A different way to sharpen a chain.

[parrisw]

Where's the OP??

 

[parrisw]

I believe he pulled out when a few here questioned his interpretations of his observations.

Great thread though!

ha ha, ya I figured that happened.

Thanks for the reply.

 

[Dennis_Peacock]

Excellent thread....once my head stopped hurting over all the various translations.

I sure wish N9 hadn't of left.

 

[Metals406]

The teeth rock no matter how tight the chain is.
If you push hard enough or tighten the chain enough to stop
the teeth from rocking you will damage the bar and chain.

Print this .PDF and take the time to read it carefully and thoroughly.
http://www.sawchain.com/images/complete book.pdf

It has taught me a lot more than anything else in this message thread.

I'm also planning to write to the show "Time Warp" and ask them
to do a show on this subject. I even have some ideas for how
they can film it w/o xrays.

Holy crap!! I had the same idea about writing Time Warp!! I was just telling the wife about it about an hour ago (like she cared :greenchainsaw: ). We should have a huge campaign to get them to make slo-mo video of a chainsaw in wood... With different chain to boot.

 

[MCW]

The teeth rock no matter how tight the chain is.
If you push hard enough or tighten the chain enough to stop
the teeth from rocking you will damage the bar and chain.

Print this .PDF and take the time to read it carefully and thoroughly.
http://www.sawchain.com/images/complete book.pdf

It has taught me a lot more than anything else in this message thread.

I'm also planning to write to the show "Time Warp" and ask them
to do a show on this subject. I even have some ideas for how
they can film it w/o xrays.

Well they're obviously wrong As if a chain can leave the bar - thats CRAZY talk

 

[Nailgunner]

polycarbonate needs to be polished to be transparent as such; it wouldn't be polished after chainsawing it! also it's very tough; too tough for a wood cutting chain, which wouldn't work as expected anyway. A third problem is specific to thermoplastics, they tend to melt under high speed cutting, and I'm sure a big cut with a fast chain would get very sticky very fast.

My vote goes with high-speed X-ray photography.

 

[Metals406]

Here's my post on the Discovery website (Which is where suggestions belong)
http://community.discovery.com/eve/forums/a/tpc/f/2501973079/m/8301993199

I just posted a reply backing you up.

 

[B_Turner]

Polycarbonate doesn't have directional internal fibers like wood.

With wood,the fibers have a big effect on the shaving. E.g. engrain dust (miling) vs long noodles vs crosscut where the tooth rocking plays the biggest role.

The shaving and the known struture of wood tell us alot about what the cutters are doing.

 

[Metals406]

Makes 3.

 

[Tzed250]

Have you ever seen a slow motion video of how a chain cuts?

Is there one?

I'd like to see it.

I see some food for thought here. The theory of how a chain actually cuts if you could be view it in 3D slow motion would be a lot different than we usually think of it. I think Z250 posted some video here a number of years back. I like to think of it as a string of cutting kites being pulled one behind the other with each one having some limited individual motion but still influenced by whatever its front and rear partners are doing. I think N9WOS has made some interesting observations that tie in with other things we have read like progressive raker lowering as the chain wears back and leverage and angle of attack change relationships. The chattering in hard wood with too much raker clearance is spot on.

The normal intermittent or bobbing action of each cutter can be influenced by raker clearance, chain tension, how far back the tooth is worn, amount of hook and sharpening angles, whether upcut or down, and by the amount of pressure applied to the saw. If you use anything within reasonable recommended dimensions and dont get ridiculously extreme in tooth sizes you may never in a life of cutting run into it or have to worry about why.

Some of those things become much more important if you are trying to make a competition chain but I guess if you do it right you really dont have to know why it works there either. One thing you will always see is the cutter taken back to the rear rivet.

Normally a cutter makes a bit of a scoop sideways at the same time it makes its shallow scoop downwards. How hard the chain is dragging its top cutter affects how much it skews out sideways too. I will attach a picture of different cuts in the same wood with only minor changes in raker and alteration of the side cutter that changed its way of cutting from intermittent to almost continuous pulls across the piece. The wood was red maple and the chain square ground. Just something I was playing with at the time. I can spend a lot of time trying to figure out what makes things tick, not that I have capitalized on much of it though.

I had not thought of the significance of the raker height of preceding same side cutter because I just dont get them that out of whack unless it is my stump and nail chain and it doesnt cut fast or smooth anyway! I think his hypothesis makes sense for a chain with higher rakers and being pushed on, more so than one with more aggressive raker and less chain pressure.

The OP is smart, but making guesses.

