I'm so confused: Shopsmith Planer Knife Sharpener

[dynabase]

I talked to Doug Reid a couple of days ago about a sharpening video. He said he just did one and he is in the process of editing it now. He will have it out shortly. I will post a note on the forum when it comes out.

Michael

[dusty]

Sterling,

I am thinking that your two sets of blades may have been sharpened at a different bevel angle than those blades shown in Johns' posts. What makes me think that is the proximity of the lower beveled edge to the jig.

http://www.shopsmith.com/ownersite/item ... tem=515781

Unless the camera angles are playing tricks, I would say that you have not more than one sharpening left on the blades shown. Any more and you will be taking off the face of the jig. Give note to the bevel angle on the blade and the angle on the face of the jig while at the same time loking at the top of the blade

ANOTHER OBSERVATION: In this photo image it appears that you set up very near the center of the conical disk. I don't do that. I move out toward the edge of the disk. I am not saying "right" or "wrong"; only that I setup differently.

I provide a photo image but I cannot do that right now!

Not A Safe Place to Play 003.jpg (2.41 MiB) Viewed 12578 times

I don't know how you setup for sharpening but be aware that the instructions for using the conical disk for edge jointing read differently that those for sharpening. One sets the table tilt so that the table is square to the surface of the conical disk and the other does not tilt the table at all.

There is a NOTE that reads as follows:

When using the Knife Sharpener with the Conical Sanding Disk, the worktable MUST NOT be tilted 4 degrees toward the disk surface as described in the Conical Sanding Disk owners manual.

This apparent contradiction of instructions is not a contradiction at all. When using the the conical disk for edge jointing, the table is tilted so as to provide an edge joint that is at 90 degrees to the surface of the work piece.

When using the sharpening jig to sharpen jointer and shaper blades, that angle is established by the jig rather than be tilting the table. IOW the jig sets the bevel angle not table tilt. The jig sets the bevel angle at approximately 40 degrees.

[JPG]

IIWM, I would tilt the table(ever so slightly) so as to give the jig some clearance.

Doing so will alter the grind angle(increase).

The jig IIUC will give one a 45 degree grind angle.

However different angles give different results with varying hardness of wood.

Consider the result a 'micro bevel' so to speak.(look an John's example)

[dusty]

IIWM, I would tilt the table(ever so slightly) so as to give the jig some clearance.

Doing so will alter the grind angle(increase).

The jig IIUC will give one a 45 degree grind angle.

However different angles give different results with varying hardness of wood.

Consider the result a 'micro bevel' so to speak.(look an John's example)

The natural angle set by the jig (with the table not tilted at all) will be 40°.

[Sazerac81]

I am going to play devil's advocate, but why not throw a thin strip of shim underneath the base of the blade to have the edge jut out enough for a light sharpening?

Any reason why sharpening just a hair under that 11/16" would be highly dangerous? I imagine that number may have been formulated in an arbitrary number vs. empiric data.

Seems that a few light sharpenings below that threshold 11/16" would still give you enough metal for the securement bars to keep a stable hold on the blades. I mean, the centrifugal force itself is likely to keep the blades firmly in place against the depth set screws.

Cheers,
John

[dusty]

I am going to play devil's advocate, but why not throw a thin strip of shim underneath the base of the blade to have the edge jut out enough for a light sharpening?

Any reason why sharpening just a hair under that 11/16" would be highly dangerous? I imagine that number may have been formulated in an arbitrary number vs. empiric data.

Seems that a few light sharpenings below that threshold 11/16" would still give you enough metal for the securement bars to keep a stable hold on the blades. I mean, the centrifugal force itself is likely to keep the blades firmly in place against the depth set screws.

Cheers,
John

This might work but the thought process needs to be carried on into usage on the jointer or surface planer. Would narrower blades be safe to use there?

[dusty]

Looking at the image I just posted, I believe the original owner tilted the table the other direction so as to take more off the lower edge of the bevel than the top i.e. lessen the bevel angle .

Michael, If you sketch this, I believe you will see that about 4 degrees in the other direction results in what you show in that image/