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Ch Ch Chain…

December 20th, 2011 2 comments
This entry is part 2 of 2 in the series Chainsaws

In my first chainsaw post I discussed saw sizes and components. No component is more important than the chain that does the work. And no aspect of a chainsaw is as controversial and creates more arguments among users than the type of chain you should use.

Chainsaw Chain Basics

A chainsaw chain consists of drive links, cutters, tie straps, guard links, and the rivets that hold them all together. Oregon has a great picture showing these parts at http://www.theoregonshop.com/userimages/ChainParts.jpg.

By Horst74 (Own work) (Public domain)

All the parts are also shown in the photo at left. The parts don’t matter to most users since most people don’t assemble their own chain. But understanding them helps when it comes to understanding chain sizes.

Chain Sizes

Saw chain size is defined by three parameters:

  1. Pitch, or the length of the links (distance between rivets).
  2. Gauge, or the thickness of the drive links.
  3. Length, or the number of drive links.

There’s a picture of this on the page at http://www.stihllibrary.com/pdfs/SawChainSelection.pdf from Stihl. Remember that chains are sized according to the bar they run on, not necessarily by the size of the powerhead, although larger powerheads tend to run larger bars, so there is some relation. In general, smaller saws with bars under 16″ run chain as small as 1/4″ pitch. Medium size saws with bars between 16″ and 20″ run .325″ or 3/8″ pitch chains. Larger saws with bars longer than 20″ may run .404″ pitch chain.

Information block stamped on guidebar.

Chain information stamped on my guidebar.

For example, my 18″ Rollomatic E bar on my Stihl MS 290 runs .325″ pitch chain, .063″ gauge, with 74 drive links. here is the information plate from the bar. I also have an older Rollomatic E bar that is the same 18″ length which I used to run on my old 032AV, which is actually a 3/8″ pitch, .050″ gauge, and takes a chain with 66 drive links.

Although it’s important to buy the correct size chain for your bar, most people don’t pay much attention to other parameters. Some people like to argue the merits of .325″ pitch chain vs. 3/8″ pitch, but most people don’t care. What people do care and argue about is the type of cutters on the chain.

Chain Cutter Types

The number one argument among chainsaw people is whether full-chisel or semi-chisel chain is better. What’s the difference? It has to do with how much of the cutter is sharpened and the geometry of the cutter on the chain itself. A simple explanation is that if you look at a full chisel chain end-on, the cutter looks like the number seven “7″. A semi-chisel chain looks like a question mark, “?”. There is also a difference in how much of a point is filed into the front profile of the cutter, with full chisel chain having a sharp point, while semi chisel is flatter.

Wikipedia says this:

Full chisel chain has a square cornered tooth, splitting wood fibers easily in the cut for fast, efficient cutting in clean softwood. Semi-chisel chain has a rounded working corner formed by a radius between the top and side plates. While slower than full chisel in softwood, it retains an acceptable cutting sharpness longer, making it the preferred choice for dirtier wood, hard or dry wood, frozen wood or stump work, all of which would rapidly degrade full chisel chain.

Chain types

Chain Types (from Bailey's)

Bailey’s, an excellent source for chainsaw parts and chain for all brands posts this picture describing chain types. (Note that what I call full chisel they call round chisel – same stuff.) For homeowners and non-professionals the choice is really between full or semi chisel. The other stuff, especially square chisel, is used only by pros and really dedicated amateurs.

The Argument

One of the best sites for chainsaw information on the Internet is Arboristsite.com. And they relish the debate over full or semi-chisel chain.

For example, see this thread from 2007. Or this thread from 2004. Or this thread from 2006. Or this thread from 2004. Or this recent thread from 2011. Get the picture?

