Sharpmaker angle rods (for measurement)

[Cliff Stamp]

I had a friend drop over with a Sharpmaker who was having a problem, the issue being that his knives were above the 15/20 dps settings on the Sharpmaker and some of the knives only on one side and thus when he created a burr he could not remove it.

There is a simple check for this which would allow people to see this very easily.

Imagine a set of rods out of polypropylene which would fit in the slots. If you take a knife and do the same motion on the rods the knife will catch if the angle is less than the rod angle, it will just slide if the angle is above it. This would quickly show people :

-if the 15 or 20 is a closer match
-if the sides of the knife are even
-if the edge is > 20 and has to be reground

Now if a knife is exceptionally dull then it won't catch so this method/addition isn't exactly "fool" proof, but it would still likely help a lot of people and is a very cheap addition/measurement set Spyderco could make/offer.

[stevenk1231]

In situations like that, I just use a marker.

[Clip]

Don't have a Sharpmaker so I don't know what's included in the DVD, but it would be helpful to mention the Sharpie trick or include a little info sheet with how to identify the angle.

[Cliff Stamp]

Joe Talmadge popularized the edge marking technique and while it does have some utility it has a few issues. The most significant one is that you will stop seeing the marker when it is less than 40 microns wide. How much under this depends on your vision, but aside from rare individuals, few people will be able to see it under 20 microns. This means the edge can still have a heavy bevel which is beyond the visible but the marker will not show it but the blade will not respond to the Sharpmaker. The polypropylene rods will show it immediately. Plus if the rods were not made straight but had a bend in the middle then you could make them measure 2.5 dps up and down and thus the same set of rods could tell you if your edge was :

<12.5 dps
<15 dps
<17.5 dps
<20 dps
<22.5 dps
>22.5 dps

This would give them a very nice second use for the people who didn't have sharpening issues but wanted to quickly measure angles as you would be able to know instantly and easily if the angle was between 15 and 17.5 dps for example.

[Brock O Lee]

I like the idea !

[bh49]

Imagine a set of rods out of polypropylene which would fit in the slots.

don't you think that straightness of polypropylene rod can be an issue?

[Cliff Stamp]

If there is an issue with getting a straight rod then just use an appropriate material.

[JD Spydo]

Joe Talmadge popularized the edge marking technique and while it does have some utility it has a few issues. The most significant one is that you will stop seeing the marker when it is less than 40 microns wide. How much under this depends on your vision, but aside from rare individuals, few people will be able to see it under 20 microns. This means the edge can still have a heavy bevel which is beyond the visible but the marker will not show it but the blade will not respond to the Sharpmaker. The polypropylene rods will show it immediately. Plus if the rods were not made straight but had a bend in the middle then you could make them measure 2.5 dps up and down and thus the same set of rods could tell you if your edge was :

<12.5 dps
<15 dps
<17.5 dps
<20 dps
<22.5 dps
>22.5 dps

This would give them a very nice second use for the people who didn't have sharpening issues but wanted to quickly measure angles as you would be able to know instantly and easily if the angle was between 15 and 17.5 dps for example.

I sort of get what you're talking about. I've been using a Bausch & Lomb 10X x 17X loupe and I've been able to detect even the finest traces and spots where the marker ink still shows under the right light. I've been looking at some top of the line ZEISS loupes here lately to hopefully give me a bit more advantage but for now the Bausch & Lomb loupe has done fairly well up till now. It sort of lends creedence to the idea I've suggested to Spyderco in the past of adding a very coarse stone to the 204 Sharpmaker kit for more rapid and more sure stock removal to hopefully remediate what you're talking about. I do agree with what you're saying Cliff because in sharpening and machinist deburring it sometimes boils down to what you can't see sometime which could indeed determine the quality of work you can accomplish. I hope I'm on the same page and I'm in line with what you're suggesting.

As much as I like the Sharpmaker unit I will admit that the tool could be improved on to give it more versatility IMO.

[Donut]

I can't imagine the wear you would have and the issues the wear would create on something that is designed to be cut into.

[Cliff Stamp]

If you are checking for angle on a plastic rod you don't actually try to whittle it like a piece of wood. You simply lay the knife on the rod and it will either slip or it won't. This is a very trivial way to measure angles, I demonstrate it to people all the time who want to measure the angles of their knives and then show how it can be calculated easy with the 1in60 rule. It can be done with whatever pen or pen they carry (not metal) and you can't even see that it was done.

[Donut]

If you have a burr, won't that stop it from grabbing, too? Even though you're at an angle that will hit the edge?

[Cliff Stamp]

The edge will catch long before it is actually sharp. It will even start catching even if it isn't apexed at all and is reflecting light.

[me2]

Could something similar be done with the brass rods placed in the grooves of either rod? I'll try it tonight in any case.

[Cliff Stamp]

I don't think that would work as well as a plastic as you want the material to be much softer than the edge so it catches into it immediately. The simplest way is just to put a plastic pen right on the rods, a shaped rod is just neater and a little less dangerous/awkward. Plus it has to be extremely cheap to just get plastic rods made.

[setldown]

How about wrapping a couple of layers of Saran wrap around the existing rods? Should slide if not on the edge and cut into it if it is on the edge.

[JLS]

Plus it has to be extremely cheap to just get plastic rods made.

I agree with you...right up to that point. Whether it's injection molded or extruded, it'll be pricey for tooling and unless there is a massive demand, short runs will be quite expensive as well. If you don't get much run time out of a setup, the setup fees will kill your piece price.

I do think it's a neat idea, but I wonder how many people would really take the time to use it properly.

[Donut]

I would say just a simple V shaped piece of plastic to set on the rod would save a lot of cost and make it easier to use.

[Cliff Stamp]

How about wrapping a couple of layers of Saran wrap around the existing rods? Should slide if not on the edge and cut into it if it is on the edge.

Yes, even a simple paper wrap will do it. However the very simple rod setup I noted not only allows checking of the edge compared to 15/20 dps, you could easily make rods which allowed a much finer increment with a simple bend in the rod.