razor sharp chain

[southernstyle]

All set!

Thanks Frank! You answerd all of my questions, and those photos were right on!

I think I like the flat chisel too, I swear it looks like red was using A 6 sided for his gullet though, may just be the picture, but it would be interesting huh?

Thanks A bunch Bro!

 

[Crofter]

Actually the gullet does not get touched as part of the sharpening. I would guess Redprospector used a combination of a narrow round chain grinder wheel and a dremel or other rotary grinder. You got a ways to go before you start needing to worry about those details, Lol!

 

[southernstyle]

...

Frank, I have A fairly new oregon 3/8" full chisel chain, if I use A flat chisel file and leave the gullet alone does that sound like A good start?

Also, what purpose does that gullet serve?
Thanks.

 

[Crofter]

Frank, I have A fairly new oregon 3/8" full chisel chain, if I use A flat chisel file and leave the gullet alone does that sound like A good start?

Also, what purpose does that gullet serve?
Thanks.

I am not sure you are familiar with what the term gullet is commonly considered to be. I feel it means the whole opening between the raker and the cutter and most especially the bottom part as it turns up into the standing part of the tooth. In normal round filing or grinding the bottom of the file or stone addresses this as the tooth gets filed back from new to worn out.

The chisel bit files only touch a bit less than an eight of an inch of the side cutter and a raggedy slug of metal prevents a nice smooth gullet. It has to be removed by a separate operation every few filings.Some people refer to this undesireable area of metal as a gullet instead of saying it is in the gullet of the tooth. Anyways if allowed to get too large it will grab on the side of the kerf as it starts to stick out wider than the top of the tooth. For the fastest cutting, good chip flow and adding more chip carrying capacity it is common to open up the gullet as much as possible without removing too much material directly over the rivet area which is the weakest link of the chain. I will add a picture of a round chisel tooth that has been square filed and the gullet left untouched. It could be put to work as is! Some of the previous posts show the gullet cleaned up and Redprospectors shows about the limit of how much can be taken out on a competition chain.

 

[southernstyle]

Wow!

Wow!I didnt imagine it looking like that leaving that chunk down there, I have A picture name "goodgullet" that shows it when finished. I ought to be able to duplicate it now.
I wonder how folks figured out that A square chisel would cut faster than A round one? I'm testing all this on my stihl 031 and I know its not up to competition speed, but I figure if I can get noticable speed increases with A properly sharpened chain on that saw, I will get alot faster with my 125cc saw when I finish it.. Just tryin to get some kind of speed reference...

Do you know of any thread where someone has done A cut with A stock chain, then one with A race chain?

 

[redprospector]

Southernstyle,
Frank's leading you down the right path. I can't think of anything to add to what he said.
Don't worry about anything fancy right now, like the "notches" in the bottom of the gullet, or beveling the straps. Just learn to put a good working edge on a chain to start with. You have to learn to walk before you can run.

Andy

 

[Crofter]

A new factory square grind will be about 15% faster than the same chain round ground. A competition chain should cut at least 40% faster.

 

[scotclayshooter]

Wow!I didnt imagine it looking like that leaving that chunk down there, I have A picture name "goodgullet" that shows it when finished. I ought to be able to duplicate it now.
I wonder how folks figured out that A square chisel would cut faster than A round one? I'm testing all this on my stihl 031 and I know its not up to competition speed, but I figure if I can get noticable speed increases with A properly sharpened chain on that saw, I will get alot faster with my 125cc saw when I finish it.. Just tryin to get some kind of speed reference...

Do you know of any thread where someone has done A cut with A stock chain, then one with A race chain?

http://uk.youtube.com/watch?v=9W1ds6kULmE

Try here!

 

[scotclayshooter]

A new factory square grind will be about 15% faster than the same chain round ground. A competition chain should cut at least 40% faster.

40%! even on a stock saw?

 

[Crofter]

40%! even on a stock saw?

Yes, but the percentage gain will be even greater on a saw that is modified to have its potential at a higher rpm.

Below is a link to a test done by Timberwolf on a stock and modified 359 giving cut times and fuel consumption on both round and square chain. Also cut times after modifications; be prepared to wade through some figures!

http://new.arboristsite.com/showthread.php?t=29247&highlight=zen+art

I have some posts on here somewhere comparing cut times with a stock 365 with new Round Carlton, then refiled round, then square and finally to a greatly modified square filed chain. So much for my search skills; cant even find my own post!

40% faster is not too hard to achieve and that is somewhat short of an outright race chain.

 

[scotclayshooter]

Yes, but the percentage gain will be even greater on a saw that is modified to have its potential at a higher rpm.

