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#1
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Based on favorable comments and reviews in this group and others, I recently
purchased a Veritas Power Sharpening System. After having used it for a couple of weeks and sharpening every tool I could find with a cutting edge (it's so easy), I'm convinced that I made the right choice. It produces an edge that cuts as well or better than any I've been able to obtain with my oil, or water stones, in a fraction of the time. I also like the fact that's it's a dry system, so I don't have to contend with the oil / water mess, which in my small shop is a huge plus! That said I'm having trouble obtaining a micro-bevel that's exactly parallel to the primary bevel. This in no way affects the sharpness of the edge, but when it comes time to re-sharpen, I'm forced to remove more metal than would otherwise be necessary to get back to the primary bevel. As an example, on a 1 5/8” wide plane blade, the micro bevel on one end is nearly 1/16” wide while the bevel on the opposite end is barely perceptible. One thing that I find very interesting is that the bevel is always heavier on the left side of the blade. This occurs even if I run the tool holder and blade on the opposite side of the platter. I'm wondering if anyone else has had a similar problem and found a solution. I've talked to the folks at Lee Valley and they've been more than cooperative and helpful. They've even gone so far as to ship me new platters and media, in case mine were out of spec. Unfortunately, that didn't solve the problem. I'm starting to wonder if maybe my technique is at fault, or my expectations are too high. Here are a few additional details: - Both 3mm and 4mm platters are flat within .001 inches (when running there is slight wobble (~.003) but this is consistent between platters. - The tool bar is parallel to the platters - I have checked this several times. - There are no air bubbles between the media and platter (LV suggested applying the PSA disks under water and even though this sounds strange, it works great - zero air bubbles) |
#2
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Try using pinpoint finger pressure to apply more pressure at the right front
corner of the blade to make the micro bevel parallel. Also check the blade when clamped in the carrier with a square to make sure it remains squared. Neill wrote in message nk.net... Based on favorable comments and reviews in this group and others, I recently purchased a Veritas Power Sharpening System. After having used it for a couple of weeks and sharpening every tool I could find with a cutting edge (it's so easy), I'm convinced that I made the right choice. It produces an edge that cuts as well or better than any I've been able to obtain with my oil, or water stones, in a fraction of the time. I also like the fact that's it's a dry system, so I don't have to contend with the oil / water mess, which in my small shop is a huge plus! That said I'm having trouble obtaining a micro-bevel that's exactly parallel to the primary bevel. This in no way affects the sharpness of the edge, but when it comes time to re-sharpen, I'm forced to remove more metal than would otherwise be necessary to get back to the primary bevel. As an example, on a 1 5/8" wide plane blade, the micro bevel on one end is nearly 1/16" wide while the bevel on the opposite end is barely perceptible. One thing that I find very interesting is that the bevel is always heavier on the left side of the blade. This occurs even if I run the tool holder and blade on the opposite side of the platter. I'm wondering if anyone else has had a similar problem and found a solution. I've talked to the folks at Lee Valley and they've been more than cooperative and helpful. They've even gone so far as to ship me new platters and media, in case mine were out of spec. Unfortunately, that didn't solve the problem. I'm starting to wonder if maybe my technique is at fault, or my expectations are too high. Here are a few additional details: - Both 3mm and 4mm platters are flat within .001 inches (when running there is slight wobble (~.003) but this is consistent between platters. - The tool bar is parallel to the platters - I have checked this several times. - There are no air bubbles between the media and platter (LV suggested applying the PSA disks under water and even though this sounds strange, it works great - zero air bubbles) |
#3
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
IMHO a 1/16" wide micro bevel has been on the grinder too long.
wrote in message nk.net... Based on favorable comments and reviews in this group and others, I recently purchased a Veritas Power Sharpening System. After having used it for a couple of weeks and sharpening every tool I could find with a cutting edge (it's so easy), I'm convinced that I made the right choice. It produces an edge that cuts as well or better than any I've been able to obtain with my oil, or water stones, in a fraction of the time. I also like the fact that's it's a dry system, so I don't have to contend with the oil / water mess, which in my small shop is a huge plus! That said I'm having trouble obtaining a micro-bevel that's exactly parallel to the primary bevel. This in no way affects the sharpness of the edge, but when it comes time to re-sharpen, I'm forced to remove more metal than would otherwise be necessary to get back to the primary bevel. As an example, on a 1 5/8" wide plane blade, the micro bevel on one end is nearly 1/16" wide while the bevel on the opposite end is barely perceptible. One thing that I find very interesting is that the bevel is always heavier on the left side of the blade. This occurs even if I run the tool holder and blade on the opposite side of the platter. I'm wondering if anyone else has had a similar problem and found a solution. I've talked to the folks at Lee Valley and they've been more than cooperative and helpful. They've even gone so far as to ship me new platters and media, in case mine were out of spec. Unfortunately, that didn't solve the problem. I'm starting to wonder if maybe my technique is at fault, or my expectations are too high. Here are a few additional details: - Both 3mm and 4mm platters are flat within .001 inches (when running there is slight wobble (~.003) but this is consistent between platters. - The tool bar is parallel to the platters - I have checked this several times. - There are no air bubbles between the media and platter (LV suggested applying the PSA disks under water and even though this sounds strange, it works great - zero air bubbles) |
#4
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Neil -
The blade is absolutely square to the holder and the final edge is square to the side of the blade. I have tried to apply pinpoint pressure to the right side of the blade as you suggest and although this helps, it's kind of hit or miss. It most often results in a MB that's kind of barrel shaped, with the right and left sides being deeper than the center. I'm starting to wonder if the tool holder may somehow be out of alignment, even though I don't have super accurate way to measure this. Joel |
#5
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
I would agree and that's precisely my problem. I don't start to get any
bevel on the right side of the blade until the left side is nearly at 1/16”. |
#6
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
wrote in message I would agree and that's precisely my problem. I don't start to get any bevel on the right side of the blade until the left side is nearly at 1/16". If you don't get an answer to your problem here, you might want to contact Lee Valley customer service. It's unusual for them not to be able to suggest proper procedures for the use of their products. |
#7
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
He did that.
