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Back To The Future: Bore Cuts (3)

Continuing on with these bore cuts... one problem that I come across time and again is poor hand position when gripping the saw. It's not only bore cuts that can go awry with poor hand position, but sink cuts too. So how can we improve our chances of getting accurate cuts? Find out more after the jump...

Looking at the picture at the top of this page, you can see how the hand at the rear of the saw is not twisted, and the throttle is being operated by the inside of the thumb. The hand on the front handle has been moved right around the handle, which you can probably see better on the image below (yes, I know I'm not wearing gloves, but the saw is not running and I wanted to make the hand positions clearer...).

Try to get in the habit of holding the saw in these positions when you're either doing the horizontal bore cut, the bottom cut of a sink, or the back felling cut. It will help you keep the saw level.

Back To The Future: Bore Cuts (2)

Now that I've started on this route, I guess I'd better finish it! So here is the second 'bonus' posting - but only because I didn't get to finish it all of in the first posting about bore cuts! In this article we'll have a look at the second of the bore cuts that you'll need to be able to demonstrate and use for the CS31, and quite likely for the CS30 too. That's CS30 as well, as opposed to CS32... just sayin'. That second bore cut is the vertical bore cut, and I feel that it's appropriate to let you know hat this one has the potential to be very dangerous, as you'll be cutting very close to the kickback zone and even with it. Be careful with this one. Find out more after the jump...

Why would we use a vertical bore cut? Easier to watch a demonstration than listen to an explanation, but I'll give it a go... Look at the image at the top of this page, you can see that the underside of this piece of timber is not touching the ground and yet there was not enough room to get the bar and chain under the timber, without the chain running into the ground. In this case, with the compression cut already made on the top of the timber, we needed to cut from under the timber, back up to meet the compression cut.

To get over this problem of a lack of space, we can bore into the timber and then cut downwards and out of the bottom, as there is enough space for the chain to pop out from under the timber without striking the ground.

The other thing that you can see from this image is just where the bar and chain are positioned - note that the cut will be started slightly behind the kickback zone, and not on it.

Ensure that the saw is running at full speed whilst you do this cut, it's actually safer, and also make sure the saw is sharp. But perhaps the best advice for this cut is keep your head out of the line of the bar. Start the cut and allow the saw to cut a little way in, before levelling the saw out and pushing through the timber completely. Now you can come out of the bottom of the timber, before cutting up to the compression cut (in this case).

Try to do this in one fluid movement, saw at full speed and head out of the way - it doesn't bear thinking about what would happen if you had kickback... Also, be confident with this cut and hold the saw securely and comfortably.

I will be revisiting bore cuts, especially as now that I've started to write about them, the more I can think of to tell you!

Keep safe.

Back To The Future: Bore Cuts (1)

This is a bit of a bonus posting, as I've got 10 minutes free to quickly add an article! And so, in this post we're going to go back to the future and look at bore cuts. Why 'back to the future'? Well, bore cuts currently form part of the CS30 chainsaw maintenance course, but are heavily used during the CS31 (and CS32) felling courses; because of this, it'll be useful to both groups of people - those undertaking CS30 and those doing CS31. I'll try to put together a short video of completing a bore cut as it's much easier to see it, rather than describe it, but for now you'll have to make do with text! Find out more after the jump...

There are two types of bore cut: horizontal and vertical. The image at the top of the screen shows the horizontal bore cut, and is used a lot in conjunction with felling techniques (rear-weighted, forward weighted, medium and large fell). The vertical bore cut is used to cross-cut timber, especially where there is not enough room under the timber to physically fit the bar and chain, and you want to cut upwards; although there is enough room to bring the chain out of the bottom of the timber without it hitting the ground.

The Horizontal Bore Cut

The horizontal bore cut is slightly safer than the vertical bore cut, but is perhaps more difficult to get all the levels correct. You will need to keep the saw level from the tip of the bar back to the rear handle, as well as keeping it flat from side-to-side.

This is easily achieved by positioning your hands correctly on the handle; remembering that your thumb on the left hand must remain around the handle (see the Bad Habits: Thumbs Up! post). First off, getting it level from side-to-side is just a matter of moving your left hand right around the handle as far as practicable, this will automatically put the saw in the correct position. Easy!

Now for getting the saw level front-to-back. Many operators continue to hold their right hand in the same position (finger on the throttle) and twist their wrists to account for using the saw on its side. However, this often results in the rear handle being held higher than the tip of the bar and so the saw is not level. Instead, as you twist the saw on to its side, getting it ready for the horizontal cut, allow the rear handle to move around in your right hand; you should find that you can operate the throttle with your thumb.

Stand so that the underside of the nose of the bar will be introduced into the timber, then cut down to about where the nose sprocket rivets are. At this point, keep the nose of the bar in the same place and swing the rear handle around so that the saw is now directly pointing into the timber. Now push. Not too hard, and keep the saw running at full power until you have bored through to the required depth.

Allow the chain to stop in the bore cut before pulling it out of the wood (it might be wise to flick the chain brake on too at this point). Now, we are going to need to refine this a little bit but that'll be what the video is for... I just need to shoot it first ;0)

I reckon my 10 minutes is definitely up, and I'll leave vertical bore cuts for another post...

Bad Habits: Part Three:

Continuing on with this short series of common mistakes made by operators is the classic "head in line with the bar" syndrome. This is such a common error and it's easy to see why; especially when you're concentrating on getting your cuts right and trying to line them up.