Below is a link to a test done by Timberwolf on a stock and modified 359 giving cut times and fuel consumption on both round and square chain. Also cut times after modifications; be prepared to wade through some figures!

http://new.arboristsite.com/showthread.php?t=29247&highlight=zen+art

I have some posts on here somewhere comparing cut times with a stock 365 with new Round Carlton, then refiled round, then square and finally to a greatly modified square filed chain. So much for my search skills; cant even find my own post!

40% faster is not too hard to achieve and that is somewhat short of an outright race chain.

Cheers i will check that out!
Tree beard is making an order up from baileys so im getting him to add some square chain and some files.
I just found Manuals 262XP mod thread and i have Dremel bits galore and a newly aquired 262XP I "think" i have a grasp of what im trying to do but cant really find how to check the port timing i have sussed out the degree wheel etc but cant find the info on using it!
Is it a visual thing on the opening closing points of the ports or am i missing something?

 

[Crofter]

The intake and exhaust are easy to see directly but the transfers are often out of direct line of sight. You can use a thin piece of copper wire to reach around from the exhaust port to feel the closing point. Careful not to shear it off, Lol!

 

[scotclayshooter]

The intake and exhaust are easy to see directly but the transfers are often out of direct line of sight. You can use a thin piece of copper wire to reach around from the exhaust port to feel the closing point. Careful not to shear it off, Lol!

Ok how would you compensate for the thickness of the wire or are we not being that picky?

 

[Crofter]

Well I was visualizing something about 10 thou. from an unwrapped extension cord or similar. You would likely be using it for a reference point to return to after dikking with gasket thickness etc. so it would be still relevant. Even how much chamfer you put on a port makes that much variance. Identical side to side is more important than exactly so many degrees. You would be surprised the variation in brand new saws one to the next. Just like headspace, you being familiar with handloading and firearms!

I think a good square filed chain benefits most when you put it to work near the max horsepower range of a saw rather than near the max torque range. Round filed might be biased a bit more the other direction

 

[drmiller100]

you can look into the exhasut port, and get true port timing by sight.

then i use the wire to see how much it changes. as an example, from memory, it was about 5 degrees on each side with the wire i used.

then, i used the same wire on the transfers, and compensated.

it isn't totally directly comparabel because teh exhaust is around 95 and the piston is moving fast. the transfers are more like 120, and the piston is moving slower, but it is really close if you run the math.

 

[Wet1]

Crofter and Red,

Thank you for posting about how to do the square filing, very informative. I recently picked up some square chain, files, and a Silvey Swing Arm (square grinder) so I could get into square chain. I haven't had the time to dig into this yet, but I'm really looking forward to seeing how this compares to the round. If I like the square, and I'm hearing I will, then I was planning on regrinding some of my round to square. Will this be an issue? Also, what are your thoughts about using a grinder for square (non-competition usage)?

 

[Crofter]

There is no difference in the chain, only the grind that is put on it. You can convert a chain back and forth or forth and back round to square or square to round. You will find you definitely work your tongue more when filing the square, Lol!
Grinding and swapping on sharpened chains is the way to go for work chains. They are harder to file on the bar than round ground. If you stick to a fairly standard set of angles on the grinder, once set up it is about as easy to square grind as round grind, however if you are experimenting with a lot of different angles you have to re dress the angles on the grinding wheel each time; that is a dusty chore and wears up the wheel and the diamond dressers! Hand filing you just hold your tongue a bit different to change angles. Learning to hand file square takes 20 or more hours of actual time filing to get decent and more than a few have packed it in in disgust. There is a fair bit of info and pictures but you have to do some searching! square ground, square filed, square filing, square filers, chisel bit, race chain, work chain, etc. If you can get someone to show you hands on it will save you a lot of time over doing it entirely on your own head scratching.

 

[046]

it's totally possible to go from round to square, but it's usually recommended the other direction. for folks who don't own a square chain grinder yet....

square chain newbies really need to purchase at least 1/2 dozen square ground chains to give it a fair trial. if you touch dirt the least little bit, square will go dull. at least 6 chains will give enough tries with a sharp chain to figure this out. then if it doesn't work out... simply file to round... so you will have lost nothing except a bit of tooth material.

factory square chain cuts 15% faster. while a properly ground square chain will be much faster yet. one gets in a habit of stopping the cut long before hitting ground, then rolling over log to finish.

learning curve is somewhat steep for sharpening square chains. this is true for hand filing and setting up your square grinder.

ask for help... it'll go much faster... I did... thanks again to all for helping me get setup!

 

[Wet1]

Thanks for the info guys, I'm looking forward to getting to spend some time with my square grinder... hopefully next month.

 

[wvlogger]

when you sharpen a chain by hand there is always some slight diffrences in angles. the only way to stop this is grind them with a bech grinder but it is kinda hard to get a chain sharper than factory. cut faster than factory maybe sharper noopcorn: