# kickback safety idea- inertial kill switch/brake



## jason j ladue (Apr 1, 2005)

is there such a thing. could an inertia sensor be installed in a chainsaw to detect the motion created in the case of kickback that would instantly engage a brake mechanism. i remember here a few months ago seeing a switch like for a table saw. it sensed the drop in voltage if the blade began to cut into the operator and stopped the blade in like 1/32 of a second, or some like that...you feelin me?


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## Proj Eng (Apr 1, 2005)

I saw that same thing on a table saw demonstrated on a show, except they used a hot dog instead of a man's finger to demonstrate. The blade didn't actually stop but dropped down below the cutting deck so no further injury could occur.

Good idea in theory, but doubtful anyone would pay for the saftey premium, especially on inexpensive saws. Besides, if you can't make the chain "drop away" or disappear, you'd have to make it stop and that would produce a heck of a torque reaction... physics, equal and opposite reaction, etc etc...

I have been thinking about that idea for a chipper somehow but to stop it in a few sconds would cause the machine to flip over. Think about the spinning bicycle wheel thing in physics back in high school.

It would be a good project for a college kid to work on though.


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## Proj Eng (Apr 1, 2005)

Well... I guess I am mental!  Must have been thinking along the lines of something else.


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## techdave (Apr 3, 2005)

Hi Project engineer, I think my 372 xp has inertia feature in the cahin brake as well. As for the paanic button on the chipper idea, here is an idea from a scrubby little degreed non-practicing engineer. You could have the infeed stop, and the rollers separate far enough apart they cant cut, or the knives/flails could retract hydraulically, or a charge could blow a stop door across the infeed throat. Better a severed limb or foot than sucked thru. Of course if you lead with your nogggin, youre SOL!!


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## Trignog (Apr 3, 2005)

Maybe I missed the point but I thought huskies inertial chainbrake is what you mean. I love chain brakes.


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## clearance (Apr 3, 2005)

This sort of talk bothers me because it gets people away from what really is important. The talk of chainbrakes, inertia brakes or anti-kickback, low kickback chain or this idea gives people the idea that kickbacks can be controlled or minimized to the point where they are not a problem. This is totally wrong, the main, important thing is to never put yourself in the path of a kickback. I run big saws all the time limbing and bucking, I never count on the brake to save me and I always run chisel chain. I do always know where the tip or upper quadrant of the bar is and I always stand to one side of the saw, even if I have to buck lefthanded. Even if you are very strong with huge arms, you cannot control a bad, full throttle kickback from a powerfull saw (372, 288, 394 etc.).


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## Trignog (Apr 3, 2005)

clearance said:


> This sort of talk bothers me because it gets people away from what really is important. The talk of chainbrakes, inertia brakes or anti-kickback, low kickback chain or this idea gives people the idea that kickbacks can be controlled or minimized to the point where they are not a problem. This is totally wrong, the main, important thing is to never put yourself in the path of a kickback. I run big saws all the time limbing and bucking, I never count on the brake to save me and I always run chisel chain. I do always know where the tip or upper quadrant of the bar is and I always stand to one side of the saw, even if I have to buck lefthanded. Even if you are very strong with huge arms, you cannot control a bad, full throttle kickback from a powerfull saw (372, 288, 394 etc.).


 
True that brother.


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## jason j ladue (Apr 4, 2005)

hey! i was just trying to make a million. is that so wrong?


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## Lumberjack (Apr 4, 2005)

Clearance, you LIMB with big saws? Must grow them big up there. Oh, and the sharper a chain is the less kickback it will produce.

Someone explain how running the saw left handed helps please. I just cant picture it.


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## tnttreeman (Apr 4, 2005)

It allows you to be on the opposite side of the chainsaw when you're in an awkward position, rather than stand with your face/body in the path of the saw kickback. Let's say that your limbing and there are limbs to the left of your body and nothing to the right. Use the saw left handed and your body is not up against something and not in the kickback path. Hope you get what I'm saying. A picture would say it better.

By the way, I think all my newer saws have inertia operated chain brakes, both Husky and Stihl.


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## 2Coilinveins (Apr 4, 2005)

This reminds me of a car commercial I saw a few years back. Went something like this:

"Lap and shoulder seatbelts
Driver and passenger air bags
Crumple zones
Side impact door beams
Side curtain air bags
Antilock braking system
Traction control system
Skid control system

The most important safety device is still the driver."


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## clearance (Apr 4, 2005)

Lumberjack-yes I limb with a big saw cause I fall and buck with a big saw. Rakers cause kickback not sharp or dull teeth.


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## Trignog (Apr 4, 2005)

Operator error causes kick back, but no ones perfect! Stay safe guys.


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