084 kickback?

[stump farmer]

Newbie here with a question maybe some of you large saw operators might have some insight on. Had an experienced co-worker get a violent kickback with an 084, 42" bar running 404 (don't have info on what type)chain. He was flushing a stump and the saw kicked back into his knee (no injury due to chaps and a knee brace) hard enough to break the knee brace. Said it was like a rifle shot when it popped and came out of the kerf. I realize there are many factors to a kickback. What I'm wondering is, given the age of this saw design, has anyone experienced or heard that these saws are more prone to kickback than say a newer model 880? Any thoughts? Thanks.

[fishpharmer]

Welcome to the Forestry Forum.
It's my understanding that newer saws have more "anti kick back" features.  I am no chainsaw expert.  I do know the 880 has an anti kickback hand gaurd brake, it works well.  Not sure about 084. 

[Cut4fun]

084 has the chain break and hand guard too.   I had a 372 has same and the other day came straight back  (rear handle) and busted my shin like that. Things happen be careful.

[sharkey]

Problem is that these kickbacks happen faster than you can react.  Ive had a big old geardrive come shooting out of the cut from being pinched.  I wonder if the stump weight was an issue in your example?  The cut closed from the weight up the stump and the chain energy had no where to go.

Make it a standard practice to completely wrap your fingers and especially the thumb  around the handles.       

[stump farmer]

I'll bet that stump weight was a large factor in this. A smaller saw would have just bogged down instead of powering itself out of the cut. We'll treat this saw with more respect. Thanks for the replies.

[Rocky_J]

Big saw, big kickback if the operator isn't skilled at operating large saws. It's not a toy. That thoroughbred kicks a bit harder than your average mixed breed, mid range saw. 

[beenthere]

Seems getting a wedge or two in the cut to lift the stump would have been very helpful. Something had to have caught the outgoing teeth on the top of the bar to shove the saw back out the cut. Wedges are time consuming, but often do the trick.

Had a logger aquaintance several years back who cut for a walnut co. They required trees to be cut at the ground to get all the wood possible. Before the day of chaps, his saw came out of the cut while he was on his knees, and severed a good 1/4 inch gash above his kneecap. Couldn't pull the tendons back together for easy fix, so he was in tough shape permanently. Maybe today's surgeons would have better techniques, but sure is a testimony for chaps.

[stump farmer]

You're right wedges would have helped with safety and with finishing the flush cut. Correct hand position ensuring the brake is actuated during a kickback was probably awkward and not done while kneeling over the powerhead. He might have been under size on the bar with the tip still in the cut as well. Good reminder to have chaps sized and adjusted (not too loose) correctly.

[sawguy21]

I wonder if he was cutting with the nose or top of the bar. Stumps are awkward to work with. Glad he was not hurt.

[Ianab]

Chainbrakes don't stop kickbacks, they just mean that if they happen, the chain hopefully stops. Only thing worse than getting whacked by a chainsaw, is getting whacked by one with the chain still spinning. 

I can see how that could happen with a long bar buried in stump, re-position the saw and the top of the tip gets back into contact with solid wood, with enough force to throw the saw back out anyway.

Ian

[Al_Smith]

You can get kickback no matter what size the saw or what kind of chain you use  or weather it has a chain brake or not .

It the case of a stump most likely the thing fell or pinched on the top side of the bar and drove it back like a shot out of a cannon .The same thing can happen cutting a wedge on a big tree  or bucking a big log for that mtter

You just have to be careful and aware that the possiblity exists for kickback and plan accordingly .

[northwoods1]

Yes I think when you get in to larger saws with aggressive chain like that the kickback thing will always be something that can potentially happen and it can be severe. Cutting hardwoods it can really happen specially if you cut your rakers a little to far  I got it in the groin one time running cutting off a stump like that, I was kneeling on the ground and had got in the very bad habit of resting the rear handle of the saw on my upper thigh/groin area to support it and when a kickback finally happened it came back and drove in to me very hard to this day that injury bothers me some times. When your sawing you simply always have to be anticipating that kickback can and will happen.

