i cut a 42 inch diameter tree with a 18 inch bar two weeks ago. took me a whileOriginally Posted by ki0eh
ki0eh - I can't imagine doing that sized tree with a 14" bar. We didn't get to do too many springpoles. All the small trees we had were too dry and would break as we bent them over.
mudhead - Yeah, the FTA training saws have the safety chains on them. On the last tree it was just spitting out sawdust and was taking forever. The instructor finally pulled out his saw with the 28" bar and a full-skip chain. Sliced right through it. Now that's a saw. I sure wish I could justify the price of a nice Stihl.
I see you were using a STIHL saw, not too bad. My father runs a STIHL and I run a Husqvarna, both great saws but I like to poke fun at my dad sometimes by saying my saw is better.
My Husqvarna does run higher RPM's though
Falling a tree just where you want to is a skill that I have had alot of fun learning...
I am fuzzy on "safety chain," and the Stihl site describes full-skip as being used to mill lumber.
I will get one at the shop eventually, but it will be what the guy hands me. (humor- We like all the teeth/cleanouts.)
mud - The safety chain (at least the ones we had) have like an extra piece on the link in front of the cutting edge and depth gauge (raker). I don't know the mechanics of it but it makes it low kickback. The full-skip has fewer cutting teeth which results in less drag through the wood. There are two tie straps between each tooth. I don't know about milling lumber but I guess that would make sense as they seem to be much more efficient. Of course they also have a greater risk for kickback.
Walter - Several of the guys have Husqies and seem happy with them. I might get one myself if I can put a larger bar on it. Say buy a 18 and put a 20-24 on it if the power head will support it. I called Poulan about my 4218 and they said it's maxed out with the 18" bar. I'm signed up for the felling course in Dec. That's something I've always wanted to do. I can hardly wait.
It is a chain that has a raised metal strap between the teeth that reduces the chance of kickback of the saw by somewhat reducing the depth from the base of the tooth to the top of the tooth.
The safety chains do not usually do not lend themselves to bore cutting very well but they will do the job if the nose of the bar has a more tapered point. Like some smaller saws.
The saws that I buy usually come with a safety chain unless I ask for the older style. I like the older style for bore cutting and I think they cut faster too. It's a trade-off.
Sorry Jax you beat me to the post.
On the safety chain kickback geometry, I think the less depth that the teeth have, the less they can dig into a piece of wood then the less force the kickback will have.
For those unfamiliar with the Danger Zone.I am talking about the critical area on the nose of the bar from "noon to 3 oclock" if one is looking at the bar from left to right. With the tip of the bar being on the right. Three o Clock being the very tip of the bar. Noon being the beginning of the chain's decline around the nose. That is where kickbacks occur.
This year Walmart was selling a Poulan saw with a semi-skip chain on it but the powerhead was too small for the chain. It was brought to the training course by a trail maintainer and he had a lot of trouble with it both power wise and starting.
No worry walkin'. Your description was better. Now that I think about it I didn't compare the height of the safety strap to the raker. I'm surprised about the semi-skip chain. I thought they (stores) had to sell new saws with the safety chain and if you want something else you have to buy it after the fact.
http://www.youtube.com/watch?v=NB243WXwVcw
I had to look up bore cut.
I figure cutting firewood is quite different from trail work.
Notice the chips and the saw type. Yo Walter.
I'll have to watch that later.
We didn't do any bore cuts. I figure we'll cover that in the felling course next month.
I'll have to check out the video when I get home later, no YouTube at work...
Bore cuts look scary.
I've dipped a saw like that, but not as first choice.
It's not that bad really. Just push down with the bottom quarter of the nose. As you penetrate the wood slowly raise the back of the saw and push forward. It is good to have some instruction on this technique actually and to have a sharp chain without (generally) the extra straps.
It may not be necessary to use a bore cut when bucking downed trees.
One of the the ideas behind bore cutting is to prevent the trunk of the tree from splitting and coming backwards toward the sawyer as the tree falls. It also saves the tree from damage if it is to be used for saw logs.
It is important to leave a certain percentage of hinge wood determined by the diameter of the tree. That will usually steer the tree in the direction provided by the notch. Which, by the way, should be more than 90 degrees open.
Another idea was to get people to use the danger zone of the bar to their advantage.
Briefly, a man by the name of Soren Ericksson developed these methods because of the appalling amount of injuries to loggers back in the day.
Sorry for this long ramble.
Peter Jensen at my last training was showing off bucking with a bore cut to make a tongue and groove to keep a big log from rolling down on you if you have to work from the bad side. http://www.osha.gov/SLTC/etools/logg.../examples.html
I had Peter Jensen for one of my training courses too. Nice guy and an enjoyable day.
How does the fiber get severed between the up and down cuts and the bore cut? Is it just the weight of the tree? I couldn't tell from the pics.
Fine ramble.
I avoid situations like this. I have cut on the downhill side first, but gravity and pressure are things I am very leery about.
Right, You need to cut through all the strong planes of the fibers so you just have the weak plane holding it. The weaker the species and the bigger the size, the longer the "tongue" should be.
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