"Upscale" wrote in message ... wrote in message I would agree and that's precisely my problem. I don't start to get any bevel on the right side of the blade until the left side is nearly at 1/16". If you don't get an answer to your problem here, you might want to contact Lee Valley customer service. It's unusual for them not to be able to suggest proper procedures for the use of their products. |
#8
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
wrote in message news Neil - The blade is absolutely square to the holder and the final edge is square to the side of the blade. I have tried to apply pinpoint pressure to the right side of the blade as you suggest and although this helps, it's kind of hit or miss. It most often results in a MB that's kind of barrel shaped, with the right and left sides being deeper than the center. I'm starting to wonder if the tool holder may somehow be out of alignment, even though I don't have super accurate way to measure this. I think you're concentrating on something the wood doesn't know or care about just because you can see it. It's cosmetic, not functional. The difference in edge deflection, if you buy something from Ed to measure it, would be in the tens of thousandths if that, and well within the elasticity of the wood you're planing. If it works, don't look. |
#9
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
I don't see how the system could not have assymetric sharpening. I
claim that with even pressure on each side, you will get a different amount of metal removal. Here's my thughts: The edge fartherest from the center of the disc, has more sandpaper go under it. I assume Veritas/Lee Valley engineers have shown the difference is neglible. Let me see if I can rough out a calculation: Assume the width of the blade in an inch and a half. Assume the inner edge of the blade is 3 inches from the center (r = 3). The outer edge is then 4.5 inches from the center (r + 1.5). Assume the disk is rotating at 600 RPM. The inner part of the blade passes over 2 * pi * r * 600 inches = 11310 inches per minute. The outer part passes over 2 * pi * (r + 1.5) * 600 = 16965 inches per minute Thus the outer edge experiences 16965/11310 * 100 = 50% more! Am I wrong? If so, how? On Dec 2, 11:37 pm, wrote: Based on favorable comments and reviews in this group and others, I recently purchased a Veritas Power Sharpening System. After having used it for a couple of weeks and sharpening every tool I could find with a cutting edge (it's so easy), I'm convinced that I made the right choice. It produces an edge that cuts as well or better than any I've been able to obtain with my oil, or water stones, in a fraction of the time. I also like the fact that's it's a dry system, so I don't have to contend with the oil / water mess, which in my small shop is a huge plus! That said I'm having trouble obtaining a micro-bevel that's exactly parallel to the primary bevel. This in no way affects the sharpness of the edge, but when it comes time to re-sharpen, I'm forced to remove more metal than would otherwise be necessary to get back to the primary bevel. As an example, on a 1 5/8" wide plane blade, the micro bevel on one end is nearly 1/16" wide while the bevel on the opposite end is barely perceptible. One thing that I find very interesting is that the bevel is always heavier on the left side of the blade. This occurs even if I run the tool holder and blade on the opposite side of the platter. I'm wondering if anyone else has had a similar problem and found a solution. I've talked to the folks at Lee Valley and they've been more than cooperative and helpful. They've even gone so far as to ship me new platters and media, in case mine were out of spec. Unfortunately, that didn't solve the problem. I'm starting to wonder if maybe my technique is at fault, or my expectations are too high. Here are a few additional details: - Both 3mm and 4mm platters are flat within .001 inches (when running there is slight wobble (~.003) but this is consistent between platters. - The tool bar is parallel to the platters - I have checked this several times. - There are no air bubbles between the media and platter (LV suggested applying the PSA disks under water and even though this sounds strange, it works great - zero air bubbles) |
#10
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
You are quite correct though, in this case, it really doesn't matter as it
happens the same way no matter what side of the wheel he sharpens on. The real question is, why put the micro bevel on in the first place? The only reason for a micro bevel is to save time when resharpening. During the initial edge formation, there is no need for it. If it were me, after initial sharpening on the machine, I would do any touch ups by hand. Only when the micro bevel got to large would I go back to the machine. Of course, I wouldn't use the machine in the first place but that's up to him. "Never Enough Money" wrote in message ps.com... I don't see how the system could not have assymetric sharpening. I claim that with even pressure on each side, you will get a different amount of metal removal. Here's my thughts: The edge fartherest from the center of the disc, has more sandpaper go under it. I assume Veritas/Lee Valley engineers have shown the difference is neglible. Let me see if I can rough out a calculation: Assume the width of the blade in an inch and a half. Assume the inner edge of the blade is 3 inches from the center (r = 3). The outer edge is then 4.5 inches from the center (r + 1.5). Assume the disk is rotating at 600 RPM. The inner part of the blade passes over 2 * pi * r * 600 inches = 11310 inches per minute. The outer part passes over 2 * pi * (r + 1.5) * 600 = 16965 inches per minute Thus the outer edge experiences 16965/11310 * 100 = 50% more! Am I wrong? If so, how? On Dec 2, 11:37 pm, wrote: Based on favorable comments and reviews in this group and others, I recently purchased a Veritas Power Sharpening System. After having used it for a couple of weeks and sharpening every tool I could