'Invention' of Square Ground Chain?

[sachsmo]

If you look at the pics some of the edges look 'ragged' it is just lint and junk that has accumulated over several years.

Up close and in person the edges are clean and very uniform.

The guy I purchased it from said it was sharpened for competition, I have never sank that chain into wood.

I bought the bar for milling (Hate to be outgunned) and the price paid for the bar and chain was less than half of just a new bar.


I think it's cool, your mileage may vary?

 

[Stihl 041S]

Like anything else, there are trade-offs.

Longer lasting equals not as fast cutting, faster cutting usually means shorter life.


Top fuel Drag Racing teams have figured how to make 8000 Horsepower from 500 cubic inches, unfortunately they only last about 4 seconds before they go BOOM!

Always a trade off.
Eddie hill was breaking a crank every other run.
Changed things so he just bent the rods every run.

 

[Stihl 041S]

If you look at the pics some of the edges look 'ragged' it is just lint and junk that has accumulated over several years.

Up close and in person the edges are clean and very uniform.

The guy I purchased it from said it was sharpened for competition, I have never sank that chain into wood.

I bought the bar for milling (Hate to be outgunned) and the price paid for the bar and chain was less than half of just a new bar.


I think it's cool, your mileage may vary?

If ya could email me a close up picture.
If there is a primary secondary and tertiary angle I'd be interested.
I ran a tool and cutter grinder. I made a 3/16" dovetail cutter one time for the stamps in aircraft fasteners.
We made all our own tooling.
Some things that looked aweful worked aweful well.
And visa versa. Lol.
Thanks Mo. Off to bed for me.

 

[sachsmo]

Yup!

as far as competitive cutting, there is NO competition around here with the guyz I cut with.

Them dudes think a new 'green chain' is the catz Ash!

They think I'm some kinda of guru, when in reality I'm just a putz with a file.



Guess we be a different breed eh?

 

[Stihl 041S]

Yup!

as far as competitive cutting, there is NO competition around here with the guyz I cut with.

Them dudes think a new 'green chain' is the catz Ash!

They think I'm some kinda of guru, when in reality I'm just a putz with a file.



Guess we be a different breed eh?

Sort of like the gun guys in the shop. Got dozens.
But if you say you are gonna do a Wildcat.....throws them off.
Once a machinist you always look at cutting relationships.
Night again. Lol
Have a good one Mo.

 

[MustangMike]

Yea, I previously referred to Madsens in another thread, really good stuff there. Also, the durability of square (just like round) depends on the angle cut. Often square is cut for racing, and does not last long, but with normal angles it should last and cut about 10 - 15 percent faster. It is just harder the master the correct sharpening.

 

[Chris-PA]

What makes it cut faster?

Philbert

There is no reason that the top plate need be any different between round and square ground chisel. My guess is that square ground just supports the point better, or rather it prevents the point from dulling as fast (because it's an angle rather than a point). So probably in the first few moments they're about the same but the point on round ground starts dulling fast. That's just my guess though.

Also the straight side plate may sever fibers easier.

 

[watsonr]

On Round grind, the top plate is separating the fibers and lifting them up for the side plate to sever.... its more or less ripping the fibers out because the side plate doesn't cut until the fiber reaches very near the center. On square the top plate lifts the fiber and they are severed almost immediately by the side plate. The cut is more efficient by cutting the fiber earlier, takes less power. You can see that it's not ripping the fibers out because the chip on a square chain is really long, as in inches. Round is little chunks and they look ragged if you look really close, the square is smooth and appears to have not struggled to remove it.

A round chain always feel rough in the cut like it's pulling you toward the log and you can feel the vibrations as its skipping along and if you've ever seen a slow motion of a chain cutting, its bouncing in the cut and about every other tooth is actually cutting. The top plate is digging in and when the chain reaches the max stretch, it is then pulled back toward the bar ripping the fibers up.

Square just slides along, the chain isn't flexing as much, it's not gouging the chip out.

 

[mdavlee]

You can get smooth cutting round chain with some different top plate angles and not as much hook on the cutter.

 

[Philbert]

On Round grind, the top plate is separating the fibers and lifting them up for the side plate to sever.... its more or less ripping the fibers out because the side plate doesn't cut until the fiber reaches very near the center. On square the top plate lifts the fiber and they are severed almost immediately by the side plate. The cut is more efficient by cutting the fiber earlier, takes less power.

You can get smooth cutting round chain with some different top plate angles and not as much hook on the cutter.

This is exactly what I am trying to understand.

Many guys on this site claim that an aggressive hook angle makes a faster cutting chain. But this brings the side plate edge in later in the cut - very different than square ground recommendations (per Madsen's and Oregon, as I understand them). The sharp point on round ground, full chisel chain also looks more vulnerable with an aggressive hook, similar to the 'beaks' that square ground chains try to avoid. Square ground chains appear to have a 'corner', versus a 'point'.

It seems like some guys are obsessed with a large gullet, that does not do any cutting, the way that they are obsessed with . . . (um, I want to be careful here . . . but they probably hear the words, "Hey! My eyes are up here!" a lot).

As always, different guys want different things from a chain. I, personally, don't necessarily want the fastest cutting chain, but one that will keep a good cutting edge for a long period of time.

Philbert

Oregon 72CL - factory grind

 

[mdavlee]

The big reason to keep a gullet clean and even with the side plate or further back is for chip clearance and ease of filing. If it gets too long it can actually be hitting the wood and pulling the tooth sideways.

