I read a lot about runout and I think I understand but I am not sure.
I have just installed a new blade and taken some readings with my new SS dial gauge.
Prior to employing the dial gauge, I used my engineers' square. The square has been my measuring device of choice for years. The observations were most satisfactory. Normally, I would go back to making sawdust and be satisfied. In fact, I did a few test cuts and was satisfied.
But I now have this dial gauge that I must use. I setup the dial gauge and took some readings at various points on the blade (rotating it slowly with the dial gauge in place). The dial readings varied around the blade with one extreme of -.002 and the other extreme of +.003.
Have I determined runout?
I understand that I have a maximum deviation around the blade of .005.
Is this good or bad?
Can it be improved upon? If yes, how?
If I repeat the same test with this blade installed on a different arbor, do I expect the same results?
If no, why?
Measuring Runout
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dusty
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Measuring Runout
"Making Sawdust Safely"
Dusty
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Dusty
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Ed in Tampa
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But I now have this dial gauge that I must use. I setup the dial gauge and took some readings at various points on the blade (rotating it slowly with the dial gauge in place). The dial readings varied around the blade with one extreme of -.002 and the other extreme of +.003.
Dusty this statement "But I now have this dial gauge that I must use."Is the key to the problem. Take a measurement anywhere on the blade. Now with just your finger push the blade. See how easily the measurement changes. Now consider what happens when you cut and the blade hits the wood, with all the changes in grain, going from hard to soft and back how much do you think the blade flexes? Now to your questions
Have I determined runout? Yes I believe that is exactly what runout is.
I understand that I have a maximum deviation around the blade of .005. Yes again you have a .005 runout.
Is this good or bad? I believe .005 is acceptable. Didn't you say you tried the blade on a few cuts and the results were acceptable?
Can it be improved upon? Yes possibly If yes, how?Put a mark on the blade and the arbor, now shift the blade 90 degrees does the runout change? Try 180 degrees etc. Also check the arbor and blade and make sure they are perfectly clean, even paint can add to runout. I clean the blade, the arbor to the point I will remove manufacture labeling to insure I have mimimized runout.
If I repeat the same test with this blade installed on a different arbor, do I expect the same results? Probably not.
If no, why?Most arbors are close but if the arbor has runout and the blade has some where you mount the blade may add to or subtract from the overall runout. Just as we did above shifting the blade 90 degrees.
Dusty if I may make a suggestion, I have come to the conclusion that dial indicators are "CRAZY MAKERS". By that I mean we make ourselves crazy trying to get perfection when perfection is not required, needed and in some cases not even desired.
I often read the forums about how this guy adjusted in his saw to .00000001" and I immediately go to my SS and start messing. After I have frustrated myself almost to the point of craziness I realize that even leaning on the table from a different direction is enough to move the dial indicator and I hopefully come to my senses and put the "crazy maker" away and get back to cutting wood.
Wood is wood and as such it expands, contracts, shifts, bends and bows with humidity and other factors. If something was built to zero tolerance it would probably explode over time because of this.
I think dial indicators are essential to machine shops but I think we have taken a giant step in the wrong direction bringing them into the wood shop. In every case when I tried to set my SS up with a dial indicator I achieved a major headache and was frustrated yet when I used SS directions and set it up with a square the adjustments went smoothly and the results produced a perfect cut.
Manufactures and Ad men in an attempt to create a new market in woodworking world have come out with dial indicators for saws/woodworking. What they don't say is how much deflection is in the blade when you make a cut, how much the wood will change before and after the cut, how pressure from just slightly different applied to the wood will effect the cut, and in the case of the SS how pressure on just the table changes all the "perfect" measurement/alignment.
Dusty I have come to the place where I'm thinking of selling my Dial indicator just so I can stop worrying if I'm out a .001" or not.
Don't make yourself crazy
Ed
Dusty this statement "But I now have this dial gauge that I must use."Is the key to the problem. Take a measurement anywhere on the blade. Now with just your finger push the blade. See how easily the measurement changes. Now consider what happens when you cut and the blade hits the wood, with all the changes in grain, going from hard to soft and back how much do you think the blade flexes? Now to your questions
Have I determined runout? Yes I believe that is exactly what runout is.
I understand that I have a maximum deviation around the blade of .005. Yes again you have a .005 runout.
Is this good or bad? I believe .005 is acceptable. Didn't you say you tried the blade on a few cuts and the results were acceptable?
