Got my 4x6 machine back together and working properly. While still waiting on parts, I figured I would give the poor neglected machine some extra love. I changed the gearbox oil with some 80/90. Perhaps they put used motor oil in at the factory. It was nasty, I mopped all the **** out. I tilted the machine over to fill it up enough to have oil on the spur gear when operating vertical.
Machined the mating surfaces flat on the guides. They are crude. The intent is more contact area with consistent pressure to make adjustments to one of the three degrees of movement at a time (height, side-to-side position, angle).
Six new 6000ZZ bearings.
Drilled and tapped for an adjustment set screw to hold the lower groove position, which is main blade twist/side-to-side position.
So much easier to adjust with the modifications. The guide bolt can be slightly loosened and fine adjustments made to one thing at a time. The set screw holds the twist pressure to allow adjustment of the height or blade angle using upper groove, mostly independently. Magic. With pivot fixed the guide's don't need to force the blade down to cut below deck. I set upper neutral and the lower to contact when loaded by material to be cut.
I had set up the saw to cut (crooked) as fast as possible. Reminds me of some Lamb of God lyrics describing the company I worked for at the time (Westinghouse Nuclear). "Pedal to the metal asleep at the wheel". So to undo this I slowed the speed down to match the blade and material I cut.
And reduced the downfeed pressure considerably. This is balance point of the spring/arm system now.
I eyeballed the guide adjustments, checked with square as best I could and got perfect cut 1st try. I also used reduced downfeed to 'break-in' the new blade. The blade tips are going to break off, how far is dependent on pressure of first cut.
Made an improved 30* wedge to share across chop and band saws. Cut out shapes on plasma, bent in brake and resulted in pretty accurate piece.
Bolts to the fixed fence. 30* is about the limit to cut anything of size. A 45* puts the workpiece too far back on the deck. Moving the fixed fence resolves this.
So all that to bring it back to how it cut new. Could have just tightened the pivot screw, installed the arm stop and installed new bearings, but I got slightly carried away and had some fun doing it.