Alaskan CSM diverting from straight line

[John Henry]

My Alaskan MKIII (with a Husky 385XP, Granberg double end bar and rip chain) has been great for me, but when using it for the first time with a new chain yesterday, I noticed it started walking off the straight cut a little. By that I mean that I had all 4 corners flat on top the cant when I started, but moving down the cut, I noticed the front left corner coming up a little from being in contact (about 1/4").

I did notice on the second cut (which I stopped early on when this happened) that the chain was loose, so will take care of that today before doing any more, but is that a possible reason? Is there anything else that would cause the chain to deviate from a straight cut?

I am using only nominal force on the forward motion, letting the saw cut at its own pace.

Any thoughts?

 

[Rockfarmer]

The only thing I can think of without a pic is that the weight of the saw itself is like almost prying up on the bar causing the mill to ride up and off the log. The instructions say to keep the mill adjusted as short as possible for the log cutting. I dont like that idea because you could have the saw maybe a foot or more from the log, now all that weight, in my case 18 #s is off set and putting a rotational force on the mill and might cause the tip side to lift. Im keeping the mil full length and adjusting the crossbar handle to the right side of the wood within 2". This way the weight of the saw is on the left side of the mill right on the log and I push and lead with the right side handle the is within 2 " of the end of the wood. Now keep in mind I only have 2 days working with this so I may be off in left field Good luck to you

 

[glennschumann]

To Rockfarmer's point, yes, it is easy to let the mill tilt a little, especially if this is your first time, and you are busy trying to watch everything else going on. With double ended bar, however, I"m assuming it is at least 44" if not more, and length like that should help balance the whole set up across your straight edge. Since this happened on your second cut, I'm assuming you didn't have your straight edge attached again. The first cut may have had a bit of a bow or twist in it that could have come from the straight edge being warped, or just bending under the weight of the mill. If there were voids between the top of the log and the bottom of your guide for any distance this happens easily. I often screw shims in places to make sure the guide doesn't rock or twist.

You may also have found a small rock or something that dulled one side of the chain, and now it is trying to cut in circles. Take a look at the cutters... if one side's cutters seem different, touching up with a file may be in order. If you can pry the bark off the log (at least the far side) that helps keep the chain sharper.

If you found that your first cut is a bit rough, attach the straightedge again, to make sure that any imperfections don't broadcast into the second cut. If you have a straight 2x for a guide, stand it on its edge to see if the first cut is straight... shim as necessary. The third cut should be fine then.

Hope that helps.

 

[John Henry]

To Rockfarmer's point, yes, it is easy to let the mill tilt a little, especially if this is your first time, and you are busy trying to watch everything else going on. With double ended bar, however, I"m assuming it is at least 44" if not more, and length like that should help balance the whole set up across your straight edge. Since this happened on your second cut, I'm assuming you didn't have your straight edge attached again. The first cut may have had a bit of a bow or twist in it that could have come from the straight edge being warped, or just bending under the weight of the mill. If there were voids between the top of the log and the bottom of your guide for any distance this happens easily. I often screw shims in places to make sure the guide doesn't rock or twist.

You may also have found a small rock or something that dulled one side of the chain, and now it is trying to cut in circles. Take a look at the cutters... if one side's cutters seem different, touching up with a file may be in order. If you can pry the bark off the log (at least the far side) that helps keep the chain sharper.

If you found that your first cut is a bit rough, attach the straightedge again, to make sure that any imperfections don't broadcast into the second cut. If you have a straight 2x for a guide, stand it on its edge to see if the first cut is straight... shim as necessary. The third cut should be fine then.

Hope that helps.

Glenn, excellent comments and tips. I tightened the chain and checked everything else, seemed to be in order. I went after it again and it seemed to be just fine, so not sure what it was.

I think maybe either it is one of the things you said, or the loose chain, or possible one of the rail guides on the side of the mill was catching part of the tree that was trying to make it ride up rather than across.

Either way, it is working now, so we are back at 'er.

 

[BobL]

The only thing I can think of without a pic is that the weight of the saw itself is like almost prying up on the bar causing the mill to ride up and off the log.

Yep, I would go with this one.

JH, posting a picture of your setup will also help diagnosis.

Cheers