Can it be improved upon? Yes possibly If yes, how?Put a mark on the blade and the arbor, now shift the blade 90 degrees does the runout change? Try 180 degrees etc. Also check the arbor and blade and make sure they are perfectly clean, even paint can add to runout. I clean the blade, the arbor to the point I will remove manufacture labeling to insure I have mimimized runout.
If I repeat the same test with this blade installed on a different arbor, do I expect the same results? Probably not.
If no, why?Most arbors are close but if the arbor has runout and the blade has some where you mount the blade may add to or subtract from the overall runout. Just as we did above shifting the blade 90 degrees.
Dusty if I may make a suggestion, I have come to the conclusion that dial indicators are "CRAZY MAKERS". By that I mean we make ourselves crazy trying to get perfection when perfection is not required, needed and in some cases not even desired.
I often read the forums about how this guy adjusted in his saw to .00000001" and I immediately go to my SS and start messing. After I have frustrated myself almost to the point of craziness I realize that even leaning on the table from a different direction is enough to move the dial indicator and I hopefully come to my senses and put the "crazy maker" away and get back to cutting wood.
Wood is wood and as such it expands, contracts, shifts, bends and bows with humidity and other factors. If something was built to zero tolerance it would probably explode over time because of this.
I think dial indicators are essential to machine shops but I think we have taken a giant step in the wrong direction bringing them into the wood shop. In every case when I tried to set my SS up with a dial indicator I achieved a major headache and was frustrated yet when I used SS directions and set it up with a square the adjustments went smoothly and the results produced a perfect cut.
Manufactures and Ad men in an attempt to create a new market in woodworking world have come out with dial indicators for saws/woodworking. What they don't say is how much deflection is in the blade when you make a cut, how much the wood will change before and after the cut, how pressure from just slightly different applied to the wood will effect the cut, and in the case of the SS how pressure on just the table changes all the "perfect" measurement/alignment.
Dusty I have come to the place where I'm thinking of selling my Dial indicator just so I can stop worrying if I'm out a .001" or not.
Don't make yourself crazy
Ed
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dusty
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Measuring Runout
ed
I believe I share your viewpoints. At least most of them. When it is time to tuneup the SS, I use my best square and my level. Shopsmith doesn't even talk about level. I use my level because it is my best straightedge.
When I am done with the procedure, I cut up some scrap wood and inspect the quality of the cut. I look for tooth marks and the pattern (if there is one) of those marks. I check for straightness of cut and angles to the edge and the face. I cut off some ends and check for squareness.
All of that is done with a good square and a straight edge.
After fifteen to twenty minutes, I am almost always satisfied and it is back to "making Sawdust".
Ed, a word of advise given your attitude toward "toys". Don't spend any money on a Wixey. Don't get me wrong, the Wixey does what it is advertised to do. It seems to be very accurate and repeatable. I am just not sure what it means for my table and blade to be within .1 degrees of right on.
How much error does .1 degrees relate to if I am ripping a 1" board.
However, I don't use it to perform alignments or adjustments.
I do use it to boost my ego when I am done doing those the old fashion way.
Are there any other comments on runout?
I believe I share your viewpoints. At least most of them. When it is time to tuneup the SS, I use my best square and my level. Shopsmith doesn't even talk about level. I use my level because it is my best straightedge.
When I am done with the procedure, I cut up some scrap wood and inspect the quality of the cut. I look for tooth marks and the pattern (if there is one) of those marks. I check for straightness of cut and angles to the edge and the face. I cut off some ends and check for squareness.
All of that is done with a good square and a straight edge.
After fifteen to twenty minutes, I am almost always satisfied and it is back to "making Sawdust".
Ed, a word of advise given your attitude toward "toys". Don't spend any money on a Wixey. Don't get me wrong, the Wixey does what it is advertised to do. It seems to be very accurate and repeatable. I am just not sure what it means for my table and blade to be within .1 degrees of right on.
How much error does .1 degrees relate to if I am ripping a 1" board.
However, I don't use it to perform alignments or adjustments.
I do use it to boost my ego when I am done doing those the old fashion way.
Are there any other comments on runout?
"Making Sawdust Safely"
Dusty
Sent from my Dell XPS using Firefox.
Dusty
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popstoyshop
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runout
Hi Dusty,
Runout is the in & out movement of the main shaft NOT the difference in blade flatness.
Your dial showed a difference in blade flatness of .005. Remember .003 is about the thickness of a human hair. Not a lot of variation there.
Runout is measured with no blade at all, just the arbor with no arbor nut on it.
Measuring runout on a Shopsmith is not going to be all that accurate. This is because the entire quill moves in & out. True the spring holds it in a fairly stable spot but not like a table saw.
