Building the wheel mounts for the 26" bandsaw
I cut four pieces to make the frame for the top from a piece of firewood.
Then I cut a rabbet into the ends of the longer pieces for joining them together. I cut a slot, removed most of the material with a bandsaw, then moved the workpiece side-to-side to smooth the bottom of the rabbet I cut. This ensures that surface is parallel to the long edge.
The bottom piece of this bracket also has a rabbet cut out of it, which I made by making two cuts with the table saw. That rabbet provides a ledge that the bottom of the tilting bracket is screwed to.
On previous bandsaws I made the part that holds the top axle as a solid block of hardwood, but most people don't have big chunks of firewood handy to cut such a block out of, and drilling the hole for the shaft straight through the hardwood and aligned properly is difficult. So this time I made that part as a plywood frame.
The sides of this frame are an odd shape, so I printed out a 1:1 template for it. But having printed just one template, I cut around it and traced it instead of cutting through it so I could use the same template twice.
I cut that out with a bandsaw.
The irony of using a bandsaw to build a bandsaw is not lost on me, but if you don't have a bandsaw yet, you should consider building my 16" bandsaw or my 20" bandsaw first, and I do show how to build one of those without already having a bandsaw. Or if you really want to start with a 26" bandsaw, you can figure out how to do the cuts with a table saw and jig saw.
Some people make special jigs for cutting splines, but I just use my table saw sled, with a block clamped on the left to help place the workpiece at 45 degrees, and another block on the other side to set the lateral position.
I had a thin-kerf blade in the saw, in retrospect I should have switched to a thicker blade for cutting these slots. To compensate, I cut a third slot in the middle.
And finishing that on the belt sander. You could also just trim them with a hammer and chisel. Building a 26" bandsaw is not a beginner project, so I figure you already know how to do it differently if you don't have the same equipment.
I made a four pointed knob for adjusting the tracking. I used to make my knobs with two, three or five points, but when I used these 4-pointed plastic knobs I already had when I made these long reach clamps I liked the feel of these more than 3-pointed or 5-pointed ones, so I guess 4-pointed knobs are the way to go.
I hadn't yet made templates for these for the plans, so I just drew a square and used a washer to mark the corners.
Then filing the hole square, and hammering a carriage bolt into the knob. its a 3/8" carriage bolt going into a 23/64" (0.4 mm smaller than the bolt), so it's an interference fit. I put the knob on top of a block with a 3/8" hole in it to prevent the plywood from chipping out on the back from driving the bolt through it.
Adding a 3/8" T-nut to a piece of hardwood to go on the top of the bracket. It's a bit of an odd 3/8" T-nut, but it's the only one that size I had around. Just tapping a 3/8" thread straight into the hardwood would have worked fine too.
Then using the two angled holes I drilled in the plywood part much earlier to attach the plywood into the rabbet ledge of the frame. I drilled pilot holes first. Also, the holes in the plywood should be large enough to provide some slack. The screws should not be very tight, so the plywood can tilt forwards and back by a few degrees.
Inserting the threaded knob I made earlier. This pushes the top of the bracket back, causing it to tilt. Blade tension will pull down on the axle, pushing the block to tilt forward against the adjustment knob.
Making a crank for tensioning the blade. It consists of a long coupler nut hammered into a slightly undersized hole in a piece of plywood for the thread, and a short piece of dowel screwed to the other end as a handle. That handle will be the highest part of the bandsaw, so I don't want to make it too long to avoid hitting ceiling beams or ducts when I roll it around the shop.
And inserting the axle through the bracket. I haven't cut the axle to its final length yet. Also note that I have the back of the bracket on the axle, but this part is not attached to the axle. That way, I can still potentially slide it side-to-side to adjust the wheel to be coplanar with the frame. Though, as it turned out, it didn't need to adjust it once it was assembled.
That layer is not so much for strength or stiffness as it is to give me more bearing surface for the table mount later, and to put the front and back part of the lower axle mounts further apart.
Because the wheels on this bandsaw are so much bigger than previous ones I built, the lower axle ends up quite a bit below the horizontal part of the frame, so I made this bracket out of plywood and a piece of 2x4. I made this part quite wide because the lower wheel mount also needs to take up sideways force from the motor's belt later.
With most bandsaws I have built, after a few years of never de-tensioning the blade, the alignment of the bottom axle needs to be slightly tweaked from the wood giving way slightly. This involved taking the lower wheel off, loosening the lower wheel mount, and adding 0.5 - 1 mm of shim under it.
On this one, I figured I should just make the back of the wheel mount axle adjustable so when the time comes, I can make this adjustment more easily.
I drilled and tapped some blocks of hardwood to fit carriage bolts. But I didn't tap the thread all the way through, instead drilling the end of the hole just smaller than the bolt, so that the bolt goes in the hole with a lot of friction.
Then gluing these pieces to the bottom wheel mount, around a hole that is about 5 mm bigger than the axle. The ends of the bolts will be able to push the back end of the axle exactly where I need it to be for alignment.
The carriage bolts don't have any knobs on them. I figure these will only need adjusting once of twice, ever, so using a wrench is fine. I would have used hex head bolts, but couldn't fine any with long enough threads at the store I went to.
In retrospect, this assembly is overkill. If I did it again I'd just put shims in to set the position, and add to the shims when adjustment is needed years later.
I got the initial alignment accurate enough that I didn't need to tweak it at all. So if I had made it non-adjustable, I would have been fine for the time being.
In the past I made the "wooden spring" for blade tensioning out of several layers. On a whim, I figured just cutting slots into the ends of a thicker piece would give it the necessary flexibility. But if you don't already have a bandsaw, cutting several thin pieces on the table saw and stacking them would make more sense.
With both wheels on their axles, time to put on a blade and check that it tracks properly. It turns out, I didn't need to tweak the lateral alignment on the top or the back of the axle on the bottom to get it to track. So my extra provisions for adjustability weren't needed on mine.
I stuck a knob in the lower wheel and cranked it up, making my first cut with the is bandsaw! The fact that I could make a cut just by hand cranking it shows how little power a bandsaw needs for regular cut. I imagine I could power a bandsaw to be fairly usable with a bread maker motor!
My 26" (66 cm) saw next to my 16" (40 cm) saw, which in turn is bigger than the very common 14" bandsaws. It's a big machine. Not as big as a 36" bandsaw, but as big as I figured I could make it and have the height of the machine not become a big problem.
Next: Adding the motor