Veritas Power Sharpening System - Primary / Micro-bevel Not Parallel

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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)
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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

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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
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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.
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IMHO a 1/16" wide micro bevel has been on the grinder too long.

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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.
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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.
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He did that.
wrote in message

suggest
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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, snipped-for-privacy@hotmail.com wrote:

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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.
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Never Enough Money wrote:

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
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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
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snipped-for-privacy@hotmail.com wrote:

Sorry, yes, the primary and micro bevels were not parallel. The course abrasives take off material faster than the fine abrasives, so more of the right side of the blade is taken off by the course. When you move to the fine abrasive, it is trying to "catch up" and remove material from the left to make the blade even. At least that's what I think is happening.
There is also another factor here. The jig that holds the blade registers against the back of the blade. (That is correct because otherwise they would have to account for the blade thickness to set the angle properly.) If you tighten the jig too much, you can deform the jig and make the bevels not parallel, even with sharp abrasives. There is an extensive discussion of that in the instructions.
Here is an experiment I would try: On either the 80x or the 100 micron abrasive, grind on the left and the right side of the disk. You can clearly see the scratches made by each because they will be at different angles. Make the scratches meet roughly in the middle of the blade. Then move to the 9 micron and do the same thing. Using this technique, you may be able to get a micro-bevel all the way across. If that method works, then it would seem that this is an issue with the abrasives. If it doesn't, then it might be the jig.
Mark
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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:

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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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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:

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snipped-for-privacy@yahoo.com writes:

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.
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Bruce Barnett wrote:

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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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, snipped-for-privacy@yahoo.com wrote:

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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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