Bill G.
Runout is the in & out movement of the main shaft NOT the difference in blade flatness.
Your dial showed a difference in blade flatness of .005. Remember .003 is about the thickness of a human hair. Not a lot of variation there.
Runout is measured with no blade at all, just the arbor with no arbor nut on it.
Measuring runout on a Shopsmith is not going to be all that accurate. This is because the entire quill moves in & out. True the spring holds it in a fairly stable spot but not like a table saw.
Bill G.
One who works with his hands is a laborer.
One who works with his hands and his head is a craftsman.
One who works with his hands, his head and his heart is an artist.
One who works with his hands and his head is a craftsman.
One who works with his hands, his head and his heart is an artist.
Bill, Wouldn't this be irrelevant if nothing is attached to the shaft? True, nothing will run well on a shaft with EXCESSIVE runout, but I don't think that's the point of Dusty's question. I think, correct me if I'm wrong Dusty, that what He's really concerned with is how much deviation is acceptable to still make accurate cuts. Obviously, to make ANY cut, you have a blade attached, so, I think most of us would refer to runout as the COMBINATION of shaft runout AND blade flatness. IMHO,of course.popstoyshop wrote:Hi Dusty,
Runout is the in & out movement of the main shaft NOT the difference in blade flatness.
Alan
'Baking The World A Better Place'
'Baking The World A Better Place'
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dusty
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Measuring Runout
Thanks for all the inputs; they are all helpful.
I think I am having a problem because of my concept of what runout is or what problems might be created by excessive runout.
It is my understanding that if a devise (a tablesaw) is perfect (with respect to runout) then the blade always travels in exactly the same plane.
Conversely, if there is a runout problem, the plane of the blade becomes a variable. It may wobble or it may slide back and forth.
Is my perception correct? If it is not, that may explain why I don't understand runout numbers.
Ed in Tampa made the point that the blades and arbor must be clean. This causes me to think.....if there is a spot of paint on the blade, when I install it in the arbor it won't be perfectly perpendicular to the drive line...thus wobble, thus runout.
Am I getting this or no?
I think I am having a problem because of my concept of what runout is or what problems might be created by excessive runout.
It is my understanding that if a devise (a tablesaw) is perfect (with respect to runout) then the blade always travels in exactly the same plane.
Conversely, if there is a runout problem, the plane of the blade becomes a variable. It may wobble or it may slide back and forth.
Is my perception correct? If it is not, that may explain why I don't understand runout numbers.
Ed in Tampa made the point that the blades and arbor must be clean. This causes me to think.....if there is a spot of paint on the blade, when I install it in the arbor it won't be perfectly perpendicular to the drive line...thus wobble, thus runout.
Am I getting this or no?
"Making Sawdust Safely"
Dusty
Sent from my Dell XPS using Firefox.
Dusty
Sent from my Dell XPS using Firefox.
This question may be at least partially answered by watching the First Hands Online that was held this morning. Nick will post it for anyone to watch early next week (I believe) He did a great job of demonstrating how to square the table to the blade. As with the rest of his presentation it was great. Jim:)
F. Jim Parks
Lakewood, Colorado:)
When the love of power is replaced by the power of love the world will have a chance for survival.
Lakewood, Colorado:)
When the love of power is replaced by the power of love the world will have a chance for survival.
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Ed in Tampa
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What Dusty posted in black with my comments in red and my final thoughts in black in the last paragraph.
"Thanks for all the inputs; they are all helpful.
I think I am having a problem because of my concept of what runout is or what problems might be created by excessive runout.
It is my understanding that if a devise (a tablesaw) is perfect (with respect to runout) then the blade always travels in exactly the same plane.
Conversely, if there is a runout problem, the plane of the blade becomes a variable. It may wobble or it may slide back and forth.
Is my perception correct? Your perception is correct. There are many things that can effect runout. Blade flatness, shaft wobble, shaft shifting, arbor wobble and etc. But they all effect the plane of the blade and making it wobble or slide back and forth If it is not, that may explain why I don't understand runout numbers.
Jim in Tucson made the point that the blades and arbor must be clean. This causes me to think.....if there is a spot of paint on the blade, when I install it in the arbor it won't be perfectly perpendicular to the drive line...thus wobble, thus runout.That is also true and as I mentioned I often clean scape my blades. My sharpener always cleans the blade down to bare metal in about a 3 -4 inch diameter around the arbor hole when he sharpens them.