find with a cutting edge (it's so easy), I'm convinced that I made the right choice. It produces an edge that cuts as well or better than any I've been able to obtain with my oil, or water stones, in a fraction of the time. I also like the fact that's it's a dry system, so I don't have to contend with the oil / water mess, which in my small shop is a huge plus! That said I'm having trouble obtaining a micro-bevel that's exactly parallel to the primary bevel. This in no way affects the sharpness of the edge, but when it comes time to re-sharpen, I'm forced to remove more metal than would otherwise be necessary to get back to the primary bevel. As an example, on a 1 5/8" wide plane blade, the micro bevel on one end is nearly 1/16" wide while the bevel on the opposite end is barely perceptible. One thing that I find very interesting is that the bevel is always heavier on the left side of the blade. This occurs even if I run the tool holder and blade on the opposite side of the platter. I'm wondering if anyone else has had a similar problem and found a solution. I've talked to the folks at Lee Valley and they've been more than cooperative and helpful. They've even gone so far as to ship me new platters and media, in case mine were out of spec. Unfortunately, that didn't solve the problem. I'm starting to wonder if maybe my technique is at fault, or my expectations are too high. Here are a few additional details: - Both 3mm and 4mm platters are flat within .001 inches (when running there is slight wobble (~.003) but this is consistent between platters. - The tool bar is parallel to the platters - I have checked this several times. - There are no air bubbles between the media and platter (LV suggested applying the PSA disks under water and even though this sounds strange, it works great - zero air bubbles) |
#11
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Never Enough Money wrote:
Thus the outer edge experiences 16965/11310 * 100 = 50% more! Am I wrong? If so, how? You are exactly right. I initially wrote very favorable reviews about the system on this forum, but after several years, have become disenchanted. I found that over time, the right side of all of my blades were ground down much more than the left. (The instructions suggest using the right side of the disk, which is why the right was always worn down more.) I suggest putting a square up to each blade. I found that every blade -- plane, chisel, etc. was shorter on the right than the left. They all had a consistent arc. After spending a bunch of time trying to adjust things to get it right, I finally just gave up. The courser the paper on the disk, the worse the blade gets out of square. The 80x blue disks is the worst offender. I am convinced this is a design problem and not a setup problem because I checked that the disk (with paper applied) was flat and found that if I move the blade to the other side of the disk, the left side will be ground more than the right. It seemed to me that the problem gets worse as the paper dulls. That may be because the outermost grit is not used as much as the inner. It seems counterintuitive, but as I use the machine, I move the blade back and forth, so the outermost edge of the disk gets hit very infrequently. If you see sparks on the 80x on the outside, but not the inside, then you know for sure the outer is sharper than the inner. The sharper grit on the outside exacerbates the problem because that part of the disk is sharper *and* traveling faster. I think the system works much better with sharp paper and that's why at first the system seems great, but it gets worse and worse. It doesn't take long for the paper to be dull enough to achieve this effect. On a chisel that is 1" or less, it usually isn't a big deal, but with a 2" plane blade, the difference is pretty significant and you end up using up a lot of the 9 micron paper trying to get the edge all the way across. You may be able to work around this problem by switching the blade back and forth between the left and the right sides. Of course the blade will be crowned, but many people see that as an advantage. As I mentioned before, I finally just gave up. Lately I have been doing the bulk of the "grinding" with 60 grit Norton 3x paper on glass and then finish up with 3M abrasives, each at a higher microbevel. I made very simple sharpening jigs based on the designs on Brent Beach's website and everything seems to be going well. When I started on the 60 grit, I was amazed at how much metal I had to remove to get the bevel square again. We'll see what I say in a few years... Mark |
#12
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Mark,
In your experience with the machine, did you also have problems with the primary and micro bevels not being parallel, or simply the fact that your blades were being ground out of square? After reading your comments, I'm inclined to think that my problem may be due to the different rates of abrasive wear between the coarse disks and the 9 micron disk used to apply the micro bevel. If the relative rate of abrasive wear at the disk circumference was slightly greater on the coarse disks than on the 9 micron disk, the effect would be exactly as I've observed. As I think about it, the problem gets worse as the abrasives wear. This would be consistent with your observations. The only problem is that it doesn't explain why the micro bevel seems to always be greater on the left side of the blade, no matter which side of the platter I run it on. I'm going to recheck that tomorrow; my observations may have been in error. Joel |
#13
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Mark,
