Just stumbled upon these tonight. I’ve never seen them before. Very clever! It’s basically a band saw mill with a circular saw instead which can swing from horizontal to vertical blade alignment, and thus be run across a log 2 times to saw out a rectangular piece of dimensioned lumber. It helps to watch these 2 videos to understand what I mean:
Obviously, no large through-cuts, so no very-wide slabs, but if you need to turn a big pile of pine, or a very huge tree into dimensioned lumber, it seems these are designed to be quickly set to swing and slide to make those cuts in 2 fast passes with a swing of the large lever between each pass. Push it forward, pull the lever, pull it back, and you have a dimensioned plank. I think I saw some 4×6s at the end of that second video, but it looks like the larger ones could make at least up to 8×8 beams.
There’s a good write-up on these saws by Peterson Sawmills here – the link at the end of the first paragraph goes to a PDF of the steps taken to saw out boards. The other name I keep seeing is Lucas, and their page on these saws is here.
One final late-entry – I found another video by Peterson of them milling a log into lumber in under 10 minutes. They really get going at about the 1/3rd mark in the video, and they have a bunch of other videos under their account that obviously I will be digging through next :)
Edit: Timberline has a version that makes both cuts in a single pass, using a secondary ‘edger’ blade pair, with several other little clever enhancements:
-- Gary, Los Angeles, video game animator