Experienced a violent kickback

[fearofpavement]

Just to clarify, I have on a number of occasions had a saw jerk a bit and trip the chain brake. Sometimes the brake has gotten tripped and I wasn't even aware of it until attempting the next cut. The purpose of my post was to reaffirm how violent a kickback can be (even with a pretty small saw) and that it is such a fast event, there is no way that someone is going to dodge, duck or have any input on the reactive forces.

Kickback is of course something that needs to be avoided by good technique. IF/WHEN it does occur though, don't trick yourself into thinking you can "hold the saw", "move body parts" or in any way influence the outcome. ie, any actions and precautions need to be taken ahead of time.

 

[B Harrison]

The helmets work great when heavy weed eating too to keep sticks and rocks from hitting me tender face. Safety gear is hot this time of year, but posts like this reinforce the need. I am glad you made it home unharmed, as we all should remember, home is why we work. New week coming up soon everyone be safe and enjoy.

 

[lumberjackchef]

if you want a thrill that will leave a lasting impression, try a big saw walking out of a bound cut. That can make kickback seem trivial.

I have had this happen many times while blocking out carvings, doing plunge cuts, with a long bar,while on scaffolding, with a ported 066. Now that does make your rear pucker a bit. I also experience a fair amount of scary kickback while trying to do to much detail with my normal tipped short bars. It happens fast and gets a little to close to my face for comfort. I've only had one trip to the ER so far and that was my own stupidity. 12 staples above the left knee later and now I always remember to wear my chaps!:msp_biggrin:

 

[madmarksolomon]

Glad to hear you made it out ok. Had a 36in bar on a 066 hit me in the forehead once on a kick back thank god I was wearing a hard hat still another lessoned learned.

 

[CTYank]

them little bastids are the worst for kickback.

if you want a thrill that will leave a lasting impression, try a big saw walking out of a bound cut. That can make kickback seem trivial.

Isn't that just another type of kickback? Linear vice rotational?

Besides keeping your left elbow locked straight and gripping front handle with opposed-thumb grip, the best advice I ever heard:

Keep your pieces out of the plane of the chain.

Similar to: don't look the down barrel of a loaded gun.

 

[diggers_dad]

Great reminder!

Thanks for sharing!

rep sent!

7

+1

dd

 

[cobey]

them little bastids are the worst for kickback.

if you want a thrill that will leave a lasting impression, try a big saw walking out of a bound cut. That can make kickback seem trivial.

is this when the saw just rolls up out of the cut when you got the bar buried during bucking? had little saw do that several time using a little saw on a big tree... kinda scary!

 

[jus2fat]

them little bastids are the worst for kickback.

if you want a thrill that will leave a lasting impression, try a big saw walking out of a bound cut. That can make kickback seem trivial.

Yes..as with the dude above...I don't understand what you are referring to..??

Could you explain what this "walking out of a bound cut" means... are you talking about a pinched bar situation..??

J2F

 

[RandyMac]

Isn't that just another type of kickback? Linear vice rotational?

Besides keeping your left elbow locked straight and gripping front handle with opposed-thumb grip, the best advice I ever heard:

Keep your pieces out of the plane of the chain.

Similar to: don't look the down barrel of a loaded gun.

is this when the saw just rolls up out of the cut when you got the bar buried during bucking? had little saw do that several time using a little saw on a big tree... kinda scary!

Yes..as with the dude above...I don't understand what you are referring to..??

Could you explain what this "walking out of a bound cut" means... are you talking about a pinched bar situation..??

J2F

I guess I spend too much time with my peers and forget the limited experience range.

This phenomena is generally a long bar, high torque, big inch saw, in big wood thing. If the kerf starts to close and you miss the change in exhaust tone, the chain on the top of the bar will grab the wood and launch the whole works straight back, with considerable force and speed. This could be called linear kickback, however the cause and effect are different from bar tip contact.
While modern chainsaws can do this, the big vintage saws will continue to cut well after a new saw would stall out. Thus giving the old saw more energy to release when the kerf closes. The big gear-drives are even worse, they will keep going long after any direct-drive smoked it's clutch. The last of this breed delivered brutal power, you needed to pay strict attention or they came out of the cut like a torpedo. A wiener saw kicking back can hurt you, catching a big inch vintage chainsaw in the torso can kill you.
Some day I'll explain plunge cuts and how to buck without using wedges, after all, wedges are for falling.

 

[w8ye]

While bucking a spruce with a Dolmar 7900 and 24" bar, I experienced a linear kick back a couple years ago.

I had my left arm locked and it jolted through my body. Was like getting a 220v DC shock.

I felt it the rest of the day.

I looked the situation over trying to figure out what had happened to cause this? At the time I thought I had touched a higher log on the back side as the bar was sticking through about 4". But, after reading this . . . The chain probably pinched on the top side of the bar?

 

[ZeroJunk]

I have had the thigh of my right leg black and blue from bucking big wood and the kerf closing. Biggest reason is you have to keep some power on it to pull it out or it will get stuck and then you have some extra work to do. I know you can wallow out enough for the kerf to close above it but sometimes I get distracted. I keep my gonads out of the line of fire.

 

[jus2fat]

I guess I spend too much time with my peers and forget the limited experience range.

