Official Luthiers Forum!

Does anyone have any experience cutting with lasers? I am looking at them for general woodworking but also for guitar building. Can they cut abalone or pearl?If so, what kind of power is needed?

Search this forum for laser cutting... someone was just in here talking about rosette cutting with a laser

Shell does not laser cut well at all. the heat cause the calcium silicate that makes up the shell to powder away To numerically cut shell it needs to be CNC cut (milled) or water jet cut and water jet cutting is an issue due to the size of shell blanks unless it is glued down to a sub straight to hold it. So the most common method to numerically cut shell is CNC milling. We have A couple members that run CNC shops that can help you John Watkins at CNC Guitar parts and Bob Garrish at St lutherie. They both do this daily

http://www.cncguitarparts.com/
http://www.saintlutherie.com/

Randolf my friend if I recall correctly Dave Fairfield has a laser that he uses for Lutherie. Also Bob Garish would be a good one to ask too.

Sounds good, thanks for the info. Too bad about the pearl not cutting well. Sure would be great.

I'd love if it laser cut well, too...I wouldn't have to spend $20 a pop on my shell cutters! As Michael said, it tends to powder the edge of the shell and it looks like crap. The issues with waterjet is first the actual piece size (they weigh so little the jet will just throw them) and, even if you glue them to a substrate, the stream size is usually bigger to much bigger than the cutters we use for inlay. The local waterjet place, at best, can do a stream size of 1/32" whereas most of my clients' inlay is cut with a 1/64".

You can laser cut shell veneer pretty cleanly, and if you're really good and it's under finish then you might be able to get away with it. The stuff is so thin that you'd need a CNC mill to cut the pocket accurately enough in depth that people couldn't tell, though!

On the plus side, if you get off shell, you can do a lot of useful acoustic guitar stuff with a laser cutter. Not so much general woodworking, as they can't cut very thick stuff, but you can cut out backs, sides, rosettes, headplates, wooden and plastic inlay, etc. Even if you can't cut all the way through, the laser can scribe a perfect line for you to cut/sand to on your bandsaw so you don't need templates anymore! Also, they can usually cut acrylic pretty well so you can use them to make router templates.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

It does sound like there are even more applications for a laser in lutherie than I even thought. I suppose I's need a 12 step program to get me off of shell, though. Love the stuff. I have never been a purist and love the idea of a good balance between hand work and technology. Guitar building is cool in that it seems to be a self-regulating system. It won't let technology run over the top of hand work. Yet, it will let us go where it would be difficult to go otherwise. I'm thinking of some of the rosettes I've seen - WOW!!!!! They're so stunning it bends the mind.
Anyway, I'll keep researching and see what comes up. Thanks for the responses - big help.

I have my headstock logos laser cut, then we cast them into the beauguard.

The material comes from rescue pearl and is the 10mil ablam (look in shell veneer section). http://www.rescuepearl.com/
The letters of my logo (name) are too delicate to cut any other way.
The company who does the cutting for me can also cut the recess into which the inlay goes.
I think he said it's a 25 watt laser.
-C

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Freeborn Guitars
and home of BeauGuard©

Bruce & Matt Petros have been using some eye-popping laser cut detailing on their guitars... amazing level of detail.

http://web.mac.com/petrosguitars/Site/Welcome.html

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Peter

VERY COOL!!

Who's this "Dave Fairfield" bloke Hesh?

Hi Randolph, I think Hesh is referring to me. I have a large format Epilog laser that I use for all kinds of woodworking things from sign-making to marquetry and now to lutherie. Its use is limited in lutherie though. I too had hoped that I could cut shell with it, but as the others have already noted, it doesn't do a good enough job, however, as Bob said, it will cleanly cut the ultra-thin ablam with plastic backing stuff (from InlayUSA amongst others), but you have to get the inlay depth exactly right first time, since the shell is too thin to allow for any sanding. I've used the ultra-thin plastic backed ablam for several projects, but not on a guitar yet.

For lutherie, I use the laser for cutting out templates from acrylic sheet and sometimes wood or paper , cutting inlay pieces out of 1/16" thick wood veneer (that I resaw on a bandsaw) for rosettes, headstocks, and other inlays, and for cutting out the basic over-size guitar shape in the back and top prior to gluing braces on. I have a few photos on my website here that might be of interest to you (more to come soon).

FWIW, Jim Olson uses a laser for the same kind of operations as I do - check out his laser photos here.

Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Hi Dave,
Thanks for all of the info. The laser is such an exciting tool, it's hard not to have really high hopes for it. Just the fact that it can cut rosette inlays the way it can, though, is mind boggling. Your rosettes are incredible and must look amazing on a completed guitar. By the way, I love both of your logo ideas. It seems that if you stay away from pearl, it can do great things with inlay. I'm curious about Jim Olsen's comment on lasers not cutting ebony. Do you know if this is because one would need a more powerful laser or would that make no difference with ebony. For your sign making etc. how many watts is yours? I love the idea that no clamping is necessary - very freeing. Are you finding that you have to adjust your strength or depth of the beam with different woods for inlay or does that matter? Am I right in thinking that a 25 watt laser would cut .062" thick wood for inlays? Anyway, thanks again for the links and the information.