Reading through all those threads the consensus opinion is that full-chisel chain cuts faster when sharp, but loses its edge quickly, especially in “dirty” wood. Semi-chisel chain cuts a little slower, but holds its edge much better. So which is better? For homeowners and occasional users it really doesn’t matter. You see, most of the argument happens between guys that cut wood for a living. Or at least serious amateurs who spend hours in the field on any given day. So to them, the speed that a chain cuts makes a difference in how much money they make. For me it doesn’t. I simply don’t cut that much wood.

And the definition of “dirty” certainly isn’t standard. Is dirty wood a log that has been skidded on the ground through a swamp and is caked in mud? Some people in those threads argue that trees which grow on the side of dirt roads count as dirty because of the microscopic sand embedded in the bark. The point is – the posters are technically right. In my experience full-chisel chain dulls quicker than semi-chisel. But since I don’t cut ten trees a day it doesn’t matter to me if it dulls and slows down much. I’ll spend a few more minutes with the file between tanks of gas if I have to – it gives my back a rest! So read the posts and make up your own mind. But realize that for occasional use, it probably won’t make much of a difference.

What do I Run?

Keep your chain out of the dirt. Here I am using a timberjack to lift a large trunk off the ground to prevent running my saw into the dirt.

Mostly full-chisel chain. Currently I have four loops of Stihl RSC (Rapid Super Comfort) full-chisel hanging in my tool shed. I also have two loops of Stihl RMC (Rapid Micro Comfort) semi-chisel hanging there. Most of the time I run the RSC full-chisel. Even in hardwood (I cut mostly oak and maple here in Massachusetts, with some white pine thrown in) and even in cold weather when the wood may be frozen. But I am very careful, and after years of experience am quite adept, at keeping the bar out of the dirt. Because it doesn’t matter whether you’re cutting hardwood or softwood and whether the wood is dirty. Nothing will kill your chain faster, whether full or semi-chisel, then running your bar into the dirt and rocks under a log!

Note that I mentioned using a file. Yes – you must sharpen your saw chain. No, taking it back to the hardware store doesn’t count. Sure, all chains need to be reground periodically, but a single chain is only going to last a couple of hours, even in clean wood, before it needs to be touched up. In this area the forum consensus is also right: semi-chisel chain will go longer between filings. If you have no intention of learning how to file a chain, you need to assume that you will go through three to six chains in a full day of work and plan on buying that many. So if you only want to to take them back to the store for sharpening, buy six or eight or ten loops to get you through a full weekend’s work.

So my recommendation comes down to this:

  • If you are careful with your cutting and keep your bar out of the dirt, full-chisel will work for most applications, if you’re willing to occasionally file and maintain the chain.
  • If you are new to using a saw and don’t want to file your own chains, run semi-chisel.
One important note: semi-chisel chain can be hard to find in typical stores. Even in some better dealers you might not find a full selection of semi-chisel. I don’t know why that is, but I have experienced it and read about it online.

Regular or Reduced Kickback Chain

In my previous post about guidebars I mentioned that manufacturers make both regular and reduced kickback bars. I said that there wasn’t a tremendous difference between them and I saw no reason not to run the reduced kickback versions. The same is definitely not true for chain, where there is a tremendous difference between regular and reduced kickback versions.

This is an argument that the guys on ArboristSite REALLY like to engage in. Look no farther than this 8 page thread from 2009. There is another good one from 2010 also. In their world, reduced kickback chain is called “safety chain” and all safety chain is shit. My experience tells me that the real world isn’t so cut and dried. I started cutting long before the ANSI B 175.1 chainsaw safety standard was introduced in 1985. So reduced kickback chain wasn’t readily available until I had already been cutting for close to ten years. And current reduced kickback chain has improved tremendously over the stuff that was originally available.

That said, it is generally accepted that modern reduced kickback chain cuts a little slower and less aggressively than regular chain. This varies considerably between manufacturers and even within a manufacturer’s line between chain types. Because I am familiar with Stihl, that’s what I’ll use for my comparison.

