OK so I'm in the process of making one of these and want to point out a few hurtles. If your printer is printing tighter than intended holes, slightly out of round circles, or otherwise imperfect prints, you'll need to make some adjustments. I discovered that my printer was making slightly oval circles due to a firmware issue so if you notice some kind of choppy movement from the bearings, they are likely being pinched along one direction causing a preferential orientation of the inner portion. While un-snugging the holes with drill bits i concluded that either Adam is very skilled at squaring off parts and hammering at them, or more likely as seen with my wire stapling abilities, i just am just terrible at it. It seems that just giving a whack at the bearings causes them to mash their way into an improperly oriented position within the groove. To circumvent this issue I made the holes ever so slightly larger so that I could nearly press the bearings in by hand, then placed the jig (squared to the surface) upon the bearing and GENTLY tapped it in with a much smaller hammer. The hammer i used is from a watch kit and weighs about 50g so basically you can use the handle of a screw driver if you don't have a watch kit hammer. The bearings have a tendency to cause a wobble for some reason and when/if this happens you'll see it once you get the dowel into the bearings of the balance wheel and give it a spin. if you do see this you need to find the side of the balance that wobbles closest to the O, orient that near the wheel as you match the two up and watch to make sure you dont end up tapping the balance against the O. If this rubs there will be too much friction for the movement to work. I'm not sure exactly why but if its not squaring up and youre getting a bunch of wobble, it got better for me when i took it apart and put it back together more gently. it helps to have a small punch and an anvil or metal plate with a hole in it to punch the rods and bearings back out. Oh and ive also noticed that the center portion of my pallet fork and the rounded portion on the opening of the impulse head-butt EVER SO SLIGHTLY on the returning motion. originally i thought this was a problem but it doesnt seem to be the cause of any issues now.