Convex shave

[Mike Davis]

I have a shave, I don't think you should call it a spoke shave since they aren't concave. Anyway this shave is convex so it makes a concave shape in the wood.

Are you with me so far? Need Pictures? :icon_scra

My problem is the shave body and the blade don't match exactly or even closely. The body has a tighter arch than the blade by several thousands or maybe tens of thousands.

I was thinking a jig to sharpen the blade would be helpful then I thought if I had that I could shape the body better. Kinda like flattening the sole on a plane.

So, does anybody have one? (whadda ya mean the shave or the jig?)
:rotflm:

I was thinking maybe if I took a heavy plastic plumbing pipe and cut it down the center it would make a sharpening jig. But since it is rather soft plastic maybe it would bend so I may need to glue it to a board that is cut roughly to the outside shape of the pipe.

Any ideas, comments, am I wasting my time, is this something you have tried and did it work or not?

If I go ahead with it I will make pictures.

 

[NCPete]

I so confused!!! [/Grover voice mode off]

 

[walnutjerry]

I have a shave, I don't think you should call it a spoke shave since they aren't concave. Anyway this shave is convex so it makes a concave shape in the wood.

Are you with me so far? Need Pictures? :icon_scra

My problem is the shave body and the blade don't match exactly or even closely. The body has a tighter arch than the blade by several thousands or maybe tens of thousands.



Any ideas, comments, am I wasting my time, is this something you have tried and did it work or not?

If I go ahead with it I will make pictures.

Mike------first of all, it is a spoke shave. Shaves can be flat with a flat sole or rounded sole, convex or concave.

Why the worry of the blade and sole radi matching? There will be very few times the radius of the work and that of the shave will be the same.
The differences in radius give you an option of lighter/heavier cut without adjusting the blade in the sole. At least that is how it seems to work for me.

As far as sharpening, I made a block with a top angle of the bevel, attach the blade to the top with screws and the bevel facing down, use a small sanding drum in the drill press and free hand the blade around the drum. Of course honing the back flat helps too.

Just my opinion and method.

Jerry

 

[Mike Davis]

Jerry,

Much of my post was in jest, You did find the main point.

I think it should work as you say, leaning to one side or the other should give a slightly finer or deeper cut. But this spoke shave has a very small sweet spot then it goes way too deep or completely out. There is no way to get it adjusted so that there is a good workable ramp up from fine to medium cutting.

So, I think if I can get the two parts closer to the same arch then I could adjust it to cut as you say it should.

 

[walnutjerry]

.

So, I think if I can get the two parts closer to the same arch then I could adjust it to cut as you say it should.

Mike------you have given me food for thought and that could be dangerous:rolf:.

Since the blade extends beyond the sole, should the radius of the blade be a little larger/smaller pending convex/concave than the sole? Like graduated circles on a template? Or am I way off base?

Jerry

 

[Mike Davis]

I don't know what is best. But, mine has a smaller radius sole and it doesn't work very well for me.

 

[Gofor]

I don't have one (yet?) but it seems to me that honing the blade to the sole contour would be easier to do, as well as possible to un-do. Once you change the sole, you are probably stuck with it.
One book I have by Michael Dunbar on storing old tools recommends honing one side a little closer and the other a little further from the sole. That way you go from light to medium (in the center) to heavy just by what point you use. The metal flat one I have (Stanley 151) has two adjusting screws on the blade, so I can slightly cant the blade which gives me the same effect.

Hope you can find an answer.

Go:dontknow:

PS: Are you using it on the inside of barrel staves, or what?

 

[Mike Davis]

No, my son is making a paddle and I saw he was struggling with this shave, but was doing great with the flat one. So, I asked him if I could sharpen it and after I got it sharp I noticed that the blade was wacky. I finally set it so the center would just barely scrape, but the sides were still too deep. You have to use the 1/4 inch of blade just off center on either side.

I'd like to have it cut paper thin at center and gradually get thicker at each side.

Working on this paddle, he is making the center shaft thicker and cutting a shallow gouge down each side of the center line to blend into the blades. Going sort of by the plastic paddle he has.

So, ideally the cutter would work symmetrically. I know he will want to make more of these paddles so I'd like to get our tools in top shape for him.

 

[NCPete]

Mike, my head was hurting an awful lot when I read this earlier. Wish I could help, but I have at best very limited experience with my spoke shave. A little more experience with the flat one. I am indeed sharpening challenged when it comes to curved blades like that. I think the cutting action you and Collin are experiencing is the same way mine works... or doesn't work, as the case may be.

 

[walnutjerry]

I'd like to have it cut paper thin at center and gradually get thicker at each side.

.

I do not see how you are going to do that Mike. If I have it pictured right, the center of the blade makes contact first and the further extended the deeper that point will cut. I think one of the other posts suggested setting the blade on a cant which would cut more to one side.
mmmmmmmmmmmmmmmmmm:eusa_thin

Jerry

 

[Mike Davis]

It's all in the geometry. I just have to make a jig to shape the blade and the sole to the right curve, then it will be adjustable the way I want it to be.

I'll probably start work on it next week, way too much going on right now.