Question about saws and kickback

[johndeereg]

I have a Husqvarna 445 that came with an 18" bar. It seems really kickback resistant. I just upgraded to a 20" bar with the same pitch and all. The new bar is quite a bit taller than the old. The chain is advertised low-kickback like my old 18" ones. Is there any difference in kickback potential?

I am also looking at upgrading to a bit more powerful saw and saw that the pitch/guage changes with some of the larger saws. Are these saws harder to control? I am in pretty good shape and have cut over 50 cords of wood. I was taught all the basics by my father as far as what to watch out for. Just wondering if the larger saws (like a 555 etc) are much different in terms of how they handle and how dangerous they are.

 

[TheJollyLogger]

Great question, and always a topic that should be addressed, especially in the homeowners forum.
To answer your first question, of course a more powerful saw will generate a more powerful kickback... simple physics.

The good news is it doesn't matter, because if you use your saw properly and follow proper saw handling techniques, and just as important, proper wood handling techniques, you will never experience kickback.

Kickback occurs when the top 90° degrees of the bar tip encounters wood, or in rare instances in a bar becomes pinched and the power of the saw overwhelms the friction of the pinch.

Injuries from kickback always...always occur from positioning your body in the plane of the bar, i.e. positioning your body or head inline with the arc that the bar travels. No one ever shot themselves in the foot with a gun if the gun wasn't pointed at their foot... oh, and their finger was on the trigger before they were aimed at the target...

So, avoiding a kickback, and more importantly, avoiding a kickback injury...

1. Never put any part of your body, especially your noggin, in the plane of the saw. Yes, it can be a less comfortable body position, and yes, it can be more tiring... so what.

2. Avoid any circumstance that will put that crucial 90° arc of the tip of the bar from contacting wood, or the ground, which of should be avoided anyways for hopefully chain related reasons, lol. If you need to reposition the wood, then reposition the wood. Take a minute to make sure it's a safe cut, with no hidden branches or pieces that might catch the tip of the bar.

Honestly, that's really kind of it, follow those 2 rules and you should be fine...

 

[northmanlogging]

I have a Husqvarna 445 that came with an 18" bar. It seems really kickback resistant. I just upgraded to a 20" bar with the same pitch and all. The new bar is quite a bit taller than the old. The chain is advertised low-kickback like my old 18" ones. Is there any difference in kickback potential?

I am also looking at upgrading to a bit more powerful saw and saw that the pitch/guage changes with some of the larger saws. Are these saws harder to control? I am in pretty good shape and have cut over 50 cords of wood. I was taught all the basics by my father as far as what to watch out for. Just wondering if the larger saws (like a 555 etc) are much different in terms of how they handle and how dangerous they are.

I'm a start with any saw can kick back.
That said, smaller saws tend to have smaller nose radiuses which can "reduce" kick back, bigger saws run bigger chain and have bigger nose radiuses so there is more potential for kickback.
If yer real concerned then the "safety" low kickback chain will help, or a full comp is a next best. Full Skip chains kick back like a motha etc.
really though just avoid using the top 1/4 of the tip and you should be mostly ok.

 

[scut207]

I'm a start with any saw can kick back.
That said, smaller saws tend to have smaller nose radiuses which can "reduce" kick back, bigger saws run bigger chain and have bigger nose radiuses so there is more potential for kickback.
If yer real concerned then the "safety" low kickback chain will help, or a full comp is a next best. Full Skip chains kick back like a motha etc.
really though just avoid using the top 1/4 of the tip and you should be mostly ok.

you no doubt have loads more experience than I do, and according to the physics of it all I recognize you're 100% correct.

However in use, I feel the little lightweight saws are more prone to kick back as people don't hold onto em like a tigers tail. Im always attempting to be extremely cognizant of where the tip is, Ive never experienced sort of serious kick back on my MS440, but have on my little ms280 when there was a hidden branch while limbing or a pinch where I read the tension wrong. If I'm limbing with the 440 and hit a hidden limb in the pile it just doesn't rotate as bad.

Little lightweights have nothing to fight the rotation and I dont think people take as serious a 30cc vs a 70cc saw even though its every bit at dangerous.

I try to be safe as much as possible, but I have cut when I'm too tired and it too hot and have made a few mistakes, never once injured, but def powered the saw off and thought about it for an hour in the shade..

 

[KostasVolos]

A 30cc saw may not have much of inertia to overcome ,due to low mass ,in case of a kickback ,
but on the other hand usually a 30cc saw does not have the "juice" ( torque ) needed for a rapid and violent kickback .

Usually the 30cc homeowner class saws have low engine torque figures,as also
low chain velocities.

Those chainsaws are really easy to be jammed (almost instantly) from the fibers of protective chainsaw chaps .

Myself wanted to get more ...
"familiar" with the concept of kick back and had experimented a bit with forcing deliberately the chainsaw to kickback ( with my sweet precious self out of the kickback's arc ( trajectory) ,while wearing a full knight's body armor ( not really ,just chaps ,gloves,safety boots and my helmet ) .Experimented with a chainsaw of this particular class ,with narrow and wide tipped bars ,with low kickback chains ( green label ones ) and with standard ones ( yellow label ) .With dull and sharp chains .Tried pinching the top tip quarter,
forcing it against overhanging branches ,pushing it against logs and so on .
They do not have the juice to arc the 14" or 16 " bar beyond an angle of 40-45 degrees from the cutting plane .It's sudden ,but not viciously uncontrollable.
Keep both hands firmly on the chainsaw handles and the beast will be tamed .
Keep also the chain sharp as much as possible ,always run the saw at WOT when cutting ,keep an eye on the bar tip and stay out of the possible kickback trajectory at all times .Teach yourself to always keep an "offset" body stance with the chainsaw bar length axis .

Oh and last but not least...
The inertia activated chain brake system worked like a charm all the times .Thus ,try to keep it clean and operational.
Chainsaw used for satisfying my curiosity is considered to be one of the lightest and most powerful of the 30cc homeowner class -
that being a Stihl MS 180 .

Side note# 1 :30cc Top handle chainsaws are far more dangerous than rear handle ones when a kickback occurs

Side note #2 : Most chainsaw accidents are not kickback related.Most chainsaw injuries are
happening at the lower part of the body ,usually the left knee,as also at the top of the left hand .



One can notice most injuries occur in the left part of the body ,using a power tool situated at the very end of the right part of the body .
This is easily explainable by the wrong body stance used .
Body trunk and limbs must always be away from the imaginary arc ( both underside and upper-side of the bar ) of the bar trajectory in case of things going south.Most of the injuries occurred because operators were leaning over the running chainsaw or having the bar edge pointing at their left knee /foot while cutting with only a wooden ..."barrier" standing in between-with the latter actually being cut in half !!!
Hand injuries are easy to avoid by keeping all times the left hand on the front handle,right behind the chain brake's hand shield,while cutting.It's a two hand power tool after all.

Just my 2 cents.

 

[northmanlogging]

you no doubt have loads more experience than I do, and according to the physics of it all I recognize you're 100% correct.

However in use, I feel the little lightweight saws are more prone to kick back as people don't hold onto em like a tigers tail. Im always attempting to be extremely cognizant of where the tip is, Ive never experienced sort of serious kick back on my MS440, but have on my little ms280 when there was a hidden branch while limbing or a pinch where I read the tension wrong. If I'm limbing with the 440 and hit a hidden limb in the pile it just doesn't rotate as bad.

Little lightweights have nothing to fight the rotation and I dont think people take as serious a 30cc vs a 70cc saw even though its every bit at dangerous.

I try to be safe as much as possible, but I have cut when I'm too tired and it too hot and have made a few mistakes, never once injured, but def powered the saw off and thought about it for an hour in the shade..

meh, might be more about attitude, so i agree.

though when a big saw kicks, its not somthing you forget, that said, i one hand them all the time, worst kick backs ive had are from pinches while bucking, chuck the saw right into yer thigh... or slightly higher and much more sensitive...hard enough to bruse.

had them kick hard enough to contact ye ole tin hat... luckily the chain brake did its job

 

[Franny K]

I just upgraded to a 20" bar with the same pitch and all. The new bar is quite a bit taller than the old

The 18" one is probably a NK bar with a 10 tooth nose and the 20" one probably has a 12 tooth nose.

Just wondering if the larger saws (like a 555 etc) are much different in terms of how they handle and how dangerous they are.

With a change of the clutch drum you can run 7 tooth drive .325 on a 555, the 560 is an european model very similar that is set up that way when new, at least in some markets. I think the .325 chain in general is safer. The more flywheel inertia the harder a push back will be, that is when the top of the chain binds and the saw is forced towards the operator.

 

[ericm979]

More recently many bars have been made with smaller tip rollers, to reduce kick back. If your new bar has a larger roller at the tip, which would be true of a taller bar, it might be more likely to kick back.

At least in my experience, more powerful saws kick back harder. I don't know if it's the wider 3/8 chain or the stronger engine, or both.

 

[Billhook]

If someone is only an occasional user of a chainsaw and is worried about kickback I suggest one of these for home owner type work. I have an old Dolmar mains electric chainsaw which I bought in the 1970s with no cut out on the hand guard, a broad 20 inch blade and a powerful motor. All the ingredients of danger. So I bought one of these or a similar device which works around the home

This is my home setup for electric cut and split as I hate the noise of a gas engine and my arthritic wrists can’t do the pull starts anymore

 

[singinwoodwackr]

you no doubt have loads more experience than I do, and according to the physics of it all I recognize you're 100% correct.

However in use, I feel the little lightweight saws are more prone to kick back as people don't hold onto em like a tigers tail. Im always attempting to be extremely cognizant of where the tip is, Ive never experienced sort of serious kick back on my MS440, but have on my little ms280 when there was a hidden branch while limbing or a pinch where I read the tension wrong. If I'm limbing with the 440 and hit a hidden limb in the pile it just doesn't rotate as bad.

Little lightweights have nothing to fight the rotation and I dont think people take as serious a 30cc vs a 70cc saw even though its every bit at dangerous.

I try to be safe as much as possible, but I have cut when I'm too tired and it too hot and have made a few mistakes, never once injured, but def powered the saw off and thought about it for an hour in the shade..

Correct. Smaller saws can kick faster than larger saws. Same principal as guns…light vs heavy and recoil. Simple physics.
the trick is knowing what causes kickbacks…and avoid it. And, be prepared for it in those iffy situations by keeping yourself out of the line of the bar.
cutting 40 yrs, had some kickbacks…never had an issue.
stay safe, always be aware

 

[fields_mj]

I'm definitely in the group that will not one hand a saw. I've had all of my saws "kick" at one point or another, but I've never had one kick so hard that it came anywhere near my body. Most of the time the kicks were while I was initiating a plunge cut and I got too aggressive too soon. That said, I follow the recommendations above and I wear a helmet and chaps. I enjoy the work, but I don't enjoy stitches or loosing a lot of blood. Haven't tried dying yet. Its on my list of things to do, but its at the VERY bottom of the list and I'd like to keep it there for quite a while.

 

[user 122190]

I experience kickback several times during a firewood cutting outing. I estimate that 100% of the time it is when using the tip, typically after rolling the log and trying to enter the kerf with the saw at speed. Never has the force been strong enough that I was concerned. Happens with all saws, no matter the size.

 

[adedeluca]

A 30cc saw may not have much of inertia to overcome ,due to low mass ,in case of a kickback ,
but on the other hand usually a 30cc saw does not have the "juice" ( torque ) needed for a rapid and violent kickback .

Usually the 30cc homeowner class saws have low engine torque figures,as also
low chain velocities.

Those chainsaws are really easy to be jammed (almost instantly) from the fibers of protective chainsaw chaps .

Myself wanted to get more ...
"familiar" with the concept of kick back and had experimented a bit with forcing deliberately the chainsaw to kickback ( with my sweet precious self out of the kickback's arc ( trajectory) ,while wearing a full knight's body armor ( not really ,just chaps ,gloves,safety boots and my helmet ) .Experimented with a chainsaw of this particular class ,with narrow and wide tipped bars ,with low kickback chains ( green label ones ) and with standard ones ( yellow label ) .With dull and sharp chains .Tried pinching the top tip quarter,
forcing it against overhanging branches ,pushing it against logs and so on .
They do not have the juice to arc the 14" or 16 " bar beyond an angle of 40-45 degrees from the cutting plane .It's sudden ,but not viciously uncontrollable.
Keep both hands firmly on the chainsaw handles and the beast will be tamed .
Keep also the chain sharp as much as possible ,always run the saw at WOT when cutting ,keep an eye on the bar tip and stay out of the possible kickback trajectory at all times .Teach yourself to always keep an "offset" body stance with the chainsaw bar length axis .

Oh and last but not least...
The inertia activated chain brake system worked like a charm all the times .Thus ,try to keep it clean and operational.
Chainsaw used for satisfying my curiosity is considered to be one of the lightest and most powerful of the 30cc homeowner class -
that being a Stihl MS 180 .

Side note# 1 :30cc Top handle chainsaws are far more dangerous than rear handle ones when a kickback occurs

Side note #2 : Most chainsaw accidents are not kickback related.Most chainsaw injuries are
happening at the lower part of the body ,usually the left knee,as also at the top of the left hand .
View attachment 1092178

View attachment 1092180
One can notice most injuries occur in the left part of the body ,using a power tool situated at the very end of the right part of the body .
This is easily explainable by the wrong body stance used .
Body trunk and limbs must always be away from the imaginary arc ( both underside and upper-side of the bar ) of the bar trajectory in case of things going south.Most of the injuries occurred because operators were leaning over the running chainsaw or having the bar edge pointing at their left knee /foot while cutting with only a wooden ..."barrier" standing in between-with the latter actually being cut in half !!!
Hand injuries are easy to avoid by keeping all times the left hand on the front handle,right behind the chain brake's hand shield,while cutting.It's a two hand power tool after all.

