Cutting a 12" radius groove in sanding block

mgdesigns · Post by **mgdesigns** » Sun Jan 01, 2012 5:09 pm

Is there any way to do this on a Shopsmith?
[ATTACH]15559[/ATTACH]

http://projectguitar.ibforums.com/index ... ntry284848

If so, how?
Also I would like to try to get a 7.25" radius block too - any way?

holsgo · Post by **holsgo** » Sun Jan 01, 2012 5:31 pm

I've seen that safe t plane before. Not used one but it looks straightforward. Anything you could use on a drill press you can use on the SS, typically. Now it looks like the safe t plane just has an arbor that goes into a drill chuck. Not sure I like that but it seems to be what they have. Cutting the radius seems to be a function of the tilt of the table. Like when cutting coves on a table saw the radius is a relation of the blade to the board being fed into it.
My guess is a tighter radius is achieved by a steeper table angle. The SS tilts differently but there's no reason you can't make a ramp for the board to travel.

reible · Post by **reible** » Sun Jan 01, 2012 5:47 pm

Hi,

I have one of these cutters for my shopsmith, but I've never attempted a cut like that. It should word.

Here is another idea, see lower in the page under coving:
http://www.shopsmith.com/academy/tblsaw_spops/index.htm

Ed

pennview · Post by **pennview** » Sun Jan 01, 2012 5:54 pm

On the Shopsmith, you'd use drill press mode and need to tilt the table the 5 degrees and then run your stock across the table with the stock going between the two way tubes for a 12" radius. One of the guys commenting on that set-up said he would do the math for the proper angles for other radii, but never posted a follow-up. Perhaps that info is somewhere on that site. Barring that, if you have a sample of the 7 1/4" radius block you likely can use it to determine the table tilt angle needed for making the cut.

It goes without saying that you need to exercise caution when using one of those Safe-T-Planer gizmos.

charlese · Post by **charlese** » Sun Jan 01, 2012 6:27 pm

mgdesigns wrote:Is there any way to do this on a Shopsmith?
[ATTACH]15559[/ATTACH]

http://projectguitar.ibforums.com/index.php?showtopic=25182&st=0&p=284848&#entry284848

If so, how?
Also I would like to try to get a 7.25" radius block too - any way?

Sure, you could use this tool on a Shopsmith. I wouldn't recommend using a drill chuck. Instead I recommend a 1/2" router chuck. Shopsmith cautions that a drill chuck is not designed for side pressure. Evidently, others ignore this fact.

You can use the normal tilt feature of the Shopsmith and feed into the center of the machine (between the way tubes). Of course you'd have to mount your guide block on the side of the table - and make sure your "Arm lock knob" is secured so the unit will not tilt toward horizontal position.

Don't know what speed is to be used and also don't know what tilt is necessary to get a 7.25" radius.

JPG · Post by **JPG** » Sun Jan 01, 2012 6:50 pm

He wants a 12" radius That would require a 24" diameter blade fed 90° to the blade.

The 7.25 radius would require a 14 1/2" blade.

Notice the coving results in coves smaller than the blade.

EDIT:

Hooookay! None so blind . . .

The SS does not tilt side to side(front to back) so feeding right to left is needed.

Oughta work if tubes etc. do not interfere. I would use a small diameter blade(7 1/4 comes to mind). Maybe stacked for stability(side thrusting going on).

Guardless spinning blades in drill press mode is a mite 'scarey' even for me!:eek:

I think I would stick to the tool suggested!;) Still kinda scarey!

mgdesigns · Post by **mgdesigns** » Sun Jan 01, 2012 7:19 pm

I have a Wagner Safety Planer and it does work well (even on the SS). But this technique seems to be more chore than glory. I'd have to make a ramp to be able pull the piece through the safety planer, and just making the ramp seems daunting to me. Just thought I'd pose the question and see if it's something easy enough for a novice like me to do.

foxtrapper · Post by **foxtrapper** » Tue Jan 03, 2012 11:16 am

I think I agree with the notion that this is more chore than glory.

Can't think of any reason the drill chuck couldn't take the side loads. Though it could have a tendency to loosen itself. Some chucks are notorious for this.

damagi · Post by **damagi** » Tue Jan 03, 2012 2:23 pm

mgdesigns wrote:I have a Wagner Safety Planer and it does work well (even on the SS). But this technique seems to be more chore than glory. I'd have to make a ramp to be able pull the piece through the safety planer, and just making the ramp seems daunting to me. Just thought I'd pose the question and see if it's something easy enough for a novice like me to do.

Why would you need the ramp? You can tilt the table and pass the piece between the ways. You could even use a pair of miter guages (one facing forward in the left slot, the other backwards in the right slot) with extension fences to create a nice tunnel setup.

rlkeeney · Post by **rlkeeney** » Wed Jan 04, 2012 5:36 am

There are lots of easier ways to make a radius sanding block. A quick Google search find plenty.

I like these:
http://tinyurl.com/7ss4v2k
http://tinyurl.com/6rqda5y