Well, no tool finds or purchases of note lately, but here are a couple "shop tools" I've built in my spare time at work when the mill isn't broke down and I'm not busy with a project:
I built this one today. It's a roller chain tensioner to help installing drive or deck chains etc. at the mill. Useful if you want to make your chain as absolutely tight as possible. You wrap the chain around the sprockets as tightly as possible (not as important if one is an idler) and install the "jaws" of the tensioner between the rollers of the two end links to pull them together like this:
That is a 60-pitch chain in the picture. I cut the tapers/relief on the tips so it'll fit 60 right at the ends like that up to 120-pitch farther up (cutting angles like that with an angle grinder and Zipcut is tedious!). The jaws are made from 3/4" square keystock steel, the bottom guide rod is a 1/2" grade 8 bolt 8" long welded solid on the one end, and it's moved by a piece of 1/2" ready-rod with a nut welded on one end to make it a bolt. The one jaw is threaded for it so it gets pulled in when it's turned.
All in all I'm pretty happy with how that one turned out, looks a far sight better than the one over in the sawmill shop that someone built, though not quite as big, but plenty big enough for what I deal with in the planer more often. It's out of alignment a tiny bit because the table on the POS drill press in the shop is slightly off-square to the chuck and the chuck wobbles a lil bit, so the guide holes aren't exactly perfect. But it'll do what I need it to.
Calling this one a "tool" may be pushing it a bit... but it's useful and helps me get jobs done, so I dunno. This is for aligning bent sheet metal to be welded flush. You weld the base of the big 1" x 2" steel block to the "low" sheet so that the tip of the bolt is over the edge of the "high" one. Weld it just enough to get the job done as you'll be cutting it off again. Then turn the bolt until it pushes the sheet down into alignment with the other, and tack into place.
Built this one a few weeks ago actually. It's a depth gauge, not much to it. Just a 3/4" square keystock base and a 1/4" dia. x 12" long rod for the feeler. Found the thumbscrew kicking around, no idea what it's from. Just drillled and tapped a hole for it to lock down on the rod. Should come in handy for measuring the depth of stuff like I-beams and whatnot, not to mention holes like pipes etc.