Question
I know some of you swing blade sawyers have hit trash, metal or lost teeth. Is it just my lack of knowledge? Or is my common sense saying "Danger, no guard!" Something to consider in purchasing a new mill. Would chaps really help in a catastrophic failure? And for the 3/32" thick piece of lexan (bullet proof glass), it takes over 1/2" thick to stop a 22 shell. I would really like to know before it happens how a 21.5" circle blade with 5 teeth at 2000 RPM really does react to metal.
Forum Responses
(Sawing and Drying Forum)
From contributor I:
I've hit metal a few times with the swing blade. Anyone that does much sawing will. It's a bit of a non-event - you hear a zing as the carbides chip off and the saw stops cutting properly. If it's a big enough piece of metal, the carriage just stops. Remember, with a big circle mill, you have 100+hp driving the saw and the log is being fed in fast and with considerable power. The power and momentum is there to bust shanks off the blade and fire them around the landscape like bullets. With a swing blade, it's generally being fed in with a couple of pounds of hand feed pressure.
If you hit something solid, the carbide tips disintegrate and the saw stops cutting. Wearing a face shield and chaps is recommended, but that's mostly for flying wood chunks. There simply isn't the power involved to launch big, fast pieces of shrapnel like a big circle saw can.
Now, I don't have any idea if what they provide is thick enough or not, but at least it's not necessarily as bad as it may first look.
I believe a blade has come free once, but that was due to an operator modifying the holes in the blade and using incorrect mounting bolts, and yes, the result was fatal.
As the mills come from the factory, they are very safe to operate. The main danger seems to be from flying wood chips and small offcuts/knots that get kicked back by the blade. The safety gear gives you decent protection from that, and it's usually flung away from the operator. It is important to keep bystanders back from the cutting side of the mill, though. All sorts of stuff gets flung there.
All that said, I managed to take a direct hit in the left on a demo job about six months ago and the memory is still fresh in my, err... mind. It is funny now, but at the time I didn't know if I was going to pass out, soil my underwear, throw up, die from internal bleeding or ever be able to stand back up. It seems that the older you get, the less tough you get in that area!
Yes, you can pinch a blade due to internal tension, foreign objects, etc. This can kick the log off the bunks or even pop the carriage up off the rails. But the mills just don't have the spinning inertia or the horsepower to throw large objects around with any great speed.
I would also suggest this is one of the reasons that the manufacturers keep the power of the mills down below 30hp. As the mill is only held on the rails by its own weight and controlled by hand, I can see things getting crazy if you had too much power involved.
If you try to rotate the blade over the log, only the tips bite into the log, dig a small gouge, then the side of the blade is rubbing on the wood and you can't rotate any further. About this point you wake up and kick yourself. I don't think it would even be possible to stall the saw. The other mistake is to swing the saw when it's low to the ground and have the blade contact the metal cross supports. That's about as exciting as it gets, but just results in an expensive zang noise and shattered carbide tips. Like the guys have said, small bits of wood can get thrown with painful force, though.
The next thing is that feeling that you are running for your life from the saw, as it scares you - big time! This particular faux pas is one which you remember a long time. That's why Peterson has that nasty label:
"WARNING! FAILURE TO... MAY RESULT IN INJURY OR EVEN DEATH!"
I have cut concrete, bullets, screws, nails, fence. No problems. It's only when my brain slips a gear (as previously confessed) that I get a scare. The guards always do their job. When I am double-cutting, however, it is time to pay extra attention to loose slivers or knots or waste which might get thrown.
The bandmill I operate has safeties that wrap down under the rails. These keep the head from falling off the track when you hit a foreign object/stop too hard. (Some who own this same model have removed these safeties, for reasons unknown, only to have a minor disaster later.) Do swing mills have safeties like these?