Am I getting this or no?" Dusty I think your getting this. However I think there is a factor we don't think about and that is how the wood and tooth geometry effect the blade. Wood grain and knots will defect the blade often more than the measured runout. Also the angle the teeth are cut and their overall geometry effects the blade and can cause the blade to shift/oscillate as each tooth deflects the blade slightly. I believe the effects of the tooth angle and overall geometry effect the blade depending on speed, I think this is a reason some people swear by a blade that another swears at. The speed of the blade and ocillation set up by the teeth sharpening angle and overall geometry can make the blade cut bad at one speed (on one saw) and most excellent on another.
Again I think blade runout that isn't bad enough to detect with the human eye really plays very little in cut quality. However being the creatures we are I know myself when I mount my blade in the arbor I always see if I can find the spot where the combination products the least runout. Something I probably wouldn't do on a regular table saw but it so easy on the ShopSmith. Also since each blade has it's own arbor it seems to make more sense to mount them carefully.
Ed
"Thanks for all the inputs; they are all helpful.
I think I am having a problem because of my concept of what runout is or what problems might be created by excessive runout.
It is my understanding that if a devise (a tablesaw) is perfect (with respect to runout) then the blade always travels in exactly the same plane.
Conversely, if there is a runout problem, the plane of the blade becomes a variable. It may wobble or it may slide back and forth.
Is my perception correct? Your perception is correct. There are many things that can effect runout. Blade flatness, shaft wobble, shaft shifting, arbor wobble and etc. But they all effect the plane of the blade and making it wobble or slide back and forth If it is not, that may explain why I don't understand runout numbers.
Jim in Tucson made the point that the blades and arbor must be clean. This causes me to think.....if there is a spot of paint on the blade, when I install it in the arbor it won't be perfectly perpendicular to the drive line...thus wobble, thus runout.That is also true and as I mentioned I often clean scape my blades. My sharpener always cleans the blade down to bare metal in about a 3 -4 inch diameter around the arbor hole when he sharpens them.
Am I getting this or no?" Dusty I think your getting this. However I think there is a factor we don't think about and that is how the wood and tooth geometry effect the blade. Wood grain and knots will defect the blade often more than the measured runout. Also the angle the teeth are cut and their overall geometry effects the blade and can cause the blade to shift/oscillate as each tooth deflects the blade slightly. I believe the effects of the tooth angle and overall geometry effect the blade depending on speed, I think this is a reason some people swear by a blade that another swears at. The speed of the blade and ocillation set up by the teeth sharpening angle and overall geometry can make the blade cut bad at one speed (on one saw) and most excellent on another.
Again I think blade runout that isn't bad enough to detect with the human eye really plays very little in cut quality. However being the creatures we are I know myself when I mount my blade in the arbor I always see if I can find the spot where the combination products the least runout. Something I probably wouldn't do on a regular table saw but it so easy on the ShopSmith. Also since each blade has it's own arbor it seems to make more sense to mount them carefully.
Ed
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james.miller
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Just for the fun of it I set each blade to its ideal position on its dedicated arbor to .003" or .004". I look at the position of the blade label or serial number in relation to the arbor set screw, measure it then rotate the blade 180 degrees measure again then rotate it 90 degrees. You can go to 45 degree increments if you have a lot of time on your hands. I usually stop if it is at .003, which produces a very smooth cut and only spend a few minuets to find this sweet spot on each blade. FYI Forrest advertises their blades are within .001" to .002" runout.
The Wixey angle gauge is useful for setting the table to 90 degrees, also 45 and parallel to the blade in both planes (drill press). Nick had a post a while back using it to set the miter gauge. 0.1 degrees is approx 0.001745" at 1 inch (if I plugged the numbers into my calculator correctly) this would be approximately .005" when making a 3" deep cut. The wood movement with humidity changes is probably a lot greater than this. So even though the Wixey angle gauge is a fun toy it is probably overkill for woodworking.
BTW Wixie also makes a digital caliper that reads in decimals and fractions to 1/64" at the same time.
The Wixey angle gauge is useful for setting the table to 90 degrees, also 45 and parallel to the blade in both planes (drill press). Nick had a post a while back using it to set the miter gauge. 0.1 degrees is approx 0.001745" at 1 inch (if I plugged the numbers into my calculator correctly) this would be approximately .005" when making a 3" deep cut. The wood movement with humidity changes is probably a lot greater than this. So even though the Wixey angle gauge is a fun toy it is probably overkill for woodworking.
BTW Wixie also makes a digital caliper that reads in decimals and fractions to 1/64" at the same time.
Jim in Tucson