Chainsaws?

[D_W]

Again not quite
The paddle on the chain brake lever in front of the top handle is really only there to enable deactivation of the chain brake. In a kickback scenario the brake will be activated eons before your hand comes into contact with the lever. Just pickup a saw and try to envisage how the mechanics work, or better still look at slow mo lab video showing how it works.
Top handle saws such as the 020 can be used with a grip that means you can’t activate the brake with your hand, but the brake will still work.....

https://en.wikipedia.org/wiki/Chainsaw_safety_features#Chain_brake
I think you're confusing the snap of an upward kick as the only thing to be concerned about vs a bound cut where a saw will push out of the cut backwards. quoted from the wikipedia summary.

In the case of a kickback event the operator's left hand may be violently dislodged from the handle and the top hand guard will be thrown onto his hand, forcing activation of the chainbrake.

I believe this is from someone at husqvarna because the next section of text talks about husqvarna's intertial chain brake. There are a lot of saws here in the states from around the time that chain brakes became mandatory on consumer saws that had only the hand activated type and not the inertial type. They were saws that didn't have a chain brake at all before one was added on.

 

[Kidneycutter]

Sounds like he's gotta pinched saw. Chain has a kink and won't move freely. New chain and check the bar is ok. I'd also check the chain catcher

 

[Phil Pascoe]

Sounds like people are speaking of different types of brakes.

 

[bansobaby]

https://en.wikipedia.org/wiki/Chainsaw_safety_features#Chain_brake
I think you're confusing the snap of an upward kick as the only thing to be concerned about vs a bound cut where a saw will push out of the cut backwards. quoted from the wikipedia summary.

In the case of a kickback event the operator's left hand may be violently dislodged from the handle and the top hand guard will be thrown onto his hand, forcing activation of the chainbrake.

I believe this is from someone at husqvarna because the next section of text talks about husqvarna's intertial chain brake. There are a lot of saws here in the states from around the time that chain brakes became mandatory on consumer saws that had only the hand activated type and not the inertial type. They were saws that didn't have a chain brake at all before one was added on.

That wikipedia article is at best misleading. It refers to " models also incorporate a link between the top handle and the chain brake trigger, applying the brake if the saw's bar is forced suddenly upwards. This is known as an "inertia" chainbrake and will allow activation of the chainbrake even if the operator's left hand is not removed from the handle. "
This inaccurate. The inertia trigger mechanism is a counterweight and spring system totally independent of any of the handles.

It goes on to say that when using a felling cut, i.e. holding the saw on its side that the hand is not in a position to trigger the chainbrake but it doesn't matter!!!!! Because any kickback is not in line with the body!!! Apart from the legs............

Generally, when people speak of operating the brake with the hand it's referring to the practice of setting the brake before moving around with the saw still running but not cutting. This is good practice and highly recommended, but does not represent the way the brake is designed to work in the instance of most kickback scenarios.

It is true that occasionally the brake could be activated by the users hand during "pushback", but usually pushback caused by the cut closing and pinching the chain will also pinch the bar to such an extent as to trap the saw as well. Also, anyone using the top of the bar should be trained or experienced enough to be aware of the potential and be prepared to counteract it.

I am fully aware that less than 30 years ago saws were produced that had no chain brake at all. I still have a couple (but don't use them often, if at all.)

It's also true that there are (or perhaps more accurately were) two types of brakes: the first from around the early seventies which was purely manually operated, and the "automatic", which was first seen around 10 years later, and is what we have now.

Sorry to bang on, but it's a subject that is still ignored, poorly taught and in some cases wilfully dismissed as OTT safety tosh.
I lost a good mate years ago to a saw that kicked back but had a broken non functioning chain brake. Yes, his fault for not checking it..........

 

[Phil Pascoe]

It goes on to say that when using a felling cut, i.e. holding the saw on its side that the hand is not in a position to trigger the chainbrake but it doesn't matter!!!!! Because any kickback is not in line with the body!!! Apart from the legs............

You must hold your saw in a very peculiar way when felling if it's anywhere near your legs.

 

[bansobaby]

You must hold your saw in a very peculiar way when felling if it's anywhere near your legs.

If you are cutting something standing vertical, and you are cutting it between zero and 3 ft from the ground it must by definition be near your legs, surely......
Unless you are standing on your head

 

[Stevekane]

In my very limited experiance with chainsaws a new chain will stretch very quickly,,its either that or it beds down but the result is the same and after just a few cuts you will need to retension it, maybe good quality saws are better engineered but with my cheap lidles variety Ive noticed that its worth only lightly nipping whatever clamping system is used on the bar and then putting some weight on the end of the bar to force it fully up before tightening, you might find that the chain becomes too tight or loose and you have to do this a couple of times to get the right degree of slack, if you dont the bar will get pushed up in use anyway and it will run tight or loose for a while. Ive had good results with the chain files and guides you can buy from ebay and also the cheap chains, and our lidles was clearing out the electric chainsaw Sharpeners just a week or two ago, might be worth checking your local shop if you fancied one of those, I also understand that its possible to use a Dremel to sharpen chains and I guess this would be much quicker than hand filing,,in fact I ought to find out about that.
Steve.