I read with much interest your analysis below. Though I'm not sure I agree. I got the Veritas power sharpener several months ago and have been wrestling with this problem since day one: the cutting edge is simply not square to the side edge of a blade. (To the original poster, Woodworker1, I do not put micro bevels on my blades.) I have determined that the problem is that the tool/blade holder flexes and therefore the blade just does not contact the platter flat. If you register the blade against one shoulder of the holder versus the other shoulder, the un-squareness also shifts to the other side of the blade. Try this: mount a blade (say 1.5 inches wide) in the tool holder and set the entire thing on a flat surface so that the blade cutting edge and the holder legs contact the table. Then tighten up the clamp nuts: you can see one blade corner lift up off the tabletop. If you shift the blade to square it against the opposite shoulder on the holder and tighten the clamp up, then the other side of the blade lifts up off the table. So, even though the blade is exactly square to the tool holder, the entire holder is flexing. It is true that the outboard part of the blade (nearer the outside of the platter) is seeing higher tangential velocities. However, as long as the blade contacts the platter flat, this is not an issue. I went back and forth with Veritas customer service about this and they kept saying that I was over tightening the clamp bar. I said that I was only tightening as much as necessary so that the blade does not shift during the sharpening process. Ultimately they could not help me. I am really not happy with either the sharpener or Lee Valley's response. Though I 'm not sure what I expected from them. If what I say is true, then the entire tool holder needs to be re-designed. If not actually re-designed, then at least seriously beefed up, strengthened. Larry Mark Wells wrote: Never Enough Money wrote: Thus the outer edge experiences 16965/11310 * 100 = 50% more! Am I wrong? If so, how? You are exactly right. I initially wrote very favorable reviews about the system on this forum, but after several years, have become disenchanted. I found that over time, the right side of all of my blades were ground down much more than the left. (The instructions suggest using the right side of the disk, which is why the right was always worn down more.) I suggest putting a square up to each blade. I found that every blade -- plane, chisel, etc. was shorter on the right than the left. They all had a consistent arc. After spending a bunch of time trying to adjust things to get it right, I finally just gave up. The courser the paper on the disk, the worse the blade gets out of square. The 80x blue disks is the worst offender. I am convinced this is a design problem and not a setup problem because I checked that the disk (with paper applied) was flat and found that if I move the blade to the other side of the disk, the left side will be ground more than the right. It seemed to me that the problem gets worse as the paper dulls. That may be because the outermost grit is not used as much as the inner. It seems counterintuitive, but as I use the machine, I move the blade back and forth, so the outermost edge of the disk gets hit very infrequently. If you see sparks on the 80x on the outside, but not the inside, then you know for sure the outer is sharper than the inner. The sharper grit on the outside exacerbates the problem because that part of the disk is sharper *and* traveling faster. I think the system works much better with sharp paper and that's why at first the system seems great, but it gets worse and worse. It doesn't take long for the paper to be dull enough to achieve this effect. On a chisel that is 1" or less, it usually isn't a big deal, but with a 2" plane blade, the difference is pretty significant and you end up using up a lot of the 9 micron paper trying to get the edge all the way across. You may be able to work around this problem by switching the blade back and forth between the left and the right sides. Of course the blade will be crowned, but many people see that as an advantage. As I mentioned before, I finally just gave up. Lately I have been doing the bulk of the "grinding" with 60 grit Norton 3x paper on glass and then finish up with 3M abrasives, each at a higher microbevel. I made very simple sharpening jigs based on the designs on Brent Beach's website and everything seems to be going well. When I started on the 60 grit, I was amazed at how much metal I had to remove to get the bevel square again. We'll see what I say in a few years... Mark |
#14
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Even if the holder is perfect, how could you ever overcome the problem
I mentioned in my earlier post on this topic? The outer edge sees a lot more paper than the inner edge so you'll always have asymmetry... Unless somehow the pressure on the outer edge is lightened up to perfectly compensate for the extra papaer it sees (that'd be difficult, I think). [snip] |
#15
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
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#16
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
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#17
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
"Mark Wells" wrote in message oups.com... I agree. I'm not happy, but not sure what to expect from them. I do know that I bought the first honing jig, which "everybody" said was great and it turned out to be worthless because the blade shifts. Then I bought this machine, which "everybody" said is great. It has turned out less than satisfactory. I'm not about to buy the new honing jig. That's why I made my own. Think I may have a thought. Go here http://www.makita.com/assets_product...als/9820-2.pdf and look at the picture and instructions in the center of page 8. I would assume that the same would be true for the Veritas, given the similarity. Mark |
#18
