Official Luthiers Forum!

What kind of set-up, jig, tool are you guys using to route out the backstrip for the purfling inlay?


Thanks

Mike

I use a lamintae trimmer, I used clamp a straight piece of ash along it to use as a fence. recently I whent high tech and attached the piece of ash to an MDF board, with a bolt through the board and ash and a wing nut to tighten it, I also glued cork to the bottom surface of the ash and marked a center line so I just put the back align to the center line tighten the bolts and run my square based trimmer along the ash.

I used to run a dremel against a straight edge clamped onto the back and then running the dremel slowly against it.... remember...a little at the time and take it slow!

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Hi Mike I just saw your other post, if it is a solid strip another method is to glue it in when you joint the back.

Thanks guys,

I set up a fence on my workboard, verified my measurments, set the cut, and went down the line nicely at first. All of the sudden it wobbled a bit and my cutting bit seemed to tail off some. It was my first pass, so I was able to fix the slight bobble. I think I must have been going to fast and put to much pressure on the bit. I was just looking for a better mouse trap. Hard & hot day at work, probably rushed things like I said.

Thanks for the ideas, and keep them coming, some with pics I hope, I have been looking at Laminate trimmers, Dremmel has been a good tool, but just so lightweight.

Thanks

Mike

Russell, I have two more to do and I have not glued up the backs yet, I will give that a try, thanks

Thanks

Mike

Mike

Dremels are great for a lot of jobs, and it is quite easy to get some flex in the narrow shank of the bits, a trimmer has 1/4" of shank so it can be worked harder, also the dremel I have has a lot of runout in the bearing.

Mine is the old one, I am told the new ones are more sturdy.

I got a nice trimmer from amazon in the USA for $90 it is a Dewalt one, I have a friend who was in California to visit his parents, he lives in the UK, so I had it delivered to his parents and he put it in his suitcase for me.

$90 works out around ?50 the same trimmer here is ? 150 and they are made in Italy !!!

A lot of the US guys swear by the Porter Cable trimmers.RussellR38826.8060648148

I have a couple of old ones as well but was using one of the new 400XP whatevers. I agree fully and like using the tool for alot of things, but some things are just not suited for it, finding out the hard way. One of my problems is that I am no longer tinkering with one that might take months to do, I have the anxiety of having four going at one time, three for player customers. I have to stop sometimes and count to 10 so I don't try and rush things. I think I just was running to fast as stated and flexed the narrow shank of the bit.

Thanks again,

Mike

Mike,
I think I figured out one of the possible causes for the bit wander. There is a rubber grommet on the rear bearing and more than likely is allowing some wobble in the motor in the upper part of the tool and thus lets the bit wander. I just rebuilt mine this past week and happened upon the possible cause. Maybe the cure would be to make that bearing fast to the housing and eliminating some if not all that wobble.
I haven`t tried anything with it just yet, but one of these days, at least before I try any more fine cuts with this tool...

_________________
Give me 50 cents worth of regular.
Check my oil too, if you don`t mind,,,

I bought the Black & Decker RTX instead of a Dremel. They have more power, they are better made, and they work with many of the Dremel accessories like the StewMac router base.

CrowDuck

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Chris Nielsen
Soquel, CA.

For that kind of job Mike, i would really trust the Porter Cable 7310

Serge

Regardless of the tool (Dremel or router), make sure you run the cutter so
that the cut is pulling the tool into your ash guide. If you run the tool so
that the cutter is "climb-cutting" you risk having the bit pull away from
the guide, creating too wide a cut.
Craig S.

I too use the dremmel method and move my straight edge to make the slot wide enough. On problem I had on one back was that I cut the slot slightly too narrow. When I slid in the purf strip it fit nice and snug and I glued it down. When I unclamped the back from my work board, it lifted up in the middle and my back was no longer flat. Fortunately, the bend wasn't too big and it conformed well to the curve of the braces once I glued them on. Just a word of warning not to make the slot too narrow. Too wide, is worse, however.

I read somewhere about shimming the offending bearing with narrow strips of tape around the outer race. Just hearsay, but it may work.

Al

Craig,

In my haste, my first pass was a climb, I did have my fence on the left side knowing the tendancy I heard about here on the OLF.

Cocephus - I will check that bushing or bearing out before I try again.

Update

I got the strip glued, but after drying I noticed that my channel did have some areas where it took a little to much off. What do you think? Can I CA and sawdust these areas to fill in the gap? It is Bubinga wood.

Thanks to all for the info

Mike

Mike,

I've patched Bubinga before, and it came out invisible.
I'd try--it beats trashing a back!
(Or a sloppy-looking joint.)
Steve

And another thought--don't use CA and sawdust--you'll darken your fill too much. Try a white glue if you are planning on using some of the Bubinga sawdust.Steve Kinnaird38827.5171759259

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From Nacogdoches...the oldest town in Texas.

http://www.stephenkinnaird.com

Mike, go ahead and try to fix it. The worst that can happen is you fail, in which case all you do is rout out the strip, make the channel 2 purling strips wider, and inlay the strip again with extra purfling.

I have some of the LMI White glue and will give it a try

Thanks guys,

Mike