Is there a specific sign/point when you should stop using a chain?

My take is that it's cutting a narrower kerf, and can take a thicker chip.

Definitely do not want a chattery chain.



Anyone else change the raker offset through the life of the chain?
yes, I call it a progressive raker guide, as the tooth wears back, the amount taken off the raker progressivly increases past the inital amount most non progressive guides allow.

ie

using a husky roller guide with progressive raker guide for example on a stihl semi chisel chain.

hg3.jpg

hg4.jpg


and the stihl prorgressive raker guide on a resonably worn chain that cuts very well.

scrg1.jpg



on a new chain for reference
sg4.jpg


well worn one
sgafteraker.jpg


sc1.jpg sc2.jpg



edited to add

I replace the chain when the cutters start to fall off.
 
I hit a point I call diminishing returns. File sharpen with a jig until even a small file size cant correct the problem. Teeth get bent. Chains get worn. Bars get worn. Such a thing as penny wise and pound foolish. I make more money when my chain cuts sharp. When it does not wander in the wood.
If there is enough meat on the tooth for another grinding, great. Let that 7.00 correct it and I'll get another day of abuse out of it. If not enough tooth to grind it within safety marks, scrap pile. Move on. Make money.
Fug all that i'mmagonna get every micron out of this chain.
 
Lots of factors on a chain that contribute to it cutting well, or it not cutting at all, along with when to keep it and when to toss it, or replace damaged drive links, cutters or tie straps, some are worth repairing, others not so much.

chain new from the factory is a compromise to sort of cut in all different situations, and you can dial in your chain to the particular wood your cutting.

setup for hard dead wood is different to a green, or soft pine etc.

The amount of hook on the top tooth, ie how high or low you place the file on the tooth, high placement of the file gives less hook, lower placement of the file gives more hook.
less hook is more durable and smoother, but slower, more hook can be faster, but the end of the tooth can be less durable, and more grabby if taken too far.

The angle the top tooth is filed to, 25/30/ 35 deg, or 10 for milling, more angle again makes the end of the tooth less durable, especially on chisel chain.

how much you take off the raker, too little and the chain will not self feed, and create dust and cause wear on the bar due to it being dogged in and leaned on to make it cut. Too much, and the chain becomes grabby and bogs the power head down. If its like that, forget trying to plunge cut, or cut smaller bits of branch.

The rakers are just there to determine how much of a bite the cutting tooth takes, and if you have different length cutters, but the rakers are all set correctly to each individual tooth, the chain should still cut straight and well, (providing the bar is in servicable condition), its not as efficient as each cutter being the same length, but it works, and enables you to get more life out of your chain instead of taking cutters back to the shortest damaged one, and loosing half of the life of the chain in one sharpening.

On hardwood, its better to run rakers higher than soft wood, as you wont overload the power head as the cutting tooth takes less of a bite into the hard wood.
on soft wood, the power head can easily drag the cutter thru the soft fibers, and you can take a bigger bite of soft wood, thus the lower raker height setting.


when a chain tooth gets worn, the height of the tooth lessens compared to its original height, along with its width, or the kerf it creates, and you can in some instances use a smaller file as has been mentioned.
Say your on semi chisel with a 5.5mm file, you could go down to 5.2, and even down to 4.8, as the 5.5 file ends up cutting into the tie straps, and leaves less hook all in one pass.
Basically what your trying to achieve is to maintain the amount of hook the tooth started out with, or what you want for your particular situation.


Ok, been trying to write this whilst being thrashed by my family playing amoung us. hehe.

hope it makes sence.
 
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So much good info here I wish I knew sooner or didn’t have to learn through trial and error! How do large tree companies teach all those new people how to sharpen chains and they actually do it well? I have 2-3 people at a time and it seems impossible to get them to understand all of this. I feel like i need a teaching manual on all of this with LOTS of pictures lol
 
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Maybe make a guide. Compile the information into a pdf for employees. They can put it on their phones.
 
Lots of good sharpening info in this thread.

Many guys hate the idea of a chain grinder but they definitely have a place. I can file, although I’m not a master at it. I’ve found the grinder takes out the inherent “human” element to a degree. It’s makes everything consistent.

I have a few chains missing some cutters but as long as it’s one here and one there and not several in a row broken off one side, they still cut straight. If the teeth are similar length and rakers are ground accordingly, they cut strait until more cutters break off.
I have encountered one 36” chain that wouldn’t cut more than 6-8” deep into a log though. Cutters were about 25% maybe. Near as I could tell, the chain no longer cut a wide enough kerf and the bar would get tight in the log. Put on a new chain and it was fine.
 
It's the problem with the ms150. The chain can barely reach its end's life due to a too thin kerf. When the cutters are well reduced, they become just a tad wider than the rivets. Add some wear on the bar's groove and it can't no longer cut over 2". I tried to push the live length of the chain by reducing the filling angle near the end (keeping the full width of the cutters until breaking them). Bad idea. The chain with straighter cutters (like a ripping chain) doesn't sway as much side to side and carves an even thiner kerf and locks in the wood. So I ditched the idea and at the contrary, enhanced the cutting angle over the 30° for the next ones at their end and that helped on the binding. Maybe less live, but still fully useful and less irritating.
 