 

[watsonr]

If you look at that picture, you can see that as soon as the fiber is lifted, the side plate cuts it, that is also allowing the top plate to slide along and lift more fiber, the cutter isn't bunching the fiber together until it's cut or ripping it out because the side plate can't cut it fast enough. The fiber never reaches the gullet and doesn't allow any drag from the gullet as it moves by. Fiber that is ripped may still be attached on the outside of the cutter, it's dragged past the gullet and waits until the opposite side cutter completes its pass. Chisel chain is not designed like a perfect L at 90* but closer to 85* or something like that, the outside will actually sever the opposite side that the side plate cuts, just a different angle. For some reason, it just doesn't seem that way on round grind, they appear to be ripped... probably because of the top plate angle.

Never tried a round top plate angle of 30*, I do know it won't self feed as good either, its not forcing itself into the cut, you'd probably have to push down some.

Look at the finished cut on a square chain compared to a round one, the cut surface is very smooth as opposed to a rough cut from round, like getting slivers running your hand over it and why I think your ripping the fibers on a round chain.

 

[mdavlee]

I run a 30° top plate on round chisel. Most of my semi s getting closer to 15° for milling.

 

[Philbert]

Look at the finished cut on a square chain compared to a round one, the cut surface is very smooth as opposed to a rough cut from round, like getting slivers running your hand over it and why I think your ripping the fibers on a round chain.

Full disclosure: I have never used square ground chain: curious about it; read a lot of the posts here, and other forums; have a Silvey RSII as a 'project grinder' that I have not gotten around to yet; asking a lot of questions to understand it better. Don't have a square ground cut log to compare!

So I am going to throw one more idea out here, which is consistent with what you are saying. Maybe the resultant angle on the side plate of square ground chain is more acute (i.e. narrower angle) so that it cuts more cleanly? You can control this side plate angle more independently with a square chain file, and with the position of the tooth of a square grinder.

With a round file, or a conventional round grinder, the side plate cutting angle is dependent on the top plate angle of the file or the grinder head angle (and grinding wheel diameter).

But I am thinking that with a round grinder that has a sliding vise (Oregon 511AX, STIHL?), you could adjust that side plate angle slightly by controlling the part of the wheel that touches the cutter?

Could I get a 'boxed corner' on conventional chain by using a very small, square edged, round stone (i.e. a thick disc), held in something like a Dremel tool? Might need to be CBN or carbide to hold up. Mount it on a small mill or drill press? Note that the side plate would be slightly dished, versus 'square', but that is also true with the larger diameter Silvey wheels.

Philbert

Poor Man's Silvey?

 

[Adirondackstihl]

My nephew (MechanicMatt) says he saw a ported 044 at an event that was an absolute animal. I'll have to ask him what chain it was running.

It was just some of my round filed junk STIHL RS.....standard raker depth.

 

[Adirondackstihl]

There is a little missing material here and there, but my no means is it "ported"!

 

[MustangMike]

There is a little missing material here and there, but my no means is it "ported"!

Whatever you did with it, he was very impressed, and said many other people (including Husky fans) were also very impressed. It is always nice to have a great running saw, and thanks for the chain info. RS has always worked well for me, but I plan to try RSLK.

If you care to share the details, let me know. Also, is it a 10 mm saw?

 

[MustangMike]

On Round grind, the top plate is separating the fibers and lifting them up for the side plate to sever.... its more or less ripping the fibers out because the side plate doesn't cut until the fiber reaches very near the center. On square the top plate lifts the fiber and they are severed almost immediately by the side plate. The cut is more efficient by cutting the fiber earlier, takes less power. You can see that it's not ripping the fibers out because the chip on a square chain is really long, as in inches. Round is little chunks and they look ragged if you look really close, the square is smooth and appears to have not struggled to remove it.

A round chain always feel rough in the cut like it's pulling you toward the log and you can feel the vibrations as its skipping along and if you've ever seen a slow motion of a chain cutting, its bouncing in the cut and about every other tooth is actually cutting. The top plate is digging in and when the chain reaches the max stretch, it is then pulled back toward the bar ripping the fibers up.

Square just slides along, the chain isn't flexing as much, it's not gouging the chip out.

Thanks for that excellent explanation. That is a reason I did not even think of that makes enormous sense.

 

[Sapo_feo]

Philbert, if you want some square I have some H84 3/8 .058 84DL. Just let me know where to send it.

 

[MustangMike]

Full disclosure: I have never used square ground chain: curious about it; read a lot of the posts here, and other forums; have a Silvey RSII as a 'project grinder' that I have not gotten around to yet; asking a lot of questions to understand it better. Don't have a square ground cut log to compare!

So I am going to throw one more idea out here, which is consistent with what you are saying. Maybe the resultant angle on the side plate of square ground chain is more acute (i.e. narrower angle) so that it cuts more cleanly? You can control this side plate angle more independently with a square chain file, and with the position of the tooth of a square grinder.

With a round file, or a conventional round grinder, the side plate cutting angle is dependent on the top plate angle of the file or the grinder head angle (and grinding wheel diameter).

But I am thinking that with a round grinder that has a sliding vise (Oregon 511AX, STIHL?), you could adjust that side plate angle slightly by controlling the part of the wheel that touches the cutter?

Could I get a 'boxed corner' on conventional chain by using a very small, square edged, round stone (i.e. a thick disc), held in something like a Dremel tool? Might need to be CBN or carbide to hold up. Mount it on a small mill or drill press? Note that the side plate would be slightly dished, versus 'square', but that is also true with the larger diameter Silvey wheels.

Philbert

I think is you use that grinding wheel your vertical side plate will end up angled wrong (aka outside side plate). None of the "square files" are actually square, they are all hexagons (6 sided). According to Madsen's, both the side and top plate cutting angles are about 45 degrees, resulting in "outside top plate" angle of 15 degrees. See their "Sharpening Angles of Square Ground Saw Chain" page, very informative.

Poor Man's Silvey?
View attachment 335050