Xmas Break & The New Year Ahead...

I'd like to take the chance to thank everyone who reads this blog and also to those who have been involved in some way, shape or form. If you are celebrating the Christmas period, then I hope you have an enjoyable time and if you're not, then all these festivities must be driving you mad! Either way, have fun over the next couple of weeks. We'll be back in the new year, looking to continue the DriveLink site with more help and advice on chainsaw related bits and bobs; find out more after the jump...
Originally I had thought that this site would be giving chainsaw maintenance and crosscutting a once over, and then maybe move on to felling. After roughly 8 months we haven't really got on to cross-cutting, which either means that I'm really slow at getting to the point, or someone out there is liking the information being put out - who is it anyway? Is it you?

The majority of readers are from the U.S. & U.K., but I notice that we've also had visits from Croatia, China, South Korea, New Zealand, Finland, South Africa, and on goes the list.

So, next year, we need to finish off the audio version of the assessment schedule, but for the next bit (essentially NPTC CS30.2 on-site preparation and crosscutting), I may take a slightly different tack by producing proper little podcast shows that you can download. Each show will deal with several bits from the assessment schedule and [hopefully] be a little lesson in it's own right. From there, we can move on to crosscutting and so on.

I hope you'll stick with us in the new year, for more great content. Until then "Happy Xmas & New Year!", thanks for reading, commenting and thanks to Makita and Oregon in particular.

Welcome to TreeStuff

I'd like to take the opportnity to welcome Luke at TreeStuff to the hallowed corridors of DriveLink HQ; if you're in the U.S. and a chainsaw user on the ground, dangling from a rope or a mobile elevated work platform, TreeStuff probably stocks something of interest to you. In fact, even if you're not in the U.S., they probably have something that'll pique your interest. Find out more after the jump...

Luke, at TreeStuff runs an internet based store (but has a real bricks and mortar store too) and blog. I'll let Luke explain in his own words...

TreeStuff.com is an online arborist supply retailer that sells its products in North America as well as globally. We are dedicated to selling the equipment that professional arborists need to get the job done right. Most importantly our stuff costs less. We opened in 2006 with the plans to use a different business model. We don't print a catalog, but instead are trying to market our products to a new generation of computer savvy arborists. We also have physical location called Metro Arborist Supplies in Indianapolis, Indiana where arborists can see and try out the equipment. In our store we sell and service Stihl and Husqvarna chain saws.

Not much to add to that, other than 'take a look'!

CS30.1.18: Fuel / Oil Filters

Finally, the last bit of your maintenance assessment - maintaining the fuel and oil filters. Although it's not the end of the test, as you'll still have to get through the crosscutting bit yet! Anyhow, back to the filters, this bit is easy - to find out how easy click on Read More...

Well, for starters this is another one of those 'demonstrate knowledge of' activities, and that means just answering a question about it; you're not expected to actually do it.

Do what you may ask? As there is no need to remove the fuel, or oil, filter, you'll be expected to explain how to set about replacing them. This essentially comes down to undoing the fuel / oil tank filler cap, using a bit of bent wire to hook the filter out, removing / replacing it and dropping it back in (you might want to mention about draining the tank out first too). Listen below to the assessment activity for this last section of the maintenance assessment.

CS30.1.17: Service The Recoil Starter

If it hasn't happened to you yet, you can be sure it will do at some point in your 'chainsawing career'. That moment when you pull the starter handle and it just keeps on coming. The cord has snapped and you are going to have to replace it; and so it is with your assessment. Find out more after the jump...

Part of the assessment is to simulate the replacement of a starter cord; fortunately you don't need to put a new length of cord in, but you will need to retension the spring and check it's OK. You will also need to tell the assessor where it's most likely to break (essentially at either end). To view the article about recoil starters, check out Recoil Starters, or listen to the relevant bit of the assessment schedule.

CS30.1.16: Service The Spark Plug

Whilst you could be asked about cleaning the electrodes, pointing out erosion, checking plug types and testing the electrode gap with feeler gauges, in reality the assessment is much easier. So, to find out more about this section, click on Read More...
You'll need to be able to give the assessor an idea of the state of engine tune based on the colour of deposits on the electrodes.

You can find out more about spark plugs here, or click on the audio broadcast below to hear what the assessment schedule says.

CS30.1.15: Reassemble And Tension Chain

This bit of the assessment is about sticking the bar and chain back on to the saw and then sorting out the tension. Now, there's an emotive issue if ever there was; chain tension. It's something that here at DriveLink HQ we've covered a little bit before, so find out more by clicking on the Read More link...

As well as being able to listen to what the assessment schedule says about reassembling and tensioning the chain at the end, here's a couple of links that you might find useful, related to chain tension: Chain Tension, Too Hot To Handle and Creating Tension In A Video.

