Saw Grinding and Crooked cutting

[hokiebob1]

I've gotten my NT grinder and done several chains - a 23RS Stihl and the H30 husky. When cutting green red oak with the 18" bar and the Stihl chain, if the wood is <16", it cuts very well and straight, but in the base pieces of the tree (~24" or so diameter), once the bar is buried, it pulls to the left. I've reground it and it does the same thing. I haven't done the rakers yet-could this be the problem or is it more likely that one side of the cutters are screwed up. I've centered the chain in the vice as best I can and when I switch sides, it appears to contact the teeth very similarly. I've tried both 60 deg head/25 deg base/10 deg up and 55 deg/30deg/10 deg--both seem to do the same.

I sure could use some help from folks that know way more than I do!

thanks
bob

 

[lawson's tree s]

your bar could have a burr on it try grinding the sides of your bar. sometimes tthey get mushroomed.

 

[hokiebob1]

Thats a good thought, but when I reground the chain, I flipped the bar. While I didn't check it for a burrr, I did check it for straightness (which it was) and flipped it to see if it helped....still pulled the same way.

 

[Timberhauler]

I have had this problem alot with stihl chain,which is why I don't use it anymore....It seems like when it gets worn down about 50% it starts cutting crooked.....I have had this problem several times especially with bigger bars.They will start to cut so crooked,they won't even go all the way through the cut.

 

[hokiebob1]

Timber, thats what happened with this chain, although its not at 50% life. It would get 1/2 way through or so and just wouldn't cut anymore. If I pulled it our and reverse cut it from the bottom, it would cut fine but something happens when the bar gets buried in the tree. I don't get it--I tried the H30 (Oregon chain, I believe) and it behaved correctly.

I haven't measured the cutters but will do so shortly. If the cutters are slightly different lengths, will this cause it? If so, I don't understand why, but I believe I've read that in here.

 

[Wismer]

Check your rakers. If they aren't ground off every so often they make the saw pull to one side.

Your saw should have a gauge that came with it

 

[hokiebob1]

Just measured the cutters and they are all within 0.010"-not sure what is normal but that seems ok to me. Rakers aren't bad either though I'll set them correctly tomorrow.

 

[Timberhauler]

Timber, thats what happened with this chain, although its not at 50% life. It would get 1/2 way through or so and just wouldn't cut anymore. If I pulled it our and reverse cut it from the bottom, it would cut fine but something happens when the bar gets buried in the tree. I don't get it--I tried the H30 (Oregon chain, I believe) and it behaved correctly.

I haven't measured the cutters but will do so shortly. If the cutters are slightly different lengths, will this cause it? If so, I don't understand why, but I believe I've read that in here.

I've done it all...making sure every tooth was at the right angle,and making sure the rakers were perfect....and I never could make a Stihl chain last more than about 50% of it's life before it started cutting crooked.....I like the way they cut when new.

 

[West Texas]

If you are using regular comp chain, instead of skip or semi skip, then the chain can simply become clogged with chips, even down into the bar groove, on a larger cut and buried saw. Depending on the wood, it can even jam it to the point that it will stop the saw. When I'm cutting green wood, I use semi skip, even on a 20" bar to avoid this problem.

 

[treeclimber jul]

stihl chain

Check the slop of the chain in the bar grove. Also as said before see if the bar has any burrs on the edges. I run all my stihl chain down to past the replace mark, and don't have any trouble.

 

[hokiebob1]

It is a full comp chisel chain--I hadn't thought of that but I suppose its not clearing properly and getting clogged, because like I said, in smaller green logs, it cuts darn good with large chuncks.

As an aside, what the view of all teeth being with .010 length--is that good or not?

 

[mountainlake]

Seems to me a skip chain would clog up faster than a full comp as each tooth would have to carry more chips cutting at the same speed. Are all the chains you sharpened doing the same thing? If you hit something on the side of the chain and the side is still curved in a little after grinding it will cut crooked. Maybe try a new bar to make sure it's not bar related. .010 seems good to me, I know some of mine are no where near that close and cut just fine. Steve

 

[Wismer]

nah, cause there is less teeth on a skip chain. Same amount of chips to clear

Less teeth, so less chips to clear

 

[hokiebob1]

The more I think about it, its likely that it wasn't clearing the chips enough. It didn't start getting goofed up until well into the cut and the bar had been buried for a little while. Perhaps its a technique thing that I need to work on???

 

[turnkey4099]

It is a full comp chisel chain--I hadn't thought of that but I suppose its not clearing properly and getting clogged, because like I said, in smaller green logs, it cuts darn good with large chuncks.

As an aside, what the view of all teeth being with .010 length--is that good or not?

The length of each tooth relative to each other is one of the least critical parts. Most important is that both sides be equally shaped and sharp and that the depth guages are equal. As long a the teeth are visually identical, a sharp chain should cut straight. Not to say it won't cut better if all are the same length.

Harry K

 

[ehgauss]

Saw Grindin g and Crookded Cutting.

This has happened to me several times because the two rails on which the chain rides on the bar have worn unevenly. Take a square and (with the chain off) see if the the tops of the rails are of equal height, with respect to the square held against the bar. If not, you can take a file and try to flatten them, or Bailey's sells a file holder/file that holds a file at right angles to the side of the bar and allows you to file them flat so that the chain cuts in line with the bar. It solved the identical problem last year on my Stihl 041 Farmboss with a 16" bar. Gene Gauss

 

[hokiebob1]

Thanks Gene. I don't get it--I can take the the factory H30 chain that I sharpened the same way and it cuts like nobody's business through that big oak, but with the Stihl chain is terrible. It definitely wants to pull to the left, and if I change chains in mid-cut, the H30 will straighten it out and git 'r done.

I put a protractor on the top plate and both sides are the same. It appears that there some funny angle on the top of the side plate and apparently it will take several grindings to remove--wonder if I shouldn't take my time and really cut them back to remove all of the goofy Stihl angles.

I presume you should grind chisel and semi-chisel the same?

thanks

 

[hokiebob1]

Ok, so in my mind, I've eliminated the bar since a different chain cuts well.

If a chain cuts from right to left, and assuming both top plates are sharp, where would the problem lie? I've looked at the bottom of the tie straps but am not sure how to tell if they are uneven. Could it be something goofy with the side plate angle? I don't know enough to understand what exactly the side plate angle does, but I do know that its apparently a product of cutting the correct top plate angle and upcut angle.

One would never thing there's this much science in sharpening chain, but I'm a believer.

 

[tawilson]

I think you may be on the right track. Possibly an uneven bar screwed up your chain. Chuck it before you screw up your new bar. And while you are starting over new, get a new sprocket.

 

[Timberhauler]

The first time I experienced this with Stihl chain,I was runnin' a brand new bar.