Metals406
Granfodder Runningsaw
There are some that have made a faux square grind with a round grinder and dressing the stone in a certain way.
'Invention' of Square Ground Chain?
- Thread starter Philbert
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Adirondackstihl
Flyz, Fuel & Fotos
Yeah, both my 044's are 10's
If you go to the GTG coming up, you'll get to meet them!
Thank you! A very kind offer. I actually have a loop of Oregon (shown in those photos), and a couple of loops of .325 that I need to covert from round ground, once I get the grinder up.
Yeah, that was just a 'proof of concept'/'show you what I mean' photo with a standard Dremel bit. It would have to be profiled, just like the edges of the Silvey wheels need shaping before use. Or, more practically, be a custom made CBN bit. Just an idea I was throwing out to adjust the cutting angle on the side plate edge.
Philbert
I would be interested in seeing what they did.
It's an old discussion, but one would think that 'someone' could make a square grinder for sale in the $500 range. More people would buy it if it was more affordable. Etc. Provide guidance on which angles cut faster, and which hold up longer. Etc. Find out if round ground has cutting advantages, or if it is just easier to sharpen a chain that way (round files, round grinder).
Appreciate all the input!
Philbert
Yeah, both my 044's are 10's
If you go to the GTG coming up, you'll get to meet them!
When & where is that? If it is after tax season, I would love to see your saws.
With a grinder if you get the wheel low enough you end up with a square ground chain which I do and they cut real good. Hand filers have asked how I get them to cut like that . Steve
With a grinder if you get the wheel low enough you end up with a square ground chain which I do and they cut real good. Hand filers have asked how I get them to cut like that . Steve
Love to see photos!
We talking the top plate edge, side plate edge, or both?
Philbert
Terry Syd
Addicted to ArboristSite
This is something that I have been considering. If you file with a round file for a top plate angle of 30 degrees, then the side plate cutting angle will be 60 degrees.
I took a look at a worn semi-chisel chain to see where the wear marks were. The file leaves fresh machine marks which get worn off in the areas of highest contact. You can see the machine marks are buffed off on the inside of the side plate cutting edge.
I tried using a small round diamond bit in a Dremel to grind out the corner of round chisel. The bits lasted only one cutter. I may go back with a Dremel cut-off wheel and try again and this time use a worn round semi-chisel chain as a template to where to remove metal. I'll just remove metal where the machine marks have been worn off by the wood chips.
I would like that post twice if I could!
Philbert
Philbert
watsonr
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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?
No, the wheel is fixed and the slide won't move far enough. A thin edge isn't the ticket, the thicker edge is and will last longer as there is more material to support the edge. Also because the stone on a square grinder is two angles, not a single round angle. The stone would need to come in at a more horizontal angle, not diagonal and the round grinders design isn't what way.
No, the wheel is fixed and the slide won't move far enough. A thin edge isn't the ticket, the thicker edge is and will last longer as there is more material to support the edge. Also because the stone on a square grinder is two angles, not a single round angle. The stone would need to come in at a more horizontal angle, not diagonal and the round grinders design isn't what way.
Adirondackstihl
Flyz, Fuel & Fotos
Greenwich. At "The Cutting Edge".
Owned by members Cuttinscott & 166.
Chris-PA
Where the Wild Things Are
After reading this thread I went out and did some work on my loop of square ground, which it needed as I had not got the angles consistent from one side to the other (I needed the vice I made). The cutting angles are definitely much sharper with square, which makes sense as you are angling the file in and under the cutter faces. You cannot do that with a round file, but must file along the top plate. The position of the file is the only thing that gives the top plate cutting angle ("hook"). But you can't really do anything about the side plate cutting angle, as Terry said above - at least not up by the top plate. I suppose you could play with it farther from the top plate, but I doubt that would do much.
I also went down and looked at some comparable chains - round and square ground.
On round ground chain, I can change the angle of the top plate edge by changing the angle of the grinder head tilt, or the height of the file. But I can't do much about the side plate edge without changing the top plate angle, unless I go back in there with a Dremel disc, as Terry Syd suggested, above. If I try to go in with a small file, I am essentially square filing.
