chainsaw cutting funny.

[flatyre]

hey folks a mate asked me to look at his chainsaw as it was cutting in a curve. Its also burning one side of the bar groove, but not the other, poorly sharpened or something else? also is the bar and chain salvageable or best to dump them?

[Steve Bullman]

Most likely unevenly sharpened, and if it's burning one side of the groove then it's probably too far gone. New bar and chain, and some sharpening edumacation

 

 

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[Stubby]

Steve has summed it up .

[spudulike]

It is most likely that the bar has been used with a blunt chin and now one rail is taller than the other. Put it in a bench vice, place a steel rule across the rails and see what sort of shape it is in.

 

I use my bench grinder to level them - just adjust the rest for correct angle and grind both sides. Having done this, you need circa 5mm of rail depth to accommodate the full length of the drive link. If you don't have this then it is scrap. If you do, the next thing is to make sure the rails hold the chain without too much roll from side to side.

 

If there is a lot of roll, you can sometimes peen the rails back in to shape by literally bashing them together carefully from both sides. You have to be careful not to get any pinch points but it can be done!

 

Or you can buy a new bar!

[flatyre]

thanks for the advice folks, I think both sides of the bar groove are the same height, but the top right and bottom left walls of the chain groove are thinner at the base, flipping the bar did nothing to help and when I ran the saw the chain seemed to be speed wobbling from side to side as it ran along the bar. Think its a case of new bar and chain but would be good to know what caused it.

[Steve Bullman]

Can you post a photo of the chain teeth

 

 

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[Woodworks]

thanks for the advice folks, I think both sides of the bar groove are the same height, but the top right and bottom left walls of the chain groove are thinner at the base, flipping the bar did nothing to help and when I ran the saw the chain seemed to be speed wobbling from side to side as it ran along the bar. Think its a case of new bar and chain but would be good to know what caused it.

 

Just sounds like poor maintenance. As said uneven chain sharpening, not dressing the bar and/or not enough oil getting on the chain.

[Mark_Skyland]

As Steve suggests it would be handy to get some pictures of the chain and bar. Make sure you take pictures of the side cutter parts of the chain too. 99% of the time I have found it to be a poorly sharpened/damaged chain that causes curved cutting, a poor bar can jam up in the cut a lot of the time.

[flatyre]

will try to get some photos when I see him again, its a four month old echo 501 but my mate isn't a tree surgeon, he only bought it for processing up firewood for himself. Did watch him the other day as he was demonstrating the saws behaviour and he doesn't use the dogs but rather brute force (he's a big guy). If he had sharpened the saw poorly so it cut in a curve then used his might to pressure the saw into cutting straight, would that cause the drive links to eat into one side of the groove?

[Steve Bullman]

if he's using force to get the saw through the wood its not sharp anyway.