Need help sharpening a skewed plane blade

Re: Need help sharpening a skewed plane blade

mikew


>Hi Wendell,

When the blade is in and slightly projecting or even flush, is there even projection and or is it flush across its width--depending on which way you check it?

If the answer to either is 'No,' then use the angle of the mouth...as long as the bed comes down to the sole evenly. I've seen some woodie skewed bladed planes that the sole has worn in such a way that the measurement at the edge of the mouth is not the bed angle.

That said, my MF plane is about 18 degrees.

Take care, Mike

Re: Need help sharpening a skewed plane blade

Dan Donaldson


>Not sure if I understand what you are saying or not, but they would not be at the same angle, I don't think. The blade is at a compound angle when installed in the plane. The bedding angle and the skew angle would interact. Without thinking a bit more, I can't say exactly what it would be, but I think it will affect things. Of course, it is very late and maybe I am not thinking straight and................ ;-)

Re: Need help sharpening a skewed plane blade

Derek Cohen (in Perth Australia)


>...I read the directions and measure the skew that came on the blade at 10 degree. I also read Derek's article on sharpening skews with the LV jig. I measure the skew of the mouth and it's 17 degree. Wait a second, shouldn't they match?

Hi Wendell

My observations are the same as MIke's.

I recently cleaned up an old ECE moving fillister (which uses a skew blade for cross grain work). The lesson I learned here was that, for old wooden planes that have some wear, you must measure the angle of the skew from the bed, not the front of the mouth, since the latter may be worn and/or cut at a different angle.

Make sure that the blade is an even thickness (ie. parallel front and back), otherwise you will need to take this into account as well.

Regards from Perth

Derek

Re: Need help sharpening a skewed plane blade

paul womack


>eyeball the blade in the plane; see if the projection is even.

If it *is*, sharpen it evenly.

If it sticks out more one side than the other, sharpen a little more on the side that sticks out (think carefully about which way is up...)

BugBear

Re: Need help sharpening a skewed plane blade

Wendell @ Murphy, TX


>The throat opening on the plane is in pretty good shape so the front and back of the opening are parallel to each other. I checked the projection of the blade through the opening. As far as I can tell, the blade projects evenly out the bottom of the plane at its current skew angle. The plane has a tapered, laminated blade but it makes my head hurt to try and figure out how that effects things :)

Wendell

Re: Need help sharpening a skewed plane blade

Wendell @ Murphy, TX


>The one I have is marked Ohio Tools 56. Do you sharpen the blade at an 18 degree skew also? Is the blade the tapered?

Wendell

Re: Need help sharpening a skewed plane blade

Derek Cohen (in Perth Australia)


>Wendell

The advantage of the LV Honing Guide Mk II for tapered blades is that it registers from the back of the blade, so calculating and honing the bevel angle is always done consistently.

Regards from Perth

Derek

Amen.

Wiley Horne


>Rolling the numbers around in your head is an interesting intellectual exercise. But learning to do basic things by hand and eye is the way forward.

Wiley

Re: Amen.

paul womack


> But learning to do basic things by hand and eye is the way forward.

Of course, I actually do (the thing I said) using a jig!!

BugBear

Re: Need help sharpening a skewed plane blade

mikew


>Hi Wendell, techinically the answer is no. Mine came with an even projection, but I wanted to measure everything anyway. I found the math formulas to calculate the blade angle from the skew and bed angles. In the end, it didn't matter and I got a headache from the math!

If I have to change the angles or profiles on woodies I slide the blade through the mouth enough to scribe the profile using an extra fine sharpie pen and grind/hone to the profile. Much faster.

Take care, Mike

A small anecdote

Wiley Horne


>Paul,

I over-reached on your initial comment (which I totally agree with) and therefore apologize for it. A little story...

I happened to be at the grocery store this morning, and went to the deli section and asked for "about a pound of muenster cheese". The lady behind the counter reached down quickly and without any calculation and pulled up a handful of sliced muenster. She put it on the scales--"1.00 lb" came up. She had hit it to within the precision of the scale. It is surprising to me how often this happens in this situation, and they're always very close.

Skills are reinforced by practice. That's why I think in the OP's situation, it would be good to set the blade where he wants it, mark a level line across the blade bottom with a Sanford sharpie, or equal. And then grind to the mark by eye. Builds hand skill which is essential for carving and other operations which must be done by hand and eye.

I often wonder how much precision can be achieved using hand/eye methods.

Wiley ... who uses a shooting board and paring block as jigs

Re: Need help sharpening a skewed plane blade

Larry Williams


>Wendell,

Once again sharpening jigs and gimmicks make things harder than they should be.

You don't need to know any precise angles. Paul and Wiley have that right. You've got more angles involved than are obvious, it's a good bet your plane also has a leaning wedge so the iron isn't set parallel to the side of the plane. Again, this little complication shouldn't have any effect on what you need to do.

Place the iron in the plane in the position you'll be using it. It be set for depth to the point that all of the edge is exposed when sighting over the sole, but just barely so. The iron should also be revealed by a hair on the escapement side of the plane.

Now scribe the location of your new cutting edge off the sole of the plane. The first grinding/roughing step is to grind/rough at 90� to the face of the iron right to the scribed line that establishes the cutting edge. This leaves a flat which I find helpful to mark with layout fluid or a felt tip pen, I prefer a red color because red is easy for me to see when I grind the bevel to a point that flat is just a faint hair line. Then hone the remainder away. These steps work for straight, angled, curved or any other cutting edges.

Sometimes I think sharpening jigs and gimmicks are designed to keep those afraid of and uncomfortable with sharpening from ever being able to sharpen. At the very least these gadgets slow down and complicate sharpening.