Oregon 511A Chain Grinder Expert Help Please
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Sagetown
Farmer and a STIHL
Fish
Tree Freak
What Gregg meant to say:
Buy three grinders, and have one for each size wheel!!!!
Buy three grinders, and have one for each size wheel!!!!
This might confound the discussion a bit. I studied Stihl's wheel recommendation here: http://www.stihlusa.com/stihl_ownersmanuals/USG_sawchainangles_chart.pdf. (ask, if you want an explanation of the angles/numbers)
I then called the big Stihl distributor in Ohio to get the widths of their 2 main grinding wheels.
Stihl 5203 750 7013 3.1 mm 5203 750 7010 4 mm
Oregon 1/8" 3.2 mm 3/16" 4.8 mm
Their chart linked above recommends the 4 mm for the .325 Stihl chain and the 3/8 chain.
Neither of the Oregon sizes match the 4mm. So, anyone using Oregon or Molemab wheels is doing it WRONG regardless of which size you use!!!! Said "tongue in cheek", of course.
This exercise once again proves that what's done in the real world often doesn't match the text book example.
I then called the big Stihl distributor in Ohio to get the widths of their 2 main grinding wheels.
Stihl 5203 750 7013 3.1 mm 5203 750 7010 4 mm
Oregon 1/8" 3.2 mm 3/16" 4.8 mm
Their chart linked above recommends the 4 mm for the .325 Stihl chain and the 3/8 chain.
Neither of the Oregon sizes match the 4mm. So, anyone using Oregon or Molemab wheels is doing it WRONG regardless of which size you use!!!! Said "tongue in cheek", of course.
This exercise once again proves that what's done in the real world often doesn't match the text book example.
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My only concern right now, being a newb to grinding, is weather the top plate cutting edge should be hollow ground or flat/chisel ground. I saw another post here somewhere that said (and had a diagram) that your wheel shouldn't go deep enough that the top of the top plate would be above the rounded/dressed edge of your wheel. (hollow grinding, same as a file would do).
It seems to me that if flat/chisel grinding is just as good then it wouldn't matter what size wheel you were using because you're using the flat side of the wheel. You wouldn't need to be too concerned about your dressing either.
I realize we're probably splitting hairs here, but I'm curious.
It seems to me that if flat/chisel grinding is just as good then it wouldn't matter what size wheel you were using because you're using the flat side of the wheel. You wouldn't need to be too concerned about your dressing either.
I realize we're probably splitting hairs here, but I'm curious.
So you can make this crazy or you can make this simple.
As far a grinder settings, you simply need: head angle (typically 60 degrees), vise rotation (typically 30 degrees) and vise tilt? (yes or no).
You want to get each cutter sharp on both cutting edges, and you want to get all the cutters on a chain the same.
For most people, it doesn't really matter if you grind 60/30 or 55/25 or 58/27.6, or . . . as long as all the cutters on the chain are the same. Theoretically, it will affect cutting speed and edge life, if you are always cutting in the same type of wood and same conditions. If you cut a variety of things, that advantage will balance out. Realistically, the scales on your grinder are probably off by a few degrees anyway.
So pick a set of angles and a wheel size for each type of chain, mark them down, and stick with those. The only time I would vary from those was if I was grinding someone else's chain and they had a preference. In those cases, I try to match the angles on their current chain, which is also faster, as it takes more time and uses up more cutter and grinding wheel material, to change angles.
And get some good wheels. The Molemab wheels from Baileys sometimes go on sale for $10, so if you are not in a hurry, keep an eye out for those.
That might have been me.
You have to remember that you are grinding both the top plate and side plate edges. Aside from the hollow ground thing, if you take the wheel down farther into the cutter you are changing the profile of the side plate. Look at a picture of the side plate and imagine what it would look like if the wheel cut deeper into it, or if the wheel was square edged instead of dressed round. The side plate does the hard work of severing the wood fibers when cross cutting, but doesn't seem to get the attention it deserves.
Philbert
Thank you Philbert and others. Having just received this grinder, there was just a bit of a learning curve. Once I learned the difference between top plate cutting edge angle vs. side plate angle (shown in the Homelight link above) the confusion over the angles subsided. I imagine that many don't realize that the 60 you set your motor/blade angle at is not necessarily the same as the side plate angle shown in many specs. (60/75/85 degrees). Supposedly, this side plate angle is met automatically with the correct hand file size. Anyway, learning this, I quickly agreed with the 60/30 angle "standard" chosen by many.
The wheel size debate (especially for the .325) piqued my curiosity mostly just in the principle. In a perfect world I imagine that a "precision" tool should have one set of standards. But, as shown here, in reality people are achieving good results not going by the book.
Grande dog's tip about referencing the wheel position to arbor was especially helpful.
The wheel size debate (especially for the .325) piqued my curiosity mostly just in the principle. In a perfect world I imagine that a "precision" tool should have one set of standards. But, as shown here, in reality people are achieving good results not going by the book.