It's not that they won't cut ebony: they definitely cut it, but they don't cut it very well. For whatever reason (maybe density, maybe composition?) the lasers I've messed with will be making ebony smoke and burn at half the thickness they can just pop through walnut.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Bob's right - it does cut through ebony, but it's very sooty and it won't cut anywhere near the depth you can cut other woods. However, it doesn't show too badly if you cut the work face down (and cut the inlay pieces face up and very slightly larger, so the kerfs match exactly). I've used it for some 1/16" ebony before. I would generally tend to avoid using it though.

Just an FYI, you will find the same kind of cutting trouble with purple heart (but not quite so bad as ebony). I believe the problem is that the cellular structure of these woods is such that it reflects the CO2 laser's frequency much more than other woods, but I'm not certain about this.

A 25W CO2 laser with a 4mil diameter beam width should be able to cut through 0.062" wood veneer like a hot knife throught butter That being said, you might regret getting a 25W model later. 25W won't get through 1/4" acrylic sheet in one pass (and two passes is very messy!). Most first-time laser owners go for a 35W machine. My first was 35W, and I wasn't happy with that even. I quickly moved up to a 45W machine.

I adjust the power, speed, and frequency (it's a pulsed laser) all the time. I do test cuts on scrap to ascertain the best combination of P/S/F before committing to the real work. Over time, you develop a feel for the best settings for your system and have a bunch of .dat files for the various wood types/thicknesses that you use. The settings that the laser manufacturers give you are a reasonable starting point in most cases (but NOT for Epilog's settings for acrylic - they suggest a P/S/F of 100%/8%/5000Hz for 1/4" acrylic sheet, but that will just give you a molten/burned edge that has a tendancy to join back together again! 100%/6%/500Hz (i.e. much lower frequency) is best by far). FYI, I have a 45W Epilog 36EXT machine.

Are you thinking of buying a laser engraver? If so, I would recommend that you read the laser engraving forum archives at Sawmill Creek before you plonk down your hard earned cash. Ask questions about the make/model you are thinking about buying over there - they are very knowledgable and helpful and several of the major laser manufacturer's have support employees that hang out there.

Hope this helps.
Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Hesh -- there actually IS a bloke called David Fairfield over on Sawmill Creek who owns a laser engraver!!

Small world.....

Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

I love the coincidence on the name Dave! Yes, I am thinking of buying a laser, although I'm probably a few months away on a purchase. I got the Epilogue catalogue and it's very slick. They look like great machines. I will definately check out Sawmill Creek. Thanks for that lead. One other question. Is it unreasonable to expect your (45W) laser to cut the cavity into ebony for an inlay or would the depth be too inconsistent?

As Bob said shell laminate (ablam) will lazer cut fairly well. My responce was in terms of natural shell blanks. The laminating coating used to make ablam disapates the heat better that the meineral of natural shell blanks

Thanks Michael. Your headstock is awesome, by the way. Are they cutting the cavity into ebony?

That is not my peghead. That is Chris' i wa just quoting chris and his phot is enbeded in the quote

Gotcha Still a nice peghead

Not at all unreasonable, however, I have all but given up using the laser to cut cavities, simply because it's too fiddly and time consuming. You have to do LOTS of test cuts in the EXACT material you're going to use to ascertain the right P/S/F for the depth of cut. Even when you think you have it right, and you run the job, you end up with areas that aren't deep enough. Also, in top wood (spruce/redwood/cedar etc.), for cutting the rosette cavity, the winter growth grain ring areas are usually only cut to about half the depth of the summer growth grain rings by the laser and you end up having to chisel out the whole area by hand (very time consuming) which inevitably leads to fuzzy edges in my experience. I cut the rosette channel with a dremel router on a Stewmac circle cutting jig (with my digital scale mod) nowadays and only use the laser for stuff that's not circular.

For headplate inlays, I vector cut all the way through the 1/16" material and insert the 1/16" thick inlays all the way through from the back. I cut the background face-down and the inlay face-up. This gives the background and inlay opposite kerf angles so the inlay fits EXACTLY with no gaps at all anywhere no matter how much you sand it (you have to cut the inlay exactly one laser beam width bigger all the way around than the background hole cut for this to work).

HTH.
Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Sorry Dave my friend....... I meant you I just got your name rong.....

Just curious, Dave, just how thick is that beam?

Fine business Hesh me ole china!

Randolph, the laser beam width depends on which lens I'm using. The 1.5" focal length lens gives the finest beam (but also the shortest depth of cut) at about 0.002" - I use this one for most of my marquetry and inlay work. The 2.5" focal length lens gives a beam width of about 0.004" and about 0.25" usable depth of cut - good for general work and template making. The 4" focal length lens gives a beam width of about 0.006" and a usable depth of cut of over 0.5" - good for marking non-flat surfaces (like paintball markers) and cutting thicker wood.

I use the "Contour" function in Corel Draw to make objects larger (or smaller) all the way round so they fit exactly.

Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Dave, thanks for being such a wealth of information!! I notice you're in San Jose. I'm just over the hill in Santa Cruz. Cheers neighbor!!!