hand carving vs machine carving

[Jim Nollman]

1. Will a hand carved instrument usually be better sounding than a machine carved instrument?

2. How much of an average time difference might we expect between the two builds?

I ask because of some unanswered questions on another thread, which discuss the differences between the KM 850 and KM1000 made in Japan in the 1980s. The former was machine carved in one shop and the latter hand carved in another shop. Perhaps bizarrely, the 850 originally cost a bit more when new. This may make sense when you consider that the 850 uses better quality maple and spruce, plus a more fastidiously applied finish.

[Marty Jacobson]

Oh yeah, here we go. Grab some popcorn.

There is no difference that can be attributed directly to the process being used.

Is a Bridgeport milling machine better than a CNC mill? What does "better" mean?

It is about the attention to detail and the care of the craftsman. The craftsman will choose whatever they think will be best for their work, but no generalizations can be made other than that.

Hand carving usually yields better results overall, because it is generally employed by people who care about what they are doing, and they pay attention to the wood in their hands as they are carving it. They learn from working with the wood directly.

However, there are hand-carved instruments made by large manufacturers of which this cannot be said. They come churning out and are very geometrically consistent (same shape, approximately), but are not acoustically consistent, and they do not tend to dramatically improve over time (as in, serial #150 being better than #50), like those "hand-carved" parts made by a true craftsman.

The key to all this is the person behind the process. I use "machine carving" in my builds. But I use it in order to give me more time to spend doing the final graduations -- the CNC in my process is not unlike the pattern carving techniques used by Gibson in the 30's or the traditional drill-press-and-depth-stop technique many of us still use.

Additionally, unless you are making more than 100 of the same thing, setting up a CNC process is not quick or easy. It is a very, very manual and thought-intensive process. I chose it because as part of my process, it would allow me to do things like fancy inlay and get repeatable inputs (consistent rough carving), which otherwise would not be possible.

But if the goal is not to pay attention at every step of the way, CNC can become a "cookie cutter" technique, and it will be obvious when that is the case. You can't fool the players.

My hands are tired from scraping by hand all morning. Now I'm going to cut some inlay for a cocobolo fretboard with my CNC machine...

[Spruce]

1. Will a hand carved instrument usually be better sounding than a machine carved instrument?

The two are not mutually exclusive...

Lots of folks around here use machines to hog out the plates to within a few millimeters of where they are going to wind up, then dial them in "by hand"...

Maybe in some factories they just sand and finish the plates as they come off the machine, but mostly CNCs are utilized for efficiency and to preserve the health and safely of the builder...

So-ooo many builders suffer from some sort of repetitive stress injury, mainly from hogging out maple plates...

2. How much of an average time difference might we expect between the two builds?

I dunno...
5 hours??
If you drill your plates with guide holes--then go for it--you could rough out a plate in a couple hours...?
It's been 25 years since I've done it, so maybe I'm waaaay off base here...

[sunburst]

So-ooo many builders suffer from some sort of repetitive stress injury, mainly from hogging out maple plates...

...even though most of them have been using some kind of machine carving in the early stages as long as they've been building. Things like band saws, table saws, saf-T-planers, sanding discs, etc..
Actually, I think most of my repetitive stress injuries are from sanding (such a romantic profession, lutherie...) but "hogging out maple plates" sure hasn't helped things. I have mine carved, like Spruce says, to withing a few mm and take it from there by hand.

[mirwa]

A machine carved instrument is about expediency, a hand carved instrument is about working with the wood, listening to how your plane cuts through the wood and so forth, the sound your tools make whilst cutting can tell a luthier a lot. Merging the two togther is smart modern economy in play, knowing where to merge the two is art.

Heres an analogy for you,

Make spaghetti bolognase, get a recipe and mix it to that recipe and serve it up (no tasting allowed whilst cooking), it will be fine and taste okay, but if you were allowed to tweak the recipe as its cooking, bit of extra salt, bit of cajun, bit of whatever the taste buds dictate you could have a sensational spaghetti bolognase or alternatively the worst one evr made.

These rules apply with manufacturing instruments, standard well known recipes work, but introduce the human factor and it can go really bad or sensational dependant on the person, remember its the little things that make the difference between a good instrument and a great sounding instrument.

[Marty Jacobson]

...listening to how your plane cuts through the wood and so forth, the sound your tools make whilst cutting can tell a luthier a lot.

Good thoughts-- but for the record, a knowledgeable and attentive machine operator can tell just as much about the wood being machined as the machine is cutting as the luthier who uses hand planes. The sound of a machine cutting is very telling, and will be different with every piece of wood (or alloy of metal). Running a machine is very much like playing an instrument -- it is an active process. Or should be, if you want good results.

