# radius blocks



## swarfrat (Jun 1, 2014)

I'm in need of a large diameter radius sanding block. Like 40" Radius, about 5" Wide. I made a 6.5" radius block out of 3/4" ply for sanding hole plugs on a drum project, using the bandsaw and sandpaper laid on the surface of the drum, but now I'm wanting some bigger blocks.

I've seen some jigs for making radius dishes, but at the moment, I'm wanting to make a long radiused "extrusion" for sanding the snare beds on this drum.

Also, I've got a few drum projects in mind where I'd like to make a variety of male and female sanding blocks in different radii, and a bit wider than I cut on my bandsaw, and in any case, lack the "truth" surface I'm building to (so I can't really use the lay sandpaper on master surface trick to finalize the block).

What's the best way to go about making radius blocks? Particularly a long large radius block for the snare beds?


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## Woodendeavor (Apr 7, 2011)

I am not sure how big the radius is but I have made many male and female jigs using a router on a pivot.

Good luck


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## swarfrat (Jun 1, 2014)

For anything that can be cut with a template following bit that will work. For 1/4 sheet blocks thats fine. But for the beds i was picturing something of about a 40" radius, 5" side and 18" long (so i can lay it across and cut the beds on a 15" drum and have some stroke length) .

It occurs to me that i dont need the entire length radius for the long block, but they do need to line up at either end.


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## Dal300 (Aug 4, 2011)

Not sure what you are saying about '*he pong block*" but you could make a 20"+ piece of your radius and pin it.
No matter where you turn your pattern it will be in line and always at the proper distance or radius.

Good luck.


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## swarfrat (Jun 1, 2014)

Sorry. Tiny phone, touch screens and ever increasing near focus distance.
"the long block". I can't easily cut a 40" radius 18" deep, but as long as a few inches at either end are radiused and lined up with each other its fine.


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## Yonak (Mar 27, 2014)

Check out this idea : http://jsevy.com/luthierie/compass/Long_compass.html

You could use the concept as a sanding jig instead of a compass, if that's what you're after. What you need to know is the length and height of your arc.


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## swarfrat (Jun 1, 2014)

Thanks. I guess I was under the impression that the cutting bit would have to go through the pivot of the long compass. But since its fixed I guess even that isnt a big deal.


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## MrRon (Jul 9, 2009)

I would use 1/8" thick strips of wood laminated together. The first layer would take a strip so many inches long and using rope or twine, pull the ends toward each other until you have the radius you want. Then laminate other strips and clamp until dry and radius is set. Glue sand paper to the lamination.


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## swarfrat (Jun 1, 2014)

That's an interesting method. I'll have to give it some thought. I saw someone making a radius dish in similar fashion. https://homegrownlutherie.wordpress.com/2012/08/21/making-a-radius-dish

My other idea was to bandsaw them in 3/4" strips, then glue the strips together. I don't currently have a bandsaw, but I was looking at picking up a 10" benchtop. (Can't afford or store a 14" right now).


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