CS30.1.14: Sprocket Types And Replacement

Sprockets. Types, replacement ratios and how to change them. That pretty much sums up what you'll be expected to tell the assessor in section 30.1.14. Once again, you'll only need to "demonstrate knowledge" of this information, and that means answering a couple of questions. Find out a bit more after the jump...

There's only two types of sprocket that you need to remember ("spur" and "rim & spline") and a replacement ratio of 1 sprocket every 2-3 chains. The bit about replacing the drive sprocket only refers to the machine that you'll have in front of you - so for those of you with a Stihl it really couldn't be easier.

With a Stihl saw, you'll have an inboard clutch and it's easy to see what needs to be done just by looking at it. You might find it a bit more difficult with a chainsaw that uses an outboard clutch, but listen in to what the assessment schedule has to say about it...

CS30.1.13: Maintain The Chain Brake

The chain brake is so important, but for your assessment it really couldn't be easier, as all you need to do is show that you know what should be done if you find that the brake on your machine is worn or broken. Click on 'Read more' to find out what the assessor wants to hear...

This has got to be one of the easiest questions of the whole assessment; forget about having to actually deal with chain brake springs and brake bands, worrying about whether you have the chain brake in teh side plate housing or integral to the power unit. Nope, all you need to say is that in the event that you find something not quite right about the chain brake, you'd 'replace the unit with a new one."

That's it! To find out exactly what the assessment schedule has to say, listen by clicking on the audio link below...

CS30.1.12: Check And Clean Power Unit

The next section of the assessment is a quick clean and check over of the main power unit. Cleaning the saw will help with maintenance anyway and so it's a good idea to give it a quick once over with a brush or (even better) an airline to get rid of that sawdust / chain oil mix. Find out more after the jump...

Whilst your cleaning every nook and cranny of the chainsaw engine housing with a toothbrush (please don't use your usual toothbrush for this - I'd recommend you keep one by specially for this purpose), take the opportunity to ensure that the engine covers are in one piece, that any missing nuts / bolts are noted and then replaced. Chainsaws have a fairly hard life, and you may well be relying on yours for your income so it pays to look after it. Follow the audio link below to hear what the assessment schedule has to say about it.

CS30.1.11: Air Filter Maintenance

This little bit of the assessment schedule is pretty simple and shouldn't cause anyone too many problems; you just need to tell the assessor how to clean the air filter and tell them what it's function in life is. Find out more after the jump...

So, it's no big deal - explaining the function of the air filter; the clue is in the name, it's just there to prevent debris from entering the carburettor / engine, i.e. to filter the air.

The assessor will also want to know suitable ways of cleaning the filter both in the field and in the workshop. For more information either listen to the audio podcast, or visit Air Filters on DriveLink.

CS30.1.10: Maintain The Guide Bar

For this section, CS30.1.09, you'll be expected to actually maintain the guide bar of the saw you are using and answer a couple of questions on why the guide bar should be maintained. Find out more after the jump...

As mentioned, you'll be expected to comment on the state of your guide bar and carry out any maintenance that needs doing to it. That means looking over the bar for signs of damage or blueing (where it has overheated), as well as checking for signs of burring on the rails and filing these off if present.

Listen to the audio for information on the criteria for this part of the assessment.

For more information on guide bar maintenance...

CS30.1.09: Incorrect Chain Tension

Section CS30.1.09 covers the activities required for incorrect chain tension; for this bit of the assessment you just need to show that you have an understanding of the effects when a chain is either too loose or too tight. Find out more after the jump...

If you want some more information on chain tension, take a look back at these previous posts before listening to the audio:

The following audio lists the activities and relevant criteria for CS30.1.09:

CS30.1.08: Sharpening The Chain

This section, CS30.1.08, is one of those potential stumbling blocks, as being able to sharpen the chain properly can be quite a lengthy process when you first start doing it. Accuracy is important, as is removing all previous damage.

CS30.1.08 consists of both practical tasks and questions, so it's worth making sure that you're happy with it. Find out more after the jump...

It should be really easy - just grab a file of the right size and use it at the right angle across the chain cutters; sort the depth gauges out and away you go. Sounds simple, but in practice it taxes a lot of people and even within the industry there's a fair amount of debate as to why people can't seem to sharpen their chains properly!

Along with having to be happy about your chain sharpening, you'll also need to answer a couple of questions about sharpening and maintaining the chain. Make sure you're OK with the effects of incorrect depth gauges, wrong angles and different cutter lengths. For the exact lowdown on the actual activities and criteria that go with section, listen to the audio...

CS30.1.07: Replacing The Chain

CS30.1.07 deals with the information needed to select a replacement chain for a given saw. One of the common (and valid) answers when asked 'How do you ensure you get the right chain?", is to provide the guide bar length. This is not necessarily the best way, find out more after the jump...

The problem with chain length is that it is not just specific to the guide bar length; the make of chainsaw will also have a bearing.