[JEStanek]

Makers who use more CNC for example Rigel and Collings. I wouldn't characterize their mandolins as slouches in the tone department. It ultimately depends on the skill of the builder. I would take a CNC made instrument from those mentioned vs one hand carved by me.

We didn't even discuss the carbon fiber Mix mandolin that is laid out! Those sound pretty good too.

Good is good!

Jamie

[mirwa]

a knowledgeable and attentive machine operator can tell just as much about the wood being machined as the machine is cutting as the luthier who uses hand planes. The sound of a machine cutting is very telling, and will be different with every piece of wood

I so agree, we have a 3.5meter by 2.5meter 8 tool auto changing cnc router, many local builders get us to rough out there plates so they can then finish them off.

[Spruce]

Makers who use more CNC for example Rigel and Collings. I wouldn't characterize their mandolins as slouches in the tone department.

Or, how about the supposed Holy Grail when it comes to tone??
The Loars sure maintain a certain suspicious consistency that points to a pattern carver, with not a lot of tweaking after-the-fact....

[Marty Jacobson]

Is it winter there already, Bruce? 'Cause that's some thin ice you're stepping in.... :-)

[Steve Hinde]

I would agree with John. Every piece of wood is different. You carve them all exactly the same, and every one will be different. I have 2 different F's in the white right now. One with a Sitka top (thanks Bruce) that is almost 4mm in the recurve, but the plate was really flexible. I have an Adirondack top that is under 2mm in the recuve that is still like a piece of steel. The Sitka F sounds loud, full and very 'woody'. The AD is tight and stiff. You have to feel it, flex it, tap it and taste it if necessary. This is why we have things like tap tuning, deflection tuning and just plain old intuition. All in an effort to get consistency or a desired tone.
Carve them close and work them down to what you are after. In the end, the carving is to save time and get close to a consistent starting point for graduating. If I have to carve the scroll in Maple by hand, it takes me an afternoon. I am carving my first plates with a CNC this weekend or next that replaces my duplicarver. The only change is carving the scroll. I never used the duplicarver for that. Just left it rough to carve out later. The carver was just not accurate enough to get a clean result. I finished out my original patterns and used the probe on the CNC to create a surface file I can duplicate. Next steps are to finish the 3D files so I can add the F holes and binding channels.

[Pete Jenner]

For some of us it's about the journey and not the destination. Using finger planes and gouges to carve plates can be very rewarding - unless of course you do it for a living, then I imagine it's just a PITA.

Also, not everyone has access to a CNC machine or a duplicate carver.

[sunburst]

You know how people always said, to you're younger self, something like: "don't lift that! you'll hurt your back!!!" and how your young self would go ahead and lift it anyway with no apparent harm? What they didn't tell you was that you'd be 45 years old before you realized lifting that did hurt your back.
Well, I won't go into my back problems because they don't apply here, but my finger problems do apply here. I've sanded acres of instrument wood and the accumulated over-use injuries have made my bulging, knobby knuckles susceptible to injury from some pretty simple things. I was the young guy who could get the most stubborn lid off of almost any jar, could squeeze a bathroom scale with over 200 pounds of pressure, that sort of thing. Now, opening packages can be very painful. Pulling open a sealed bag of chips or the bag inside a cereal box can be close to impossible, and one of the worst ironies, opening a bottle of ibuprofen really hurts! If there is a stubborn lid on a jar now, I just hand it to someone else.
Anyway, yes, I find carving with gouges and finger planes to be very rewarding, not a PITA, but a PITF! (pain in the fingers). I wish I had started getting them roughed out by CNC several years ago, because if I'm going to continue to do this (building mandolins) I need to do less damage to my hands in the process or plan on a shorter career, and with no real possibility of retirement that's a pretty good incentive to take it easy on my joints.
So, all you young luthiers out there, here are some words of advice, most likely to be ignored:
Don't lift that, you'll hurt your back!!!!
and: Let the machine do the hard work, save your hands for the fine work. You won't realize you've hurt yourself until later.

Oh, and one more thing. If you meet me somewhere and shake my hand, please take it easy! A firm hand shake is one thing, but if you see a look of pain come over my face it's not because I don't want to meet you, it's because you're hurting my hand. (Thanks )

[Pete Jenner]

As a fellow not so young any more person who has spent most of the last 35 years lifting heavy things for a living, I feel your pain John.

[Spruce]

Let the machine do the hard work, save your hands for the fine work. You won't realize you've hurt yourself until later.