The narrower the kerf, the greater the need for a straight cutting chain.

If I'm temporarily fighting a j-cut, reaming helps.

I really like how a well worn chain cuts, the narrow kerf seems to speed it up, its a dissapointment when I put on a new chain, as its slower, and look forward to putting a file to it after a few tanks, or when needed to get it to suit what im cutting better.

if its J cutting, the chain will cut and bow towards the sharper side, so look at the other side, and check the corners of the cutters, to make sure any damage has been corrected fully by filing away whats needed, not just number of strokes, and then set the rakers and try it.
Again, assuming the bar is ok.
 
It's the problem with the ms150. The chain can barely reach its end's life due to a too thin kerf. When the cutters are well reduced, they become just a tad wider than the rivets. Add some wear on the bar's groove and it can't no longer cut over 2". I tried to push the live length of the chain by reducing the filling angle near the end (keeping the full width of the cutters until breaking them). Bad idea. The chain with straighter cutters (like a ripping chain) doesn't sway as much side to side and carves an even thiner kerf and locks in the wood. So I ditched the idea and at the contrary, enhanced the cutting angle over the 30° for the next ones at their end and that helped on the binding. Maybe less live, but still fully useful and less irritating.

1/4 chain is so small, and the cutters so short and small, you dont get much life from them sadly, add to that the joy of bumpers on the chain, and its a royal pain in the butt, I prefer my 3/8p on older pole saws to the newer 1/4 chain, fine when its new, but it just dosent last.
 
So much good info here I wish I knew sooner or didn’t have to learn through trial and error! How do large tree companies teach all those new people how to sharpen chains and they actually do it well? I have 2-3 people at a time and it seems impossible to get them to understand all of this. I feel like i need a teaching manual on all of this with LOTS of pictures lol
They buy a new chain after sharpening it 2 or 3 times if any. You'd impress a lot of pros running a chain filed down anywhere near the guide marks and have it cut well, because they think it's time to throw away a chain at 2/3 to 1/2 life, probably because they never file the depth gauges, but by then the teeth are too messed up.
 
I really like how a well worn chain cuts, the narrow kerf seems to speed it up, its a dissapointment when I put on a new chain, as its slower, and look forward to putting a file to it after a few tanks, or when needed to get it to suit what im cutting better.

if its J cutting, the chain will cut and bow towards the sharper side, so look at the other side, and check the corners of the cutters, to make sure any damage has been corrected fully by filing away whats needed, not just number of strokes, and then set the rakers and try it.
Again, assuming the bar is ok.
I clipped a nail head the other day, just barely, on one side only, between the two facecut kerfs.

Chased the backcut around.

Filed afterward.
 
When heavy grinding is needed to correct damage/human error. What is a good grinder that’s not $1000? We only use round ground chain 3/8lp, .325, and 3/8
 
one that has the 2 adjustments on the neck of the unit, so you can set up proper angles when using it.
Those with just one adjustable angle on the neck/ where the unit pivots down towards the chain, are no good.

Get a stone dressing file as well, as you need to keep the radius clean over time on the different grinding wheels you will use for those different sized chains.
 
When heavy grinding is needed to correct damage/human error. What is a good grinder that’s not $1000? We only use round ground chain 3/8lp, .325, and 3/8
Knowing how to manipulate a grinder to do what you want regardless of it's quality goes a long way.

I think I'm faster at hand filing because I can actively correct for any errors in sharpening that I see without having to stop and tweak an adjustment knob, and I can file aggressively without fear of hardening the teeth, which would otherwise require a slow gentle pass on the grinder to correct. I find having the bar tip pointing towards me helps a lot, so I can lean into the tooth as I file if it needs a lot of filing, or if the file is getting dull. I find some files dull quickly and stop working, but the Oregons I've been using will dull, but keep filing well enough for a long time if I lean into them. So now I can sharpen like 10-20 really dull chains with 1 file rather than 2 really dull chains with 3-5 files.

I try to avoid sharpening in a way that gets filings on me (not easy) and use a magnet filter I made to catch the filings in the wash so they don't ruin the drain pump as fast.
 
Roller guides and guides in general are often for a specific chain model.

Raker can be checked and set easily by using file or ruler over three teeth and check rider in middle.
New chains are pretty low when new. I rarely touch them until they are half or almost half filed. It is not needed.
How low raker can be is not a universal setting, it is depending on saw, user and wood.
Low rakers may feel fun, but in timed cuts you see it is actually slower. If saw can hold rpm the chiseled wood the tooth cut will not curl up right and tooth stop cutting. It is often seen on chains were the filing is not that great. A try to compensate sharpness...
Low rakers increase risks, fuel used and wear on cutting attachments.
 
the teeth don‘t needto be equal length. waste of time and chain. just sharpen each individuel tooth to perfection and afterwards take a raker gauge to each raker/tooth. i sharpen mychains until most teeth hit the mark and then keep them for dirt/nail work. usually the one thing that makes me swap a chain is that the tiny cutters will snag my ropes more.
 
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