Can chainsaws be more safe?

[Mark Bolam]

Paul is 96 Mick.

[spudulike]

I have recently replaced two chain brake springs on two MS260s. Funny thing is ( not so funny) is that both came in because both machines had packed up.

I can deduct from this that both machines were being used with no working chain brake until they clapped out...both with impulse lines off if of interest.

I regularly have 200s and 201s in with their chain brake mechanisms stuffed full of chip to the point it is obvious they are becoming ineffectual.

These are all from pro commercial outfits....perhaps it is time saws had preventative maintenance or MOTs as the only time I see 90% of saws is when they don't run or are smashed.

BTW, I am not looking for more work as am semi retired now but reporting back on how it is out there!!

I agree much of the issues are with weekend warriors knowing nothing but the lack of maintenance in this industry is at odds with my past in the manufacturing industry.

[spuddog0507]

20 hours ago, Mark Bolam said:

Exactly Dog.

I’d love to see the stats of chainsaw injuries suffered by those who have had pro training and mentoring vs. DIY ****************wits.

 

 

This guy in question is supposed to be a fully trained arbourist but just watching him with a saw for ten minuets makes me think he is not, He was not shown or told to roll his saw pants up to his knees when using a saw when he did his CS 30/31 and any of the other tickets he claims to have,,,,

[Dendrologen]

I think there is merit in looking at the inertia brake on top handled saws. I read an article written by someone about his son years ago, who had cut into his neck using a top handled in a tree and died. The inertia brake didn't engage when the saw kicked back. I have tried to engage the inertia brake on a 201 when turned off by shaking the saw and it's impossible to get it to engage. This is how I test the inertia brake on a rear handled saw because I don't like dropping it down onto it's nose on a log, like my trainer showed me. I keep it all clean inside, the mech has a tendency to clog up. I can't recall a time I've had the 201 kickback and the chain brake engage, thinking about it and I've been doing it a good few years now. Kickback happens less with these saws because of the chain profile and you obviously want to avoid it when in a tree especially. I don't trust that the inertia brake would work every time if one of these saws kicked back. It's partly to do with how short the saw is and leverage. There's also apparently no legislation for how much it takes to engage this mechanism. Maybe a mechanical, rather than electrical fix, but worth looking into as a safety issue IMO. 

[Pete Mctree]

Properly sharpened chains would massively reduce accidents- a blunt chain radically changes how a saw is operated.

[Treewolf]

Ultimately you'll run into two well-known psychological phenomena which mean a "safe chainsaw" is an impossibility, the Pelzmann Effect of risk compensation (which says people become more careless when they perceive risk to be low, and conversely more careful when risks are greater, and possibly explains why more pros suffer Silky injuries than chainsaw injuries), and the Dunning-Kruger Effect, which says (essentially) that stupid people overestimate their abilities because they are too dim to recognise their limitations.

 

These two effects ensure that however safe you make any potentially-dangerous machine, tool, or task, there will always be people who damage themselves with it.

 

[Doug Tait]

1 hour ago, Dendrologen said:

I think there is merit in looking at the inertia brake on top handled saws. I read an article written by someone about his son years ago, who had cut into his neck using a top handled in a tree and died. The inertia brake didn't engage when the saw kicked back. I have tried to engage the inertia brake on a 201 when turned off by shaking the saw and it's impossible to get it to engage. This is how I test the inertia brake on a rear handled saw because I don't like dropping it down onto it's nose on a log, like my trainer showed me. I keep it all clean inside, the mech has a tendency to clog up. I can't recall a time I've had the 201 kickback and the chain brake engage, thinking about it and I've been doing it a good few years now. Kickback happens less with these saws because of the chain profile and you obviously want to avoid it when in a tree especially. I don't trust that the inertia brake would work every time if one of these saws kicked back. It's partly to do with how short the saw is and leverage. There's also apparently no legislation for how much it takes to engage this mechanism. Maybe a mechanical, rather than electrical fix, but worth looking into as a safety issue IMO. 

I remember that article too, it was a sobering read. I think it gave statistics including the time taken for the bar tip to travel through an arc and contact the body (milliseconds) being potentially quicker than the brain registers it happening. 

[Haironyourchest]

Let us consider the mechanics of the inertial chain break:

 

If we open it up (goggles!) we find that different makes/models have the assemblage constructed in different ways. Whether one way is better who knows, but they all follow the same principle - a spring keeps a trigger cam primed in the "open" position. A tiny bit of pressure on the plastic break handle, rotates this trigger cam to the closed position and allows the spring to "fire" pulling the break band tight around the clutch drum.

 

This action requires the whole mechanism to move freely, without undue friction. Build up of wood dust and oil can gum up the works. So it's essential to regularly clean out the mechanism and lube it with silicone spray. 

 

Also consider taping a weight to the top of the break handle, like a bit of lead flashing. This will increase the inertia and make it more likely to trigger in a kickback.

[Mark Bolam]

It’s easier just to learn how to avoid kickback in the first place.

[5thelement]

4 minutes ago, Mark Bolam said:

It’s easier just to learn how to avoid kickback in the first place.

And position yourself so if kickback does take place, it doesn’t hit any part of your body.