Bandsaw blade guard and first resaw test
I had temporarily fastened some horizontal pieces to the bottom of the bandsaw frame so I could stand it up. I liked how this worked out and wanted to put caster wheels on the bottom. But as it was, the saw would have been too low, so I glued together some thicker pieces to bring it up to the right height, then squared them up on the jointer.
Having drilled the screw holes in the horizontal leg pieces, I positioned them against the bottom of the bandsaw's legs (by tipping the bandsaw frame on it's side). I then placed the screws in the holes and hit them wit a mallet to leave divots where pilot holes need to go in the frame.
Long wood screws hold surprisingly well in end-grain. The limiting factor is how well the screw head holds, so I put washers behind the screw heads.
I then cut out a big hole for the cover that goes behind the top wheel, clamped that in the right spot behind the top wheel, and marked the wheel and frame outline on that. I'll use that later to work out the dimensions of the top part of the enclosure. The top part of the enclosure needs to fit around the blade guard, so I worked on that next.
In the past, I cut up PC cases for this. The corner of a PC case cover already has a nice sharp bend to it, so only one extra bend would be needed. But I didn't have any scrap PC cases kicking around.
A metal brake would be ideal for making this bend, but I don't have one and it's not worth making one just for this. So I clamped the metal in the vise, bent it, then repositioned it sideways, bent some more, working my way back and forth along the metal, each time adding about 15 degrees to the bend.
The resulting bend was not as sharp as I hoped. It was about 3 mm radius, which is adequate.
I hadn't used a guide for the angle grinder when I cut out the piece out, so my cuts weren't that straight. To make it look less ugly, I straightened out the edge that will be front-facing. I clamped a piece of hardwood to the piece and used that as a guide to grind off the parts that stuck out the most.
I had the idea of tapering the bottom part of the guard back a bit towards the guide for more visibility. The part near the guides doesn't need to fit around the wheel, so it doesn't need to come forward as far. I made a diagonal cut with tin-snips for this bend.
I thought about welding this overlap, or maybe a screw to fasten it together, but then had the idea of cutting back one part a bit and then folding the other part over and around to hook the pieces together.
After that, drilling the screw holes. First some small 1/8" (3 mm) pilot holes, then 3/16" (5 mm), then adding a slight countersink on the inside with the tip of a larger drill bit.
The guard needs to be about 5 mm to the right of where the blade will be. I then marked where the holes ended up, drilled pilot holes...
The dangerous part so far is that this saw has the bandsaw blade right where I would reach for the switch on my 20" bandsaw. I was afraid I might reach there for the switch without looking.
First, squaring up this piece of ironwood.
Then cutting a thick slice off of it. But the blade somehow snagged on the wood and got stuck. It then came off the wheels. The image at left is just after the blade came off. Nothing much happened as a result of this, other than the blade coming off. So now you know what happens when the blade comes off.
I think after the blade got jammed on the wood, the bottom wheel kept spinning because I had too little blade tension. With the blade slipping on the wheel, the crown makes it slide off.
Looking at the blade, the teeth have quite a bit of "hook" to them, which I imagine can really pull the blade into the wood. That in turn can cause it to snag on the wood, if it's hard enough. And ironwood (American hophornbeam) is extremely hard.
I later experimented some more to look into this phenomenon.
With the blade back on and more blade tension, I cut through this time. But the 2/3 hp motor I have on the saw is somewhat underpowered for this kind of resawing. But for resawing, my 20" saw is a better saw anyway. The larger wheel size doesn't help for resawing -- so long as the wheels aren't so small to cause metal fatigue in the blades from bending and un-bending around too-small a radius.
I kept getting the occasional "bang" from the wheel snagging itself on the wood, but with more blade tension, this didn't cause it to jam or come off the wheels.
Bandsaw on a dolly sawmill (2017)