Chainsaw mill wandering

[SteveR]

I have recently purchased an Alskan mill for my 3120 Husky saw with a 72"bar. I am using Granberg ripping chain. I have been using it for a few months now and have sucessfully milled about 6 large logs into nice, even slabs. Over the last two weeks, for reasons unknown to me, the saw is wandering part way through a cut...to the point where the slab is 1" thinner part way in. The saw is rising up and I can't determine the cause. I sharpen the chain manually after each cut. Any help is appreciated.

[tnaz]

All I can saw is welcome to the Forestry Forum SteveR; but other with a lot more smarts than I will chime in before long.  Good luck and post some pictures when you can.

Terry

[newoodguy78]

Just a thought but do you have one side of the chain sharpened slightly different than the other side? I don't know for sure but I wouldn't think it would take much to throw a chain of that size off. Good luck.

[boscojmb]

I milled with a 3120 for several years. Here is a picture of my mill and a a few logs. The logs pictured are about the average size that I would cut.



I typically sharpen after about 20 logs. that is about 200-300 cuts inbetween sharpening. The logs are clean, northern spruce, cut and skidded out wintertime on top of the snow.

It sounds to me like you are sharpening way too often. We all tend to favor one side of the chain when we sharpen. If you sharpen after every cut, eventually the blade will cut better on one side than the other. This will cause your bar to climb, (or dive) in the cut.

Machine sharpening your chain to restore the correct profile, then setting the raker height with a raker gauge may solve your problem.

Moving forward, I think you can sharpen a whole lot less, pressure wash your logs if you need to.

I hope this helps,
John B

[doug olsen]

MY thoughts exactly on the uneven sharpening.  Would be nice if you had another NEW ripper to change out and I'm sure your problem would be solved..

[thecfarm]

SteveR,welcome to the forum.
Yes,bandsaw people put another blade on to see if the problem goes away.
I know I sharpen by hand and can do a better job on one side than the other. But I am only cutting down trees,not lumber.Really don't make no sense,but when my saw starts to cut at an angle I sharpen the side when the motor is on the right and that does it. Does not happen often,maybe once every 6 months?,but seems to work. Maybe a guide would keep you true.
Whats all the lumber being used for?

[SteveR]

Thanks all for the input. The logs I'm cutting with the chainsaw mill range from 40" to 60" in width. I am also cutting end grain "cookies" up to 5'5" wide. Have ordered new ripping chains...hoping this helps. Will maybe try to put more space between sharpening. Slabs are being used for large, one-piece tables (harvest or board room style). Will try to take some pics to post.

[bandmiller2]

Likely its your chain and uneven filing but it could also be a worn bar groove. Frank C.

[terrifictimbersllc]

Yes the end of a slabber bar is when the groove is worn so that the chain isn't held straight on the bar by the groove. 

A good test is to flip the bar to the unused side and see if that fixes the problem.

Minimizing bar wear and bar alignment are important but different topics.

[mad murdock]

Terrifictimbers touched on what my thoughts were. I would add that like was already said about chain maintenance, tooth symmetry is real important and getting things very close to the same from tooth to tooth is important including depth gauges. The more exacting you are with overall chain tooth shape and equality over all the better it will cut. Also bar rail evenness is just as important. When you get a new chain and put it on, put a new drive rim on also, it will give you longer chain life if you change drive rim withe the chain as they wear in together and should be kept as a set once worn in. The granberg filing guide is a must ,imo, to maintain optimal performance.  Also recheck alignment of your posts and frame on the mill as it can get out of whack and or loosen up with all the vibration over time. Welcome to the FF btw!

[losttheplot]

Here is a short clip on bar maintenance, it may help.

If you dont already, get one of the small blue raker gauge's from husky.
They only register on the top plate of the cutter your sharpening, not across two.
Then you wont have to worry about your cutters all being exactly the same length.


https://youtu.be/32-aptHv1Es

[richhiway]

All good advice. Your chain has to be perfectly even when milling. I use a set of 5 chains. I use a bench mounted grinder to keep a perfect 10 deg angle and the cutters the same length. I start with a sharp chain. I use a ez lap diamond sharpener to touch up the chain,usually after each log. These work fast and you take very little material off your chain. If the chain gets to where it is not cutting true, I switch to another chain. I turn the bar each time I change the chain. As already mentioned, your bar has to be in good shape too.
If you don't have a bench grinder , there are a number of good manual guides to keep your cutters even. There are a lot of videos on you tube that show you that very few people can file a chain evenly without a guide. It does not show up when you are not ripping.

[PineHill4488]

Steve,
I run a 36" granberg and have seen a little what you describe.

Will Malloff's book Chainsaw Lumbermaking describes bar maintenance and sherpening in a fashion that even I understand.

I also got granberg's little 12-volt sharpener and multi-angle guide gizmo, life is much better.

My $0.02, Greg

[Bluejay27]

Does the cut wander evenly across the width or does it belly out in the middle? I'm running an 84" bar (although i've only cut a half dozen logs) and my issue was the bar sagging and continuing to do so in the cut. I added two additional uprights and lose on max cut width, but the bar is held much stiffer.

I just welded up a simple copy of the granberg uprights, except a few inches wider to fit further down the bar. I've cut as wide as 60" and flat within 1/16" width wise.