Conical sanding disk and blade sharpening jig.

ibskot · Post by **ibskot** » Tue Oct 14, 2014 4:53 pm

I can't find any videos for the setup and use. Are there any?

thanks.

ibskot · Post by **ibskot** » Wed Oct 15, 2014 6:20 pm

Does anyone use this to grind/sharpen jointer/planer blades? Is the learning curve difficult? Thanks.

JPG · Post by **JPG** » Wed Oct 15, 2014 6:41 pm

ibskot wrote:Does anyone use this to grind/sharpen jointer/planer blades? Is the learning curve difficult? Thanks.

That is it's primary purpose.

I do not own one, but did make my own. A word of caution! Make sure the grind amount is kept small and fed in minute steps. Also registration of the blade(s) to the jig.

I have had decent success with my plagiarized version.

Keep table free from anything that will divert the jig from it's normal path.

charlese · Post by **charlese** » Wed Oct 15, 2014 7:56 pm

Shopsmith makes a jig for blade sharpening with the conical disk. http://www.shopsmith.com/ownersite/cata ... rpener.htm
With the jig it is an easy matter to sharpen blades. No particular skill needed. Just ability to read instructions.

ibskot · Post by **ibskot** » Wed Oct 15, 2014 10:06 pm

Thanks. I wonder why there are no videos.

billmayo · Post by **billmayo** » Wed Oct 15, 2014 10:35 pm

I have been using the Shopsmith conical sanding disk with 150 grit paper with the planer/joiner knife sharpener for many years. I am still using the original 150 grit disk as joiner and planer knife sharpening is all that I use it for. It is very easy to use, just make sure the knives are seated in the jig as I believe the spring washers can get in the way of seating the knives. I use around a 43 deg angle so the grinding begins at the heel and goes out to the point of the knife. This helps keep the knife height from decreasing too much when sharping the knives. I use a beall tilt box digital angle gauge to check this angle. I keep my Mark V Power Station set up for knife sharpening which uses a modified 500 main table so the table angle can be adjusted.

rcplaneguy · Post by **rcplaneguy** » Thu Oct 16, 2014 1:20 am

Likewise I have the conical with 150 grit, use it for the jointer and planer knives. Love it, very easy to use. Do you have the instructions from SS? If not, pm me.

ibskot · Post by **ibskot** » Thu Oct 16, 2014 9:40 am

Thanks, I will.

Stupid question.... when I look at pics it looks like the disk is rotating towards the edge of the bade being sharpened. Doesn't this pose a safety risk? Obviously it works as people do it. Also, how long does it take? Thanks

BuckeyeDennis · Post by **BuckeyeDennis** » Thu Oct 16, 2014 10:13 am

ibskot wrote:Thanks, I will.

Stupid question.... when I look at pics it looks like the disk is rotating towards the edge of the bade being sharpened. Doesn't this pose a safety risk? Obviously it works as people do it. Also, how long does it take? Thanks

No question is stupid!!!

The magic of the conical disc sander is that it only makes contact with the workpiece in one straight line. On the disc, this line runs from the spindle axis up vertically to the top edge of the disc. Anywhere on that line, the radial motion of the sandpaper is always parallel to the surface of the table, i.e. horizontal. So if you are sanding the edge of a board, for example, the sanding direction is directly in line with the grain.

I've never detected any tendency for the operation to "kick back" the knives/jig. But regardless, I find it easiest to position the table & headstock at the right end of the tubes. Then I can stand at the right end of the machine, directly in line with the spindle, and grasp both handles of the jig very comfortably. And I'm out of the line of fire.

As for how long, I'd guess that it takes me about five minutes per blade, with most of that being installation and removal from the jig. With more practice, it would go faster.

JPG · Post by **JPG** » Thu Oct 16, 2014 10:21 am

ibskot wrote:Thanks, I will.

Stupid question.... when I look at pics it looks like the disk is rotating towards the edge of the bade being sharpened. Doesn't this pose a safety risk? Obviously it works as people do it. Also, how long does it take? Thanks

The 'line' of contact with the conical disk is on a vertical line passing through the central axis of the disk. Therefore there is a slight clearance at the periphery of the disk. However there is some risk here! One must make sure their body parts do not come in contact with the spinning disk!!!

Secret is to grind a small amount at a time. That prevents over heating, and minimizes amount of material being made into fine powder.

Notice there are two handles. Place one hand upon each handle!! That helps keep them 'out of harm's way'.

It is important to keep any obstructions away from the path the jig slides on. Also maintain contact with both the table top and the fence.

This can get a bit 'tricky' since the fence tends to get in the way, hence the long handles.

Bill mentioned it, but to make sure you understand it, the blades must be flush against the bottom of the 'slot'. A spring on the clamping screws has a tendency to prevent that(IIRC, I made mine, and do not have the SS version).

Realize the grind angle will be determined by the table tilt. FWIW, the conical disk is closer to about 3.3° than 4°. I believe the jig angle is 45°.

How long depends upon how many passes and dexterity in changing the blades in the jig. I recommend a slow attack the first time using it.

One caveat! Tis far too easy to increase the amount of grind(quill feed) too much. So take teeny tiny quill advancement steps!!! Helps prevent over heating and excessive material being converted to steel powder.

P.S. Dennis snuck in here as I was hunt n pecking this!