When I bought my MS290, it came from the dealer with a loop of Stihl RSC3 full-chisel reduced kickback chain (identified by a green master link). When I first started the saw and cut with it I thought it worked pretty well, though it didn’t “pull” into the cut in the way I was used to with my old saw. But it cut well enough. After a while I switched over to a loop of RSC full-chisel regular chain. And the saw instantly felt more like I was used to. It really grabbed and pulled into the cut. But this same aggressiveness is what can make the saw kick back if the operator isn’t careful.

So I’m not going to get deep into this argument. From my personal experience, modern reduced kickback chain works well. I had no real problems with the RSC3 chain that came on my saw, and I certainly have the loop sharpened and ready to go. If I ever loaned my saw to someone, this is the chain I would give them until I really trusted them. But I admit that I do use the yellow link regular RSC chain most of the time. With all the years I have behind the saw I feel I’m prepared for the increased kickback potential. Your situation may be different. On your first saw I would always recommend a modern reduced kickback chain. Read the threads I referenced above if you want to learn more.

Good luck and safe cutting.

Categories: Tools Tags: ,

A Chainsaw Primer

December 11th, 2011 1 comment
This entry is part 1 of 2 in the series Chainsaws
My old Stihl 032AV

R.I.P. - 1982 to 2011

A couple weeks ago, Mr. Murphy paid me a visit and I had to replace my beloved 29 year old Stihl 032AV chainsaw. Soon after I wrote about how awesome and reliable it was, a valve in the chain oil system cracked and the part wasn’t available for a saw that old. So I had to buy a new one.

What I realized during my research is that there is a lot of confusion about the basic components of a chainsaw and few places where someone can find comprehensive answers. There are some great sites with very comprehensive answers and where professionals share their experience with homeowners, but it would still help to have an grasp of the basics before wading into these arenas.

What gives me the right to talk about this? I consider myself an advanced amateur. I grew up in a time and a place where there were far fewer nanny state rules. I was given my first real gas powered chainsaw at 10 years old and, after watching my dad for a while was given the intensive safety training of, “Don’t kill yourself,” and turned loose on brush piles with a Homelite saw with a 12″ bar. Bu the time I was 13 I was given a new Stihl 032AV (pictured above) and turned loose on 75 acres of fields and woods to cut whatever the hell I wanted. As long as there were a few cords of firewood for winter, no one cared. I used to practice felling trees by driving sticks into the ground in a field where I wanted the tree to fall and trying to drive them into the ground by dropping the trunk on top of them. Since then I’ve felled hundreds of trees, cut many cords of firewood, and cleaned up after dozens of storms. For a summer I worked for the US Forest Service in the early 90′s and that’s where I actually learned about safety and technique. I didn’t get to run the saw, but I was on work crews with guys who really knew what they were doing. And I soaked in everything I could.

What I wear now.

Gone are the days of being an invincible kid with no safety gear at all. You will never catch me cutting now without my full compliment of chaps and forestry helmet (hard hat with built in face shield and ear protection).

So, based on that experience, here’s what you need to know.

Types of Chainsaws

Manufacturers usually divide their chainsaw lines into three categories. Known by various names, I will call them: Homeowner or Occasional Use saws; Medium Duty saws; and Professional or Heavy Duty saws. In general, as you move up from Homeowner to Professional saws you get larger sizes (both bar length and engine displacement), more power, and more advanced features (like high efficiency engines and anti-vibration features).

I am partial to Stihl chainsaws, for no reason other than I have always lived near quality Stihl dealers. So I’ll use their line as an example.

A middle of the pack Occasional Use saw might be the MS 211. Offering a 2.2 in3 engine that produces 2.3 horsepower, Stihl recommends guide bars in 12″, 14″, or 16″ length. Other than some new engine technology Stihl is introducing, there are no special features to this saw, though some Homeowner saws have “convenience” features like easy start systems. Saws in this class would typically be used for cutting small trees (up to maybe 16″ in diameter), large branches and pruning ornamental plants, and light cutting of firewood.

