I am cutting some walnut lumber. Using the advice I got here, and a new
Timberwolf 3tpi blade, things have been going reasonably well. The first 40
cuts (4' long, averaging 5" thick) were perfectly straight, but the last few
have developed a significant drift angle; the ends have become too thin to
be used and the wood is getting curved. I readjusted everything, but it
doesn't help. All I can think is that the blade is getting dull, but I
would expect a blade to last much longer than this.
Frankly though, I am a complete beginner with a band saw (14" Delta 1hp) and
really don't know. It was actually getting easier as I picked up a little
skill in feeding the wood, but I can't continue like this.

Could the blade be getting dull after 160' of 5" thick fresh walnut, or is
there another possibility I am over looking. Thanks.