This means that if you ask for a chain to fit an 18" guide bar, you might get the right length, or you might not. An 18" bar on a Stihl chainsaw will likely need a different length chain to the 18" bar fitted to Husqvarna, and that's where the problem starts. Anyway, listen to the assessment activity and relevant criteria for this section...

CS30.1.06: Chain Components

CS30.1.06 covers chain components and their function. The criteria shown for this activity does not actually supply all the information needed to answer the questions you're likely to get. So what's missing? Find out more after the jump...

Although not mentioned in the assessment schedule, you will need to demonstrate knowledge that you know the different types of cutter profile, their uses and (dis)advantages - on top that asked for in the criteria. Let's start with the criteria first...

For more information on the chain components, check out this previous post: Chain Components.

CS30.1.05: Chainsaw Safety Features

CS30.1.05 covers the safety features of the chainsaw; you'll need to identify and provide a short explanation of those safety features. There are ten listed features and a number of optional extras that could be fitted, but you're really only interested in those main features. Find out more after the jump...

So, optional 'safety' features such as heated handles, easy-start systems or manual oilers can be forgotten about for the purposes of the assessment. For the full list of the criteria, listen to the audio...

CS30.1.04: Advantages Of A Workshop

CS30.1.04 asks you to demonstrate your knowledge of the advantages of carrying out chainsaw maintenance in a workshop. Find out more after the jump...

This is a pretty simple question, and you should be able to get this one without any other input - with better heating and lighting in a workshop, it's a more comfortable environment to be in.

But, more than that, you've probably got better access to tools and spares in your workshop than you would have in the field. Access to a vice means that you can hold the saw securely whilst you sharpen it, making sharpening more accurate. Anyway, here's the audio...

CS30.1.03: Emergency Planning

CS30.1.03 covers emergency planning details. This is a very important part when you're out working, and especially on a new site; knowing what to do, who to call and where to go in the event of an accident could mean the difference between life and death. When you've got a seriously injureed casualty laying on the ground, it's no time to start looking up in the A-Z Guide to find out where the nearest hospital is. Find out more after the jump...

Emergency planning then is critical, and just jotting down a few pieces of information can make all the difference in an emergency situation - but as well as the items listed in the assessment schedule, make sure that everyone knows where the first aid kit actually is, where the keys to vehicles / gates are and that the vehicle you may have to use is not blocked in and is facing the right way - reversing the van with a trailer / chipper attached to it in an emergency is not easy, so face it the right way round as soon as you get on site.

CS30.1.02: Risk Assessments

CS30.1.02 covers risk assessments, and you will be asked about what goes in to making a risk assessment and the areas that it should cover. Find out more after the jump...

You will not be expected to create, or complete, a risk assessment form; but you will be expected to demonstrate your knowledge of risk assessments, mentioning that they should be relevant to the...

  • Site

  • Task

  • Machine

CS30.1.01: PPE

The assessment is broken up in to two main parts - the maintenance aspects are covered in Part 1, and crosscutting / site preparation is covered in Part 2.

Starting at the beginning then, we'll go through the 18 activities included in Part 1. Find out more after the jump...

Part 1 (CS30.1) starts with you 'observing safety precautions and wearing appropriate PPE'. Remember this just refers to the maintenance aspects, rather than actually using a saw, so things like wearing gloves when handling a chain are covered here.

Introducing The Activities

The main bulk of the assessment schedule is broken down in to a whole heap of assessment activities and their relevant criteria; against which you will be assessed. Find out more after the jump...

There are 18 activities for part 1 of the assessment and a further 17 for part 2. Sounds kinda daunting put like that, but in reality, due to the split of practical tasks and questions, it's not that bad.

There's no writing involved in the assessment, so there's no need to worry if your writing looks like a drunk spider crawling over a page, or your spolling is bid spelling is bad. It's just not an issue.

The remaining audio sections, as we work through this series, just list the assessment activities and criteria as they appear in the schedule itself. I've made a separate audio recording for each activity so that you can just refer back to the one or two where you might be weaker - rather than sit through the entire lot.

If all goes according to plan, when it's all over, I'll try making the whole lot easily accessible from the front page of this site. And so, to get the ball rolling:

CS30 Assessment Schedule: 'Small Print'

As well as listing what you are expected to achieve in the assessment, there's also the obligatory small print, and you might just be interested in one particular snippet. Find out more after the jump...

The five recordings below cover the general introduction to the schedule, safe practices, the complaints and appeal process, objectives (learning outcomes) and assessment / site requirements. The bit you may be really interested in appears in the safe practice bit - but more of that when we come to it..

Introduction to the assessment schedule:

The safe practice section from the assessment schedule lists what might be an important point, and one that might just put your mind at rest for the assessment... item 13 tells you that you can refer to the chainsaw operators manual and/or appropriate training publications.

