Using the Conical Disk along with the Planer/ Jointer Knife Sharpener

[dusty]

Here is what I found on the shopsmith site:

"As a point of information, Shopsmith Jointer Knives are factory ground with a straight bevel
at 45-degrees. This is a multipurpose cutting angle that will produce smooth cuts at a variety of
speeds in both hard and soft woods. The straight bevel (rather than a hollow-ground bevel typically
produced by a grinding wheel) offers more steel backing up the cutting edge. This helps to produce a
longer-lasting cutting edge.
Depending on the materials you work with, you may wish to change this angle slightly. If you
work entirely with soft woods, 47 to 48-degrees will give a smooth cut. If you work entirely with
hard woods, try grinding your knives at 42 to 43-degrees."

I guess one has to figure out the angles if you want to make changes, I personally have none of this hardware so I will bow out at this point.

Ed

OKAY Tell me what I have yet to read. I don't find this anywhere in my documentation.

[reubenjames]

http://www.shopsmithhandson.com/archive ... mytips.pdf

[dusty]

Thank you very much. You and Reible have jointly exposed me to applicable documentation that I have not read before.

[jsburger]

When using the conical disk along with the planer/jointer and the work table at 0° (no tilt) you certainly do not get a 45° bevel.

The instructions that came with the Planer/Jointer Knife Sharpening Jig (555471) reads as follows:

Quote:
1. Mount the worktable on your Mark V, then move the worktable to the far right end of the way tubes and lock in place. The worktable must be set to 0° (parallel to the way tubes)".

NOTE

When using the Knife Sharpener with the Conical Disc, the worktable MUST NOT be tilted 4 degrees toward the disc surface as described in the Conical Sanding Disc owner's manual. (End Quote)

Please, don't tell me you have been following these instructions for years and have had not trouble. You may not have problems but then you are not following these procedures.

I too have been using the jig along with the conical disk for years but I have not been following these instructions.

I have been following those procedures for years with no trouble. With the table set parallel to the way tubes it is at zero degrees and vice-a-versa. This is according to the angle scale on the table. That is exactly what the SS instructions say. Please explain what is wrong with those instructions. I really don't understand why you think they are wrong. The first picture shows the SS set up per the instructions and the second picture shows that the table is at 0* with that setup. Where is the problem?

The third and fourth pictures show the table set up for conical disk sanding. The 4* (nominal) table tilt is so the edge of the stock remains square with the face. I tilted the table using a square so it was 90* to the face of the conical sanding disk. The scale under the table is hard to read but it is around 3.5*. Wixey says 3.8-3.9*.

[jsburger]

Missing so far here is the angle the blade is mounted into the cutting head. Angle of attack do to speak.

Not that it is anything we can change, but it does enter into back side clearance 'figuring'.

At shallow depth cutting I would assume the 'attack' angle is slightly greater than the blade mounting angle.

FWIW SS procedure does not specify any resultant angles.

Yes that is the other part of the equation that I forgot about. So again, SS produced a sharpening guide that works with their instructions.

Just use it and it works perfectly.

Not if you follow their procedures verbatim. Do you not tilt the table and if you do to what angle do you set it? The procedure does not tell you!

The instructions read as follows:

1. Mount the worktable on your Mark V, then move the worktable to the far right end of the way tubes and lock in place. The worktable must be set to 0° (parallel to the way tubes)".

Yes I am following the instructions verbatim as far as I am concerned and no I don't tilt the table because the instructions tell you not to. See my previous post.

[dusty]

When using the conical disk along with the planer/jointer and the work table at 0° (no tilt) you certainly do not get a 45° bevel.

The instructions that came with the Planer/Jointer Knife Sharpening Jig (555471) reads as follows:

Quote:
1. Mount the worktable on your Mark V, then move the worktable to the far right end of the way tubes and lock in place. The worktable must be set to 0° (parallel to the way tubes)".

NOTE

When using the Knife Sharpener with the Conical Disc, the worktable MUST NOT be tilted 4 degrees toward the disc surface as described in the Conical Sanding Disc owner's manual. (End Quote)

Please, don't tell me you have been following these instructions for years and have had not trouble. You may not have problems but then you are not following these procedures.