Old and new chainsaws.

Out with the old and in with the new. My new MS290 and my old 032AV

A Medium Use saw is the MS 290 (my most recent saw). The 290 has a 3.45 in3 engine making 3.8 horsepower (65% more than the MS211). Stihl recommends guidebars in 16″, 18″, and 20″ lengths. In addition to the basic features, medium range saws offer adjustable chain oil rates, anti-vibration systems (which help reduce fatigue when using the saw for hours at a time), and easy access maintenance features. Medium use saws might be used for felling trees up to 36″ in diameter, limbing large trees, and bucking (cutting into smaller lengths) trees for firewood.

A Professional saw is the Stihl MS460. With a 4.6 in3 engine making 6.0 horsepower (58% more than the MS290). For this saw, Stihl recommends guidebars in 18″, 20″, 22″, or 28″ lengths. Saws in this range get the latest features to make them light and powerful. This saw might be used for felling trees to 48″ in diameter and bucking large trees. The largest Professional saw in Stihl’s line, the MS880 Magnum can take a guidebar up to 59″, for felling trees 6, 7, 8, or even 10 feet in diameter.

What Size Saw Do You Need?

Because chainsaws tend to be tools for men, there is a perception that bigger is always better. That perception is commonly held by people who have watched too many episodes of Ax Men on TV and have never spent a day bent over cutting firewood with a 20 lb. chainsaw.

Chainsaws can be dangerous, and a bigger saw can let you get into dangerous situations faster than you might expect. So it is important to match the saw to the job you will actually be doing. For example – even when I fell a 30″ diameter tree, that whole process might take 120 seconds of actual cutting. But the next two hours will be spent limbing and bucking that tree into firewood. So as nice as an MS880 Magnum would be during the felling process, my back is much happier limbing with my MS290 for the next two hours because it weighs ten pounds less.

You need to realistically assess the size jobs you will really do. Will you really be felling three or four foot diameter trees? That can be difficult and dangerous work and it’s way too easy to drop a tree on your home or car if you don’t know what you’re doing. Want proof? See this video:

Or this one:

Or this one:

Remember – each of these guys thought they were smart enough to handle the job. Although lack of safety equipment, no felling wedges, or no notch and back cuts is usually a dead giveaway that someone doesn’t have a clue.

Here’s your first pro tip – the saw binding in your felling cut is nature’s way of telling you something is screwed up and the tree isn’t going the way you expect. This is why they invented the felling wedge.

Here’s your second pro tip – if you don’t know what a felling wedge is, stick with an Occasional Use or smaller Medium Duty saw.

If you want to know and see how they are used properly, this guy on YouTube gives a great lesson in cutting a tree that’s leaning in the wrong direction and safely directing it where he wants it using wedges. When you can do cuts like this, you’re ready for a large saw and larger trees.

Chainsaw Parts

To many people, this whole system is a “chainsaw.”

In fact, a chainsaw is made up of several components, and it is common to mix components from a variety of manufacturers. The basic anatomy of a chainsaw is:

  • The engine or powerhead. This consists of the engine and related controls, the oiling system, and related components.
  • The guidebar. This is the bar on the front of the powerhead around which the chain runs.
  • The cutting chain. Exactly what the name says. This is the chain that does the cutting.
Information block stamped on guidebar.

Information about the proper chain to use is on the guidebar, not the powerhead. Here's the block on my Stihl MS290.

On all but the cheapest Occasional Use saws, you can buy chain and guidebar systems from a different manufacturer than made the powerhead. For example, many Stihl chainsaw owners use guidebars and chain made by the Oregon company.
Here’s the important thing to know: the chain on a chainsaw must be matched to the guidebar, not to the powerhead model. And the drive sprocket must be matched to the chain as well. So there really is no answer to the question, “What chain do I run on a Stihl MS290?” The answer is, it depends on what bar you have. The picture on the right shows the information from my MS290. It tells me I should run a .325″ pitch chain, .063″ gauge, with 74 drive links on this 18″ bar.