If, for some reason, you are not happy with the assessment, NPTC do have a formal procedure for dealing with complaints and appeals. This information is shown in the schedule; or you can listen to it here...

The learning outcomes, or objectives, of the assessment (and therefore also of any training you receive to help you achieve success in your CS30 assessment) are listed in this next recording.

Finally, the assessment and site requirements are also listed in the 'small' print of the schedule, before we get to the real nitty-gritty of the assessment activities and criteria.

In the next post we'll start our journey through these assessment activities and criteria, taking a quick look at each one as we go.

CS30 Assessment Schedule: Welcome!

So here's the deal - I recently had a student that was unable to read the assessment schedule before their CS30 assessment. I felt very aware that this student was at a disadvantage to the others on the course, as it meant that any revision was going to be very difficult. I mulled over a solution in my head and then asked the student whether they thought an audio version of the assessment schedule would be useful; find out more after the jump...

Well, the general feeling was that it might be useful and so I've created a whole series of audio (MP3) podcasts that cover the entire NPTC CS30 assessment schedule.

Now, I realise that this may not be the most exciting broadcast you've ever listened to, but if it helps a couple of people then I'll be happy! I'll be adding more to this post, but initially I just want to make sure everything is all setup correctly.

Congratulations to...

I'd just like to congratulate the latest students that passed their NPTC CS30 assessment last week.

And so, a "Well done" goes to...

  • Gary

  • Alan

  • Simon

  • Jason

  • Kevin (take care in those woods of yours!)

  • and last, but by no means least, Suzanne (the assessor was well impressed with your answers to the questions).

Hopefully, I'll see some of you back on the CS31 small fell course at some point in the future!

Starting From Cold

Following the new video about starting your chainsaw, I mentioned that we'd have a look at a couple of things brought up in the video. So, to begin, here's a few pointers to watch out for when starting the saw. Find out more after the jump...

The sequence used for cold starting should include those safety checks:

  1. Chain Oiling: make sure the chain is being lubricated.

  2. Chain Brake: the chain brake must work properly before you use the saw.

  3. Chain Creep: the chain should remain stationary whilst the chain brake is off and the engine is idling.

  4. On / Off Switch: ensure that the off switch really does kill the engine

But, we're getting a bit ahead of ourselves here, as I want to take a quick look at positioning and how to hold the chainsaw.

To my knowledge, there are no left-handed chainsaws which means that whether you're left-handed, or right-handed, the hold on the saw is the same - left hand on the front handle, right hand on the rear (or top) handle. This mean that when you start the saw, it's probably easier to keep hold of the front handle and use your right hand to pull the starter cord. Get your right heel on the rear hand guard and either adopt the 'crouching' or the 'kneeling' position. Try to put a little bit of weight on the saw just to stabilise it whilst you pull the starter cord.

Naturally, you could start the saw in the standing position, which you might want to do if the ground conditions prevent you from getting down on the floor. In this case, make sure that you've got a firm grip on the rear handle by using your legs to hold it in place.

For many occasions however, starting on the floor will be the easiest and most comfortable option. Make sure that you don't start the saw right next to your stash of fuel - keep that well away from the saw unless you're refuelling. Try to choose level ground, clear of any debris that the chain could flick up whilst you do the safety checks; and ideally maintain a safe working distance of 5 metres during the startup procedure.

Once the saw has been started, you'll hear that it is essentially idling very high, but as the chain brake should will be on, it'll also sound a bit strained too. You need to give a quick squeeze on the throttle in order to get the idling down to normal levels. However, if you're still in the 'correct' position, then you'll find that you can't your hand to the throttle as your foot is in the way; use this as a prompt to take up position behind the saw. You can crouch down, or kneel down, but if you elect to kneel only do it with one knee; having both knees on the ground will restrict your movement in the event that you need to get out of the way.

So, where are we in the proceedings? Well, the saw is ticking over nicely and you've adopted a comfortable position behind the saw; try to keep your head out of the line of the bar. You're ready to do the safety checks, so in the next post we'll take a closer look at the chain lubrication.

Here's The New Video...

So here it is - the new video. Shot on a cold, but sunny morning at Sparsholt College, Hampshire (UK). This six and a half minute video covers the basics of how to start your chainsaw safely and is really aimed at those about to take their CS30 assessment. Find out more after the jump...

In the past I've found that breaking the starting procedure down in to steps, to make it easier, actually makes it more confusing! This video is really aimed to be used as a quick bit of revision if you are about to undertake your CS30 (chainsaw maintenance and crosscutting) assessment.

It covers cold and warm starting, ground starts and standing starts as well as the safety checks and the action to take if these checks reveal something is wrong.

I hope you find it useful and over the next few posts we'll be taking a look at some of the points raised in the video.

PS: No instructors were hurt in the making of this video! When you see the kickback bit, you'll know what I mean.

