I wasn’t hurt.. but here’s what puzzles me. I was helping a friend take three inches off the bottom of some Aztec carved pillars he bought in Mexico. The diameter was nearly 12 inches.
I had a Timberwolf 1/2″ 4 tpi blade on my Grizzly 14 w/riser. I was pushing the pillar through the blade against the fence while my friend was handling the other end six feet away. (We had the pillar on a roller stand)
After completing this task on three other pillars.. the blade suddenly went off track.. chewing up the table insert.. as well as a piece of metal that latches the bottom wheel door closed. The blade was chewed up, too.. and bent seemingly beyond repair. Now I’m waiting for a new table insert from Grizzly, which they’re sending me at no charge.. and wondering..
Wha happen??
Replies
Bill... If the machine was running but you were not cutting wood, three different things COULD have happened
FIRST ... the tension of the blade probably changed (loosened)while cutting the pillars.
SECOND ... the camber adjustment of the top wheel probably changed. (adjustment not properly tightened when changing blades)
THIRD ... the blade overheated and expanded enough to cause the blade tension to loosen.
Item one and two are generally caused by vibration of the blade.
If the blade 'went' in the middle of a cut you probably twisted the pillar just enough to pull the blade out of the guides OR backed the wood out ever so slightly, again pulling the blade out of the guides.
As long as you were not injured, this is a minor inconvenience and nothing major to worry about. I have popped my share of blades while backing out of a cut to make a minor correction to my cut. Noisy, YES. Something to panic over, definitely NO. SawdustSteve
My deep-in-the-gut hunch is, as you venture, that the blade pulled out of the guides for one or more reasons. Since everything was going smoothly for awhile.. the blade must have lost tension. Disconcerting to say the least. Thanks, Steve.
Bill,
About a week ago I chewed up the bottom tire on my bandsaw using a similar 1/2" Timberwolf blade. ...cutting 6" maple. After much discussion with people more expert the best guess is that the blade stopped (slipping) which then led to a series of events ending with the tire being chewed badly. The advice I was given was to make sure the blade is tight...tighter than recommended .... on the wheels.
I have wondered about the Timberwolf edict about tensioning the belt so loosely. Maybe I'll give it an extra turn from now on. Thanks, BG.
Bill,
If you were in the cut, my guess is that the pillar rotated a bit, which snagged the back of the blade and forced it forward out of the guides.
There is nothing restraining the blade from being pulled forward on a bandsaw, it only takes a pound or two of pressure on the trailing edge of the blade, something you wouldn't even notice while maneuvering a piece of wood that large. Once the back of the blade moves far enough forward for the blade to clear the side blocks, only 3/8ths of an inch on a 1/2 inch blade, it would act exactly the way you described. What happened wasn't a fault of either the blade or the machine.
A cardinal rule of bandsawing, but one I rarely see mentioned, is that you never ever try to back out of a cut with the blade moving. You probably weren't trying to back out, but the wood shifted enough to force the blade out of the guides in any case.
John W.
John, that sounds exactly right and your explanation is very instructive. I don't have much time on the bandsaw and I'm learning what you have to say at just the right time.
You may not care to hear this, but I would have looked around for another option to using the bandsaw for such a large piece, especially if the bandsaw was only a 14-inch one. Like -- a handsaw or bowsaw. Even when I use my 16-inch bandsaw to slice a piece off a large turning blank, it's sometimes not the way to go even though I use a 3/4 or one-inch blade for large diameter pieces. It's just too hard to guide a big or heavy piece without twisting.
Yeah, in thinking about how to accomodate my buddy with this job I considered the bandsaw my best option because of the diameter of the work.. but even with the riser it's not something I would do again. The pillar most likely rotated knocking the blade out of the guides.
Sounds right. At least you're OK. Good luck.
John W nailed it...it happens, a rotation will get scary real fast..btdt.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Just to add a point others did not mention. Using the fence in this situation is like using a fence with a miter gauge on the table saw. It's a bad idea and a sure way to cause pinching. Sometimes it's hard to beat a hand saw if you aren't scared of a little work.
I have to agree with you about the handsaw except that accuracy was an issue here and I'm a hacker when it comes to a handsaw.
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