Official Luthiers Forum!

Hi

Can anyone advise me on what router bit works well with a dremel for cutting rosette and soundhole

Thanks

When using a dremel you must be carefully as they have runout on the shaft. I only use an upcut bit. Using a down cut will push the chips into the groove increasing the risk of tearing up the separators. ALWAY use a sharp bit. Take smaller nibbles for better end result. I like to start inside and work out to the lines and climb cut both directions on the final pass. If you smell smoke your going too slow so be aware of matching the feed to cut rate for the cutter.
I would suggest a smaller 3/32 bit and take your time. Use a set up piece to adjust your cutter.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Another member recently posted a link to a fellow making and installing his rosette. He routed the channel only a safe distance from the edge. Then he used basically a compass with a razor knife to cut the exact line inside and outside the rosette. Then he used a chisel to cut out the wood between the routed area and the finish line. This will not solve the problem of the bit moving in the collette, but it will avoid most instances of tearing out wood outside the desired area.

I've used a dremel on about 100 guitars no problem. Just slow and weak. I also use a downshear bit for fuzzless edges. But I only do single channel routs. Haven't found runout to be an issue.

Have upgraded to laminate trimmer on a wells/Karol jig. Much happy.

I've had good results using a dremel with the cheep dremel circle cutter attachment and the stew mac 3/32 down cut spiral bit. There are certainly better tools for the job, but if you are carefull, use a sharp bit and only remove a little bit of material at time it is possible to get a decent finished product. Here are the three I've done.

Back in the day I cut plenty of rosette channels with a Dremel -- We use down spiral bits for all inlay including rosettes, with the Dremel and in our CNC machines.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Hi

I have got a laminate trimmer but just wasnt sure how to get it cutting the circles as it seems to big

The start of my last build video shows me using a Makita laminate trimmer to cut a rosette slot. I just made a plexi base for it and drill holes for the various rosettes I use.

https://www.youtube.com/watch?v=jUerpqmdlPA

Thanks david.. thats a good video you got there.. your guitars look class

I use the LMI jig for the rosette and a circle cutter turned by hand for cutting out the soundhole.

I would use those small 2 flute end mills.

By the way I just got the Dremel 4200, it has no runout that I can tell, in fact it is comparable to the Foredom style rotary tool I used to have in Taiwan. I would say those single/multi speed Dremels (300, 400, etc.) probably have runout issue but the 4200/4000 seems well built.

I just measured it on a dial caliper, and the runout seems to be about .005", but that's with a really imprecise method of using the smooth part of an end mill... I think my old Powermatic 1150 had more than this.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

The specific answer to the original question

We are currently using RBDC-062-FTDD 1/16" Which is a fish tail down draft carbide bit. The feed speed for our rosette programs is 2.5" per second so these are durable and very sharp and leaving a nice clean channel.

We purchased from Midwest Circuit Tech surprisingly inexpensive!

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Ken Cierp

http://www.kennethmichaelguitars.com/

Ken, thanks for posting the info about Midwest Circuit Technology. I went to their site and ordered a couple things to try out. Soon after, I got a call from one of the reps. They noticed that the items I ordered didn't seem to match up (one of them didn't seem to fit with what someone who ordered the others would use). As it turned out, I had selected the wrong item. he asked what I was using them for and then made some recommendations and changed my order. This was great because I don't really know much about router bits and their geometry. Now I will have some things to try out and decide what I like. All in all, I was very pleased with he customer service I got for a small dollar order. I too was surprised by the low prices.

Thanks again

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I don't use a dremel for this but if I did I would use a fairly small bit of the multi fluted design. I use a proxxion router with an 1/8" multi fluted bit and have never got anything but outstanding results.

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Michael F Smith
Goat Rock Ukulele
http://goatrockukulele.com

Hey GRU

Ive got a laminate trimmer and a dremel with stewmac base.. not sure what to use or is best... do you find the router to big for the radius you need?

Im open to ideas or any pics of the router setup would be great

Thanks

You can make jigs for laminate trimmer, but even then I do find laminate trimmers to be too clumsy for the work. Rotary tools is the perfect size for this.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

I guess I must be the only one who still does rosettes freehand, with a hobby knife and chisels.
I will use the dremel to hog out material, but that's also done freehand.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Yes you can do it free handed, but I would never free hand with Dremels simply because it's too easy to mess up. If it's just a simple circle channel then there's no point doing it free handed, but if you are doing irregular (non circle) shapes, I can see the value...

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

As John said, I have gotten my cleanest channels always doing a climb cut on the outside edges. Shellac the top first. Usually a 1/16 or 3/32 sprial downcut bit.

I made a jig I learned in the Fox course years ago. It works. I have no experience with a Dremel but it sounds like guys do fine with them.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Dremel on a stewmac jig will get the job done, it a bit slowly.

Google Welles/Karol circle cutter. I think Sylvan Welles gas some available for sale.