I've used a bandsaw for decades but have only been "in charge" of my own for a much shorter time so I'm running into problems for the first time (since they used to be taken care of for me). For the first time, I bought made-to-order blades (from Spectrum) rather than buying whatever pre-made blades Laguna or Woodcraft wanted to sell me. I've got something weird going on, and I'm not sure what to do about it. The saw is a Laguna LT14SUV in case it matters.
A few weeks ago, I bought 3 new bandsaw blades. 2 were the Lenox Kerfmaster stock and one was the Diemaster 2. Today, it was time to change to a new blade and I went to install the 3/4” Kerfmaster. While dialing in the tracking on the saw, I noticed that the blade would track stably for almost the entire revolution of the blade but at one point would jump forwards relative to the blade guides (towards the teeth) nearly 1/4” and then immediately settle back and run true for the rest of the loop. This is with the blade guides fully backed off, they were just used as a visual reference once I noticed the blade was moving. No amount of dickering with the tension or tracking could resolve this issue. Eventually, I realized that the jump forwards was occurring right at the weld. Thinking perhaps it was just bad luck, I then tried to install the 1/2” Kerfmaster. The same scenario repeated, though the jump forwards and back was less; right around 1/8”. Finally, mounting the 1/2” Diemaster 2, the same thing happened a 3rd time, though the jump this time was quite small, perhaps 3/32”. Going slightly crazy by this point, I put the original blade back on the saw and it actually ran true and stable the whole way round, showing that it’s an issue with the blades, not the saw.
I checked all 3 blades to see if I could determine why they were doing this. In the end, I’m not sure, so I’m hoping you can help me figure out what’s going on. Feeling the flat sides of the blades between my fingers, the welds a very ripply like they change thickness considerably over a short distance but I don’t see how this could possibly produce the result I observed. Putting a straight edge up against the back/spine of the blade, all three had a bit of a hollow at the weld, as though the two ends of the band were not perfectly parallel to each other when they were welded. I could see this resulting in the blade jumping forwards at the weld, but the size of the hollow (against a 12” straight edge) was much smaller than the amount the band was jumping forwards on the saw.
How do I resolve this issue with the new blades?
Thanks!