Uneven bevel using Veritas Mk2 jig

[Mike Cherry]

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So I dont think I need to say much, this is the result of using my Mk2 jig and I cant figure out what I am doing wrong with it. I have lapped my Shapton ceramic waterstones using a dmt duosharp diamond plate. The funny thing is, I did all my chisels with this jig and as I look at the microbevels, the effect is more pronounced the wider the blades get. My 1/4" chisel has an almost even bevel.

Is this a technique problem, or a tightening of the blade problem? Maybe the jig needs to be replaced?

Thank you in advance for your help!

[David Barnett]

...I cant figure out what I am doing wrong with it.

You simply need to square your blade more accurately to the jig. Adjust your blade slightly until the bevel becomes even.

If it still persists on the same blade check the blade for variations in squareness and thickness.

...as I look at the microbevels, the effect is more pronounced the wider the blades get. My 1/4" chisel has an almost even bevel.

You would more readily see the error on the wider blade, of course.

[Prashun Patel]

I suspect this is the result of over-tightening. That jig does not like its nuts torqued down (do any of us?). You don't require much pressure. Tighten them alternately until the blade is snug but not tight. When sharpening, you don't need much pressure. Let the stone do the work.

I used to have the same problem until some users here told me the above.

[Mike Cherry]

You simply need to square your blade more accurately to the jig. Adjust your blade slightly until the bevel becomes even.

If it still persists on the same blade check the blade to see if thickness varies.

Isnt the point of the jig having a fence and stop so that the blade is square already? It sounds like you are saying that I can rely on the depth to be accurate for the intended angle, but the fence of the jig is a variable because of blade thickness or how square the side is in relation to the cutting end of the blade. Am I on the right track here?

[Mike Cherry]

I suspect this is the result of over-tightening. That jig does not like its nuts torqued down (do any of us?). You don't require much pressure. Tighten them alternately until the blade is snug but not tight. When sharpening, you don't need much pressure. Let the stone do the work.

I used to have the same problem until some users here told me the above.

Ill admit, my first hunch was that because I am a righty and have a tendency to crank down on clamps that I might have went hulk-mode a bit and caused the problem myself.

[glenn bradley]

I have used this jig for years. As Prashun states, even if all else is great you can skew the blade by uneven tightening; a few turns on each side till it snugs, then a 1/4 or 1/2 turn on each till you feel secure. You are correct that if the sides are parallel and the edge is perpendicular, the guide used to position the blade should be dead-on.

Other things that could happen:
1. You square the edge to the side while bevel forming BUT, the sides are not parallel (they taper away from the front as you move toward the handle).
2. You didn't get a good square front to side reference prior to moving to the jig.
3. The blade thickness varies a lot from side to side.

All things being correct we (and I mean us woodworkers) can still apply more pressure to one side of the chisel that the other but, you pic looks too consistently off to be just that ;-)

[Prashun Patel]

No. If you preferentially tighten one side, the blade will be square to the front of the guide (per the fence) but will now not be parallel to the stone. You can get the same effect (sometimes desirably) on a properly tightened blade by pressing harder on one side of the jig as you sharpen. This is how you can use your jig to get a small amount of camber on blades for your low angle planes so the corners don't dig into your work.

I learned this from Derek Cohen, and it has borne out in practice.

[Mike Cherry]

Ok this makes perfect sense thank you sir! So should I just take a couple strokes and check the bevel, then adjust the clamping pressure accordingly?

No. If you preferentially tighten one side, the blade will be square to the front of the guide (per the fence) but will now not be parallel to the stone. You can get the same effect (sometimes desirably) on a properly tightened blade by pressing harder on one side of the jig as you sharpen. This is how you can use your jig to get a small amount of camber on blades for your low angle planes so the corners don't dig into your work.

I learned this from Derek Cohen, and it has borne out in practice.

[Prashun Patel]

Yes - until you get comfortable clamping, which will happen quickly.

You might swipe the bevel with a marker so you can gauge yr setup easier.

[Mike Cherry]

Glenn - So basically I could be setting a non square blade up in a jig that assumes you are using a square blade? If that is the case, should I go spend the time to ensure the sides are parallel to each other and square to the cutting end? Or should I just adjust the blade in the jig accordingly?

[Mike Cherry]

Thanks again Prashun, Ill give it a go and report back.

[Jessica Pierce-LaRose]

What others have said has been my experience too - too much pressure on one side can lead to this, as can over tightening one side, or tightening one side of the jig completely, and heavily, before tightening the other, rather than alternating the two screws, and blades that are thicker on side vs. the other, or have non-parallel edges also contribute.

Also - you're doing a secondary bevel there - did you use the same jig setting to do the initial bevel? If you're simply adding a secondary bevel to a factory grind, there is always the possibility that your new grind is actually square, and the original grind was off ( given that you're saying you see this in multiple tools, [and I'm assuming still "leaning" to the same side], I would guess this is not the case, but you never know.) Are you checking the squareness of the finished edge simply by the light reflected, or are you taking a square to it? (I use a small wooden square to avoid accidentally damaging the cutting edge.)

I would hazard to think that the condition of the stone could also possibly cause this effect - given that one may polish primarily on one end of the stone, with the roller riding primarily on the other, if the stone was in wind, couldn't that also cause this?

At the end of it all, though, how far out of square is this in reality? On occasion, I end up with edges that aren't as square as maybe I'd like, but look much worse gauging by the bevel than actually measuring with a square. At the end of it all, it's easily taken care of with a light rap of a hammer when doing the lateral adjustment, and honestly, there's probably more need for lateral adjustment in my planes do to poorly-assembled chipbreaker/blade attachments, imperfectly aligned frogs, or just plain old slop in my older planes. If it's not so far off as to dramatically effect the usage of the plane, and can be taken out by adjusting things, it's probably fine.

[Andrae Covington]

Along with being careful about locking down the nuts the same, make sure your blade is centered as close as possible in the jig. If it is shifted towards one side, heavy use can skew the blade as you sharpen.

If you use the micro-bevel knob... even if the blade has been set up perfectly square in the "base" position (i.e. the micro-bevel knob indicator is pointing up), I have found that if I turn the micro-bevel knob for a steeper angle, it can shift the jig slightly out of square... or at least the microbevel appears skewed compared to the primary or secondary bevel. It seems to look worse on the bevel than it really is checking with a square, as Joshua said.

[Mike Cherry]

Good food for thought guys. Thanks for the pointers, it makes me feel a little more relaxed about the situation. I just got done resharpening the blade and I think I did a bit better. I took the advice off adjusting the blade with a hammer when I noticed the bevel going skewed and that helped. The only downside is.....

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I appear to have jacked it up on the far end there. The microbevel, if you can call it that anymore on account of me trying to hone the bevel all the way across, is not all on one plane. But it is more even than before and the cut on my finger tells me its pretty sharp hehe.

[Jessica Pierce-LaRose]

I took the advice off adjusting the blade with a hammer when I noticed the bevel going skewed and that helped.

While I have used a light hammer rap to adjust blades in the guide, I was actually referring to letting things slide, and that hammer-tap adjustment taking place when the blade is in the plane!