Common Lumber Name | A | B | C |
Hardwoods | |||
Alder, Red | 9.9 | 19.2 | 2506 |
Apple | 10.9 | 31.7 | 4132 |
Ash, Black | 9.3 | 23.4 | 4132 |
Ash, Green | 14.3 | 27.6 | 3590 |
Aspen, Bigtooth | 10.3 | 18.7 | 2439 |
Aspen, Quaking | 10.3 | 18.2 | 2373 |
Basswood | 6.2 | 16.6 | 2174 |
Beech, American | 8.9 | 29.1 | 3793 |
Birch, Paper | 8.8 | 25.0 | 3260 |
Birch, Sweet | 11.9 | 31.2 | 4065 |
Birch, Yellow | 9.2 | 28.6 | 3723 |
Buckeye | 8.9 | 17.2 | 2235 |
Butternut | 11.3 | 18.7 | 2440 |
Cherry | 13.8 | 24.4 | 3184 |
Chesnut, American | 11.6 | 20.8 | 2708 |
Cottonwood | 8.5 | 16.1 | 2102 |
Dogwood | 6.8 | 33.3 | 4331 |
Elm, American | 10.2 | 23.9 | 3116 |
Elm, Rock | 12.2 | 29.6 | 3860 |
Elm, slippery | 11.5 | 25.0 | 3251 |
Hackberry | 11.8 | 25.5 | 3319 |
Hickory, Bitternut (Pecan) | 14.7 | 31.2 | 4062 |
Hickory (True) | |||
Hickory, Mockernut | 9.1 | 33.3 | 4332 |
Hickory, Pignut | 9.3 | 34.3 | 4332 |
Hickory, Shagbark | 10.9 | 33.3 | 4333 |
Hickory, Shellbark | 6.6 | 32.2 | 4195 |
Holly, American | 8.3 | 26.0 | 3387 |
Hophornbeam, Eastern | 7.9 | 32.8 | 4266 |
Laurel, California | 15.1 | 26.5 | 3456 |
Locust, Black | 21.2 | 34.3 | 4470 |
Madrone, Pacific | 7.8 | 30.2 | 3925 |
Maple (Soft) | |||
Maple, Bigleaf | 12.8 | 22.9 | 2980 |
Maple, Red | 13.1 | 25.5 | 3318 |
Maple, Silver | 12.4 | 22.9 | 2981 |
Maple (Hard) | |||
Maple, Black | 12.3 | 27.0 | 3523 |
Maple, Sugar | 12.3 | 29.1 | 3793 |
Oak (Red) | |||
Oak, Black | 11.7 | 29.1 | 3792 |
Oak, California black | 16.4 | 26.5 | 3455 |
Oak, Laurel | 6.3 | 29.1 | 3791 |
Oak, Northern red | 13.6 | 29.1 | 3793 |
Oak, Pin | 13.0 | 30.2 | 3928 |
Oak, Scarlet | 13.2 | 31.2 | 4065 |
Oak, Southern red | 9.6 | 27.0 | 3520 |
Oak, Water | 10.4 | 29.1 | 3793 |
Oak, Willow | 6.4 | 29.1 | 3790 |
Oak (White) | |||
Oak, Bur | 15.4 | 30.2 | 3928 |
Oak, Chestnut | 10.1 | 29.6 | 3858 |
Oak, Live | 17.5 | 41.6 | 5417 |
Oak, Overcup | 10.7 | 29.6 | 3860 |
Oak, Post | 11.0 | 31.2 | 4063 |
Oak, Swamp chestnut | 10.7 | 31.2 | 4063 |
Oak, White | 10.8 | 31.2 | 4062 |
Persimmon | 7.0 | 33.3 | 4332 |
Sweetgum | 8.9 | 23.9 | 3115 |
Sycamore | 10.7 | 23.9 | 3115 |
Tanoak | 9.0 | 30.2 | 3926 |
Tupelo, Black | 10.4 | 23.9 | 3116 |
Tupelo, Water | 12.4 | 23.9 | 3115 |
Walnut | 13.4 | 26.5 | 3454 |
Willow, Black | 8.6 | 18.7 | 2438 |
Yellow-poplar | 10.6 | 20.8 | 2708 |
Common Lumber Name | A | B | C |
Softwoods | |||
Baldcypress | 13.2 | 21.9 | 2844 |
Cedar, Alaska | 14.4 | 21.9 | 2844 |
Cedar, Atlantic white | 10.9 | 16.1 | 2100 |
Cedar, eastern red | 16.4 | 22.9 | 2981 |
Cedar, Incense | 13.1 | 18.2 | 2371 |
Cedar, Northern white | 11.1 | 15.1 | 1964 |
Cedar, Port-Orford | 12.6 | 20.2 | 2641 |
Cedar, Western red | 12.2 | 16.1 | 2100 |
Douglas-fir, Coast type | 12.3 | 23.4 | 3049 |
Douglas-fir, Interior west | 13.2 | 23.9 | 3116 |
Douglas-fir, Interior north | 14.0 | 23.4 | 3048 |
Fir, Balsam | 9.9 | 17.2 | 2236 |
Fir, California red | 10.6 | 18.7 | 2437 |
Fir, Grand | 10.7 | 18.2 | 2371 |
Fir, Noble | 10.1 | 19.2 | 2507 |
Fir, Pacific silver | 10.4 | 20.8 | 2711 |
Fir, Subalpine | 10.5 | 16.1 | 2101 |
Fir, White | 12.2 | 19.2 | 2506 |
Hemlock, Eastern | 12.6 | 19.8 | 2573 |
Hemlock, Western | 11.5 | 21.8 | 2847 |
Larch, Western | 11.3 | 25.0 | 3251 |
Pine, Eastern white | 12.3 | 17.7 | 2303 |
Pine, Lodgepole | 11.5 | 19.8 | 2576 |
Pine, Ponderosa | 12.6 | 19.8 | 2573 |
Pine, Red | 12.2 | 21.3 | 2777 |
Southern yellow group | |||
Pine, Loblolly | 12.9 | 24.4 | 3183 |
Pine, Longleaf | 15.0 | 28.1 | 3658 |
Pine, Shortleaf | 12.9 | 24.4 | 3183 |
Pine, Sugar | 12.6 | 17.7 | 2302 |
Pine, Western white | 10.0 | 18.2 | 2370 |
Redwood, Old growth | 14.9 | 19.8 | 2573 |
Redwood, Second growth | 13.2 | 17.7 | 2302 |
Spruce, Black | 11.3 | 19.8 | 2575 |
Spruce, Engelmann | 10.0 | 17.2 | 2234 |
Spruce, Red | 10.6 | 19.2 | 2506 |
Spruce, Sitka | 10.8 | 19.2 | 2506 |
Tamarack | 12.0 | 25.5 | 3318 |