The Diary of a Chain Builder

[kent0242]

About Stones

When it comes to using abrasives with metals...
hard metals require soft stones, soft metals require hard stones.

I'm not sure about the hardness of the cutting teeth on a chain, but if you can ascertain the RC of the metal, you will be able to determine the proper abrasive to use.

As far as burning the teeth with an improperly dressed wheel, what happens is you 'work-harden' the metal and it becomes very tough. That's why you cannot file the metal after that. A file simply can't cut the metal unless the metal is soft enough.

Same thing happens if you let various tool steels overheat when drilling with high speed steel bits. If the metal work hardens, you can sharpen the drill, change speed and feed rates, but still cannot get past the hard spot. The drill bit won't make chips and will only become hot and dull for your efforts.

Besides keeping the grinder wheel properly dressed, plenty of coolant and/or cutting fluid is required to prevent overheating the workpiece.

 

[sedanman]

Kent, I have not built any race chains and don't claim to be an expert but here are a few things I did pick up. A big portion of the work on a race chain has a lot to do with making room for chips. The angles are special but they are not soley resposible for the increased speed. A race chain would be junk if used for cutting firewood. Racers don't like to cut bark or knots. Some builders go so far as the chain cannot be sharpened once it's finished because there is not enough tooth left.

 

[Hatchet Jack]

Some builders go so far as the chain cannot be sharpened once it's finished because there is not enough tooth left.

I don't no who told you that but why would you want to waste all that tooth lenght. I'll sharpen my chain when needed or if its not cutting good. There to hard to make and a chain will start cutting better as you bring the tooth back. The back rivet is a rule of thumb for when the chain starts cutting best but not always. Fred

 

[Hatchet Jack]

KM the grit of the gringin wheel also makes a difference. Even with coolant a fine grit wheel will blue the tooth. Fred

 

[Kneejerk Bombas]

Originally posted by Hatchet Jack
I don't no who told you that but why would you want to waste all that tooth lenght.

Originally posted by Hatchet Jack in the very next sentence

a chain will start cutting better as you bring the tooth back.

Good one Fred, question asked and answered in one post.

 

[Kneejerk Bombas]

Re: About Stones

Originally posted by Kent Marshall
I'm not sure about the hardness of the cutting teeth on a chain, but if you can ascertain the RC of the metal, you will be able to determine the proper abrasive to use.

That'll surely depend if you are de-chroming the cutter.

 

[Crofter]

I'd like to see some ideas about just what stoning the side of the tooth accomplishes and what aspects cause the decrease in cutting times. I know it works but why?

Frank

 

[Kneejerk Bombas]

When you stone a knife, you hit bot sides of the blade equally, are you hitting both edges of the cutter with the stone?

 

[Gypo Logger]

Hi Frank, I stoned my first chain last night, although it's just a work chain, I wanted to try it.
I would post a vid of a before and after, but I have been told that my vidoes are mundane and serve no purpose here. If that's the general concensus, than I will cease and desist. LOL
Anyway, from what I can gather, stoning not only isolates the working corner, thereby making it thinner and sharper, it also compensates for any teeth that may be cocked too far left or right.
John

 

[Crofter]

John, I am wondering about lateral angle of attack or clearance. To make a cutting tool feed you must have clearance. I see it as destroying the tooths tendency to feed out into the edges of the cut and widen it. Its only ambition is to cut down after you destroy the lead. It stops the teeth from splaying. But this explanation is only conjecture on my part.

Frank

 

[jokers]

I hope that the true experts will correct me if I`m wrong, but in stoning a tooth you maintain the ~6° lead as manufactured and you are merely removing the chrome to produce a sharper sideplate and working corner.

Marky,

Not everyone on this site cares to deal with Tom or Dennis. I don`t feel that way personnaly, but I understand the perspective of SOME of the other guys, atleast relating to Tommy`s behavior here. On the other hand, Dennis and Tommy will not make a chain for just anyone either. It must be that your unholy alliance with the devil has made you welcome to them, LOL.

Russ

 

[Crofter]

Jokers

empty your PM inbox, your mail is bouncing!

 

[Hatchet Jack]

Your making every tooth the same width on the vertical edge. Fred

 

[jokers]

Hi Fred,

If you are stoning by hand, how do you ensure that each tooth is the same on the vertical plane?

Russ

 

[glens]

What do <i>I</i> know about racing chain, so why am I posting?

See?&nbsp; You, gentle reader, are not alone in wondering.

Here's my theoretical stance on the subject, based in part on my actual experience with wood chisels and hand planes.

