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I've built two guitars so far, and have had no difficulties with the rosette work; until now! For one thing, Dremel quit making a circle cutter small enough for classical guitar rosettes, and I've had to resort to modifying the router assembly that they put out. I do not like the cutting bits that several Luthier suppliers provide, and have found that the small cutting bits provided by my Dentist, work the best. The problem is that none of the router assemblies that are sold allow the dremel tool to be close enough to the board, to allow use of these short dental burrs. I tried the longer bits provided by Stew/Mac with a Dremel circle cutter two nights ago, and ruined the nice cedar top for my latest build. Any suggestions, guys on what works out there??? I'm pretty ingenious at making different assemblies that work, but this one has me baffeled now???
Another problem. I do not want to waste the cedar that is left over from the above situation, but in order to make it work, I will have to glue several peices together (four) in order to make these pieces fir the top profile. Is this going to effect the sound on the classical guitar I'm using? If so, I guess I'll have to order some new wood. Advice requested? Thanks, Greg

regarding the dremel base, what i did was cut out a section wide enough to allow a delrin block with a row of dowel pin holes reamed through it to be adjusted inward and outward from the spindle. this block uses the fence rails that dremel provides and allows me to position the pivot to within an inch of the spindle. very easy mod and i only used delrin because i had a lump of it hanging around but you could use aluminum, hardwood, etc..if you wanted. with this setup i can make much tighter circles now.

regarding cutters, try reverse spiral endmills, 1/8'' diameter. SM sells them. i can chuck them right up to the spindle nut with only about a 1/2" poking out.

how did the longer bits ruin the top?

Thanks for the info, but I'm not sure what you did without a photo. I don't know just what happened with the longer bits, but they somehow worked their way through the ceder. Everything was secured as well. Also - do you think I can still use the cedar top with three glue joints instead of the single long joint, without compromising the sound?

I have a dedicated Makita 1hp router
set up with a circle cutting attachment.
check out their website !
I use it for all my rosettes.
I never use it for anything else.
It's lite in weight &has a small baseplate.
Sorry I do not have a pic of it.
I use from 1/8" bits to 19mm bits
depending on what I need.
I use down-cutting bits .
Except the 19mm one.

Since I have gone to this system I find it easier
to make any rosette channel that I need very quickly.

MIke

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Mike Collins

When I use dental bits I make the shaft bigger and longer to fit my rotary tool by soldering copper tubing over it that I get from a hobby store. It usually takes two pieces of tubing: the first one just fits over the dental bit shaft and the second just fits over that. The second piece of tubing has the 1/8" outer diameter needed to fit the rotary tool. Just put the two pieces of tubing on the bit, heat it up and wick in the solder. Soon as it's cool, you're good to go. Make a bunch up at once.

Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

As far as a four piece top, that should be OK. Torres sometimes used more than two pieces for a top. I think Romanillos has, also.

The Wells/Karol jig is a fantastic design. You could probably use it along with a dremel base if you are not ready to step up to a laminate trimmer. My setup uses the Ridgid laminate trimmer, SM's 1/8" collet adapter and less expensive Monster endmills from Fastenall.

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Good judgement comes from experience. Experience comes from poor judgement.

Thanks for all the suggestions. I have a Porter Cable router, which I consider too large for rosette work. Where do you get info on the Wells/Karol jig?

Here is a tutorial that Chris Paulick did. http://www.youtube.com/watch?v=9oRqUK-CMIo

_________________
Good judgement comes from experience. Experience comes from poor judgement.

I hear that lots of folks can get good results with a dremel tool, but I just hate the little devils. I find the low power & the sloppy bearings make it hard to do a good job.
I have a dedicated router I use only for circle cutting. A nice old (and very smooth running) 1/4" Makita router I picked up for $20.00 at a pawn shop. Coupled to a home made precision adjustable circle cutting jig, it has never let me down.
Good quality 'high speed steel' spiral downcut bits do a better job (in my experience) than the solid carbide bits.

This contraption is way overkill, but these are the parts I had around to make a rosette cutter. Works great, I can set inside and outside stops, move in or out, up or down in 1000's of an inch, the Foredom has a Jakobs type chuck, so going from bit to bit is easy, however it does not go up to 1/4" bits, almost. The Foredom also goes round and round without an electric cable twisting. Fun contraption.

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http://shastaguitar.com/
http://www.kalimbakit.com/
http://www.youtube.com/user/comfyfootgr ... ature=mhee
http://www.facebook.com/robert.renick.7

John Bogdonovich sells an acrylic circle cutter for classicals (and can be used on a wide variety of rosette sizes) on his website (at least it used to be there...I bought one a while ago).
It's made for a lam trimmer but could be retrofitted for your Dremel, I imagine. Price was right.

Sylvan will make you one, but he also has a detailed tutorial available on his website with pictures, instructions, and a parts list. You'll need to subscribe, but you'll get you access to 20-25 other "premium" articles/tutorials. The downside to subscribing is the password. It's pretty cryptic, and you can't customize it. Keep that thing flagged in your Gmail!

Sylvan's tutorial on the circle cutter

Just watch my video on the Karol base. If you want to spend money you can always send me $20 for the viewing...