I too have been using the jig along with the conical disk for years but I have not been following these instructions.

I have been following those procedures for years with no trouble. With the table set parallel to the way tubes it is at zero degrees and vice-a-versa. This is according to the angle scale on the table. That is exactly what the SS instructions say. Please explain what is wrong with those instructions. I really don't understand why you think they are wrong. The first picture shows the SS set up per the instructions and the second picture shows that the table is at 0* with that setup. Where is the problem?

The third and fourth pictures show the table set up for conical disk sanding. The 4* (nominal) table tilt is so the edge of the stock remains square with the face. I tilted the table using a square so it was 90* to the face of the conical sanding disk. The scale under the table is hard to read but it is around 3.5*. Wixey says 3.8-3.9*.

First let me thank you for the reply and the photo images. I know that doing this took some time and effort.

As I believe I stated earlier, I have been sharpening blades using the conical disk and the sharpening jig for years. It was not until I read the instructions that said not to tilt the table that I had questions.

In one of your first photos, you show the setup at 0 tilt and the conical disk. Yes that is what the instructions say to do but because of the bevel angle on the conical disk you cannot be getting a 45 degree bevel on the blades. If I am wrong about that, please say so but if not, please tell me what angle you get.

Then later you show your setup again with the conical disk but with the table tilted. This is the setup that I have been using but I see this as contrary to the Shopsmith instructions (which I just recently became aware of). Let me ask...why do you tilt the table since you have said that it works with no tilt. Are you striving for a different bevel angle??

With the table tilted as you show, the bevel angle should be very close to 45 degrees. This too is following procedures within Shopsmith documentation except that in those procedures they do not discuss blade sharpening. They are setting up to do face sanding and though it is not mentioned any angle can be achieved by changing table tilt.

Saying that you were "wrong" was inappropriate on my part. If you want a bevel angle other than 45 degrees then you can certainly get it by what you are doing and if that gives you the desired result you certainly are not wrong.

I guess that I have two questions to close out this discussion. Do you sharpen blades using the sharpening jig and zero table tilt? If you do, what bevel angle do you get?

Question 3: Do you ever sharpen blades with the table tilted so as to be square with the face of the conical disk and do you ever sharpen blades with other than the tilt angles that we have discussed.

[JPG]

I believe John has already answered question(1) and 3.

1 - yes

3 - to show how he sets the table perpendicular to the conical disc.


I dare say he gets a 41° to 42° bevel angle.

[jsburger]

When using the conical disk along with the planer/jointer and the work table at 0° (no tilt) you certainly do not get a 45° bevel.

The instructions that came with the Planer/Jointer Knife Sharpening Jig (555471) reads as follows:

Quote:
1. Mount the worktable on your Mark V, then move the worktable to the far right end of the way tubes and lock in place. The worktable must be set to 0° (parallel to the way tubes)".

NOTE

When using the Knife Sharpener with the Conical Disc, the worktable MUST NOT be tilted 4 degrees toward the disc surface as described in the Conical Sanding Disc owner's manual. (End Quote)

Please, don't tell me you have been following these instructions for years and have had not trouble. You may not have problems but then you are not following these procedures.

I too have been using the jig along with the conical disk for years but I have not been following these instructions.

I have been following those procedures for years with no trouble. With the table set parallel to the way tubes it is at zero degrees and vice-a-versa. This is according to the angle scale on the table. That is exactly what the SS instructions say. Please explain what is wrong with those instructions. I really don't understand why you think they are wrong. The first picture shows the SS set up per the instructions and the second picture shows that the table is at 0* with that setup. Where is the problem?

The third and fourth pictures show the table set up for conical disk sanding. The 4* (nominal) table tilt is so the edge of the stock remains square with the face. I tilted the table using a square so it was 90* to the face of the conical sanding disk. The scale under the table is hard to read but it is around 3.5*. Wixey says 3.8-3.9*.

First let me thank you for the reply and the photo images. I know that doing this took some time and effort.

