Chainsaw Kickback

[Guido Salvage]

I bought several saws that had the safety tip on the end of the bar to prevent kickback. In fact my Homelite 540 (88cc's) came with one on a 20" bar when I bought it new. Here is the best picture I can find of one.

 

[timbrjackrussel]

Kickback video
Kickback Demonstration by Chainsaw Instructor Joe Glenn - YouTube

 

[angry inch]

Also make sure your break is working properly. I was cutting with a friend last year and his break handgaurd was broke off, it was a on a stihl not sure what about a 50 cc saw I would guess. Anyway. I just happen to look over and I could not believe what happened the saw flipped out of his hand spun around cutting his right hand wide open also cut his car hart jacket on his forearm thankfully the fuzz from the lining stopped the chain of core after it was too late. If he would have his break handle on this would have been avoided!

 

[Philbert]

Stihl has a useful training video:
Reactive Force Events - Chain Saw Safety 7 - YouTube

Also, only my opinion, if you have a choice, use the smallest saw with the shortest bar to get the job done. Bigger saw and longer bar = bigger reaction if things go wrong and harder to control.

I like this STIHL video - it helps to explain the range of reaction forces: pull-in, push-back, kick-back. If your chain is going 55 to 60 miles per hour (at 12,000 - 14,000 rpm), the reaction force to the chain moving forward and down around the top of the bar nose, will be the bar moving backwards and up at comparable speed! Some guys think that they are strong enough or fast enough to react and control this movement. They are wrong.

'Low-kickback' (aka 'safety chain') has additional bumpers on the drive links or tie straps to reduce the chance of the cutters digging in as they travel around the nose. The design of the depth gauges also plays a part. The downside to some of this chain is that it is less effective for bore cuts (if you do those), and does not carry the chips away as effectively on longer bars. But if properly sharpened, it will cut well, especially for limbing and firewood type tasks.

Low-kickback bars have smaller diameter noses to reduce the surface area exposed to kickback.

ian89 did not say what type of saw/bar he was running, but some Poulan, Echo, and others come with an optional tip guard to prevent contact with the bar tip. Again, an option that prevents bore cutting and large diameter falling, but compatible with a lot of other limbing and bucking tasks.

Other tips in the STIHL video I like include: keeping the chain sharp; starting the cut with the saw at full speed; and working so that if the saw does kick back, the path of the bar will be to your side. A firm stance, and not cutting on wobbly branches also helps, along with PPE (boots, chaps, helmet, gloves), although, he mentioned the saw buzzing close to his neck.

Cutting into a tangled brush pile is one of the situations where kickback is highly likely to occur. Dragging branches or logs out a bit so that the bar nose is clear of potential obstructions can help in these situations.

I don't fully agree with Philip's opinion, above. Low-kickback chain is sold on smaller displacement saws because they more likely to be used by less experienced consumers, but also because they are less able to resist reactive forces. All things equal, a heavier saw with a longer bar has more mass ahead of the operator's grip, and a larger engine is less likely to 'stall' (using the term from one of the videos).

Small, top-handled saws offer the least resistance to kickback due to the short distance between the user's hands (assuming two-handed use).

Philbert

 

[WillBrayJr]

It's ALL about common sense. If you're new to Chainsaws, do some research by reading articles, watching safety videos, and start with a tiny model cutting small stuff.

 

[Cantrellc123]

One good way to stay clear of kickback injuries:
keep all your pieces out of the plane of the chain.

The b&c will move (very rapidly) in the plane they are in. Bad place to be, very bad.
If you're not there, you might see it go by. :msp_rolleyes: Or, you might not.

It also helps to:
avoid monkey grip (keep thumb opposed to fingers on the front handle)
keep your left elbow locked straight
keep a grip on the rear handle
absolutely minimize time spent running saw left-handed (cannot keep everything out of the plane doing that)
test kickback mechanism on saw often, and repair problems ASAP.


Not a good idea to stand behind another sawyer, obviously. :msp_wink:

Seeing as I'm left handed and cut that way, would that mean that a lefty would more often than not be on the same plane as the bar thus be in more potential danger than a right handed person? I'm away from home at the moment but as I recall it seems as though I'm always looking at the top of the bar,not from any angle.
I've never had a kickback that was great enough to engage the brake but then again safety first is always in my mind with a saw in hand.

 

[WillBrayJr]

I'm a southpaw and it feels natural running a Chainsaw with my right hand in the throttle handle.

 

[Philip Wheelock]

I don't fully agree with Philip's opinion, above. Low-kickback chain is sold on smaller displacement saws because they more likely to be used by less experienced consumers, but also because they are less able to resist reactive forces. All things equal, a heavier saw with a longer bar has more mass ahead of the operator's grip, and a larger engine is less likely to 'stall' (using the term from one of the videos).

Small, top-handled saws offer the least resistance to kickback due to the short distance between the user's hands (assuming two-handed use).

Well, you may be right. I was looking at this as a matter of torque in ft-lbs about the top handle of the saw. The longer the bar, or moment arm, for an upward force at the bar tip, the greater the torque value. But, as you point out, the inertia of the larger mass of bar and motor of a bigger saw would counteract this. Good point.

 

[Philbert]

Seeing as I'm left handed and cut that way, would that mean that a lefty would more often than not be on the same plane as the bar thus be in more potential danger than a right handed person?

Modern chainsaws should be operated with the Right hand on the Rear handle, and the Left hand on the top (anybody got an 'L' word I can use here?). One reason is the kick-back issue you mention. Another reason is to reach the On/Off/Kill-switch/Master Control Lever with your right thumb, without letting go of the handle.

Several years back I was reading one of those 'homeowner helper' type pamphlets at Lowe's, were it stated that 'right hand users place their right hand on the rear handle, and left hand users simply switch positions'. I wrote them a letter pointing out how this contradicted the information in the Owner's and Safety Manuals for all of the saws they sold. They never responded, but those pamphlets dissapeared.

Apparently, there were a few 'left handed saws' that were made (bar on the left side) a long time ago - I think that there might have been photos even posted here on A.S.

Philbert

- http://www.arboristsite.com/chainsaw/30300.htm

Found these on the Internet:

 

[woodchuck357]

Kick-back most often happens when pulling the bar out of the cut

or at the end of the cut, when you let off the throttle. A slow moving chain has enough force to move the saw in an arc and enough speed to rip your arm or neck up. At full speed chain cuts every thing it touches, it is the slow chain speeds when moving from limb to limb that causes most limbing kick-back injuries.

A pinch with the bar at full speed while bucking can cause the saw to push back as the saw chain comes to a full stop, but not kick up, unless it is a very small log.

Always stay out of the line of the saw, if you're looking into the kerf, you're in the danger zone. If you are a lefty, think of the hand on the front handle as the main one. Keep your thumb around the handle. And keep your saw running full speed when going into and coming out of the cut.

Don't let your saw lug down in the cut. Use wedges to keep your kerf open.

Under controlled conditions cut with the tip, and even cause a kick-back on purpose.

The mass of the saw body is not a factor in kick-back, as the saw motor is the point the kick-back rotates around.

 

[avason]

I laughed my ass off when I read your post. I laughed because the way it was typed. Be safe for god's sake and get some safety gear kid! Always take your time when using a saw and if your not sure of something check, recheck and check your options again. I'm glad your o.k.

 

[graybear13]

Keep a death grip on your saw and assume that it wants to cut pieces parts off you at all times. Pay very close attention to what you are doing at all times.