The outside corner, where the top and side plates meet, is not a perfect angle.&nbsp; That is to say, there is actually a radius present.&nbsp; Best results are when there is no radius (and both the top and side inner surfaces perfectly converge on that perfect point).&nbsp; I don't think there's very much bad conjecture on my part so far.

So the term "de-chrome" is usually used.&nbsp; That's not to say the tooth cuts better without the chrome.&nbsp; The process isn't to remove the chrome, but really to make that outside corner radius-free.&nbsp; If <i>that</i> could be done without removing the chrome, it would be better to do so.&nbsp; Okay, I'm starting to "conject" a little.

Reflecting on my experience with hand-sharpening my wood chisels and hand planes, in attempts to produce the finest edge possible, it's sometimes tempting to touch the non-bevel side of the tool.&nbsp; If great care is not taken to ensure no angle is introduced (that is, if it's not kept perfectly flat), it's going to be counter-productive.&nbsp; Especially so in the case of a chisel.

It would seem the same is actually true for saw chain.&nbsp; In fact, just the other day I had an unpleasant experience.&nbsp; A decorative hunk of shale was lodged between a failed tree and the lawn on which it fell.&nbsp; The obstruction was not visible, but my chain found it nonetheless.&nbsp; After carving a several inch path about cut width deep with the nose of my bar, my chain had totally stopped cutting wood fiber.&nbsp; The top plate forward edges are sharper than I get them with my round file, yet they're ineffective.&nbsp; That's because the material was taken from the wrong side of the plate, but more the reason because that was done by changing the (or introducing an) angle on <i>that</i> surface.

The process of producing the sharp outer corner on chain <i>must</i>, in my estimation, be done in such a way that the side, top, or both plates have material removed the same amount over their entire surface or it's ultimately counterproductive (or at the least, not <i>as</i> productive as it could be).

As for stoning surfaces, if I were so inclined, it would only be the <i>inner</i> surfaces for the above reasons.

Glen

 

[Hatchet Jack]

Glens I don't no for sure but it sounds like you stayed at a Holiday Inn last nite. Fred

 

[Crofter]

Glen

you are right about the radius on the corner being a detriment and probably about the chrome, but factroy angle of lead is much more than necessary on a racing chain. It is indeed the outside that gets stoned.

Frank

 

[Hatchet Jack]

how do you ensure that each tooth is the same on the vertical plane? Russ

It amazes me that a couple of dumb sons a ?????es like me and Gypo logger can figure it out and you can't. lol Fred

 

[jokers]

Originally posted by glens
......So the term "de-chrome" is usually used.&nbsp; That's not to say the tooth cuts better without the chrome.&nbsp; The process isn't to remove the chrome, but really to make that outside corner radius-free.&nbsp; If <i>that</i> could be done without removing the chrome, it would be better to do so.&nbsp; Okay, I'm starting to "conject" a little.

Glen

Glen,

I agree with your conjecturing regarding elimination of the outside radius on the tooth, but disagree with your belief that de-chroming is not necessary. I repeat what I stated earlier, I`ve never built a race chain, but I haven`t been sleeping through all of the discussions either.

I have in my possession a chain which was de-chromed by Ken Dunn which has minute remnants of the corner radius leading me to believe that Ken`s objective was not to remove the radius, but rather the chrome as was his stated intention. This has been discussed many times involving the likes of Ken, Art Martin, and Walt Galer to name but a few with significant experience, and the consensus seems to be that you can`t get a chromed cutter any sharper than the thickness of the chrome since files will not abrade the chrome, but will break it off instead, leaving a microscopic blunt edge. That pesky chrome is the reason that your experience with chisels doesn`t carry over 100%.

A perfect convergence of the inside angles on the tooth would be likely to cause turbulent flow of the chips wouldn`t it? Applying my spud farmer logic to the vision in my head of what goes on inside the tooth during a cut tells me that a smoothly radiused inside corner would be optimal for flow, similar to the flow of air through round ductwork vs square or rectangular. I`m not forgetting that all chips will not be identical in size or shape, simply don`t consider it important in this case.

Russ

 

[jokers]

Originally posted by Hatchet Jack
how do you ensure that each tooth is the same on the vertical plane? Russ

It amazes me that a couple of dumb sons a ?????es like me and Gypo logger can figure it out and you can't. lol Fred

Fred,

Are we talking about the offset of the outside of the cutter as compared to the edge of the drive tang or something else?

BTW, you don`t seem like any slouch, but Gypo is the worst kind. He hides his true intelligence to sucker people in for the kill and then displays what he knows and understands.

Russ