I have heard of race chain filers 'tunneling' under cutters to thin them out. Anyone familiar with this? Can I use a similar technique to change the side plate edge of round ground chain?
(Might just be easier to square grind).
Philbert
On round ground chain, I can change the angle of the top plate edge by changing the angle of the grinder head tilt, or the height of the file. But I can't do much about the side plate edge without changing the top plate angle, unless I go back in there with a Dremel disc, as Terry Syd suggested, above. If I try to go in with a small file, I am essentially square filing.
I have heard of race chain filers 'tunneling' under cutters to thin them out. Anyone familiar with this? Can I use a similar technique to change the side plate edge of round ground chain?
(Might just be easier to square grind).
Philbert
Terry Syd
Addicted to ArboristSite
The buffed areas on the inside of the semi-chisel extend from the apex of the curve, that is, the mid-point of the round curve down the side plate. Essentially, it is the entire side plate of the cutter. Since the round file puts a curvature on the underside of the cutter (hook), the wear marks don't extend out under the top plate below the chrome.
However, since the hook is curved back again, the wear marks appear on the bottom edge of the cutter surface just before the chip leaves the cutter edge. Since I use 10 degrees of down angle on my files, I have a progressive hook which makes the edge thinner as the distance from the corner of the cutter increases. This creates a change in how the chip moves across the cutter face. It is thinner to begin with, but then the angle increases much faster. Thus, the wear on the underside of the cutter edge increases just before the chip leaves the cutter.
Probably be easier to understand if you look at one of your own chains with a magnifying glass.
I'll take the Dremel and put a slower angle on the side plate area, at least 45 degrees, up to the mid-point of the curvature. I'll also trim the underside of the cutter where the wear marks are.
The entire side plate thickness shows a high wear area. That indicates to me that the side plate is trying to shift the chip to the side before it is freed from the wood by the top plate. If I remove some of the material on the inside of the side plate, there will be less force applied to the cutter by the wood. I'll probably end up with longer chips as a result. I don't think at this stage that it is necessary to take the new angle all the way out to the edge of the chrome.
I'll just take it in stages, try a mod, then check the wear marks again, try another tweak, etc. Hopefully, I can end up with an easy sharpening method that results in a fast cutting chain that wears like a semi-chisel work chain.
However, since the hook is curved back again, the wear marks appear on the bottom edge of the cutter surface just before the chip leaves the cutter edge. Since I use 10 degrees of down angle on my files, I have a progressive hook which makes the edge thinner as the distance from the corner of the cutter increases. This creates a change in how the chip moves across the cutter face. It is thinner to begin with, but then the angle increases much faster. Thus, the wear on the underside of the cutter edge increases just before the chip leaves the cutter.
Probably be easier to understand if you look at one of your own chains with a magnifying glass.
I'll take the Dremel and put a slower angle on the side plate area, at least 45 degrees, up to the mid-point of the curvature. I'll also trim the underside of the cutter where the wear marks are.
The entire side plate thickness shows a high wear area. That indicates to me that the side plate is trying to shift the chip to the side before it is freed from the wood by the top plate. If I remove some of the material on the inside of the side plate, there will be less force applied to the cutter by the wood. I'll probably end up with longer chips as a result. I don't think at this stage that it is necessary to take the new angle all the way out to the edge of the chrome.
I'll just take it in stages, try a mod, then check the wear marks again, try another tweak, etc. Hopefully, I can end up with an easy sharpening method that results in a fast cutting chain that wears like a semi-chisel work chain.
I'm not looking to create some special chain that takes an hour to sharpen. I will try square ground, at the angles recommended by Madsen's and see if I can get the hang of sharpening it and if it works more efficiently for me. If not, I will go back to RS, which has always worked well for me. You can always play with angles and stuff if you want to make a short duration race chain. My objective is a fast working "work" chain. The big draw back of square grind seems to be whether you can get the hang of sharpening it properly. If you can, it is more efficient and smoother. If not, don't use it.
