom, then the 2 holes would have been on opposite sides. Now this disagrees with the picture of a one piece J2 arm, where they are on the same side. One of the 2 part J2 arm is symmetrical as far as I can see (whereas the other has an extra hole on one side) so I assume I can reverse the 2 parts so that the 2 holes on the sides appear on the same side. I hope I am correct, but does there need to be a correction on the STL of the 2 parts?
To see this working, head to your live site.
As far as epoxying them together the bottom piece should be symmetrical. Just make sure that on step #3 on page 41 that the 2 holes are as shown when inserting the J2 spindle - so that when assembled the limit switch can be mounted as shown in step #4 of page 46