The other day, I accidentally tilted the blade (well, tried to) while the zero clearance insert was in. Oops! Quickly tilted it back up, but noticed that the blade was no longer centered in the insert (I widened the hole a little to avoid the "zing" noise - I'm using the ZCI more as a better regular insert than a ZC one). It also no longer ran right against the cut edge of my crosscut sled. Damn.
No big deal, I know how to adjust the trunnion. Bad news - I can't adjust them far enough to put the blade back! Ok, what ELSE could have gone wrong? Did I bend the blade? No, that checks out. Could I have pressed the drive shaft into the cast iron? Hmmm, possible - it's off by 1/16". So, out comes the pivot shaft so I can get the drive iron out... tap, tap, tap, SPROING! Hey, am I going to need that? Where did that go? It turns out the pivot shaft was spring loaded with two "crinkle washers" both of which are now in the sawdust pile somewhere.
Oh well, found them, at least I had the drive iron out. Hmmm, the shaft and bearings ride against shoulders, no way they could have moved at all. Now I realize I can't get that piece back in with the trunnion still in the saw, so out comes the trunnion mount (er, contractor saw - they're bolted to the table) and the whole blade holder assembly comes out. Of course, there's no way I can get those two crinkle washers back in, and I even end up scratching the shaft in the attempt. Ok, a little lathe time to un-scratch it, decide to leave one of the washers out, and everything goes back together. Goes up and down a bit easier now too, small bonus.
The blade is still off. It's not straight either. Sigh, more fiddling with the trunnion - I need to at least get the blade straight again. No amount of fiddling seems to be working, it's off by about 0.025 front to back (yes, that's 25 thou).
So, I'm staring at the inside of my saw, trying to figure out what else could have gone wrong. Think, think, think. What could have happened when I tilted the blade. Ok, take the insert out, tilt the blade a few times, try to imagine it getting stuck...
Hmmm... the two ends of the trunnion assembly are held together with two steel rods. I wonder if they're loose? YANK! Yup, they're loose, and now the blade is in the right spot. Sigh. Two days fixing a five minute problem.
As a side note, I did figure out why my handle lock for the up/down handle wasn't working right. The pressure shaft was a hair too short to make contact properly, an additional washer solved that easily.