PPS: If you're an instructor and would like a better quality copy of this, then drop me a line via the comments and I'll send you out a copy on CD (it'll be in AVI format, MOV also available but I'm having trouble with the sound right at the start of the video in this format). You can also drop me a private message via the ArbTalk forum - see right hand side of the page.

Starting The Chainsaw.

With the knowledge that the final touches are being put on the new instructional video, I figured we should have a quick look at a couple of pointers to consider when starting your chainsaw. Find out more after the jump...

Whether you're looking to carry out a cold, or warm, start of your chainsaw, it's a good idea to check around you first. In particular...

  • Check the chain brake is ON. You really don't want to be starting the saw with the brake off and the chain potentially flying around. Keep in all under control and keep it safe - put the brake on.

  • Think about those around you... yep, it's not all about you, you know! Try to maintain a safe working distance of 5 metres when starting the saw, so that no-one is within this 'danger' zone.

  • Don't start the saw next to your fuel - particularly easy to fall in to this trap when you've just filled up the saw. Move away from the saw bearing in mind that 5 metre safe working zone.

  • If you are starting the saw on the ground, try to use level ground that's not covered in mud, brash and so on. Bear in mind that if you are carrying out a cold start you'll be doing some safety checks on the ground too - and that means the chain will be spinning; make sure it's not going to catch anything.

So, whether you're doing a cold start, a warm start, standing start or kneeling on the ground, just be bit careful and check out the site and those who might be around you.

In the next post, I'm hoping to bring you the new video and then we'll probably pick up on a few things from it.


Video Update...

Quick update on the new video - it's nearly done! My little Mac laptop is currently telling me that it's "Preprocessing Movie", and I guess that's a good thing. Find out more after the jump...

The video concentrates on the 'correct' ways to start a chainsaw - i.e. not drop starting it! It takes a look at the basic checks that you might want to get in the habit of doing and what to do if those checks don't quite work out the way you wanted.

It also takes a quick look at warm starts and starting the saw if you don't want to kneel on the ground (like when it's too boggy, or your knee has had it after all those years of climbing...). It finishes off with a short clip to highlight the danger of kickback.

I hope you like it and find it useful - if you're about to take your CS30 assessment, this could be a good bit of revision for you. You'll see it here first in the next couple of days all being well.

New Video In The Pipeline.

Production of another DriveLink video is just about to start this morning. Find out more after the jump...

This video, which will hopefully be the best yet, aims to cover the starting procedure for a chainsaw; it deals with cold starts, warm starts, potential problems and how they should be solved.

I'm literally on my way out now to do it, in order to make the best of the nice weather as it's due to change later on today!

Anyway, look out for it, if all goes well then it should be completed by the end of the week.


Working Edges: Part Two.

In the last post we looked mainly at how cutting angles affected the working edge and how not using the file with an even stroke causes the working edge to become rounded. In this post, we'll compare the working edge of a semi-chisel cutter and a chisel cutter - and look at one of the most common faults when sharpening the semi-chisel version. Find out more after the jump...

We of course know that the working edge should be kept at the correct angle and that the edge itself should be straight. This is pretty easy to see when maintaining a chain with chisel cutter as the top plate very definitely meets up with the side plate. After all, it's this that gives the chisel cutter its characteristics - the working corner that comes to a well-defined point that allows the wood fibres to be severed.

However, the semi-chisel cutter does not have this same defined point as there is a curved surface between the top and side plate. This affects the working edge as it no longer stretches the entire width of the cutter, in fact, it almost looks as if the corner has been knocked off or made blunt! The main thing here when sharpening is to ensure that there is a straight edge running from one side to the other side of the top plate - and this is where I see many people who are just learning to sharpen get it wrong. They tend to stop filing slightly too early, achieving a straight edge which, unfortunately, does not go right across the leading edge of the top plate; placing a straight edge against it shows up the problem. The solution? On most occasions it takes just one or two more strokes of the file to sort it out.

I tend to use the straight edge of a file guide to check this leading edge, it just acts as confirmation, but you should be able to see it fairly clearly in good light. You'll see where the curve starts as it leads from the top plate round to the side plate - there'll be a difference in the way the light hits the cutter and it shows exactly where the edge of the top plate is. Follow this line forward to the working edge and make sure that it's straight from this point to the other corner of the top plate - hopefully the picture shows this better than I can explain it.


Just thought I'd say a quick "Well done" to the guys on the latest CS30 course. They all passed with flying colours which is great news.

So, congrats to Andy, Jim, Tom & Dan - perhaps I'll see you back for the small fell or climbing course?!

Keep in touch, you can use the comments on this site. Cheers, David.

Working Edges: Part One.

Post number three in this quick look at common sharpening problems takes a closer look at the working edge of the cutter. This is the crucial bit that slices through the wood and so it must be sharpened correctly. I've seen a number of common errors when filing the cutters and getting the working edge correct is probably the most difficult. Click on the jump to find out a bit more...