This phenomena is generally a long bar, high torque, big inch saw, in big wood thing. If the kerf starts to close and you miss the change in exhaust tone, the chain on the top of the bar will grab the wood and launch the whole works straight back, with considerable force and speed. This could be called linear kickback, however the cause and effect are different from bar tip contact.
While modern chainsaws can do this, the big vintage saws will continue to cut well after a new saw would stall out. Thus giving the old saw more energy to release when the kerf closes. The big gear-drives are even worse, they will keep going long after any direct-drive smoked it's clutch. The last of this breed delivered brutal power, you needed to pay strict attention or they came out of the cut like a torpedo. A wiener saw kicking back can hurt you, catching a big inch vintage chainsaw in the torso can kill you.
Some day I'll explain plunge cuts and how to buck without using wedges, after all, wedges are for falling.

Much thanks Randy for the explanation...I had never heard of it before...

I see now you mean top pinched bar/chain and a "straight-back"..."kick-back" rather than a vertical kick-back.

Pardon my ignorance..around here a 24/5 " bar is seldom seen...so had never heard of that phrase or event happening

Around here..it's mostly U.S. Forestry land and that means NO cutting..!!

Homeowners with fallen or blow-downs of big trees call the Pros..the only time you'll see a 60+..70+ cc saw..!!

J2F

 

[SawTroll]

While bucking a spruce with a Dolmar 7900 and 24" bar, I experienced a linear kick back a couple years ago.

I had my left arm locked and it jolted through my body. Was like getting a 220v DC shock.

I felt it the rest of the day.

I looked the situation over trying to figure out what had happened to cause this? At the time I thought I had touched a higher log on the back side as the bar was sticking through about 4". But, after reading this . . . The chain probably pinched on the top side of the bar?

Both are possible - but you always need to know where the tip of the bar is, and keep it from hitting something! :msp_wink:

Also your post illustrates how important it is to keep a firm grip on the saw with both hands. You were able to contain the "push back", but that isn't always the result.

 

[CJ1]

them little bastids are the worst for kickback.

if you want a thrill that will leave a lasting impression, try a big saw walking out of a bound cut. That can make kickback seem trivial.

I can remember quite a few bruises and 1 or 2 scars on my shins from that. I won't let anybody run any of my bigger saws because of this. Chaps help a little but it still hurts. Dropped a 30+" Ash last evening [ash borers] and was reminded about the top pinch. As far as regular kickback, usually just about everytime I cut I will trip the break at least once. CJ

 

[nmurph]

I guess I spend too much time with my peers and forget the limited experience range.

This phenomena is generally a long bar, high torque, big inch saw, in big wood thing. If the kerf starts to close and you miss the change in exhaust tone, the chain on the top of the bar will grab the wood and launch the whole works straight back, with considerable force and speed. This could be called linear kickback, however the cause and effect are different from bar tip contact.
While modern chainsaws can do this, the big vintage saws will continue to cut well after a new saw would stall out. Thus giving the old saw more energy to release when the kerf closes. The big gear-drives are even worse, they will keep going long after any direct-drive smoked it's clutch. The last of this breed delivered brutal power, you needed to pay strict attention or they came out of the cut like a torpedo. A wiener saw kicking back can hurt you, catching a big inch vintage chainsaw in the torso can kill you.
Some day I'll explain plunge cuts and how to buck without using wedges, after all, wedges are for falling.

Everytime I look at my 890 I think of your warnings about big inch gear drives.

 

[MCW]

This phenomena is generally a long bar, high torque, big inch saw, in big wood thing. If the kerf starts to close and you miss the change in exhaust tone, the chain on the top of the bar will grab the wood and launch the whole works straight back, with considerable force and speed. This could be called linear kickback, however the cause and effect are different from bar tip contact.

I know exactly what you mean Randy and had the same thing happen to me with my 3120 and 42" bar knocking off a large pine stump. The top of the chain bit and launched the saw at full noise directly back out, the handle caught me in the upper right thigh, lifted me clean of the ground, and threw me down an embankment into a creek bed (I'm 6'3" and at the time weighed 120kg). I laid there for a good 5 minutes in the foetal position sucking my thumb and calling for my mummy while the saw idled away happily above me. I got out of that one lightly but was lucky to bare children.
I had exactly the same thing happen with my ported 390XP but this time the handle caught me in the shin and this was stumping too. It hit me that hard through the chaps that for a few seconds I honestly thought it had broken my leg. If it was my 3120 I think it probably would have broken my leg. I still have a lump of scar tissue in my shin from a few years back and the bruise was pretty awesome to boot.
I can only imagine what an older all metal gear drive could do.

 

[JanThorCro]

Glad the OP is OK.

And I like the Kickback review and to here from others with loads of experience. I originally watched those kerfs from directly behind but NOT anymore...

Like Captain Jack Sparrow say's "Keep a weather eye".

 

[ShaneLogs]

Glad your ok!

 

[Doug Fir]

...If the kerf starts to close and you miss the change in exhaust tone, the chain on the top of the bar will grab the wood and launch the whole works straight back, with considerable force and speed. This could be called linear kickback, however the cause and effect are different from bar tip contact.
...A wiener saw kicking back can hurt you, catching a big inch vintage chainsaw in the torso can kill you. ...

Great post.

In many years of cutting firewood I have never experienced kickback caused by bar tip contact, but I have experienced "linear kickback" many times. As RandyMac notes, you get a warning as the exhaust note changes when the top of the bar starts to bind. If you don't react quickly the saw kicks straight back.

Fortunately I only use what RandyMac describes as "wiener saws"!! Otherwise things might have turned out much worse. :msp_w00t:

There's something to be said for "wienier saws". Wiener saws FTW! :msp_biggrin:

Doug

 

[alderman]

Had one seriously close call several years ago with a saw without a brake. Once was more than enough.