why does this scoring happen when milling but only sometimes?

[cluelessmontana]

https://dl3.pushbulletusercontent.com/OvtRcQsL26tyWuclaROyqzYctPaoi8jX/20230514_203724.jpg
when I mill small logs with my ms180, i get no scoring, even with a normal non-milling chain (it uses 3/8 lo pro)

When I mill with my 460 rancher or 555, i get this scoring if i use a normal non-milling chain, but only sometimes as seen in the picture. If I use a chain ground to 10-15 degrees, then I usually get very little scoring. I'm just curious why it happens only with the bigger saws and how to prevent it.

 

[J D]

https://dl3.pushbulletusercontent.com/OvtRcQsL26tyWuclaROyqzYctPaoi8jX/20230514_203724.jpg
when I mill small logs with my ms180, i get no scoring, even with a normal non-milling chain (it uses 3/8 lo pro)

When I mill with my 460 rancher or 555, i get this scoring if i use a normal non-milling chain, but only sometimes as seen in the picture. If I use a chain ground to 10-15 degrees, then I usually get very little scoring. I'm just curious why it happens only with the bigger saws and how to prevent it.

Rocking the saw backwards & forwards will cause similar, as will poor technique. How well the chain is sharpened can make a difference too. I have experienced similar with some cuts & I believe it was to do with the width of the cut being sort of resonant with the saw & making vibrations worse. The greater the angle your top plate is filed at the further out from the bar the cutters are pulled which exacerbates things.
Using a plank for every cut so the mill has something smooth to run along may help

 

[muddy42]

Wow that effect looks really pronounced and more extreme than is produced by non-milling chain or poor technique. Could the chain be cutting off at an angle and then getting pulled back into line by the mill? Does the chain cut straight out of the mill? If so try dressing the bar flat and making sure each side of the chain is sharpened the same. Or try a different chain.

For what its worth, I use standard cross cutting chain rather than milling chain in my mill with an 120cc chainsaw.

 

[blades]

You could have a bar that one side of the chain channel is worn thinner than the other- only a new bar will fix that. it is not an unusual condition

 

[BobL]

That effect (more commonly seen on narrow boards) is calked "washboard" and is cause by a "synchronicity" between chain speed, chain cutter setup, speed of cut, board width and wood softness etc. If any one of those factors differs markedly the washboard effect will disappear

Here is an example of two successive cuts - so same log and same (new) log saw/mil/chain.
Only difference is board width with the LHS being the first (narrower) cut, the second cut was about 4" wider.

 

[tJKrider]

That effect (more commonly seen on narrow boards) is calked "washboard" and is cause by a "synchronicity" between chain speed, chain cutter setup, speed of cut, board width and wood softness etc. If any one of those factors differs markedly the washboard effect will disappear

That's what interesting. Reminds me of metal cutting in a way. You can go from long continuous chips to short manageable ones that self break with just one variable change.

 

[Up A Creek]

That effect (more commonly seen on narrow boards) is calked "washboard" and is cause by a "synchronicity" between chain speed, chain cutter setup, speed of cut, board width and wood softness etc. If any one of those factors differs markedly the washboard effect will disappear

Here is an example of two successive cuts - so same log and same (new) log saw/mil/chain.
Only difference is board width with the LHS being the first (narrower) cut, the second cut was about 4" wider.

View attachment 1083728

Wow.
This is something I haven't managed to do yet.
I would have thought maybe the teeth were sharpened uneven.

Crazy how different those cuts are with just a 4" difference.

 

[cluelessmontana]

mine did it with a brand new bar and chain, tho it was a 20" forester brand bar a chain, which im sure is just some cheap china stuff but it had better reviews than oregon advancecut

 

[buzz sawyer]

Kind of looks like an harmonic effect. Suggestion - try feeding the saw at an angle, leading with the nose instead of perpendicular to the log. It should cut more easily.