[Al_Smith]

Once again I think we are stuck on terminoligy .Kickback or anti kick back chains or aggresiveness of the chain has nothing to do with pinching the top of the bar on essentually a down cut .In that situation the wood closes in on the portion of the chain which is running away from  the saw,not towards it .Action,reaction and it comes back on you .

All so called anti kick back chain will do is lessen the amount the thing can rise or come back if the tip portion gets caught but it doesn't totaly prevent it as some would suggest .

That term of kick back seems to be as misunderstood as the usage of the word "porting " .With that some seem to think that reworking a muffler is the same as "porting " a saw engine and I assure you it's not .Ah ,the English language,ain't it grand .

[Kevin]

He might have been under size on the bar with the tip still in the cut as well.

This would be my guess too.

[Rocky_J]

It isn't the fault of the bar size. I cut stumps bigger than my bar size all the time, in fact almost 100% of the time. If my bar reaches to the middle of the stump then I'm good to go. If I have a 7 foot stump and a 42" bar on my MS880 then I'm not going to go buy a 7 foot bar to make the cut. In fact last week I didn't even bother dragging out the 880 for a 7 foot stump, I managed just fine with the 395XP and 32" bar.

Avoiding kickback is about technique, not bar size. Anybody who says differently could probably stand to improve their saw skills.

(Take note of my signature line before getting all butthurt over my comments) 

[Kevin]

Yes it can be done, we've all done it with a shorter bar but with a longer bar you remove that hazard all together.
I don't care how good you are, when the bar nose is making contact with the wood bad things can happen, not all the time but the risk is present.

[Rocky_J]

Of course. But a risk is always present when walking across the street as well. A reasonable warning for those inexperienced at walking across the street, but rather redundant for those who walk across the street every day.

I'm going to go out on a limb here and say that anybody who is running an 084 should most likely have a good amount of experience working with smaller saws and fully understand all aspects of kickback. You don't take a teenager with his first driver's license and stick him in a Formula One race car or a semi truck. Saws over 100cc's should not be used by amateurs, period.

[northwoods1]

You can't get away from having the bar fully in a cut some times and cutting with the top nose of the bar to try and do that would be severely limiting the usefulness of the saw for sure. If its because of a pinch or the nose grabbing the wood to hard because type of chain is prone to it or filed incorrectly, and regardless of what term you call it by, the saw can be jerked or pushed around. When it comes back at you or does something unexpected it is kick back. The key and answer to this is to be able to control the saw at all times. People say don't cut over shoulder height. These people do not work in the woods professionally it isn't realistic. You can not cut without having having the top nose of the bar being in contact with the wood some times also or doing all manner of dangerous things with the saw, but the key is to be able to physically control the saw... if it is bigger than what you can handle taking in to consideration the dangerous results of it than a person shouldn't attempt it. Sometimes when you cutting a stump like that with the top of the bar you can have the saw fuly resting against the wood using the dogs to rotate the saw in the cut, that is safer as it eliminates the possibility or operator error of pushing it into rather than through the cut. Than just position so that when or if it does come out of the cut there is no harm done.

[John Mc]

It's not clear to me whether what happened here was what most people tend to think of for "kickback" -- that is, catching one or more teeth when cutting with the upper half of the nose of the bar, which throws the nose "up" (in relation to the plane of the bar) and back. Or was it the saw getting thrown out of the cut when the stump settled on to the upper straight portion of the bar. The latter could happen whether the nose was in the stump or not -- though I'd think this would tend to shove the handle/powerhead back into the operator, rather than the bar.

[Al_Smith]

I don't care how good you are, when the bar nose is making contact with the wood bad things can happen, not all the time but the risk is present.

That too but once again you don't have to catch the tip to get kick back .

Case in point ,by little bud Tom the tree guy nearly  lost a couple of fingers when an 066 caught the top of the bar and tossed him and saw from a big oak ,maybe a few years back .He had miss cut the wedge and went back in to trim the bottom loose without driving a wedge to hold it up .That 100 pound chunk of wood came down and out he came  saw on top .Saw won .Got in a hurry which will get you every time .