There are a number of things that need to come together to end up with a good sharp chain that's capable of cutting effectively and efficiently. When we sharpen a chain we need to know:

  1. the file size;

  2. the filing angle;

  3. the depth gauge setting.

We've already seen in the previous post that selecting the wrong file size will affect the side plate angle, or the amount of hook, given to the cutter; and this time we'll have a look at the issues surrounding the filing angle.

The filing angle, given by the manufacturers, lets you know the best angle for the type of work that the chain is to be put to. For example, a crosscut chain will have a filing angle between 25o and 35o, whereas a ripping chain is much shallower - the ideal is 0o but values in the range of 5o to 15o is more common. This is because of the different way the cutter has to remove the wood when cutting across, or with, the grain. Cutting across the grain (cross-cut) the cutters must be set up to sever the fibres, when cutting along the grain (rip-cut) the cutter must essentially chip the wood away. We'll take a closer look at rip cutting and cross-cutting in a later post and see how it actually works.

Back to our filing angle; there are several ways of filing the cutter - from using just the file on its own, to using a Dremel with an attachment, through to the professional grinding wheels for accurate setting. Each has it's own merits and drawbacks (perhaps that could form another post in the future!). Here, we'll stick to using the good ol' file with a file guide.

The potential problem with using just the file is that you have no control over the height that you are filing at, making it all too easy to set the incorrect side plate angle. The file guide, used properly, should reduce the chance of this - notice that it doesn't completely alleviate it as you can still place it incorrectly or put too much pressure down on it. But it helps, and it's also got the lines etched in to it to make lining it up to the correct angle a simple task.

Stihl recommend a filing angle of 30o with their Rapid-Micro and Rapid-Super chains which makes it easy to remember, but you need to be a bit more careful with Oregon chains, even those with the same identifier on them. An Oregon #21 or #22 chain could have it's filing angle set to either 25o or 30o depending on whether it's a 'round ground chisel' chain or a 'micro chisel' chain.

Once you know the angle, the problem then is that it can be hard to achieve if your filing stroke is not even. The picture at the top of this post shows what happens if you change the angle right at the end of the stroke; you can see that the working edge of the cutter is no longer straight. To correct this, make sure that you keep your filing stroke completely straight from the beginning to the end, and maintain an even pressure.

In the next post we'll continue with the working edge and the difference in shape between a chisel cutter and a semi-chisel cutter. Chisel cutters tend to be very easy to file with a straight edge all the way across, but time and again I see semi-chisel cutters not done to their best, so we'll pick up on this and have a look why...

Cutter Lengths.

Continuing our look at common problems encountered when sharpening the chain, in this post we'll take a look at the effects of variable cutter lengths.

When you first start sharpening your chain, it's natural to wonder where to start, i.e. which cutter do you choose to begin the process? Does it even matter? Well, yes it does! Find out more after the jump.

Many of those coming to the chainsaw maintenance and cross-cutting courses don't realise that it's important to start filing the correct cutter when sharpening as you must end up with all the cutters filed to the same angle and the same length. And the clue is in those last few words - they should all be the same length.

This means that you have to base the length of all the cutters on the shortest cutter; but why does it matter? Surely as long as the filing angles are correct, the length of the cutters is irrelevant? Errr, no.

The main problem with having the lengths all different is that it will cause the chainsaw to cut in a curve rather than a straight line. There is a very noticeable drift from the cutting line, and I've seen it referred to as a 'banana cut' on the ArbTalk forum just recently. This is a good description!

So, when we start to sharpen we must find the shortest cutter - but what if there's a longer cutter that has lots of damage? What if they're all the same length? What if you don't have a set of vernier calipers to hand to check? Let's deal with each of these in turn...

Damaged Cutters

In theory, as long as you only cut wood with your chain the cutters shouldn't get damaged. But life being what it is, sooner or later you'll cut through some timber only to see sparks coming out of it - then there's the sinking feeling that you've just found a nail, or part of a wire fence, in the middle of the wood. Maybe you touched the chain on the ground as you exited a cut, or maybe there was just lots of small bits of flint in the rough bark of an old Birch tree. Whatever it is, one day you'll end up with the leading edge (or working edge) of the cutter getting damaged.

The main thing is to file away all the signs of damage. Now in our example where there is a longer cutter which is damaged, it makes more sense to file this first of all and then check it's length against the [previously] shorter one. If it's still longer, then it'll need to be filed more; if it's now the shortest one, then this is the one you'll base the rest on.

Same Length

If all the cutters are the same length, and none are more damaged than any others, then you've got no worries - start anywhere!

No Vernier Gauges

For the utmost accuracy you can use vernier calipers - but there really is no need, unless you pride yourself on engineering tolerances that NASA would be proud of. Use the simple nut and bolt trick - one bolt, fitted with two nuts is all you need. Fit the head of the bolt between the working edge and loosely tighten the first nut up against the trailing edge of the cutter (use the second one to lock it in place). For more information, check out this post...The Nuts And Bolts Of Meaasuring.

