Timed Cuts, Factory Round Vs Square Filed

[Crofter]

Did a buch of times today to see what gains might be had with square filing. I started out with a fresh Carlton 3/8 round ground chisel chain, 16 inch on my 365 S Husky, muffler modded only.

10.25" (under the bark) Poplar, freshly felled and up on blocks. Stop watch timed 3 cuts rounded off and averaged.

6.3 seconds out of the box chain

5.6 seconds with touch up, maintaining factory angles, but gullets deepened quite drastically.

4.6 seconds after converting by hand filing square. Rakers untouched. This took me 1 1/2 hours. Sure would like a grinder.
This is with a thinner side angle than factory square ground

I then put on the chain that I have been dinking with for about 20 or more hours, pretty well skeletonized and taken back to rear rivet. Rivet heads ground down, and cutters narrowed 15 thou a side.

3.4 seconds (3.31 low)

There was hardly any difference in diameter of first and last cuts.
Since the razzing Rob has been getting, I'm not sure whether to post this or not. My Husky ain't shy though, it''ll do it with everyone watching! Lol!

Frank

 

[cliff-1972]

You got to love a square filed chain

 

[Rotax Robert]

Crofter, your times seem accurate so I doubt you will get the sky falling in on you. Looks like you made the effort to take as many variables out of the equation as possible and did your home work. I have found that in a stock chain race round verse square the square will almost always be about 20% faster. Also it should be noted that a chain will probably never be duller than when it was new off the roll in a experienced filers hands. (excluding rocking out) Thanks for the times and effort.

 

[G-MAN]

According to my math, if you cut 60 trees down that were 60 ft high and made 18" cuts( good average firewood length) you would save 68 minutes of cut time after 1 1/2 hr of sharpening. My question where is the saved time? You lose time sharpening.

 

[dbabcock]

Frank,
I agree with Rotax. Your methodology was excellent. Your data indicates real world realizable gains in performance. Being almost twice as fast as stock chain, your 20 hour tickle chain is certainly impressive in relative terms, indicating that you're certainly doing something right! Only one question: is your 20 hour chain the same type as the stock one?

 

[Chainsaw_Maniac]

Originally posted by G-MAN
According to my math, if you cut 60 trees down that were 60 ft high and made 18" cuts( good average firewood length) you would save 68 minutes of cut time after 1 1/2 hr of sharpening. My question where is the saved time? You lose time sharpening.

You're right G-MAN. Hand filing for and hour and a half would never pay off cutting firewood. Lets say those 60 trees had a full cord each. That would be at least 10 full days work (not including spliting). In that time I would have round filed both my bucking and limbing saws at least once a day each (20 filings=30 hours filing!!!).

Now if you had a grinder to round file (and mastered using it), that would be sweetness.....

 

[Crofter]

Db : Unfortunately the chain that I have put all the hours in, started out as an Oregon with guard links. OF course there is nothing left of them. I have a few things to experiment with on it yet, but there gets to be little tooth left to play with so you got to start all over. Sure makes you appreciate what Art has under his belt!
Regarding the hour and a half tickle; that is not to merely sharpen. It involved taking a flat file to each round filed tooth top plate to bring the angles to around 18 Degrees then square filling from scratch. This all by hand. Just to resharpen with square file would probably take 5 to 10 minutes. I'm sure that could be improved upon too. I don't in any way think it practical for day to day cutting. It is not easy to do on the saw either. As for the 1 second difference in the same chain when converted from round to square, I am sure that gap could be narrowed too. The factory top plate angle on that Carlton chain is quite blunt. Putting an aggressive round file job on it, would have been a good thing to have done in the comparison. Have to make that another experiment.

Frank

 

[rahtreelimbs]

--------------------------------------------------------------------------------
Originally posted by G-MAN
According to my math, if you cut 60 trees down that were 60 ft high and made 18" cuts( good average firewood length) you would save 68 minutes of cut time after 1 1/2 hr of sharpening. My question where is the saved time? You lose time sharpening.

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Originally posted by Chainsaw_Maniac
You're right G-MAN. Hand filing for and hour and a half would never pay off cutting firewood. Lets say those 60 trees had a full cord each. That would be at least 10 full days work (not including spliting). In that time I would have round filed both my bucking and limbing saws at least once a day each (20 filings=30 hours filing!!!).

Now if you had a grinder to round file (and mastered using it), that would be sweetness.....

These times were on a chain that converted to square ground. What are the factory square ground chains like? Any good?

 

[glens]

Rich,

I opt for more posts per page than standard, so I don't know if this link will work exactly the same for you as I see it, but Ken pretty much answered that on the 15th of last month.  See what might be the second article in http://www.arboristsite.com/showthr...page=20&highlight=factory+square&pagenumber=2

Glen

 

[rahtreelimbs]

Originally posted by glens
Rich,

I opt for more posts per page than standard, so I don't know if this link will work exactly the same for you as I see it, but Ken pretty much answered that on the 15th of last month.  See what might be the second article in http://www.arboristsite.com/showthr...page=20&highlight=factory+square&pagenumber=2

Glen

Thanx, Glens

 

[Kneejerk Bombas]

I use the "goofy" files for sqaure filing. They cost about $5 each and don't last as long as round files. They can be used for taking down depth gages or other flat filing.
It does take a little more concentration to square file, and a little more time, probably twice as long to touch up a square chain. It is tricky.

 

[Crofter]

Slippery chain

This is one chain I have been working on, lightened it up a bit, though my saw probably doesn't rev out enough to make much use of that, but the extra chip space does seem to make a difference. Timed cuts are less thalf of factory round and considerably faster than factory square. The photograpy sucks!

Frank

 

[Crofter]

Top view of teeth compared to basic squared filed unmodified cutter. May have almost gone too far in narrowing and changing angles, so have not taken tooth back to rear rivet yet. Got a little bit of meat yet to play with. It sure slides down through the wood nicely though.

Frank

 

[Kneejerk Bombas]

I thought you ground the inside of the cutter to narrow the kerf it cut.

 

[jokers]

Hi Mike, grinding the inside is for chip clearance. Russ

 

[crowe]

Crofter
I notice you are squaring off the back of the tooth. Any particular reason for that. Also it looked as if you beveled and rouneded the inside top plate or is that just the way it looks in the picture. Later.....Wade

 

[Crofter]

Art showed pictures of grinding 20 thou off the inside of cutters and then reassembling the chain to narrow the kerf also he has pictures on jigs for "dechroming " the outside of the cutter to thin it and establish an abdsolutely sharp corner profile. That is what I did. I'm sure that some blending in and polishing could improve chip flow.
I didnt grind any off the rear of the tooth. That is Carltons shape. Tho other chain is Oregon. Notice the top plate angle is sharper.(faster).None of this is original thinking on my part. My thanks to Art Martin and gleanings I have picked up from posts by KD Hotsaw and Rotax Robert etc.

Frank

 

[Kneejerk Bombas]

I was asking about the surface of the cutter that has the rivet holes. The surface you need to disassemble the chain to get at.
In the top veiw of the chains it does not look like there was any metal removed there. In a previous post Frank said he had ground this surface. I was wondering how that all went and what it looked like.