Just my 2 cents.

Yes you are 100 per correct on everything

Years ago I did not have my left hand in my Mini Mac saw . I hit a knot in the maple and almost loses two left fingers Thank God they did a great job fixing my fingers

By the way my wedding ring prevented a complete lose of my fingers . It bounced off the ring

Please guys do not think chainsaws are not to be respected .
Mokev

 

[scut207]

I should have been more clear My 2cents:

As described by some of the more experienced, kick back on a larger saw definitely will generate much more force. However, when using a larger saw, body position and people having a more firm hold on it, and just generally where and how and by who its situationally being used will have fewer overall accidents associated. The length of the bar and the weight of the powerhead all work to counter the rotation.

Smaller cc more homeowner class (because of who is using them) along with more powerful pro-saws (especially top handles) will have higher frequency of kickback injury associated. This is either due to one handing them, or ignorance or someone with more money than experience being told their first saw shoudl be a MS261.

I dont think anyone has any data on which type(s) of saw kick back more frequently where no injury occurs. Its just anecdotal data.

Numbers, Statistics and confidence interval all pulled out of an area only a proctologist would be interested in.

 

[KostasVolos]

"Smaller cc more homeowner class (because of who is using them) along with more powerful pro-saws (especially top handles) will have higher frequency of kickback injury associated. This is either due to one handing them, or ignorance or someone with more money than experience being told their first saw shoudl be a MS261."

In the same way someone can claim that fatigue that mostly pros experience ,as also being in a hurry to meet time frames ,or too much self confidence built up and so on can be the main reasons behind the fact that more chainsaw accidents occur amongst the pro users.
No?

"Numbers, Statistics and confidence interval all pulled out of an area only a proctologist would be interested in."

A very bold statement ...
If you search you will discover .

A small example:
https://tcimag.tcia.org/tree-care/chain-saw-injuries-us-versus-them/

 

[scut207]

"Smaller cc more homeowner class (because of who is using them) along with more powerful pro-saws (especially top handles) will have higher frequency of kickback injury associated. This is either due to one handing them, or ignorance or someone with more money than experience being told their first saw shoudl be a MS261."

In the same way someone can claim that fatigue that mostly pros experience ,as also being in a hurry to meet time frames ,or too much self confidence built up and so on can be the main reasons behind the fact that more chainsaw accidents occur amongst the pro users.
No?



A small example:
https://tcimag.tcia.org/tree-care/chain-saw-injuries-us-versus-them/

I think we are largely in agreement. However my attempts at humor and self-degradation failed to transit through the language barrier.

my 2c = my two cents = slang for: my opinion = not claiming any sort of expertise

"I dont think anyone has any data on which type(s) of saw kick back more frequently where no injury occurs. Its just anecdotal data."

The above is without a doubt, true, no one reports kickbacks that did NOT result in injury, I cant imagine anyone aggregating data on a non-event.

"Numbers, Statistics and confidence interval all pulled out of an area only a proctologist would be interested in."

Meaning I pulled my opinion from my own arse. I was making no attempt to scientifically back it up, nor conduct any sort of cursory research. What I am saying is based on a hunch. I'm not in any way debating the validity of the data you posted.

What I mean is: kickbacks could occur with both small saws and large saws. Im sure a large saw at full throttle will violently kick back. But I personally havent had it happen to me with my MS440 nor the times ive run my 1130G or the 076Super... sample size me = 1.

My personal opinion based on how I work with a chainsaw (properly described as rarely, a novice and a hobby more than a requirement) is that the only sort of kick back I've ever had that made me stop and consider how it occurred (because it happened in an unexpected manner) was while using as smaller cc saw (an 015 top handle and my delimber bucking saw MS280)

Usually delimbing the main trunk and it catches some branch that I didnt see or bucking by misreading the tension.

I dont use my 70cc saw for bucking(unless its a really large diameter) or delimbing for 2 reasons, my MS440 has a what I view as a weak oiler(not uncommon for the model) and I dont want to burn up my bar, and its heavy compared to my MS280 so I am far less likely to use the larger saw in the 2 scenarios where most homeowners(me) and groundsman would experience kickback.

Most accidents may occur by pro's but I dont think the data indicates pro's are less safe. Pro's are interacting with dangerous equipment every day in more challenging environments under pressure to do it in a timely manner, therefore a larger number of them show up to the emergency room, which is not to be confused with more likely to show up at the emergency room per use.

There is no way to quantify chainsaw use by home owner (frequency) or per home owner (population of owners) that did not result in injury (non-events).
There is a way to quantify it with pro's based on time sheets and roles, but it would be a difficult task.