 

[Phil Pascoe]

If you are cutting something standing vertical, and you are cutting it between zero and 3 ft from the ground it must by definition be near your legs, surely......
Unless you are standing on your head

The saw isn't between you and the tree - if it kicked it would kick away from you. Or it would every way I've ever felled a tree.

 

[Noel]

https://en.wikipedia.org/wiki/Chainsaw_safety_features#Chain_brake
I think you're confusing the snap of an upward kick as the only thing to be concerned about vs a bound cut where a saw will push out of the cut backwards. quoted from the wikipedia summary.

In the case of a kickback event the operator's left hand may be violently dislodged from the handle and the top hand guard will be thrown onto his hand, forcing activation of the chainbrake.

I believe this is from someone at husqvarna because the next section of text talks about husqvarna's intertial chain brake. There are a lot of saws here in the states from around the time that chain brakes became mandatory on consumer saws that had only the hand activated type and not the inertial type. They were saws that didn't have a chain brake at all before one was added on.

Exactly. Safety can be compromised by not understanding basic manufacturer guidance and design.

As for legs being in the way when felling..........I've no idea how that can happen. As @Phil Pascoe mentions, the saw should not be between you and the tree. Really.

 

[bansobaby]

The saw isn't between you and the tree - if it kicked it would kick away from you. Or it would every way I've ever felled a tree.

I agree that you would do it like that every time ideally, but occasionally you have no choice (other than walking away, which is often the right call). If space is tight sometimes you are cutting with the bar in relatively close proximity to your body. Certainly when climbing.....

When putting in the gob cut it's not unusual to have your leg against the top of the powerhead. It provides stability of stance, but agreed, the bar still would not kick towards you. That is most likely in the most common cuts, bucking and limbing.

Also with a powerful saw, a kickback could spin the saw through a full revolution at least, so in theory you are never in a truly safe place....

It's all becoming a little bit detailed and down to semantics now........the right/wrong ways to use a chainsaw have been debated since about 5 minutes after they were invented.

I just wanted to point out that wikipedia, although a fantastic and useful source of information, is not gospel and is sometimes plain wrong.

Apologies for dragging the thread sideways somewhat.

 

[D_W]

Kickback takes a lot more forms than the type you guys are thinking of (the vertical type that the newer inertial brakes are designed for).

As time has gone up, saws go lower torque and higher chain speed, but a strong saw can to bind and send you backwards. you end up with a saw between your legs instead of snapping up at you (they can snap downward, too) when a saw is top bound in a cut and pushes you backwards and out.

When you're bucking something thick and it's about waist height, if the saw binds and pushes you out of the cut, you can end up with it on your lap.

One of the reasons that saws have the two part throttle now is due to that type of kickback - so you don't end up with a saw on your lap running.

The saw that ate my grandfather was a Deere (echo) 66SV. Not a really big saw, but bigger than most consumer saws. I have no idea if it pushed him out or if it bound and bounced out. He cut and split wood about 20 hours a week for years after he retired from farming Sooner or later with that much exposure, something will happen. If he'd taped the safety throttle at some point to stop from getting hand fatigue squeezing it, I wouldn't be surprised.

I dreamed of running chainsaws as a boy but my dad and grandfather weren't really the "teaching" type who would let a kid get involved in anything if it slowed the work at all - I remember seeing that saw (it had a weird look - a grille that covered all of one side) and I remember asking how big it was and my grandfather said it was 66cc and would take up to a 27" bar (the former isn't correct, but that was before the internet was around for everyone to disprove everything you say!).

He would've never been in position under a cut, though - not because of safety, but because you have no leverage to maneuver a saw. He was probably bucking something that laid over and was bound around waist height.

No clue what happened to my great uncle stanley. If grandpa and dad didn't really look out for keeping the kids entertained, stanley was good for driving up with a cooler of bottled coke, handing one to the adults and looking at all of the kids and closing the cooler.

 

[Phil Pascoe]

I remember seeing my uncle about 40 years or more ago using a compressed air saw with a three foot bar - he said afterwards he'd never been so scared in his life.

 

[D_W]

I remember seeing my uncle about 40 years or more ago using a compressed air saw with a three foot bar - he said afterwards he'd never been so scared in his life.

There are various older chainsaws that were sold over here to go along with industrial compressors or hydraulic systems on backhoes or maybe early skidloaders.

They are *mega* dangerous. Extremely high torque and low chain speed - a recipe for a human launcher. I don't know if a lower power and higher chainspeed version is still sold with skid steers here (skidsteers seem to have every attachment known to main available, and only at 14 times the cost of the original item...but it goes with the set!).

The early saws that caused the problems here that were gas powered were either geared or made with large displacement high powered motors that were timed to develop their horsepower at sort of a normal RPM. Chainsaws with low range torque are bad news.

The original chains here were often 1/2" pitch and some may have been larger - then demand (with more access to old growth wood) to try to turn those saws into large felling and bucking saws must've necessitated the gearing. Maybe they didn't have the snappy vertical kickback, but they can knock you off of your feet like a battering ram.

 

[ivan]

Stihl suggest the chain should be tensioned tight, but still possible to move it round the bar by hand with a firm pull (using a rag...) It's hard to imagine a new chain stretching so quickly from a few small cuts, let alone enough to come off the bar. Unless all was old, badly worn, loose, and under tensioned at the start.

We were taught to run 2 chains in turn on one sprocket, then all wear out more or less at once