 

[rarefish383]

Usually those things are driver error, being new to milling. When I first got into milling with my Homelite Super 1050 and a 36", bar I tried milling chain. I didn't see much difference in it and out of the box Stihl chain. So, being my lazy self, and not liking to change the chain every time I had to use the saw at work, and when I wanted to mill, I just left the standard chain on. First pic is a White Pine wind blown tree that I milled slabs with the 1050, I later made a fold down table for deer camp in WV. The pink wood is Dawn Redwood. I milled it with the 1050 also, the pics show a piece I gave a friend for a mantle. It went through my Jet 16-32 drum sander 3 times and all milling marks were gone. The last is a Red Oak mantle with bark on. It went through my planer 3 times and all milling marks are gone. The two long Oak boards , standing upright, are the ones in the mantles. No milling chain was used on any of those cuts. Read the 101 stickie above, use rails on all cuts, elevate one end, and don't rock the saw back and forth. Soon all of those rookie things will disappear.

 

[JYC]

In adition to the above, I think not using enough wedges in the cut behind the saw can lead to the slack side chain being pulled away from the bar, and allowing it to wobble. Very much like a loose chain. This may eventually stretch your chain to the breaking point.

 

[Lil'Skeet]

In adition to the above, I think not using enough wedges in the cut behind the saw can lead to the slack side chain being pulled away from the bar, and allowing it to wobble. Very much like a loose chain. This may eventually stretch your chain to the breaking point.

Agree, extra friction on chain & bar means faster wear and unnecessary heat. More unnecessary load on engine and clutch. Wedges are your friend and allow the saw to work on the cutting rather than the dragging and binding. Every little bit helps when ripping.

 

[Coralillo Lo Pro]

Lo-pro is a consistently cleaner cut because of the small teeth and low profile of the chain. There is very little side load and the low profile keeps the chain from oscillating side to side nearly as much as larger chain. The larger the chain you use, the higher the teeth are above the rail, the more it's going to rock side to side. When you use an aggressive non-milling chain, the side load is going to be even stronger. The newer and sharper the chain is, the more the teeth are going to dig in and likely increase that oscillation. Once you get into that rhythm it stays in it unless you change something up. I tend to pull back on the saw with new chain when it wants to dig very aggressively. Any slop in your rails is going to increase the problem exponentially too. Cheap Chinese bars seem to be machined to very sloppy tolerances and a lot of people have terrible washboarding with new bar and chain. Or chain may be made w sloppy tolerances too. Wiggle your chain side to side in your saws and see how much your chain rocks. I just got an ancient McCulloch with a .404 .063 bar that the chain has no wiggle in at all. Quality bar still after over 50 years. My lo pro is tight in the rails of my GB bars too.

Just as a matter of curiosity, I checked the .404 chain on my 880 and it's incredibly sloppy in the rails, I've worn out that 42" Stihl bar far more in the past four years than I realized, which explains the poor washboarding results with new chain the last time I milled with it and why I soured on .404 due to inconsistent results. My bad for not keeping on top of that, time for a new bar. Abused that bar horribly learning how to mill every wrong way possible. Because manufacturers don't make bars or chains with milling and precision in mind and China manufacturing has kept diminishing quality, I feel like there are poor tolerances in a lot of bars for sale now, and lower quality steel for the most part that wears easier.

I see people routinely attribute this kind of thing to newbie technique problems, but I've seen very little discussion of side load forces on chain and how to minimize them, or have people check how much side to side play their chain has. A lot of the milling veterans who have smooth results just chalk it up to experience, but a lot of them use much older pre-China equipment or only buy top quality new bars and chains which makes all the difference in the world if it means tighter tolerances and far less chain slop. When people have bad results with new bar and chain, the first question often is "are you using .050 or 058 chain in an .063 bar?" But the sad fact is there are supposedly matching new bars and chain that come with at least .005" of slop in them. And the more slop, the quicker the rails wear out and become even more sloppy and the worse your washboarding gets.