Building a bandsaw on the cheap from mostly scrap wood

[glatt]

5/29/16 part II

I tested the fit after planing. It slid nicely with minimal slop.


I waxed the runners anyway to help it slide more easily.


I screwed the L brackets down to lock the frame in place. The plans call for a lot of screws because there will be a lot of force pulling against this frame. I used good structural grade screws. Then I took the bearing block and placed it in the frame and clamped it there to check the alignment.


I used a framing square to be sure the top and bottom shafts were square with the frame before I held the block in place with a couple little drywall screws. The drywall screws just keep the bearing block in the proper location. The frame holds it securely in place when blade tension is applied.

[glatt]

5/29/16 part III

I put the shaft in the top bearing block. I drilled a hole in the side to anchor the shaft in place with a drywall screw.


I put the wheels on just to see how it goes together and to admire it. The wheels make it want to tip over, so I set the motor in the area where it will go and weigh it down.


I cut 3 strips of maple to act as leaf springs to support the top wheel. These wooden strips will break before anything else, so they are a safety device, like a fuse.


These are the leaf springs installed, and a good picture for an overview of the whole top wheel mounting system. You adjust the blade tension by turning that nut at the top and raising the frame that holds the bearing block and top wheel. That’s why the frame needed to slide in those L brackets.

[glatt]

5/29/16 part IV

I tried to put the blade on, and was unable to do that. The frame wouldn’t lower far enough to give me the blade slack I needed. My bolt was too short. I needed a longer one. So to just make do for this test, I removed on of the leaf springs. That meant I could make do with a shorter bolt for now.


The blade seemed happy with this inner tube tire. I adjusted the tracking by turning the bolt in the bearing block which bears against my old hacksaw blade on the frame. It worked well. The blade is right on the crown of the wheel.


The two leaf springs, however, were not happy. They needed their third buddy. I needed to get a longer bolt. But it’s neat to see how far they can flex without breaking.


I spun the wheel by hand, and the blade stayed nice and centered on both the top and bottom wheel. It seemed to track well. So I grabbed a popsicle stick piece of wood, and I CUT MY FIRST WOOD ON THE BAND SAW!!! Just held it against the blade after spinning the wheel by hand and getting it going.

[glatt]

5/29/16 part V

So the evaporator motor I bought on Ebay for like $20 is nice and round. No mounting bracket. But it has a rubber bushing mount. I figured that if I took advantage of this when I mount it to the saw, it will reduce vibrations just a little.


So I measured the diameter of the rubber mount, and divided it in half to get the radius. Set a compass to that distance and drew some semicircles on the edge of a board. I cut them out with a coping saw. I sure would be nice to have a band saw for this. It would have been a lot easier to cut and better quality.


I cleaned up my sloppy cuts with my home made sander in the drill press.


And I screwed together a motor mounting bracket. I tested the fit in the motor location on the frame. It looks good here. I’ll need to clamp the motor down in the bracket. I’ll probably use steel baling wire attached to a couple screws on each end of the bracket, and twisted to snug it down tightly against the rubber bushings.


Not shown: I made a couple of large wooden washers to go on the shaft behind the lower wheel to keep it from rubbing against the frame.

[xoxoxoBruce]

Well done, you're making good progress.
I don't understand the three maple "leaf springs"? If they are to compensate for minor out of round differences in the two wheels, I suppose they would give a little. But if the blade seizes in the work, either the blade will slip on the wheel, or more likely the motor belt will slip. Barring that, the motor stalls. But absolutely nothing should pull hard enough to break those "springs".
Experience has taught me painfully, when the shit hits the fan, even if the motor switch is handy, it's often dangerous to let go with either hand. They make foot switches that plug in before the motor for $15.

Now, sally forth brave hobbit, bandsaw the Ents into furniture, but for god's sake, safety first.

[Griff]

Most excellent.

[glatt]

Originally Posted by xoxoxoBruce

I don't understand the three maple "leaf springs"?

I think they are meant as a safeguard against over tensioning the blade. They are supposed to break before the blade does if I go nuts tightening the blade.

And I have no idea who's bare toes those are. Certainly not mine. I have a rule against bare feet in the shop, and I would never just scamper down into the shop for "just a few minutes this time" without putting shoes on.

[xoxoxoBruce]

OK, I can see the anti-over-tensioning. You will find the necessary tension for making the saw work well is a lot less than you think it is. The friction between the blade and drive tire is surprisingly big with a tight blade so unlikely to slip. Most of the tension (plus the guides) is to keep the blade from twisting when you're cutting shapes that make you glad you have a bandsaw. Charge!!