I do have the video that Frank mentioned, but I have never been able to post it here(still VHS).

The video shows the cutters diving in and out of the fiber in a sine wave motion. They do not stay seated on the bar rail.

Let's not forget that the real work done by the cutter is done with the side plate, not the top plate.

Pulling the fibers away from each other is easy. Severing the fibers is much harder.

Tzed250;
You mean all you got to back up you hair brained ideas is a bunch of facts?????




Well okay then, very nice post. mongo sorry.

Hopefully one day that slow-motion video of the chainsaw chain will make it to You Tube.

Let me make it easy on you...I have seen the oscillation. The video I have is called "Cutting, Kickback, and Combustion". I was produced by Stihl Inc. in the late '80s. The video of the cutting clearly shows the cutters intermittent action. The cutter has to cut in this way. The chips must break so they can fit into the gullet. If they did not break they would pack the gullet, then wedge the cutter away from the wood. The depth guage regulates the depth of cut by controlling the angle of attack as the cutter enters the wood. As soon as the cutter is to full depth on the rock-back, the depth guage helps to steer the cutter back out of the fiber.

It is all in the video. Sorry that I have not had it converted to digital yet. Art Martin asked me to post it years ago. Maybe this winter I can get it done.

Interesting.

I'll tell you what isn't a wise tale.

Victory.

Since you seem to have made some kind of quatum leap in the understanding of wood cutting, it is time for proof that your theories are correct.

You believe that you have a much better understanding of the mechanics and function of a saw chain, it should be easy for you to file a chain that will cut measurably faster than any other.

Bring a 60 or 72DL chain to a GTG and run it against another chain, on the same saw, in the same wood. If your chain is faster then you might be on to something.

If your chain is not faster then it doesnt matter what you think about how a chain works because all you know how to do is file a slow chain.

Hypothesis-experiment-proof

Are you a Scientist, or a Mad Scientist?




.

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You guys are gonna make me get that video on here aren't you...


.

Well....the video has been located. Now all I need to do is find an economical way to transfer it to digital.

.

 

[tomtrees58]

This guy is clearly identified as someone who has never had a date.


wow tom treesopcorn:

 

[TheRickster]

When a chain gets dull I normally just put it on backwards and cut a little to resharpen it:greenchainsaw:

I figure if running it forward dulls it then running it backwards must sharpen it right?? lol..

There really is a lot of good theory and info here.. I would be interested to actually see a slow motion vid of a cut taking place to really get a sence of what is going on.. Easy to visualize but would be better to see in reality...

Rick

 

[madmax]

after the luck I had with my pickup today, I say pull the chain off, sling it back and forth horizontally against the paint on the Dodge, then lay it on the hood of the pickup and throw rocks at both of them.

 

[scotclayshooter]

Well....the video has been located. Now all I need to do is find an economical way to transfer it to digital.

.

:wave: :wave: :wave: :wave: :wave: :wave:

 

[scotclayshooter]

Well....the video has been located. Now all I need to do is find an economical way to transfer it to digital.

.

If you have a paypal account i will chip in £10 $15 towards it.
Someone must have a VHS to DVD recorder. They are on sale here so you guys must have one.

 

[Biker Dude]

WOW! My head is swimming with dolphins and I haven't even had a beer yet!
If you wanted to see how a chain cuts couldn't you just set up the saw to cut the width of the cut off of the end of a log, basically shaving the end of the log? The only down side is that one side of cutters would not be in wood so it might not act the same as a normal cut would.

 

[ropensaddle]

You just open the package and pull the nice shinny new chain out of its box
and go to cuttin Ok Thall you owe me big buddy pay up lol

 

[scotclayshooter]

WOW! My head is swimming with dolphins and I haven't even had a beer yet!
If you wanted to see how a chain cuts couldn't you just set up the saw to cut the width of the cut off of the end of a log, basically shaving the end of the log? The only down side is that one side of cutters would not be in wood so it might not act the same as a normal cut would.

There was a thread a short while ago about how the chain cuts, This vid will solve once and for all that the chain must leave the bar to cut.
Like a porpoise was the description.
I cant remember who started the thread now.
But a searching we will go!

It was this thread lol

 

[GASoline71]

Well....the video has been located. Now all I need to do is find an economical way to transfer it to digital.

.

That is friggin' cool mang!!!

But please start a new thread so this worthless debacle will die away somewhere...

Gary

 

[Tzed250]

That is friggin' cool mang!!!

But please start a new thread so this worthless debacle will die away somewhere...
Gary

Trust me...it will get its own place. I just wonder what happened to the Nostradamus of saw chain???