Shopsmith Forums

Is there really advantages in owning a conical disk ?
If you have one conical disk, do you find that you use it more than the flat one ?

If you have a jointer or planer, the conical disk with the addition of the jig to hold the knives gives you an excellent way to sharpen these knives.

I've also used the conical disk to sand exact angles on narrow strips for a dome top "treasure" chest. Doing this on the jointer or table saw would have been much more hazardous. On one occasion I've even jointed plywood for a glue up.

I like to have one conical disk with 150 grit for sharpening, and another disk with 80 grit for sanding.

8iowa wrote:If you have a jointer or planer, the conical disk with the addition of the jig to hold the knives gives you an excellent way to sharpen these knives.

I've also used the conical disk to sand exact angles on narrow strips for a dome top "treasure" chest. Doing this on the jointer or table saw would have been much more hazardous. On one occasion I've even jointed plywood for a glue up.

I like to have one conical disk with 150 grit for sharpening, and another disk with 80 grit for sanding.

They are on sale right now !

Yep! The conical disk is the only one I have used for quite a while. Use it for the same things 8iowa posted.

In my shop, the flat disk is most valuable for sanding curved edges.

I find the flat disk much more aggressive than the conical.

charlese wrote:Yep! The conical disk is the only one I have used for quite a while. Use it for the same things 8iowa posted. In my shop, the flat disk is most valuable for sanding curved edges.

I find the flat disk much more aggressive than the conical.

Charlese, there is something I do not understand, did you mean : " in my shop, the conical disk is most valuable for sanding curved edges." or really the flat disk ....
Just want to make sure ...

Sorry for the confusion. Re-stated - The only thing the flat disk is used for in my shop is smoothing convex curved edges. Sanding concave curved edges is done by hand, sanding drums or the Strip Sander

Conical disk is best for straight edges, and sharpening planer/jointer blades.

charlese wrote:Sorry for the confusion. Re-stated - The only thing the flat disk is used for in my shop is smoothing convex curved edges. Sanding concave curved edges is done by hand, sanding drums or the Strip Sander

Conical disk is best for straight edges, and sharpening planer/jointer blades.

Hey, I use the flat disk to sharpening my lathe chisels. Until at least I learn to use the new grinding wheels on the new grinder that I have.

bigeddy wrote:Hey, I use the flat disk to sharpening my lathe chisels.

You are correct - you can't use the conical disk for sharpening chisels, and you cant use the flat disk for sharpening planer/jointer knives.

When you sharpen chisels you bring the disk to the work, so you need the full flat face of the disk. Since planer/jointer knives are wide you must move the work across the disk. If you do this with a flat disk the knife will buck & jump when it reaches the outfeed (rising) side. The conical disk makes a point contact on the knife, so you have a smooth straight line as you move the knife along the disk.

michaeltoc wrote:You are correct - you can't use the conical disk for sharpening chisels, and you cant use the flat disk for sharpening planer/jointer knives.

When you sharpen chisels you bring the disk to the work, so you need the full flat face of the disk. Since planer/jointer knives are wide you must move the work across the disk. If you do this with a flat disk the knife will buck & jump when it reaches the outfeed (rising) side. The conical disk makes a point contact on the knife, so you have a smooth straight line as you move the knife along the disk.

If you remain on the downward side of the rotation can you use the flat disk? I ask this understanding that if you are doing something like a planer blade you cannot remain on the downward side.

Not meaning to tota lly disagree, but if the fence is biased(away from the rear of the disk - like edge sanding wood) the flat disk can be used on jointer knives.

However the conical disk works far better, and is not so susceptible to either overheating and damaging the abrasive disk. That was my method before I became aware of the conical disk.

One caveat! This works with the aluminum disk since it has a slight bevel at the periphery. The steel disks do not.