saw chain

[Toparboring]

Re: Anti-kickback

The only thing that I can say to this is that I have witnessed a kickback and luckly it was not fatall. Alot of meat in the upper part of his arm is was gone. He has a nasty scar from it and all that he and I remember was a flash and holy f%ck what just happened. As I was taught to take your hand make that looser sign put it over the end of your bar having the upper 90 degrees showing. If that hits something just right yes you will loose it,and hopfully not your life.

 

[Avery]

Raised Bumper

Glens,

The second photo portrays my current chain. I understand the 'dangerous' 90 degrees of the tip of the bar, and also understand why a larger tip will kick faster than a smaller one (seems simple, to me). As far as experience, I pointed out that I'm a homeowner, but I keep my wits about me and have a fair bit of time logged with my saw.

I may try the full-on (bumperless) chain, but still value everyone's caveats and recommendations to stay with the reduced-kickback variety of chain. I've got nothing to prove.

Thanks for all of the advice.

 

[Jay]

Re: Raised Bumper

Sorry to hear about any injury. The point I was trying to make is that kickback is a predictable mechanical response to the moving chain coming in contact with something at the upper bar end, or along those lines, and I don't associate kickback with injury necessarilly, although there is certainly the potential for that as cudg explains. It comes down to where you are in relation to the bar coming back, and how far the bar is allowed to move back against the strength being used to support the saw. To my mind the evil is not kickback, the evil is not being prepared for it by not holding the saw in a sufficiently protective manner if it does occur. Accidents can occur in a split second, even in the best of circumstances when using a chainsaw. Awareness of what you are doing, and being prepared for the possible consequences can't be over emphasized in my opinion. My experience tells me that this is far more important than any current day available devices that to some degree may reduce the hazards. "Safety" or low kickback chains are a product of someone else's intelligence. I think that using your own intelligence takes priority in the broader perspective, both in the here and now when using the saw, and when considering if the current hazard reducing devices are applicable to the way you want to work.

 

[glens]

Re: Raised Bumper

I wouldn't normally equate a "weekend warrior" with a "homeowner". The latter would only use a chainsaw on the rarest occasion whereas the former would use one on a fairly regular basis, though not as part of a main profession (a category I'm currently much closer to than many here).

So long as you're not using the most "aggressive" form of anti-kickback you might not notice any real change in cutting speed by stepping to the least.

One thing we haven't discussed and which might well be more worth your while to consider is whether you're using a semi-chisel chain or a chisel chain at this time. All things being equal the chisel chain will typically cut 15% faster than the semi-chisel when they're sharp. The semi-chisel will, however, also typically stay at its level of performance much longer between sharpenings and can be a little less "grabby" in the mean time.

Another thing we haven't discussed is the most effective means of anti-kickback; the bolt-on nose guard

 

[Avery]

Re: Raised Bumper

Glens,

I guess I thought that a weekend warrior was the same as a homeowner. I'd say that I fall somewhere in between, since I use my saw a good bit but have never done any kind of cutting for money.

I think my chain is semi-chisel; I use a round file to sharpen it and it throws rather sawdusty chips, as opposed to big, individual ones.

As for the nose-guard, it's not for me. I do a bit of rough carving (attached photos) and like being able to manipulate the nose of the bar.

 

[caryr]

Re: Raised Bumper

[ QUOTE ]
I think my chain is semi-chisel; I use a round file to sharpen it and it throws rather sawdusty chips, as opposed to big, individual ones.

[/ QUOTE ]
Your depth gauges may be a bit too high.

Cary

 

[glens]

Re: Raised Bumper

What Cary said is a good possibility. The uniformity/quality of your filing job may also be a factor. I'm pretty sure there are historical threads here covering filing techniques.

You can round or square file chisel-tooth chain, semi-chisel is round file only. I haven't yet experimented with it, though do still intend to, but I hear that square filed chisel chain is as much again faster than round filed chisel as the round filed chisel is than semi-chisel.

 

[Toparboring]

Re: Raised Bumper

We had a training course for part of the day Sat. during which I spoke of this post( relating to the kick back part ) and asked about the chians out there. The guy giving it was just talking with about the low risk chains and basically said that that chain is like the reasurance to the buyer that you will have less of a chance of kick back,and just like the nose guards. His main deal with us was to pass on the most important thing is to make sure that you have a [what???] good grip, proper stance ,and watch where you put the nose of the saw. We took him some saws that we use and he tested them with us on the inertia braking systems, and as before just a safety. As with sharping the chain flat or round files will sharpen the cutters but lower the depth gauges need lowering too, warning though do this carefully too much and you could run into problems.

 

[Mark Chisholm]

Re: Raised Bumper

Reduced kickback chain will definitely have slower cutting times than regular chain. If you are cutting heavy all day (like Jeff in the woods) it will have a pretty big impact on your day. But, if you are just using it here and there I would say you won't notice the difference much.

One thing that I believe is that the larger nose of a bar may kickback stronger but it should happen a little less frequently than smaller tips. I believe this to be true due to the fact that a tighter turn will reveal a lagrer "bite" for the tooth when trying to make the turn. The chain is designed to work on a flat cutting plane and not when tilted. Anyone disagree with this?

 

[glens]

Re: Raised Bumper

Larger "bite" yes, but less duration of time doing it.

The drive-link bumper will reduce the tip-bite just a tad; the side-strap bumper reduces it considerably, making swinging the tip through a section wider than the bar is long (pivoting on the bumper spikes) nigh unto impossible.

The couple of Stihl RM2 chains I've ended up with have been modified to work much better by snapping the rear bumper tips off with pliers. I took a triangular file and scored one side, then took a pair of slip-joint pliers and snapped along that line. It took a few minutes per chain (one 25" and one 20") but I've already made that time back while using the chains in the nasty stuff I saved them for.

Definitely give a side-strap-bumper chain on a small-radius-tip bar to someone who only gets maybe a couple of hours per year on a saw.

I'd put a drive-link-bumper chain with a small-radius-tip bar on a saw given to an employee working cleanup.

For myself I like to go whole hog but my saws are typically run only by me 95% of the time.