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Mark Wells wrote: I agree. I'm not happy, but not sure what to expect from them. I do know that I bought the first honing jig, which "everybody" said was great and it turned out to be worthless because the blade shifts. Then I bought this machine, which "everybody" said is great. It has turned out less than satisfactory. I'm not about to buy the new honing jig. That's why I made my own. Mark Mark, I had the Veritas Honing Jig, and had the same trouble - the blade would not stay square. I returned it and got the Mark II Jig which is just great. Everything that is wrong with the original jig was fixed with the Mark II. As for the micro-bevel, the Mark II jig accomplishes it by offsetting the wheel - which has the effect of twisting the blade in relation to the abrasive, resulting in the microbevel not being parallel with the primary bevel. Maybe this is just how Veritas chose to handle the microbevel on all of their sharpening systems. With the Mark II jig, I've just used a playing card under the roller to create an even microbevel. If you end up returning the powered system, look into the Mark II jig - I've been very happy with it. Mike |
#19
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
George wrote:
Think I may have a thought. Go here http://www.makita.com/assets_product...als/9820-2.pdf and look at the picture and instructions in the center of page 8. I would assume that the same would be true for the Veritas, given the similarity. Good thought. I think there is one big difference with the Makita, though. It actually uses a stone, which wears away so the wheel ends up sloped down toward the outside. The Highland Hardware instructions have more detail about that: http://www.highlandwoodworking.com/library/9820-2.pdf (Disclaimer: I have never seen or used a Makita sharpener.) Mark |
#20
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
"Mark Wells" wrote in message ups.com... George wrote: Think I may have a thought. Go here http://www.makita.com/assets_product...als/9820-2.pdf and look at the picture and instructions in the center of page 8. I would assume that the same would be true for the Veritas, given the similarity. Good thought. I think there is one big difference with the Makita, though. It actually uses a stone, which wears away so the wheel ends up sloped down toward the outside. The Highland Hardware instructions have more detail about that: http://www.highlandwoodworking.com/library/9820-2.pdf (Disclaimer: I have never seen or used a Makita sharpener.) Principle behind the technique is to take the entire piece off the stone edge smoothly, so that the grind is equal all the way. Think that might work regardless. Stone doesn't wear very fast anyway, especially not with the lube. I downloaded the Highland pdf. Not the same one they sent with mine years ago, so I'll make a comparative to see what might have changed since then. Tough to believe the number of planer and jointer blades I've run through it. It's repaid many times over. Used to run a pair of blade sets every month up at the school. |
#21
Posted to rec.woodworking
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Never,
I don't think that this is true. As long as the blade holder holds the blade perfectly flat to the abrasive platter, how can the blade be ground out of square ? Yes the outboard side of the blade does see a greater platter velocitiy, or as you put it: the blade sees extra paper. Agreed. But as long as the blade is held rigid, flat and in its original geometry relative to the platter, the entire length along the bevel must be ground uniformly. Maybe, one way maybe to think of it is: even though the outer edge of the blade wants to be ground at a faster rate, the opposite end of the blade, the inner end (where grinding is going slower) is holding up the rest of the blade, up off the paper. So the entire bevel eventually gets ground down to the same level. Now if the blade holder deforms, as I maintain, then you get crap. Larry Never Enough Money wrote: Even if the holder is perfect, how could you ever overcome the problem I mentioned in my earlier post on this topic? The outer edge sees a lot more paper than the inner edge so you'll always have asymmetry... Unless somehow the pressure on the outer edge is lightened up to perfectly compensate for the extra papaer it sees (that'd be difficult, I think). [snip] |
#22
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
George wrote:
Principle behind the technique is to take the entire piece off the stone edge smoothly, so that the grind is equal all the way. Think that might work regardless. Stone doesn't wear very fast anyway, especially not with the lube. Going off the edge of the platter is a good thing to try. I never did try that because the Veritas instructions explicitly say to stay away from the edge of the disk. If my patience returns, I'll give it a try. Mark |
#23
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
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#24
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
I spent some time experimenting this morning and I think I may have figured
out what's going on. First, I agree with Larry, as long as the blade is held parallel to the platter surface, the amount or speed of the abrasive passing under the blade should be of no practical consequence. Consider a worst case scenario; no abrasive at the center of the disk tapering to unused abrasive at the circumference. Even in this worst case, the difference in the amount of metal removed between the inside and outside edges of the blade, would be limited to the size of the abrasive particle. In the case of the 100 micron disk, this would be hard to measure. It certainly wouldn't account for the error that I and others on this group have observed. On the other hand, there is no question that Mark's observations are correct. The outside edge of the blade definitely gets ground down more than the inside edge, and by a rather significant amount. As I gave this some thought, it occurred to me that the thickness of the platters may not be consistent. Sure enough, when I measured the thickness across the radius of the platters, I found that the outside edge is approximately .004 inches thicker than the remainder of the disk, probably as a result of a manufacturing operation. I verified this on three disks. I'm sure this is one of the reasons why Veritas recommends that you stay clear of the outside edge. My second thought was that