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I'm looking for some ideas for making a base for a PC 7310 laminate trimmer for flush-cutting the overhang on the top/back to the sides, and/or for routing binding channels. I tried it with the stock flat base, but it didn't work so well, I ended up finishing it with sandpaper to get it totally flush.

It seems like a lathe would be necessary for most of the designs I've seen. I read once that it could be done on a drill press with a file or sandpaper, but I don't remember where I read that first.

I've got one of the misc assortments of UHMW from Woodcraft, so that's what I'll probably make it from.

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Jonathan Kendall, Siloam Springs AR

Why wouldn't this binding jig from our sponsor work?
Because that one indexes off the sides instead of the top, I think it should work for you.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

Or check Don williams binding rouer jig in the tools and jigs section above this page

Thanks for the link, but I'm mainly just looking for a simple (and cheap) concave base for now so that I can easily freehand trim the back and top to the sides after glue-up with a pattern bit. That's what we had in the Fleishman class, it was pretty foolproof.

I'm less concerned with binding and purfling channels, I'm going to give the gramil/chisel route a good try before I invest time/money/space on a binding jig. If I do, then I'd probably lean more towards a Fleishman style jig, and I'd still need a concave base for that.     

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Jonathan Kendall, Siloam Springs AR

Any good binding system uses the sides to square to and the top or back contact is nothing but a height plane that the base rides on. you can get Teflon donuts at Wally World that are use in nitting and glue one on the base. they are about 1-1/2" od x 1" id these work well for the ledge on the router base. Small enough not to be an issue with the dome slope. Trying to use this hand held is near impossible as the surface area of the base is now so small that it is hard to keep level, but on a floating base with a pilot guide indexing to the side in workse well. I use Johns Halls binding fixture



I addapted mine for a PC 7310 and added an adjustable pilot guide for setting the cut depth.MichaelP38733.5093634259

I probably shouldn't have mentioned "binding" in my original post. I'm mainly a little nervous about using my drill press as a lathe to make a concave trimmer base, so I wanted to see if there were any tips in regards to that, or other suggestions.

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Jonathan Kendall, Siloam Springs AR

Thanks for the teflon tip Michael!

Serge

I think there is some "overthinking" going on here.

1 Take a spare cutout from a soundhole or make one about that size.

2. Double sticky it to your router bass.

3. Double sticky some sandpaper to your guitar back where it is domed,
mine is domed equally as are most these days.

4. sand the stick on until it is domed. Keeping the router upright by eye
should do it.

You may need to make one for the top and one for the back.

Ken that is a simple way to approch a base for hand held routing binding channels. My only concern wold be as you turn the apex of the upper bouts, due to the small area of the dome there, I would think you would loose the some surface contact on the base there by causing the vertical depth to change fractionaly by tilting slightly right or left, till you complete the tight corner. This may not be a big issue depending on the width of the base, but is the reason I like a free floating vert. fixture with a small base contact point.MichaelP38733.5896759259

I just realized I've been saying "concave" all this time instead of "convex," which is what I meant.

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Jonathan Kendall, Siloam Springs AR

Would this work, only set to cut flush?

Scroll down about 3/4 of the page, to Arnt's jig.

http://luthiersforum.3element.com/forum/forum_posts.asp?TID= 2613&KW=arnt#forumTop

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now known around here as Pat Foster
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http://www.patfosterguitars.com

[QUOTE=MichaelP] Ken that is a simple way to approch a base for hand
held routing binding channels. My only concern wold be as you turn the
apex of the upper bouts, due to the small area of the dome there, I would
think you would loose the some surface contact on the base there by
causing the vertical depth to change fractionaly by tilting slightly right or
left, till you complete the tight corner. This may not be a big issue
depending on the width of the base, but is the reason I like a free floating
vert. fixture with a small base contact point.[/QUOTE]

In practice you are right about it not being the best approach to getting a
perfect binding ledge, but to cut the overhang, which was the original
question, it works fine.

But it works okay for a binding ledge depending on the users hand skill.
Some people don't want to build one of those big X, Y, Z contraptions
that you can use blindfolded.

[QUOTE=burbank] Would this work, only set to cut flush?

Scroll down about 3/4 of the page, to Arnt's jig.

http://luthiersforum.3element.com/forum/forum_posts.asp?TID= 2613&KW=arnt#forumTop

[/QUOTE]

Pat, I'm sure you coud use it for that. I just use a flush trimmer bit in another router for the overhang however, it's faster.

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Rian Gitar og Mandolin

If you have a dish just put sandpaer in that and sand the base.

[QUOTE=Arnt] Pat, I'm sure you coud use it for that. I just use a flush trimmer bit in another router for the overhang however, it's faster.[/QUOTE]

Yes, this is exactly what I want to do... Do you use a special base on that router, or do you just eyeball it close to vertical?

I could get it close with the stock base, but to really get it flush I'd have to lift up on it to get it vertical, and then the base would only be supported out at the edge resting on the back/top. If I had a concave base, the router/trimmer would be riding right on the edge, next to the bit. Then only a minimal amount of bit would have to be exposed, minimizing the chance for damage if I accidentally tip too far off vertical.

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Jonathan Kendall, Siloam Springs AR

Jon, I just do it free hand with a small router; I don't worry too much about the edge as it will be trimmed further for the binding later on. But the flush trimming gets it pretty close.

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Rian Gitar og Mandolin

Thanks Hesh for that great tip, very detailed explanations in there !

Serge