Ripping chain chatter

[pshupe]

Hello - I've been using an Alaskan saw mill for a number of years now.  But it's just a hobby so have not done a lot.  I was buying skip chains and it seemed to create dust instead of chips.  Recently I went to a full comp rip chain, (10 degree).  I cut up a bunch of pine for a friend and these chains worked really well, as would be expected in pine.  This is the first time I had cut softwood with my mill.  I just recently cut a large black walnut log and used the same type of chain, brand new.  It cut like crazy and pulled chips, not dust, but there was quite a bit of chatter.  I assume because it's new it may be a bit aggressive.

Is that the way the chain should cut or are the rakers too low?  It is a brand new chain, so I assume it should be setup properly?  Love to hear from some experienced people here.

I've read a few threads here, as I am very new.  I joined yesterday.  I have read that using regular cross cut chain is more cost effective.  Just start a 10 degree angle and you are good to go.  Is this true?  I can't remember the difference in price between cross cut and rip but I know I have a hard time getting a "real" rip vs a skip.  The local place wants to grind a 10 degree angle but I think they take too much off and charge $15 on top of the brand new cross cut chain price.  Thoughts?  Thanks a lot.

Cheers Peter.


 

[lxskllr]

I'm using full comp RM2 as ripping chain. That's NOS chain, semichisel, with a triple humped tie strap. In a milling context, I think the semichisel is the important part. First cut on a new chain, I don't even touch it. I slowly bring it to 10° as I sharpen it through normal use. I leave the rakers a bit higher. That means I don't adjust them as frequently as I would crosscut chain, but I don't make any initial adjustments on new chain either(I guess that would entail removing a bunch of tooth). I haven't noticed any chattering issues with my setup.

[pshupe]

Thanks.  I'll look into the RM2 chains.  I've been using regular chain skip tooth and notice it's mostly dust, even with a new chain.  It's pretty smooth and find I have to guide / lightly push it more.  The new chain I just tried is very aggressive.  Full comp rip chain.  Chatter may be the wrong word but I can definitely feel it grab into the wood.  I do not have to guide it into the cut as it seems to pull in nicely.  It does cut fast and shoots out chips rather than dust, so I think this is how it should work.  As I said I do not have a lot of experience at this.  I was thinking the exact same thing as you mentioned.  I'll sharpen a few times and not touch the rakers and see how it cuts.

Cheers Peter.

[lxskllr]

RM2 is old stock. Aside from ebay or other secondary markets, you won't find it. It's just a style of safety chain, and I don't think it matters for milling purposes. The modern equivalent would be RM3, or for non safety chain, RM. For milling, price would be the only differentiating factor. They should cost the same, but if you found one or the other cheaper, that's what I'd get.

[esteadle]

I've had this happen recently and what I found is that the bolts that clamp the frame to the bar weren't tightened uniformly and the bar was pitched slightly compared to the frame. This tilts the bar slightly allowing the chain on the back side of the bar to dig into one of the boards (top or bottom, depending on pitch). 

Also, when I loosened them up to re-tighten, I saw my bar "bend" slightly as my powerhead cantilevered down and the bar flexed up. So as you are tightening the clamp bolts, be sure to support the saw head with a piled up rag or a piece of wood or something to help prevent that flex. 

Don't use cross cut chain on a Granberg mill. You won't be happy with the results as you'll be going away from your solution instead of toward it. Cross cut chain is for cross cutting. Ripping chain is for ripping. They are different by design. Ripping chain gives a much smoother result. Cross cut will give you hours of planing and sanding work. 

10 degrees is the right filing angle for ripping chain. You don't need semi chisel. I would recommend learning to file your chains yourself. I file 3 strokes after every other cut, right on the frame. Get a 2-in-1 file to make it easy to file the cutters and the depth guides in 1 pass. The PFERD saw files on Amazon are pretty good. Check the size of your chain and order the right one. NOTE: the PFERD are set up for 30° so you have to eyeball it to get yourself 10°. 

Best of luck to you! 

[pshupe]

Thanks I'll check that.  I'm usually pretty aware of that but might have been rushing as I did change chains at one point.  I have always used a dedicated chain for ripping.  I have tried full skips, semi-skips, and full comp rip.  I prefer the full comp rip as it seems to work the best and I have a Stihl chain sharpener and usually label chains that are dull.  I replace often and find 10 to 15 light strokes on each tooth seems to be about right.  I'm starting to get the feel for it.  It seems it takes a number of strokes to feel a consistent pressure across the tooth and and then a few more to get it nice and sharp.  If hit something or damage a chain, I have an electric grinder and it works well also.  Thanks again for the tips.

Cheers Peter.