Setting The Lengths

Once you have sorted out any damaged cutters, and you know which one is the shortest, make sure that it's sharpened correctly and then measure along where the side plate and top plate meet. Set your measuring apparatus to the required length and don't forget to mark it!!. I just use a permanent marker to colour in the top plate so I know when I've gone round the whole chain.

Try to get the cutters all the same - if you don't you'll find it more difficult to get accurate felling cuts, particularly when using the medium fell technique as the saw will drift of course as you cut around the back of the tree. You might also find that you suffer from more vibration when you use the chainsaw, as the chain reacts to the odd lengths.

In the next post we'll take a look at filing angles and the working edge.

Left Hook

There's a lot of criticism within the industry surrounding the ability of chainsaw operators to correctly sharpen their chains. It's not helped by those in the industry who persist in setting out the same old myths that have been around for years. If you want the best performance from your chain then it needs to sharpened correctly.

Incorrect sharpening of the chain can lead to varied problems, from slow cutting performance to a greatly increased chance of kickback. Knowing how your chain should be maintained is extremely important - yes, it's a drudge but it needs to be done.

Here on DriveLink, sharpening the chain was covered in the following posts:

So, let's try and take a closer look at some of the problems encountered when sharpening. Find out more after the jump...

First off, it's important then when using the file that we keep it flat and straight whilst filing. We also need to maintain the correct pressure to ensure that the correct side plate angle is maintained. Now, it's difficult to measure the side plate angle correctly, although Stihl have attempted to make things a little easier with the various markings on their depth gauge tool; instead, when I teach sharpening I tell the students to use the angle specified in the manufacturers literature as a guide to how much 'hook' their should be on the side plate. An angle of 85o would suggest little hook, whereas an angle of 60o would show a definite hook in the side plate of the cutter.

The picture here shows a chain where this hook is completely wrong - the cutter actually appears to lean backwards and there's no hook at all. There's two major reasons for this:

  • the file used to sharpen the chain was too large;

  • too little pressure on the file whilst sharpening caused the file to ride up.

If you suspect the file you used was too large, check it against the filing table for your particular chain. If you use Oregon chain, check out their maintenance and safety manual at the manual - it's full of really useful information.

But what if you used the correct file size? It's likely that the lack of hook on the cutter was due to the file riding up as you sharpened - you'll be able to see this if you look at the shape of the gullet (between the cutter and depth gauge). If there's a ridge starting to form then it's a sign that you should have used a little more pressure - get rid of this ridge before you continue sharpening.

There is another possibility, and that is that you did not hold the file correctly - if you used a file guide, it should rest on the cutter and the depth gauge.

Try to maintain an even pressure on the file - not too much and not too little. Too much pressure results in the opposite problem; i.e. too much hook as the side plate is being filed by a different part of the file, resulting in what is sometimes referred to as a 'birds-mouth'.

Next post we'll take a look at cutter lengths.

Calling Out Around The World.

I've just been taking a look to see where the readership of this blog is located, and I was pretty surprised! Find out more after the jump...

It seems we have a truly international readership; from the good ol' US of A to Japan, and all points in between.

So, if you are one of those readers from Norway, Canada, Croatia, Chile, Laos, New Zealand - or indeed from anywhere other than the UK - do please get in touch, even if it's just to say "Hi!".

But, even better, let me know something about how the forestry or arboriculture business in your neck of the woods. Felling and logging must be quite different in Norway, when compared to New Zealand. The trees that you work on are probably somewhat different from here - the huge Eucalyptus trees of Australia to the Baltic Pines of Scandanavia.

Just drop me a line via the comments...

Give Me A Hand...

How much attention do you give your personal protective equipment? Do you just throw it in the back of the wagon once you've finished the job? How do you dry out your gear once it's been soaked in the latest summer downpour? In this post, I'll take a look at chainsaw gloves - and hopefully they don't look like the pair in the photo. Find out more after the jump...

As you can guess from the picture at the top, these chainsaw gloves were not in a condition to provide any protection - if you're gloves look like that, do yourself a favour and replace them. New chainsaw gloves are not really that cheap - not like a pair of work gloves at £1.99, and so you should look after them. But how?

Ever read those little paper booklets that come with new gloves / jackets / helmets / boots / etc.? Stihl recently sent us a new pair of gloves and I thought I'd take a moment to browse through the leaflet and report my findings.

During the course of normal tree work, chainsaw gloves live a hard life, dragging brash, using a chainsaw, winching and so on. They get pretty grubby, pretty quickly and if they then get wet as well they'll set rock hard - making them difficult to put on and uncomfortable to wear. Improper care will also accelerate the demise of the stitching caused by fuel, oil and maybe stump protection fluids - all things that are not recommended to come in to contact with the gloves.

