Getting the best from your chainsaw
Having a good chainsaw is essential if you’re really into woodturning. Being able to source your own timber opens up a whole array of possibilities. Not only will you be able to use unseasoned green wood, but you’ll also be in full control of the size and shape of the blanks you intend to use. A gnarly piece of yew, which would otherwise be thrown for firewood, can be quickly cut down to size and probably make a much more interesting piece, than a similar sized disc of wood picked from the shelf of a store.
However, chainsaws, like any other machine need to be maintained. The chain itself, slides along a guide bar and requires constant lubrication, due to the absence of any kind of bearing. Unchecked, this can loosen and cause all kinds of problems – not to mention the risk of it coming off!
Without getting too technical, I’ve a few tips to help with maintenance…
1) Keeping the chain sharp:
I guess this is the most obvious one, but isn’t all that straightforward. Each tooth on the chain is angled for the optimum cutting path. Although this needs to be followed, it is more crucial that your sharpening file passes at the correct height.
Forget sharpening your chain freehand, without a guide (yes, I still see people do this!). You need either a file holder, or better still, a roller guide. It is essential that you use the right size file, so that the full gullet on each tooth is sharpened on every pass of the file (the gullet is the curved inner surface of every tooth). The photo below should illustrate this…
A file and roller guide...
Find the tooth which is the most worn and count how many passes you make with the file, until it is sharp. Then file every other tooth with the same amount of passes – this will ensure that each tooth will be the same length once the chain has been sharpened.
2) Make sure the chain is tensioned correctly:
Again, this should make sense, but is easily overlooked. Imagine this scenario… You’re cutting up a really nice piece of elm, but hit a nail and carry on. The chainsaw is getting blunt, so you increase the downward pressure to make it cut. This forces the chain against the bar, to an unnecessary degree (metal against metal) and it starts to heat up. The hot chain expands and becomes loose on the guide bar, causing it to come off… This is easily done, so care must be taken in making sure the tension is correct. If the chain is getting loose, stop and sort it out.
When the two clamp bolts have been loosened, tighten the tension screw, so that the chain can still move along the bar freely, when pushed by hand. It is a good idea to lift the tip of the bar upwards, before re-tightening. This removes any play from the system and offers a more efficient chain line… I told you I wasn’t going to get technical!
3) Check your guide bar:
If your chainsaw doesn’t cut straight and you’ve done all of the above, a bit of guide bar re-shaping is due. The constant pressure from the chain, causes burs to develop and sometimes the bar can also wear unevenly. This is not too hard to spot and can easily be remedied with a flat metal file and some elbow grease.
With the bar removed and placed in a vice, you will see any unwanted imperfections. Run a flat file along the top, sides and angled (to soften the edges) and this should do the trick. Clean out the groove with the tip of a knife, clean the oil hole and you’re done. If you have a bearing in the end of your bar, pop some grease in it through the little hole.
My guide bar is okay, but not great...
Re-assembling is easy – just make sure the chain isn’t on back to front and that it’s located properly on the guide sprocket. Unfortunately petrol and carburettor problems take a bit more explaining, so best to have a chat with a local expert.
Best of luck with your next project!
