How does a properly sharpened chain compare to a new chain?

[Al_Smith]

Then the conversation comes up about what  would really be considered a race chain .Thinned cutters ,modified square  chisel .First of all it takes forever to file .It works great on almost green cut poplar cants but not so good on dry as a bone dead ash or hickory .You'll break the teeth right off .It's a waste of time for anything but racing and I doubt seriously if many on this site or anybody else  does that .There's a few tricks you can do but really the rest who  ever designed the chain had already  figured out .It's like redesigning the wheel .It get's about like the oil thread after a while ..Which is fun too 8)

[medved]

I never saw the point of semi chisel. Now I'm cutting pine that feels like it's made of sand. My full chisel chain is either constantly dull or I'm constantly doing long full resharpens it seems, so I'm going to pick up some stihl RMs and see whether life improves

[moodnacreek]

I always file the rakers a bit below specs and my chains cut like a champ!!
Tuning the saw with the jets to get maximum RPM helps enormously too.
Pete

So do I but it's not the right thing to do on a new chain. If the chain saw is under powered or over barred, not always good. I think it helps because we are filing by eye.

[moodnacreek]

Another brainstorm; anybody ever file the tops of chisel chain to flatten the surface so to get a sharper point? On some chains it seems like they stay a little rounded like semi chisel.

[Old Greenhorn]

Another brainstorm; anybody ever file the tops of chisel chain to flatten the surface so to get a sharper point? On some chains it seems like they stay a little rounded like semi chisel.

I square file my chisel chain and yes, after I file all the teeth I go around one more time and take a light swipe or two across the top plate to take the burr off. I file from front to back so as not to roll the burr over the cutting edge, and I only remove the burr, I don't remove much, if any material from the top plate. Then I do the rakers if they need it.

[lxskllr]

I can't find the video now, but there was a Swedish guy that did a custom grind, primarily to speed up bore cuts. Assuming there were no shenanigans, he got noticeable results. I can't remember everything he did, but the most interesting thing was grinding the back of the cutter to the witness mark, holding the witness mark angle. IOW, the back edge paralleled the cutting edge when he was finished. I wish I could remember where I saw it.

[John Mc]

I square file my chisel chain and yes, after I file all the teeth I go around one more time and take a light swipe or two across the top plate to take the burr off. I file from front to back so as not to roll the burr over the cutting edge, and I only remove the burr, I don't remove much, if any material from the top plate. Then I do the rakers if they need it.

I've wondered about deburring, but when I've checked, the burr is gone anyway after the first few seconds of cutting, so I've never bothered.

[lxskllr]

It's getting a little nitpicky, but I think the idea is to remove the burr on your terms, not at the whim of what you're cutting, and damaging the edge underneath. Makes sense on fine knives, but I don't know how much difference it makes on saw chain.

[John Mc]

I've not seen signs of damage on the edge after deburring by simply cutting wood, but I'll admit my eyes are not what they used to be. Sometime I can knock the burr off with my fingernail. I've also seen guys who use a small chunk of hardwood to knock the burrs off by just rubbing across the chain.

[moodnacreek]

Taking off the wire edge [bur] is not what I ment.  On some chains the surface of the tooth top plate and maybe the side are not made like machined or polished steel and the top corner is not a perfect corner so when you file up the point there is very slight roundness . The extreme point of a chisel chain cutter is the 'lead' that makes it self feeding.  Just the slightest roundness there slows down the action.

[Old Greenhorn]

Taking off the wire edge [bur] is not what I ment.  On some chains the surface of the tooth top plate and maybe the side are not made like machined or polished steel and the top corner is not a perfect corner so when you file up the point there is very slight roundness . The extreme point of a chisel chain cutter is the 'lead' that makes it self feeding.  Just the slightest roundness there slows down the action.

I am guessing you are round filing your chains, not square and that would explain why you see some rounding. It's pretty hard to have a square corner with a round file. Double bevel files, when used right leave a square corner, and also a small burr sometimes.
 As for the comments about the burr removal being nit-picky, well perhaps you all are right. Understand that I have been a machinist and tool maker for a very long time. I have made and evaluated a LOT of cutting edges in my career, I have studied them under a microscope, and studied how a cutting edge breaks down as it creates a chip in various materials, as well as the effects of various cutting lubricants. Seeing a burr on a newly formed cutting edge is something I cannot suffer, so I take it off. Doing otherwise, for me, would be sloppy work. I want to give that edge every chance to have a long productive life. That's just me.

[John Mc]

Taking off the wire edge [bur] is not what I ment.  On some chains the surface of the tooth top plate and maybe the side are not made like machined or polished steel and the top corner is not a perfect corner so when you file up the point there is very slight roundness . The extreme point of a chisel chain cutter is the 'lead' that makes it self feeding.  Just the slightest roundness there slows down the action.

Yeah, I followed what you are saying. An interesting idea. Kind of taking the difference between a semi-chisel and a chisel chain one step further. I wonder if this is a trick that people who sharpen for racing use.
Can you tell much difference? If so, how long does the difference last? I would think a needle-sharp point might be a little fragile.

[moodnacreek]

John Mc, Thanks for understanding. It is not a filing defect it is a manufacturing defect you see when trying to file up a perfect point. If filed with too much hook angle, that would be too weak and the point would tend to bend or crumble. I would think someone besides me has noticed this small defect. After all, that point is everything on a chisel chain.