the turntable that the platters rest on may not be perfectly flat. I checked this by installing a new (without abrasives) 4mm disk and then laying a precision straight edge across it. After accounting for the slight increase in platter thickness at the circumference, everything was dead flat, or at least within .001 inches. As I indicated in my original post, I was able to measure a slight bit of wobble at the outside edge as I rotated the platter, but this was consistent between platters at around .003 inches and shouldn't affect the bevel. I next installed a new 100 micron disk on the 4mm platter and a new 9 micron disk on the 3mm platter. I used a spare 1 5/8” plane blade that I checked to make sure was both flat (no warp) and had parallel sides. I also ground the edge square to the sides and put an edge on it using conventional methods (water stones). I installed the blade in the holder and verified that it was absolutely square. I also checked to make sure that the edge remained flat after it was tightened into the holder. I mounted the 100 micron disk and proceed to sharpen the blade, moving the holder back and forth along the guide bar, until a slight burr formed across the entire edge. When moving the holder, I remained approximately ½” from the center and outside edges. With the care I used setting everything up and the new media, I expected that I would initially see an edge that was pretty much square. It wasn't! At this point I didn't know what to think, so out of frustration I once again put my straight edge across the platter, this time with the abrasive disks applied. I was really surprised to see a depression toward the center hold down. When I measured the disk without media, it was dead flat. I think what's happening, is that the rather thick cloth backing on the 80 grit paper is being compressed by the brass hold down and pulling the center of the platter with it. I measured the depression at around .004” which combined with the slight rise at the circumference, is more than enough to account for the error we're seeing. It also accounts for the micro-bevel not being parallel, because the thinner media on the 3mm platter doesn't result in the same problem, in other words, the 3mm platter remains flat. Your thoughts? |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Mark Wells wrote:
I put a 2" plane blade on the left side of the jig. Then I tightened the left nut and made the right nut match. In that case, the right side of the blade (as viewed from the jig) was slightly up off the glass. As I tightened that nut tighter and tighter, it got worse. Ah ha! Then I switched the blade over to the right side of the jig. I did the same experiment in reverse. Unexpectedly, the right side of the blade still didn't touch. I repeated both experiments a couple of times and got the same results. Maybe the blade is warped? They said in the instructions to look out for that. Mark, When you switched the blade to the right side and tightened up, did maybe one of the legs come up off the glass, rather than the blade. I found this to happen, that the blade was still sitting flat, but the holder had deformed and one of the legs was now off the table and you could rock the entire blade/holder. Then I switched to a 1" chisel. No matter how hard I tried, I couldn't make a blade corner come up off the glass. That's odd. I found that the narrower the blade, the easier it was for me to get the blade/holder to deform. However, because the blade was narrower, it was harder to see: the absolute amount that the blade corner lifted up off the table was less. (am I explaining that clearly?) Larry |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Excellent explantion. Thank you. It does, as you say, put high demands
on the holder: it must be dead nuts flat. On Dec 4, 3:52 pm, wrote: Never, I don't think that this is true. As long as the blade holder holds the blade perfectly flat to the abrasive platter, how can the blade be ground out of square ? Yes the outboard side of the blade does see a greater platter velocitiy, or as you put it: the blade sees extra paper. Agreed. But as long as the blade is held rigid, flat and in its original geometry relative to the platter, the entire length along the bevel must be ground uniformly. Maybe, one way maybe to think of it is: even though the outer edge of the blade wants to be ground at a faster rate, the opposite end of the blade, the inner end (where grinding is going slower) is holding up the rest of the blade, up off the paper. So the entire bevel eventually gets ground down to the same level. Now if the blade holder deforms, as I maintain, then you get crap. Larry Never Enough Money wrote: Even if the holder is perfect, how could you ever overcome the problem I mentioned in my earlier post on this topic? The outer edge sees a lot more paper than the inner edge so you'll always have asymmetry... Unless somehow the pressure on the outer edge is lightened up to perfectly compensate for the extra papaer it sees (that'd be difficult, I think). [snip] |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
On 5 Dec 2006 21:24:05 -0800, "Mark Wells"
wrote: For the poor sap who finds all this on Google ten years from now, here's a summary of the problem again: With the Veritas Mk. II Powered Sharpening System, blades are not ground perpendicular to the edge. This is usually first noticed when the primary and secondary bevels are not parallel to each other, but can also be seen if you put a square up to the edge after grinding. This is not a cosmetic issue. The edge can easily be out of square enough to impact performance of the blade and/or make it very difficult to grind a secondary bevel all the way across the edge. This may be a stupid question, but if the setup consistently makes the blade out of square then why can't you just set up the jig slightly out of square to compensate? -Leuf |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Bruce Barnett wrote:
