broken blades

woodweasel · January 08, 2013, 11:24:25 PM

Is it common for a blade to break, or get slung off? My old sawer would not let me stand on the left side of his mill for fear of this happening? :P

isawlogs · January 08, 2013, 11:45:05 PM

Is it common, no, that being said they do break and they come out of the mill with some velocity.

I also do not let anyone stand on the out bound side of my mill, even though I have a sawdust shoot that will stop a blade I have had one go through it and stick out three feet after a break.
Blades will go around the wheels only a certain amount of time, stress builds up and micro cracks form and they break, metal fatigues after a while. We prolong the life of the blade by grinding the gullets and teeth but eventualy the cracks gets the better of the blade.

Migal · January 08, 2013, 11:56:44 PM

Quote from: isawlogs on January 08, 2013, 11:45:05 PM
Is it common, no, that being said they do break and they come out of the mill with some velocity. I also do not let anyone stand on the out bound side of my mill, even though I have a sawdust shoot that will stop a blade I have had one go through it and stick out three feet after a break.
Blades will go around the wheels only a certain amount of time, stress builds up and micro cracks form and they break, metal fatigues after a while. We prolong the life of the blade by grinding the gullets and teeth but eventualy the cracks gets the better of the blade.

well said Left or Right I prefer spectators to stay behind the saw head due to Murphy's Law be Safe.

Ianab · January 09, 2013, 12:10:17 AM

Common enough that you should keep the guards in place, and not stand close to the sawhead when it's cutting. Usually the band breaks in a "nice" way and just rattles around inside the guard while you stop the mill. But random physics and Murphy's Law sometimes lets pieces fly out....

Ian

ladylake · January 09, 2013, 06:54:23 AM

Most blades break. The only ones that don't are the ones I find cracked when sharpening and a few the get sharpened down to 1" without breaking. Steve

terrifictimbersllc · January 09, 2013, 07:48:22 AM

Not common but that doesn't matter. In 12 yrs of sawing I've seen it happen once. In my first year, blade literally shredded and ended up on the sawdust side in many pieces out as far as 20 ft. Would have been a practically new blade. Don't know how the pieces escaped the housing, but for that reason I tell people that's the danger side, and don't run the saw until that side is clear.

thecfarm · January 09, 2013, 07:52:07 AM

I would also be concerned about pieces of wood,bark, knots coming out on the discharge side too.

Warren · January 09, 2013, 07:55:02 AM

Quote from: Migal on January 08, 2013, 11:56:44 PM
Quote from: isawlogs on January 08, 2013, 11:45:05 PM
Is it common, no, that being said they do break and they come out of the mill with some velocity. I also do not let anyone stand on the out bound side of my mill, even though I have a sawdust shoot that will stop a blade I have had one go through it and stick out three feet after a break.
Blades will go around the wheels only a certain amount of time, stress builds up and micro cracks form and they break, metal fatigues after a while. We prolong the life of the blade by grinding the gullets and teeth but eventualy the cracks gets the better of the blade.

well said Left or Right I prefer spectators to stay behind the saw head due to Murphy's Law be Safe.

+1 ... I require everyone in the saw shed to be behind me and the sawhead when the blade is moving...

terrifictimbersllc · January 09, 2013, 07:59:58 AM

Those bits of wood sticking off the ends of logs because of incomplete chainsaw cuts, are also a convenient source of projectiles.

POSTON WIDEHEAD · January 09, 2013, 08:03:05 AM

No, it is not uncommon for a blade to break. But the whole blade slinging off? I would not say that is common.

Chuck White · January 09, 2013, 08:06:47 AM

Last summer I had a blade break and completely exit the sawdust chute in one piece!

The next thing I did to the mill was install new blade stoppers.

Now, remember blade stoppers don't necessarily stop all blades, but in most cases they do.

There are pictures posted on here showing blades that exited the blade housing, I'm sure someone will post a couple.

Be careful and don't get near the sawdust chute when the mill is running.

woodweasel · January 09, 2013, 10:59:27 AM

Thanks fellows !! My old sawer had a hole in the corragated metal approx.20'
away from saw! He said it was from a blade!I had no reason to not believe
him!! Just wanted some feedback!!

Daniel aka woodweasel

pineywoods · January 09, 2013, 11:09:57 AM

My mill has a sheet metal duct on the sawdust exit. It connects to a sawdust blower. I have seen pieces of broken blade punch a hole completely through that sheet metal. I never thought much about it until I installed a bicycle speedometer on the bandwheel. I was some surprised to see that the band is traveling 55 - 60 mph. If the blade is in the log when it breaks, it's usually a non-event, just noisy. The nasty breaks usually occur when the blade is up to speed, but not yet in the log, like jigging back for the next cut without idle down.
Be carefull, a broken band around a body part could ruin your day..

Bogue Chitto · January 09, 2013, 11:16:05 AM

Don' stand on the right side ether. That swinging debarker could do some bad flesh damage.

beenthere · January 09, 2013, 11:20:33 AM

Quote from: woodweasel on January 09, 2013, 10:59:27 AM
Thanks fellows !! My old sawer had a hole in the corragated metal approx.20'
away from saw! He said it was from a blade!I had no reason to not believe
him!! Just wanted some feedback!! Daniel aka woodweasel

Sounds like you are talking a circular sawmill, and not a bandmill.

Magicman · January 09, 2013, 08:29:16 PM

I had one this past year that broke in two different places. One piece was on the ground beyond the logs staged at the loader. I have no idea what all took place to get it over there.

isawlogs · January 09, 2013, 08:31:19 PM

Its called momentum ;)

LeeB · January 09, 2013, 09:48:21 PM

I broke one yesterday and it is the first one that I broke that went nowhere. Didn't get stuck in the cut. No damage to the B57's. Just a pop and a broke blade. Never got that luck before.

isawlogs · January 16, 2013, 10:01:47 PM

You're on a roll Lee! :D

Magicman · January 16, 2013, 10:23:36 PM

Yup, it all depends upon where the break is when it breaks. If it is in the log, on the drive or driven wheel, or somewhere in between. They can do nothing or really make a mess.

drobertson · January 16, 2013, 10:38:48 PM

It seems to me that it has been about 1/2 and 1/2. Lately just before I enter the log. the blade has a slight ball up on the drive side of the mill. Not much more than changing a blade, but still a pain. In the log is most definetly a pain.

Slab Slicer · January 16, 2013, 10:56:39 PM

My first break was a few weeks ago. I had sawed a bunch of Norway Spruce with this blade, and then started into a red oak for some bench slabs. Got about 2 feet into the log, and BANG!!!. The blade bunched up against the log, and a little in the mill head. It broke right on the weld. Luckily I was able to pull it out of the log very easily, and drop a new one in the mill head. I've had some issues with them popping off the wheels due to sap build up on the belts, but never a break. I hope this doesn't happen too often.