I'm with you Mike. I want a long lasting work chain. The purpose of this thread was to understand how some of the sharpening choices affect performance of all cutters, and to de-mystify square ground cutters.
For example, is a deeper hook really better on round ground chain? How much difference does a change in side plate cutting angle make? Do most of us use round ground chain just because it is easier to sharpen, or are there other advantages? Terry's mention of the 10* down angle might make sense in context of these choices. Screwing around with a Dremel is just a way to test or validate these factors to me. But maybe there are a few things we can use.
Guys who make race chains spend a lot of time on these fussy details, but their chains only need to last '2 downs and an up'!
Philbert
For example, is a deeper hook really better on round ground chain? How much difference does a change in side plate cutting angle make? Do most of us use round ground chain just because it is easier to sharpen, or are there other advantages? Terry's mention of the 10* down angle might make sense in context of these choices. Screwing around with a Dremel is just a way to test or validate these factors to me. But maybe there are a few things we can use.
Guys who make race chains spend a lot of time on these fussy details, but their chains only need to last '2 downs and an up'!
Philbert
Terry Syd
Addicted to ArboristSite
I'm not interested in having to work on a chain for an hour either. I think it may be possible that once I learn where I need to take off some material I can just take off the material as I need it.
It may be possible to stretch back the area of removed material so that it may only need to be touched up every couple of times I sharpen the chain. Once I know where to touch up, that should be fairly quick with a Dremel.
Even round filed chisel is a no-go for what I cut. I prefer dried out Ozzie eucalypts for firewood. Usually the termites get there before I do and add their grit to the wood.
I'll give it a go and let you quys know what I found.
It may be possible to stretch back the area of removed material so that it may only need to be touched up every couple of times I sharpen the chain. Once I know where to touch up, that should be fairly quick with a Dremel.
Even round filed chisel is a no-go for what I cut. I prefer dried out Ozzie eucalypts for firewood. Usually the termites get there before I do and add their grit to the wood.
I'll give it a go and let you quys know what I found.
sachsmo
Addicted to ArboristSite
Redprospector can freehand square in the field.
But I believe he used a round file to clean out the gullets?
It's been many moons since I saw that video, but some people can make it look TOO easy!
I have a pretty good 'handle' on freehanding full chisel round, seems to last longer than factory grinds, and is much quicker than NIB. (rakers seem too high outta the box)
Someday I may venture into square, but it has taken 8 years to get decent at the round file.
But I believe he used a round file to clean out the gullets?
It's been many moons since I saw that video, but some people can make it look TOO easy!
I have a pretty good 'handle' on freehanding full chisel round, seems to last longer than factory grinds, and is much quicker than NIB. (rakers seem too high outta the box)
Someday I may venture into square, but it has taken 8 years to get decent at the round file.
Terry Syd
Addicted to ArboristSite
I was out in the shed thinking about making up some kind of jig to hold the chain. Then I just popped it in my lap and started with the Dremel. Too easy, I should have tried the Dremel before I went and bought a bunch of the tapered diamond points. I figure I can do a cutter in less than a minute. The taper goes back so I'll probably only need to freshen it up every two/three times I sharpen.
A good pair of magnifying glasses are helpful, they also protect your eyes. I sit with my back to a window in the dark shed and I can see the cutter as I trim the inside dimensions. I can shift it around on my lap to check the reflections, something I wouldn't be able to do with it in a jig.
I'll sharpen up two chains, both with 5.6 degrees of cutting angle, one will have the side plate and lower edge of the cutter mods. I'll have to wait until I get a chance to do some cutting, so it may be a week or two before I can report back.
A good pair of magnifying glasses are helpful, they also protect your eyes. I sit with my back to a window in the dark shed and I can see the cutter as I trim the inside dimensions. I can shift it around on my lap to check the reflections, something I wouldn't be able to do with it in a jig.
I'll sharpen up two chains, both with 5.6 degrees of cutting angle, one will have the side plate and lower edge of the cutter mods. I'll have to wait until I get a chance to do some cutting, so it may be a week or two before I can report back.