Grande dog's tip about referencing the wheel position to arbor was especially helpful.
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You're right. I've been paying more attention to the top plate.
I know that the corner is important and I imagined that only the top .030"(depth to raker) of the side plate was important.
I picture the width of a wood chip being cut by the top plate and the thickness (.030") being cut by the side plate. That's why I've been more focused on the top plate.
So...is it important that the side plate edge be round from the corner down, or is a straight 60 deg. just as good ? (this would also answer the hollow or chisel top edge question, I think :msp_smile
.
Grande Dog
ArboristSite.com Sponsor
Howdy,
In my experience, the flat, or chisel type shape on the top plate is a more effective. I had actually hit on while experimenting with ripping chain. With a "hollow ground" type of top plate, the chip would curl, or crinkle more and cause more chip binding on the bar. The chisel, or "flat ground" grind produces a longer flat shred that is way less likely to bind the bar. Certainly the shorter the cut, the less chip binding would be noticed.
Just use the wheel suggested for your size chain and dress it the way (half round shape) you normally would. Then what I do is lay the dressing brick on the chain guide of the grinder and bring the wheel into contact. Then I slide the brick back and forth lengthwise with the chain guide until I've taken enough of the wheel to get my top plate fully onto the side of the wheel.
You can get by with wheels that are smaller than recommended but, you might have to go back and clean the gullets. Using the right sized wheel will grind the gullets out at the same time.
Regards
Gregg
In my experience, the flat, or chisel type shape on the top plate is a more effective. I had actually hit on while experimenting with ripping chain. With a "hollow ground" type of top plate, the chip would curl, or crinkle more and cause more chip binding on the bar. The chisel, or "flat ground" grind produces a longer flat shred that is way less likely to bind the bar. Certainly the shorter the cut, the less chip binding would be noticed.
Just use the wheel suggested for your size chain and dress it the way (half round shape) you normally would. Then what I do is lay the dressing brick on the chain guide of the grinder and bring the wheel into contact. Then I slide the brick back and forth lengthwise with the chain guide until I've taken enough of the wheel to get my top plate fully onto the side of the wheel.
You can get by with wheels that are smaller than recommended but, you might have to go back and clean the gullets. Using the right sized wheel will grind the gullets out at the same time.
Regards
Gregg
GD,
How about the differences between cross cutting and ripping? The type of chip and the build-up would be significantly different. Also, when ripping, the top plate is severing the fibers instead of the side plate so the profile and angles can be different.
Just to be clear, you are describing dressing the wheel to a half-round shape, then cutting a slight bevel on the lower side to clear the tie straps, right?
After I have ground a chain several times I sometimes go back and clean out the gullets, if they look funny, by setting the positioning dog back several millimeters. Depending upon the space available and the size of the buildup, I might do this with a larger size wheel, taking care to not hit the cutting edges.
Philbert
Grande Dog
ArboristSite.com Sponsor
Howdy,
That's correct. The relief on the wheel edge allows you to get the whole top plate on to the side of the wheel without grinding into the frame. The other thing I do is to lay the grinder head all the way over as far as it will go (Italian Grinders) with a 25 degree vise angle. This setting will net you about a actual 20 degree on the tooth.
The only time laying the head all the way over is an issue is when the tooth is new. What happens is the wheel will contact the raker and grind the back side off on the way in. A very important point that has been mentioned previously is that the optimum telemetry ultimately depends on the species you're cutting, it's degree of dryness, and whether you're cross cutting, or ripping.
From the differences I've seen across the board, this method is worth trying most peoples cutting environment.
Regards
Gregg
That's correct. The relief on the wheel edge allows you to get the whole top plate on to the side of the wheel without grinding into the frame. The other thing I do is to lay the grinder head all the way over as far as it will go (Italian Grinders) with a 25 degree vise angle. This setting will net you about a actual 20 degree on the tooth.
The only time laying the head all the way over is an issue is when the tooth is new. What happens is the wheel will contact the raker and grind the back side off on the way in. A very important point that has been mentioned previously is that the optimum telemetry ultimately depends on the species you're cutting, it's degree of dryness, and whether you're cross cutting, or ripping.
From the differences I've seen across the board, this method is worth trying most peoples cutting environment.
Regards
Gregg
Always a pleasure GD.
Is there an app for that?
Seriously, if one gets that specific on optimizing chain angles for different cutting situations, they are probably better off to have a variety of chains, like a golfer has a variety of clubs to select from, rather than grinding and regrinding away the cutters to change angles.
Philbert
Is there an app for that?
Seriously, if one gets that specific on optimizing chain angles for different cutting situations, they are probably better off to have a variety of chains, like a golfer has a variety of clubs to select from, rather than grinding and regrinding away the cutters to change angles.
Philbert
john taliaferro
Addicted to ArboristSite
So ripping when i cut the top to 5 degrees in stead of 0 ,why it cuts better is probley the change in side plate not so blunt . duh cutting not plowing . Some times iam so dum i scare my self . edit is their an app for that Grand Dog ?
