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Back at the end of January, Nelson started this discussion on modifications for an oscillating spindle sander.

Several of us batted around the idea of making a template guide for the OSS (which was Nelson's original question). And I wondered if anyone would give it a shot.

I haven't noticed if anyone did it or not but I've had an idea brewing in my head how to do it for some time now and I finally got the chance to do it.

I made it out of MDF, although I would really like to make it out of aluminum as I think the guide ring would most certainly be stiffer. This really did work though so I'll walk through the steps I did to make it. Maybe someone else will make it out of aluminum.

I have a ridgid OSS but I'm pretty sure something like this could work for what ever model you have.

I didn't take pictures of the entire process (I'm pretty bad that way) as once I got working, I just kept on going and forgot about the camera. So, I'll give written details with some pictures at the end.

OK, I started out with a small piece of 1/4" MDF. 10"x14". I roughly layed out where I wanted the hole to be, based on the deck of my OSS. I drilled a 1/4" hole there.

Then, I put the largest diameter sanding drum on the OSS (which is a 2") and I cranked it down as much as I dare (I wanted the rubber drum to expand as much as possible) to make sure the drum was as large as it was going to get. I measured this with my calipers and that turned out to be 2.090".

Now, I wanted the offset of the template guide to be small so I decided on 1/8". So, I added 0.125 to the OD of the drum and that was going to be the OD of my guide.

Also, I needed a second ring which would locate the base plate onto the sander table, based on the center of the spindle. So, I measured the spindle and that would be the center diameter of positioning ring.

Back to the MDF base plate. Using my Wells/Karol precision router base, I cut a shallow channel which the guide ring would sit in. Now, I wanted a tiny bit of clearance between the OD of the base plate channel and the rings, so I made that 0.003". This is where a CNC or even a lathe would be a good idea. But the MDF worked out alright.

Now that the OD of the base plate was cut, I then cut the ID out. Clearance between the sanding drum and the ID of the base plate, and guide ring I decided would be 0.045". So this made the ID .090" larger than the sanding drum.
So I cut the ID on the base plate and on the guide ring.

OK, so here are all the parts that I made.



Here's the positioning ring in the base plate. I drilled and tapped for #10-32 machine screws in the OSS deck. This way I could ensure my new base plate was held solid, also based on the positioning ring.



I also drilled and taped the positioning ring and the guide ring with a set screw to help keep it in place (again, steel or aluminum would be better for this too).



Now, I screwed the base plate in place and the center of the guide ring Should be on the center of the spindle.



Then I put the sanding drum on.



And checked to see if my math worked out.



Yup, I'm 1/8" offset from the drum. Just like I wanted

I also made a template for my bridge shape, which was offset by 1/8" (having CAD capabilities makes this much easier).



So, I attached a bridge (cut out to within 1/16" of final side) and had at it.

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Con't.

And the results were great.







Now, I just need to make a locating jig for the pin holes. Then I cut the saddle slot and final shape.

I hope this helps someone with the idea to make a template guide for their OSS and maybe someone with more tooling than me can make it out of aluminum or steel, which would really be more accurate. But this proved to work out just fine.

One thing to note, the MDF guide ring was easy to push in toward the sanding drum. So I had to be careful not to push to hard and just let the sander do the work.

Cheers.

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Cool Rod, thanks for posting.

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David White, Toronto

"All my favourite singers can't sing."

Great looking setup, Rod. I typically use a router table and pattern following bit for such operations but I can see the merit of the sander especially when the pattern is more complex and blowout can potentially be avoided.

Thanks for posting!

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JJ
Napa, CA
http://www.DonohueGuitars.com

Actually I have a router template guide adapter that fits over the smallest rigid spindle. It is brass, won't flex and is threaded. This might be a good starting point for such a project.

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David White, Toronto

"All my favourite singers can't sing."

Looks pretty snazzy! And something easy enough for anyone to make. Something this useful really should be part of the standard parts for the tool, or at least the after market offerings.

Thanks for taking the time for the proof of concept effort!

Now, all I need is one of those sanders...

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my dream come true!

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Jordan Aceto
Ithaca, NY

That should be, "My dream come True!"

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Waddy

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Very cool! I was following that discussion and it was on my list of things to do. How did you attach the guide ring. I see the set screw, but it doesnt look like it is what is holding it in place. Did you glue it on?

Would some phenolic plastic product be a little stiffer to avoid flexing toward the drum? However, not pushing too hard and letting the sander do the work is probably a good thing.

Looks very handy.

Darrin

Very cool, Rod! Thanks for showing this.

You've got the gears in my head spinning... yeah, unless someone has a metalworking lathe, maybe a ring of polycarbonate/Lexan?

I'm also going to check out David White's suggestion, as that may work out well for intricate shapes.

Thanks!

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Well, I wanted to make the entire thing out of acrylic but when routing the channel in the base plate, there was much more melting instead of cutting so I switched to the MDF. I don't have a good circle cutter for the drill press otherwise that might work too to cut the ring. I'll give that a try maybe.

I would love to have a more solid guide ring for it.

Darrin, it is quite a snug fit. Even though there is some clearance. I also flooded the ring with CA and let it cure, it gave a bit more of a tight fit in the channel. The set screw really doesn't do much. It more just locates the ring so it can't turn in the slot. Mind you with the moderatly tight fit, it doesn't turn really.

For now, this will have to do for me. I have too many guitars to make to keep "playing" but if someone else comes up with a better version, I'm right there.

Thanks for the props folks. This was a fun little project and one that will save me blowing out the back side of bridges with my router guide bit (I've done it twice and never again).

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Nice job with it Ron.
Here's a jig for sanding the wings on the bridge that I got from Mike Doolin that's pretty handy.
I've been making fixtures and jigs for a pinless bridge so don't be concerned with the setup bridge in the pictures as it is a sacrificial bridge.

Cool Rod. Every time I walk into a woodworking store I always ask them if anyone makes a template guide for a spindle sander and apparently no one does. You've got me excited about making one. Nice job!
Terry

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