conical disc sanding

rdewinter · Post by **rdewinter** » Wed Feb 13, 2008 2:01 am

Just tried my new conical sanding disc. I'm not sure I've got the setup right. I mounted some 12" flat disc sand paper and installed the disc and tilted my table until I was square. I used an engineers square to check square but my gauge only read 3+ degrees. Since I was square I didn't bother refining my table top. I set the table about 1/16" from the disc. Used a scrap 3" test piece and set my fence at 2 7/8".

It seemed like the leading edge of the disc is like the leading edge of a saw blade. Won't that produce excessive wear on the paper? How do you measure from the disc to set the fence as the disc has a 4 degree tilt? When I set the fence with a blade I measure from a static point, ie saw tooth tilting toward the fence. I produced a really square edge and face with my test piece but how do you achieve accuracy (for example, I want square stock at 2 1/2")?

Any reference material available on how to use the conical disk?

charlese · Post by **charlese** » Wed Feb 13, 2008 2:35 am

... I mounted some 12" flat disc sand paper and installed the disc and tilted my table until I was square.

How did you use flat sand paper? Did you cut out a pie slice?

I used an engineers square to check square but my gauge only read 3+ degrees. Since I was square I didn't bother refining my table top. I set the table about 1/16" from the disc. Used a scrap 3" test piece and set my fence at 2 7/8".

I'd check your trunnion indicator plate.

It seemed like the leading edge of the disc is like the leading edge of a saw blade. Won't that produce excessive wear on the paper? How do you measure from the disc to set the fence as the disc has a 4 degree tilt? When I set the fence with a blade I measure from a static point, ie saw tooth tilting toward the fence. I produced a really square edge and face with my test piece but how do you achieve accuracy (for example, I want square stock at 2 1/2")?

I don't set my fence the way you did. I set it at the same thickness as the board before sanding, then use the spindle to make adjustments.

Any reference material available on how to use the conical disk?

One good tip from the Forum is to never sand off (in one pass) more than the depth of the grit in the sand paper. If you are planning to remove 1/2" of wood - first rip saw it! I believe the conical disk is for smoother finishing - not ripping.

dusty · Post by **dusty** » Wed Feb 13, 2008 7:58 am

rdewinter, It sounds as though you are trying to resize lumber rather than edge sanding.

The conical sander does an excellent job of doing what it is designed for but is terrible (and dangerous) if you are trying to take off too much material.

If you haven't viewed this Sawdust Session, you really should:

http://www.shopsmithacademy.com/SS_Arch ... Sander.htm

I'm interested in your comment about using standard sand paper. Please explain how you did this.

ryanbp01 · Post by **ryanbp01** » Wed Feb 13, 2008 9:50 am

Wouldn't it be easier to use the paper that is sold for the conical disk?
BPR

dusty · Post by **dusty** » Wed Feb 13, 2008 10:56 am

Yup, it would BPR. I was just curious. You never know what situation one might find oneself in someday. That's what makes "tips and tricks" so valuable.

ryanbp01 · Post by **ryanbp01** » Wed Feb 13, 2008 11:48 am

For me, the convenience of having the correct paper for the correct disk far outweighs trying to jerryrig something that would fit. I guess it all goes back to the saying "the right tool for the right job". However I suppose if one wanted to make a jig to set over a piece of sandpaper to cut it to fit on a conical disk is easy enough. But I fail to see any real savings.

BPR

jfran2 · Post by **jfran2** » Wed Feb 13, 2008 1:52 pm

I just watched the Sawdust session on the Conical Sander. Thanks, Nick and Shopsmith, for making these available on the web. I've learned so much from them.

I'm still not totally sure what the conical sander will do that the flat sander won't, though. Can't I just angle my fence a little and do the same thing Nick was doing - taking off a precision amount from my workpiece, as the PTWFE suggests? How is the conical disk any better?

dusty · Post by **dusty** » Wed Feb 13, 2008 2:22 pm

jfran2,

Yes, you can sort of do the same thing with a flat disk but not near as well and certainly not as safely.

Just stop and think about the machanics of this task. The flat sanding disk tends to pull the stock down against the table (on the infeed side) but then the stock passes centerline of the sanding disk and it nows tends to push the stock away from the table and back at you (sort of like a kickback).

With the conical disk, the stock being sanded only meets the sanding disk at one very narrow location (top dead center). Yes, at that point the tendency is to push the stock back at you.

If you are using the conical for very fine edge surface sanding, that won't be a problem.

HOWEVER, if you attempt to take off too much, you could be eating it.

reible · Post by **reible** » Wed Feb 13, 2008 2:37 pm

A few things to note.

1) you end up sanding with the grain not across it. At the point of contact the sandpaper is traveling in the same direction parallel to the wood. Rule one for sanding is sanding with the grain.

2) Course girt lets you take off a good deal of wood on a pass if you wish to, upto 1/8" per pass. Finer grits you take off less but get a more finished surface.

3) If you somehow don't have the manual please order it and read and understand the information, especial safety issues.

Have fun using it!

Ed

ryanbp01 · Post by **ryanbp01** » Wed Feb 13, 2008 3:13 pm

My conical disk is dedicated for sharpening jointer knives. I figure I will purchase another flat disk for sharpening purposes since I have the lathe tool sharpening guide if I decide not purchase this system.
BPR