Of course, the real problem with this is that should you suffer any kickback then you can guess where the bar is heading..? If you look at the picture on the left, you can see that this student has his head right in line with the bar (I realise that it's unlikely that he's going to get any kickback here, but it's just to show a poor head position). Find out more after the jump...

With you head in line with the bar, should you get some kickback then that chain, which is doing something approaching 50mph, is heading straight for your face. That's not good, and definitely would constitute a 'bad day at the office'. I tend to find that students want to get their cuts as accurate as possible, and hence they can line up the cuts if their head is over the bar, so how are you supposed to line everything up if you can't put your head in line with the bar?

Easy! Line it all up, then move your head before you start cutting! Now, I'm not suggesting that you try and hold the saw way out to your right hand side, just that you move your head slightly to left to take it out of the line of kickback. That's really only just a few inches.

This point is very important and can be a potential failure point on your assessment; it's written in the assessment schedule under part 2 (CS30.2) where it expects safe usage of the saw, and specifically states that your head must be out of line of the chainsaw. So remember, line everything up, move your head slightly to the left, chain brake off and cut. Stay safe...

Crossword answers...

So now that the crossword competition has finished (and we do have a winner), I thought you might like the answers! Find out more after the jump...

You can click on the image above and then print out the answer sheet - how did you get on? I've had some favourable comments on the idea of using a crossword as a teaching aid, so if you want to see more then let me know. I've got plans to make another one covering CS31...

If you'd like to use this crossword for yourself, or as a trainer for your learners, then please feel free to copy it as you see fit.

Whad'ya mean you wanna know who the winner is? I'll tell you in the next post...

Crossword Competition

Fancy winning an Oregon Timber Vice? Well, now you have the chance with DriveLink. Find out more after the jump...

This is your chance to win an Oregon timber vice - real useful out in the woods for getting a more accurately sharpened chain whilst out in the woods (or anywhere where you can find a chuck of wood to stick the prongs in!).

It's new, boxed and waiting for a winner of this competition. So, how do you enter? Download and print off the crossword puzzle shown in the image above (it's A4 sized in real life, when printed).

Complete the crossword puzzle - it's all related to the CS30 NPTC schedule, so if you're not too sure of an answer you should be able to go looking for it.

Print the puzzle off and complete it. Send your copy to me by the start of May (01/05/2010) and I'll choose a winner. Make sure to include your name and address, or at the very least your name and email address so I can contact you if you are the winner!

I can also assure you that I won't be selling your details off to anyone, but I might contact you if there are any exciting developments in the world of DriveLink (however unlikely that is!).

If you are a chainsaw trainer and would like to use the crossword with your students, then please feel free to download, copy and use at will.

Terms & Conditions: there is just the one prize and no cash alternative! The competition entries must be in by the 1st May 2010. This is a UK only competition.

I should also mention that many of you know that I work for Sparsholt College - this competition has nothing to do with the College! Despite that, competition entries should be sent to:

David Vickers
c/o Sparsholt College
Forestry & Arboriculture
Winchester
Hampshire
SO21 2NF

How Time Flies...

I can't believe it's been so long since my last update - so much has been going on! Find out more after the jump...

The new NPTC assessment schedules are in full force now, and I've personally been busy delivering the new CS30 (chainsaw maintenance and crosscutting), CS31 (small fell) and CS38 (climbing and aerial rescue) courses.

There's not too much difference with the CS30, or the CS31 for that matter, but the CS30 does now include a bit more information on problems with chain components (look out for an post on that soon), and bore cuts (I'm thinking that a video would be good for that?).

The CS31 now includes a little bit more on winching, but the big change is with the CS38 as that now includes spiking up a pole and carrying out pole rescues (and that means both 2-man and 3-man (belay) rescues).

So, I haven't forgotten about you - I've just been really busy, but I still have some plans to write a few more articles and might just also include some small fell material too...

Latest Update On Assessments

As I mentioned way back in my last blog article, the chainsaw certification process is to be changed at some point in the future, and I had some doubt as to what the changes would be. However, NPTC had made the proposed schedules available and after reading through them and forwarding on my comments before the consultation period ended, I think (on the whole) the changes would be good. Find out more after the jump...

So what are the changes? Firstly they are proposing to amend the actual structure of the certification, as well as changing the schedules. Here, in brief, is a summary of those changes...

The risk assessment, emergency planning and various other knowledge elements are to be brought together and made in to a 'knowledge unit' that is to form part of the foundation certificates. The CS30 is the other foundation course and, by and large, remains similar to the existing one.

The CS31 small fell is to include rope / winch work (winching is currently part of CS32).

The CS32 (medium fell) is to now include the felling of weighted trees. This is a major change and one which makes some sense as although the same cuts are used as small fell, the method of achieving them is different.

The climbing and aerial rescue course is to be called CS38 (as it used to be!) and some major changes are being proposed for this; including... a tree identification element where the student will have to recognise 10 different tree species. The aerial rescue will also have to include a pole rescue as well as a 'tree' rescue. I think this is to be applauded and definitely a move in the right direction.

The CS39, using a chainsaw from a rope and harness, is to have additional cuts added to the schedule. This will result in the student having to complete both horizontal and vertical cuts, which is basically simulating the cuts required for dismantling.

The above summary of changes is only a proposal at the moment, and I'm not sure that anything will happen until LANTRA get the National Occupational Standards approved - which could take some time.

For now, the courses and assessment schedules remain as they are - so I can get back to creating some new videos and writing some more about chainsaw maintenance and cross-cutting.

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...

Guide Bars

Guide Bars - Part 2

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:

Chain Tension, May '08.

Too Hot To Handle, May '08.

Creating Tension In A Video, May '08.

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...

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