Chainsaw milling bar angle

[Arky217]

Has anyone modified the angle of the chainsaw bar on their chainsaw mill so that instead of being perpendicular to the log, it now points somewhat forward. In other words, as the chain begins to enter the end of the log, the part toward the end of the bar starts cutting first ?

If so, how much of an angle change did you make and did it make a significant difference in the cutting speed ?

Thanks,
Arky

 

[Brmorgan]

I haven't tried it personally, but I presume it would not be beneficial for two reasons:

1. As you move away from perpendicular, you proportionately increase the surface area of wood being cut by the chain. So you could be cutting a 20" log, but be cutting the equivalent of a 22" or whatever.

2. When you cut with the grain instead of across it, you end up with big long pigtail shavings which really can clog your clutch area up badly. This is especially true for green wood.

I guess I kind-of have done it though, like when maneuvering the mill around obstacles like big knots etc. and at the cut lead-out. Definitely didn't speed anything up.

 

[BobL]

I have 2 sets of 2 x 10 ft long rails. I can use 1 set for logs up to about 8 ft long, leaving a 1 ft overhang. Above that log length I join the two sets together - here is a 16ft long log - note the limited overhang.

So when I don't have much overhang I often start cuts using a angle - see set up C and D below. This gets the milling started much quicker than cutting full on into the log and trying to hold the mill level while starting

For regular milling of logs, when the chain is sharp, I have timed both straight and angled cuts and it makes little difference in cutting speed [BTW In Aussie hardwood you won't get many curlies to clog the chain]. When the chain is blunter, straight on is faster than constant angle.

However, particularly when nearing the end of a widish, very (Aussie) hardwood slab and the chain is getting blunt (see pic below) I sometimes rotate the mill, angling first one way and then the other. What I do is cut first with the saw angled one way (A) and then the other (B) and then (C). Provided you don't cut all the way across at an angle this uses a shorter cutting length. It ends up taking about the same time to cut, but I think it places a lesser load on the saw. However, it also makes a less smooth cut so if I feel the need to do this, it's definitely time to change the chain!

 

[hazard]

BobL - nice pictures

Your last picture is pretty much what I do all the time unless the I am cutting smaller wood. It just seems like the saw handles it better.

The 066 doesn't seem to like cutting thru 28" of wood all the time.

Chris

 

[glennschumann]

I usually just mill straight across the log. I find that it is easier to control the mill if the 'rub plates' near the power head are more of less flat against the side of the log. (I don't have fancy guide wheels on mine)

Sometimes I do angle the saw back and forth. Like Bob said, when the cutting is getting slow due to width and or chain dullness, cutting a smaller piece of wood seems to make the process go faster, or at least you feel like are accomplishing more.

Even at an angle, I have not found 'curlies' to be a problem at the clutch end... I still get small shavings even at a pretty steep angle. I do get curlies sometimes cutting through vee's and other figured wood where the grain becomes parallel to the bar.

Try it several ways, but just stay safe. If something seems to work better for you, that is your answer. Just let us all know. Happy Milling!

 

[Nikko]

If I have little overhang on the ladder I'll come into a fresh cut on an angle exactly like Bob shows. And I usually leave a cut on and angle as well because I find it easier to control the saw that way. But for the cut itself, I generally run perpendicular to the log the entire length.

Nikko

 

[petersenj20]

I remember a book I read from the library that recommended that exactly. I don't remember why though.

 

[ShoerFast]

Maybe it just seems faster at an angle?

But I do notice less hop at an angle, or when your pushing a dull chain just a little further, and angle seems get the chain into the wood better, and the chain dose not tend to ride up-over knots as much.

IOW: Looking down a plank cut at an angle seems a little more correct then a 90 deg. cut.

 

[Brmorgan]

If I have little overhang on the ladder I'll come into a fresh cut on an angle exactly like Bob shows. And I usually leave a cut on and angle as well because I find it easier to control the saw that way. But for the cut itself, I generally run perpendicular to the log the entire length.

Nikko

Same for me. For me, I think the reason it's easier to start and finish the cut on an angle is that there is more of the center rail (that the push handle is attached to) in contact with the guide board or cant surface, so it's easier to keep it flat.

Maybe it just seems faster at an angle?

But I do notice less hop at an angle, or when your pushing a dull chain just a little further, and angle seems get the chain into the wood better, and the chain dose not tend to ride up-over knots as much.

IOW: Looking down a plank cut at an angle seems a little more correct then a 90 deg. cut.

I also tend to notice a bit less hop and vibration if I push the powerhead end of the mill a bit forward so that just the front curve of the guide shoes are in contact. Not sure why but it's probably similar to why it's much easier to buck a log right tight up to the saw rather than out in the middle of the bar.
I don't notice that it cuts any faster except MAYBE if I do as Bob illustrated in his last drawing, and I only tend to do that if the chain is dull as stated above. The downside of this is that I find it's really hard to keep the cut anywhere near as smooth as just pushing straight.

 

[BobL]

I also tend to notice a bit less hop and vibration if I push the powerhead end of the mill a bit forward so that just the front curve of the guide shoes are in contact.

That's reduced frictional contact in action - if you put a wheel where the guide shoes are you'll notice an small additional improvement

On the BIL Mill I have 2 pairs of adjustable height wheels like this

Full details here.

 

[aquan8tor]

I like the wheels there, Bob. I might have to turn myself some of those. I just have to figure out how to put them around a square tube. Maybe some angle-iron with a cutout around the tensioning bolt. Hmm... Will post pics when done; could be a while.

 

[BobL]

I like the wheels there, Bob. I might have to turn myself some of those. I just have to figure out how to put them around a square tube. Maybe some angle-iron with a cutout around the tensioning bolt. Hmm... Will post pics when done; could be a while.

here is how I did one on my small (24") mill.

 

[BobL]

I like the wheels there, Bob. I might have to turn myself some of those. I just have to figure out how to put them around a square tube. Maybe some angle-iron with a cutout around the tensioning bolt. Hmm... Will post pics when done; could be a while.

here is how I installed a wheel on my small (24") mill.

It works well when milling cants or the top half of the log. The wheel doesn't touch the log when cutting the bottom half.

 

[aquan8tor]

That's pretty ingenious. I have a homemade steady-rest for turning deep bowls on my lathe that uses urethane scooter wheels; maybe I'll have to borrow a wheel from it. Thanks for the idea. Off to set it up on the saw.