Guidebar Types

In America, there are really only two guidebar manufacturers. Stihl and Oregon. Any brand of chainsaw other than Stihl uses Oregon manufactured bars, even if their own brand name is on it. And regardless of which manufacturer you use, there are two broad categories of guidebars, regular and reduced kickback.

Kickback is the rapid and unexpected movement of a chainsaw towards the operator caused when the chain on the top of the guidebar sticks in a cut or contacts something in a dangerous and unexpected way. If this happens at the tip of the bar, the movement of the saw and running chain is both back toward the operator and up towards the operator’s head. This is perhaps the most dangerous type of chainsaw accident and a very common occurrence. A good demonstration by a chainsaw instructor is in this video:

A common way for kickback to occur is during plunge cutting (when the tip of the guidebar is pushed straight into a cut, rather than a slicing cut made with the top or bottom of the guidebar). To lessen this, reduced kickback guidebars tend to be fatter in the middle and tapered towards their ends. Compare the Stihl Rollomatic E reduced kickback bar against the Duromatic E standard bar on this page for an example. Note that in the picture, the Rollomatic bars have a green dot at the end and the Duramatic bars have a yellow dot. Stihl uses this color coding system to designate bars and chain as reduced kickback (green dot) or regular (yellow dot). Oregon uses blue dots for reduced kickback and yellow for regular.

I have run reduced kickback bars on my saws for years and never missed my old straight bars once. In my mind, there really isn’t a decision to be made here. If you’re reading this you should be running a reduced kickback bar.

Chain

The next discussion is about chain types. But this discussion among chainsaw people is like asking someone what beer is the best or which football team to root for. There is a lot of fighting and arguing that takes place, so I intend to cover this in a second post. Keep an eye out.

Categories: Tools Tags: ,

Snowtober

October 30th, 2011 No comments

A few weeks ago I wrote about how country people and city people do things differently. This weekend’s weather reminded me once again how true those words are.

We had a rare early-season Nor’easter that dumped record-breaking snow on much of New England.

Really?! This is BEFORE Halloween?

The big problem is that this snow was really heavy and wet, and most of the trees still have their leaves, so the storm snapped off millions of tree branches. There are power outages everywhere … by this afternoon (Sunday, 10/30/2011) the Boston Globe was reporting that 669,000 customers were without power.

We lost power around 6:45 pm on Saturday. It stayed off … for 10 seconds because my whole-house backup generator came on. But my generator has been running for 22+ hours now. My local town news website reports today that we can expect to have no power for the next four days. I may need to beg my propane company for an emergency refill, but that shouldn’t be too much of a problem. As of this morning I calculated that I had at least 50+ hours of generator runtime with my current propane supply. If I am careful about my use I can probably get 72 hours out of it.

But none of this is what made me think about the country people / city people thing. What got me thinking about it was this:

Can you see it in there ... yup, that's my car.

This was what greeted me this morning. My car under the top of an oak tree. Upon closer inspection there didn’t appear to be any real damage. The glass was intact at least. But it was certainly under there.

Here’s a view from the backside:

It's certainly under there alright...

And based on the reactions of a couple of neighbors, I realized this was the perfect symbol of my country/city comparison. Because I realized that when presented with these circumstances…

City people call their insurance company and get the phone book to try and find a tree cutting service for an emergency call. Country people get their 19 year-old chainsaw and just cut their damn car out.

And that’s what I did …

About an hour's work.

Car Cut Out 2

Now I can open the door ...

And I owe it all to the fact that I am prepared and have the experience to run a chainsaw without killing myself. Above all I’d like to thank my Stihl 032 AVEQ, which is at least 19 years old.

Never failed me!

So which are you? A country person? Or useless …

Weather forecast by WP Wunderground & Denver Snow Service