As I believe I stated earlier, I have been sharpening blades using the conical disk and the sharpening jig for years. It was not until I read the instructions that said not to tilt the table that I had questions.

1.In one of your first photos, you show the setup at 0 tilt and the conical disk. Yes that is what the instructions say to do but because of the bevel angle on the conical disk you cannot be getting a 45 degree bevel on the blades. If I am wrong about that, please say so but if not, please tell me what angle you get.

2.Then later you show your setup again with the conical disk but with the table tilted. This is the setup that I have been using but I see this as contrary to the Shopsmith instructions (which I just recently became aware of). Let me ask...why do you tilt the table since you have said that it works with no tilt. Are you striving for a different bevel angle??

3. With the table tilted as you show, the bevel angle should be very close to 45 degrees. This too is following procedures within Shopsmith documentation except that in those procedures they do not discuss blade sharpening. They are setting up to do face sanding and though it is not mentioned any angle can be achieved by changing table tilt.

Saying that you were "wrong" was inappropriate on my part. If you want a bevel angle other than 45 degrees then you can certainly get it by what you are doing and if that gives you the desired result you certainly are not wrong.

4. I guess that I have two questions to close out this discussion. Do you sharpen blades using the sharpening jig and zero table tilt? If you do, what bevel angle do you get?

5. Question 3: Do you ever sharpen blades with the table tilted so as to be square with the face of the conical disk and do you ever sharpen blades with other than the tilt angles that we have discussed.

1. First, by my measurement of the blade bed of the sharpening jig it is not 45*. Wixey says 43.2* pretty consistently. The blade is put in the jig with the tapered side down on the bed. What does that add to the equation. I think you said a degree or just over. Now the bevel is off 3+* and is approaching the angle of the conical disk. To get this perfect one would have to have access to the prints for the conical disk, the sharpening jig and the blades to do a stack up for all the angles. Suffice it to say from the picture it is very close. As you can see there is a line down the center of the bevel. This is a blade that has been sharpened once with two very light passes across the disk. The dark side on the left is the original grind. The shiny side on the right is the sharpening jig. That shows that the angle is not perfect but trust me when I say it is more optical than it is mechanical. I can not feel any angle change. Yes of course there is some but it is so insignificant as to not make a difference.

2. I don't ever tilt the table for sharpening. As I said in the post I am just illustrating the set up for sanding.

3. I don't think so for reasons stated above.

4. I always sharpen blades with 0* tilt on the table as per SS instructions. The angle obtained is VERY close to the SS original grind. BTW,, the picture is of a jointer blade. The planer blades look identical.

5. No I never sharpen blades with the table tilted to any angle period. I follow the SS instructions verbatim.

[BuckeyeDennis]

I think I can account for some or all of the missing degrees. First of all, the blade-holder slot in the jig is not at 45 degrees (see photos below). The fixed clamping surface is 47 degrees from vertical, or 43 degrees from the horizontal. So if the conical disc angle is 3 degrees, that would seem to result in a 46 degree grind angle.

But wait! The blade itself is wedge-shaped. And my 43 degree measurement is to the clamping surface on the opposite side of the blade from the cutting edge. So if the blade wedge angle is one degree (which I didn't measure), that would put the grind angle right at 45 degrees (if measured from the side of the blade with the cutting edge).

sharpening jig measurement.JPG (614.61 KiB) Viewed 3461 times

I was a bit wobbly when trying to hold the Universal Bevel Protractor with one hand and shoot a cell-phone pic with the other. But the angle was locked in with the blade precisely aligned with the clamping surface.

Sharpening jig angle.JPG (710.62 KiB) Viewed 3461 times

And the result shows an angle of 47 degrees. (Or 46 degrees, 55 minutes, if you want to be fussy.) But since I have it sitting on the acute-angle attachment, that's actually 47 degrees from vertical.

Edit: I see that jsburger beat me to press!

[jsburger]

Thanks Buckeye! That just confirms what I thought I knew. I don't do a lot of this stuff every day anymore so the mind gets rusty sometimes.