It sounds logical, but as I picture it, the one corner wears faster, and to hold it rigid you have to do so without the edge near the center. This seem unstable like a 4-legged chair with one leg shorter than the others. Yes, exactly. As long as someone or something (the tool/blade holder) firmly holds the chair in its original orientation with the 3 longer legs in contact with the ground, the one shorter leg cannot contact the ground until the 3 longer legs are all equally shortened or ground down. |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
"Never Enough Money" wrote in message ups.com... Excellent explantion. Thank you. It does, as you say, put high demands on the holder: it must be dead nuts flat. No, the tool holder must be a constant distance across the highest point of the paper or stone. The Makita directions I mentioned refer to it when they say take the edge off the stone and cut uphill by tilting the rest. Where you've ground already needn't be a drag on the stone or grit, you're done with it, and would rather it grabbed air. The obsession with flat abrasives and holders is nice, but if you pass the blade across a 1/16 wide jeweler's blade at a consistent distance, you'd get a straight edge. Don't take the work away from the holder by pressing into the stone, that's honing. This is still grinding. |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Mark Wells wrote:
Yes, I understand. I went out and conducted the test again. This time I used a 3/4" chisel and a block plane blade. I paid more attention to the legs. I couldn't get the jig to deform with the chisel using the methods of measure I had. With the block plane blade, I was able to get the jig to deform, but only if I really, really pushed it. Normally to tighten blades in the jig, I would tighten the nut closest to the blade and then make the other nut match by looking at the threads on the post. Then I would turn the jig over and make sure the clamping bar was not obviously deformed. Using that technique, the blade seems to be secure and the jig not deformed (at least for me!). That is what I try to do: count threads or use a caliper to make sure the gap between the top of the tool holder and the clamping bar is equal on both sides. I find that if the face and back of the blade are co-planar (like a plane iron) then I don't need that much clamp pressure to hold it still. If I try to clamp up a chisel that has some angle, however slight, between the face and back surfaces, then there is no way I have been able to clamp it up, so that it doesn't move, without deforming the holder. I've even tried a strip of the self-adhesive high friction tape on the tool holder, but it just squishes away to nothing. I guess the point, which you have already made repeatedly, is that one shouldn't have to go through all this fussing to simply grind a square edge on a blade with a $350 *sharpening system*. I'll have to lookup when I bought my machine. It was several years ago, so it is possible that Larry and I have different jigs. The top bar (attached to the legs) on my jig is pretty beefy. I got my machine about 6 months ago. It is beefy-Not. It is significantly thicker than the clamping bar. The clamping bar is easy to deform, but I don't think deformation of the clamping bar alone impacts the performance of the jig. I agree. It doesn't matter that the clamp bar bends. On the issue of grinding at different rates against the inboard and outboard edges of the blade, I still think that might be an issue. The experience of woodworker1 and myself seem to corraborate that. I agree that if the blade were completely rigid that the rotational speed wouldn't matter. However, the blade is not rigid, so let me start speculating: As you grind away material, the blade moves, ever so slightly, back toward the bar. Furthermore, the operator is applying pressure to the blade. I know from my hand sharpening that a plane blade will deform relatively easily under pressure. In hand sharpening, I use that to my advantage by putting pressure where I need more honing. That compensates for slight misalignments in the jig. It seems like blade and/or jig deformation could happen as the operator applies pressure, which would allow the faster moving abrasive to take off more material. Think about it this way: The operator starts grinding. The outboard side of the blade gets ground a little more quickly and gets very, very slightly shorter than the inboard side. The operator's pressure then causes the outboard side to again be next to the disk by very slightly deforming the blade, jig, bar, or some combination. This process continues until you reach a limit in which the deformation wouldn't happen any more. Now the operator picks up the blade and the edge is not square to the side of the blade. Maybe try very light pressure? In the past, I have tried only holding the jig and just applying force to the jig against the bar and not near the edge of the blade. That seemed to help slightly, but not significantly. This could indeed happen, that finger pressure near the gringing edge slightly rocks the blade, forcing it to go out of flat relative to the platter. Maybe when I have an afternoon to totally flush down the toilet I will experiment once again. However, I was, just like you, mindful of this possibility and believe that I purposely did not apply pressure to the blade near the grinding edge. I very patiently let the abrasive do its work, applying minimum pressure nearer the holder and main bar. Again, if the holder is deforming given my method of operation, then this just reinforces my main gripe - that the tool holder is too flimsy and needs to be re-designed. I was thinking that it wouldn't be horrible to have two or several types of holder. A universal design would be nice, but it doesn't have to be so. For parallel sided blades, either plane irons or chisels, a side clamping mechanism would be best. It would solve the two main issues: 1. It would be self squaring. 2. You would need much less force to hold the blade still. For the poor sap who finds all this on Google ten years from now, here's a summary of the problem again: With the Veritas Mk. II Powered Sharpening System, blades are not ground perpendicular to the edge. This is usually first noticed when the primary and secondary bevels are not parallel to each other, but can also be seen if you put a square up to the edge after grinding. This is not a cosmetic issue. The edge can easily be out of square enough to impact performance of the blade and/or make it very difficult to grind a secondary bevel all the way across the edge. Mark |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
