Thread: Scale Wedge Geometry

Guys, this may be covered somewhere in Wiki or a thread but I have done some looking and not found the answer.

When making the scale wedge, is there any rules of thumb regarding the thickness of the large and of the wedge? eg same as the tang width etc.

Also is there any particular angle between the scales with the wedge is pinned in place but before the blade is pinned?

Thanks in advance.

Stu

When I make a wedge I first measure the width of the blade at the depth that I want it to rest in the scales (I figure that out when I draw the scales). I taper it depending on the flexibility of the material. If the angle is too great and the material too flexible it will wing out really wide, looking strange. If the material is really stiff I also don't put too much of an angle since it won't want to flex with the angle.

I hope that makes sense. It is mostly about trial and error, then using previous knowledge to assume the qualities of your materials.

I'm nowhere near as precise as Gerrit (I don't measure), but I create an initial taper and then tweak it from there to get the blade to sit how I want. Test fitting with the screw/nuts from microfasteners helps me out a bunch.

Originally Posted by holli4pirating

I'm nowhere near as precise as Gerrit (I don't measure), but I create an initial taper and then tweak it from there to get the blade to sit how I want. Test fitting with the screw/nuts from microfasteners helps me out a bunch.

Thanks, good idea. I just ordered some screws and nuts from microfasteners yesterday, along with some washers. I have made a wedge which I think looks okay, I might wait until my screws get here (Australia) before doing to much more. I hate waiting.

Generally I'll shoot for about the same angel that the shank has at the pivot.

As far as the width, the widest/rear of the wedge having a thickness of about half the width of the shank at pivot area seems about right usually.

That seems to be a good guide at least pending variables.

What was noted above, including over time you get a feel, and test assemble first is valuable too
******
my edit

Originally Posted by gssixgun

Edit: I guess DC and I were typing at the same time

In my original post, I was going to credit where I learned that, but wasn't positive. I was just researching, came back to add a credit, and see I was too slow, lol. I realize Glen likely didn't create this observation about wedge geometry originally, but thankful he and others openly share what they do learn.

Off topic, but I gotta say it- thanks to all. I certainly have learned a ton through this forum.

Start the wedge at 1/2 the thickness of the tang then adjust from there... That is a general rule of thumb for starting this, after a few 1000 you'll just do them by looks but you asked for a rule of thumb... BTW it is buried in the Wiki and in the Workshop sticky Good luck


Edit: I guess DC and I were typing at the same time

Good discussion. I've just been making them by eye. Ill try the 1/2 the tang approach next!

The wedge should be close to zero thickness at its rear end - about as much, say, as will stop the material breaking up while you are working on it. I'd epoxy it to one scale, then file or grind its taper until when the other scale is held tightly against it, it puts the pivot ends just far enough apart to put a reasonable amount of flexure into the scapes when the pivot is in place.

When filing or grinding the wedge, I stick a piece of wood crosswise across the other end of the scale with double-sided tape, to avoid putting any sideways taper on it. You have to work lightly, with most of the pressure on the wedge area of the scale, to prevent its flexure from altering the result of the filing.

The most important is to have the wedge to taper at angle similar to the tang then you will have the scales bend naturally to accommodate the razor.
Thickness of the wedge can be used to adjust how much of the razor will stick out of the scales.

Of the erm...one... that I've done () I did it by trial an error. I started out with the wedge a bit thinner than the tang and then just sanded off material until I had the angle I wanted and the wedge nice and thin.

It took me a bit of time, maybe 40-50 minutes or so, to get the angle right but I suspect it's like a lot of these things where the time drops off with practice!

The best advice in my very limited experience is to get stuck in and you'll work it out as you go.

Good luck and keep us posted!