I've never read the leaflet that comes with gloves and I'm as guilty as the next person of just abusing them until they fall apart and then getting another pair - but what I found was interesting. For instance, were you aware that you can wash those gloves? I wasn't, but it turns out that these Stihl gloves can be washed gently in warm, soapy water when they get dirty. Or contaminated with petrol. Or oil. Or indeed, anything else. Of course, they need to be dried, in just the same way they should be if they get thoroughly soaked during inclement weather.

Drying gloves should be done without unnatural sources of heat, i.e. don't go putting them directly on a radiator, or use a hairdryer to drive off the moisture. Put them somewhere where they can dry out slowly over time and once dry, they should be treated with a leather feed - I'm thinking something like NikWax should do.

So, it seems that looking after your gloves might just save you some money - but there's obviously a 'fiddle-factor' involved in maintaining them. Having said that, I've got an oldish pair of Husqvarna gloves that could do with a good clean, I might just try it and see what happens...

Back from holiday!

Well it's back to work after a couple of weeks holiday, and straight back in to running a couple of chainsaw maintenance (CS30) courses. It's always great to meet new faces on these courses and watch beginners tackle chainsaw sharpening, or listen to the more experienced users views on how they have carried out certain tasks. This got me thinking if there was a way to bring the questions, answers and information to a wider audience. There is, it's obvious and you can find out more after the jump...

Naturally, I get asked many of the same questions on the various courses and quite often also get those 'off-the-wall' questions, that often start with "This may sound stupid, but...". Well as we all know, there's [generally] no such thing as a stupid question - if you need an answer then you've got to ask the question!

So, I thought that as I'm about to start another year of chainsaw maintenance, felling and climbing courses that I would put some of these questions up here - along with answers, or put the question out to you lot to answer. This way, if you've got a 'stupid question' you won't have to ask it as someone else will have hopefully asked it already!

So, when it comes to questions about chainsaws, just remember not to hold the pointy end.

Carb101: Setup & Troubleshooting

In this final article about carburettors we will take a quick look at setting up the carburettor and how to spot some of the problems that can arise due to carb failures. Find out more after the jump...

In the last post we saw that the amount of fuel drawn through at idle was limited by the "L" low speed screw. The "H" high speed screw has a similar function when the saw is running at full revs - controlling the amount of fuel entering the air stream. This obviously affects the fuel:air mixture and setting this screw incorrectly has the potential to cause catastrophic damage to the saw.

The high speed jet needs to be adjusted with the saw at maximum throttle (fitted with the bar and chain, but otherwise unloaded); because this jet affects the fuel:air mixture, it's very important that adjustments are made with a clean air filter (setting the high speed screw with a dirty air filter will potentially leave you with a weak mixture when you do clean it). The picture on the left shows the high and low jets.

To set this screw, you really need a tachometer to measure the engine revs - refer to your manual to find out what the setting should be. For the Stihl MS260, the "H" screw should be set to allow the engine to run at 12,500rpm - but if you screw the adjuster in and out you'll find that by turning anti-clockwise the saw starts to 'four-stroke' (you'll hear the difference) and the revs will drop off; screwing it the other way and the revs are liable to increase beyond the recommended maximum as the fuel gets weaker. However, be warned, with the saw running at it's (unrecommended) maximum, it will lack cutting power and worse still, due to the weak mixture, it will not be getting enough lubrication either. Result? An overheating engine that's liable to seize. If you don't have a tachometer, set the "H" screw to the manufacturers recommended setting and leave it there.

The idling screw (not to be confused with the "L" screw) makes no difference to the fuel:air mixture settings. It's connected to the throttle and depending on where it's set, will hold the throttle open just enough to allow the saw to idle normally but leave the chain stationary (with the chain brake off).

So, to set up the carb, set the "L" and "H" screw to the manufacturers recommended setting (usually, but not always) this equates to screwing them all the way in, then backing them off 1 turn. With this done, fire up the saw and adjust the "L" screw until the revs reach their maximum, then back off about 1/4 turn. Now set the idle screw, so the saw idles happily, but the chain remains still when the chain brake is off. With this accomplished, open the saw up (full revs) and adjust the "H" screw until the tachometer reading shows the setting recommended by the manufacturer.


There are a number of problems that can be caused by the carburettor and if the saw is playing up - for example, it keeps stalling (especially when turned on its side), suffers from 'lumpy' running then I would recommend that you reset the carb settings back to normal, clean the air filter and start from there. If resetting / cleaning do not solve the problem, then it could be the diaphragm has had it; or the needle in the metering chamber has started to wear. In these cases, just purchase a carburettor kit which contains everything you need, replace the lot in one go and try again.

Well that's it for Carb101, I hope that you've enjoyed the series as much as I have writing it.
- DV -