George wrote: "Never Enough Money" wrote in message ups.com... Excellent explantion. Thank you. It does, as you say, put high demands on the holder: it must be dead nuts flat. No, the tool holder must be a constant distance across the highest point of the paper or stone. The Makita directions I mentioned refer to it when they say take the edge off the stone and cut uphill by tilting the rest. Where you've ground already needn't be a drag on the stone or grit, you're done with it, and would rather it grabbed air. The obsession with flat abrasives and holders is nice, but if you pass the blade across a 1/16 wide jeweler's blade at a consistent distance, you'd get a straight edge. Don't take the work away from the holder by pressing into the stone, that's honing. This is still grinding. Yes. I agree. I like the example of the very narrow abrasive. Still, the tool-holder/blade/abrasive geometry must remain constant throughout the grinding operation. The blade can be slid side to side, as when you use a narrow belt sander, but the tool-holder must not deform. |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Leuf wrote:
This may be a stupid question, but if the setup consistently makes the blade out of square then why can't you just set up the jig slightly out of square to compensate? -Leuf Not stupid at all. I had just about gotten to this, when I ran out of steam and soured on the whole thing. I'm not sure that the out of squareness is consistent enough to compensate simply by skewing the jig bar. (I still think flexing of the holder is the issue) Still, I bet you could get much closer to accceptability. |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
On Dec 6, 5:41 am, "George" wrote: [snip] No, the tool holder must be a constant distance across the highest point of the paper or stone. Doesn't that mean "flat" -- flat with respect to the paper? |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
Excellent summation Mark. Now at least there is something on the Web
regarding this issue. When I posted my initial message, I couldn't find a single mention of the problem. Maybe someone from Veritas will read it and come up with a permanent solution. Stop to think of it, maybe I'll just forward the Google link to them for comment. According to their web site, Lee Valley will be at the Milwaukee woodworking show in February. I live in Chicago, which is only 80 miles away, so I may just pack up the sharpener along with my sacrificial plane blade and haul it up there. If they can't make it work either, and I'm confident they won't, they might be more inclined to address the problem. It's been my experience that both Lee Valley and Veritas have a genuine concern about quality and once they're convinced that a problem really exists, they do something about it. |
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Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel
I just got the Veritas system. In trying to sharpen a plane iron,
I can't seem to get an edge which is square to the sides of the iron. I just found this thread while googling for solutions to the problem. I should admit now that I'm a newbie when it comes to hand planes. I'm trying to learn. I've got Garret Hack's book and Lee's book and I've watched two of Charlesworth's videos. Anyway, here's my question: If the edge is very slightly out of square, how big of a problem is it? Is it possible to even use a plane which has a blade that is sharpened very slightly out of square? In my latest attempt to use the Veritas, the result looks pretty good. It's not square, but it's awfully close. With a precision square, I can barely see light coming through at one side of the sharpened edge. But when I put the blade into the plane (a Record #4) and try to take a shaving, only one side of the blade cuts at all. I am of course still going to try and figure out how to get a square edge, but I'm guessing the squareness of the edge is not my only problem. The results I'm seeing make me think that my real problem is in the setup of the plane. So I'm looking for any advice from those with more experience. I'm sort of anticipating one of two responses: 1. Yes, Eric, you're probably doing something wrong in the setup of the plane. A plane iron with a slightly out of square edge can basically be used, even though it's not optimal. Go study more of the beginner-oriented plane stuff. 2. Sorry Eric, actually the edge on the plane iron has to be perfectly square. The tiniest error will basically render the plane unusable in the manner you describe. Thanks in advance! Eric Sink -- wrote: Excellent summation Mark. Now at least there is something on the Web regarding this issue. When I posted my initial message, I couldn't find a single mention of the problem. Maybe someone from Veritas will read it and come up with a permanent solution. Stop to think of it, maybe I'll just forward the Google link to them for comment. According to their web site, Lee Valley will be at the Milwaukee woodworking show in February. I live in Chicago, which is only 80 miles away, so I may just pack up the sharpener along with my sacrificial plane blade and haul it up there. If they can't make it work either, and I'm confident they won't, they might be more inclined to address the problem. It's been my experience that both Lee Valley and Veritas have a genuine concern about quality and once they're convinced that a problem really exists, they do something about it. |
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