The most important and insightful words uttered in the whole "CNC vs. Hand-Carved" debate...
It's all about safety and health, and not about saving a dime and time....

I can't even tell you how many conversations I've had with folks who are truly suffering from the effects of luthiery-related repetitive stress, and it's mostly from maple-hogging...

Try going to a cello-maker's convention sometime, and see where conversations lead...

[Dobe]

the 850 originally cost a bit more when new. This may make sense when you consider that the 850 uses..... a more fastidiously applied finish.

Wouldn't that be contradictory to the pricing conundrum?
Still, I feel were in the 2nd "Golden Era" for instrument building. Tons of great deals out there. I think it's a fine line between sound & longevity.After seeing more than a couple stellar builder mando's that needed to be re-topped in a relatively short life (say decades), what would you rather have ? A killer out of the box mando, that may need MAJOR services in twenty or thirty years, or a pretty darn good one that improves nicely in 5 or 10 years of loving spanking? I guess I'd go for something in between those two examples, maybe leaning a little more towards the out of the box cannon side. Modern man just isn't that patient. Optimally of course, I want the out of the box cannon that will last forever !

[Stephen Perry]

One thing I suppose I learned looking at woodworkers when I was a kid - big slick or big gouge, razor sharp, and use body weight for roughing out. I just don't have the gouges I saw people working with then. Two handed things. I do get tired on maple, and if I can get enough time to make it worthwhile, I'll get a copy carver or CNC system going. I don't have room now - or I could get rid of my lathe! Certainly sugar maple will tear me up.

As to retopping - I'm surprised. My tendency would have been to put in reinforcing wood and new stronger bars. As we would with a violin.

The general hand v. machine debate sort of mystifies me. Most people don't need a handmade car. Why a handmade instrument? But they sell - even quite rustic ones. So long as they perform!

[Texas]

ArtDecoMandos said it best:

"It is about the attention to detail and the care of the craftsman. The craftsman will choose whatever they think will be best for their work, but no generalizations can be made other than that..."

I have woodworked for just about my entire long life and have seen work go from almost completely hand to mechanized. Heck, I even still have an old accordion folding ruler on my work-bench.

The 'heart' of any item built comes from the attention to detail per the craftsman more than any other single piece of equipment.

For years I hand cut dovetails until I was in Sears years ago and they had this new fangled jig for cutting dovetails and I don't remember hand cutting a dovetail since, and NO one has ever known the difference.

If I started building instruments today I would have every piece of equipment/cnc I could find to bang out the repeatable work and when that was done I would add my touches to the finish.

Just my opinion...

[HoGo]

I know few builders who built their own CNC and programmed it... Where does this count?
I believe all this machine vs. hand made thing is result of thousands of cheap inferior (chinese or other country) factory/machine made instruments flooding market. Even Gibsons are largely made on machines.
So if I were to answer original Q1 I'd say if you take 100 random machine made instruments and same amount of handmade ones the handmade instruments will be without doubt averagely much better group.
to answer original question 2: I can carve pair of plates within 5-6 hours down to state where they can be glued to body and will require just final scraping/ sanding (including scrolls). On CNC router/mill the time is highly dependant on machine and program. Beefier machine can cut faster with larger tools. Faster machine can go to better detail in shorter time. Automatic tool change can make it quicker when doing details with different tools etc.
There is additional time with CNC machines that folks often don't count but they should- creating the model (takes less time per build if it's used many times), making and de-bugging the program and perhaps doing few test pieces, setting up the machine and securing the workpiece...
So I'd sum it up it saves your knuckles more than time. And best of all is, machines will save you from repairing your mistakes. :-)

[Marty Jacobson]

I know few builders who built their own CNC and programmed it... Where does this count?

I'm one of those. I'd be happy to share details if anyone is looking to build a 24" x 48" machine for under $3000. Rapids at 1000 inches a minute, cuts at 300. That's fast.

There is additional time with CNC machines that folks often don't count but they should- creating the model (takes less time per build if it's used many times), making and de-bugging the program and perhaps doing few test pieces, setting up the machine and securing the workpiece...

Amen. You are basically going to spend just as much time per part if you are a small builder. You just decide if you want to spend your time on the computer or on the bench. Gotta factor in the 500 hours of your life it takes to learn CAD well. And the other 500 it takes to get good running a machine.

Also, much more material is wasted with CNC in the early prototyping stages. I run tests on scrap, but basically, a CNC part is either perfect or completely useless. Not as much "I can make it work" as when you're hand carving. CNC is IFR, carving by hand is VFR (in pilot's terms)...

It isn't easier or harder. It's just a different approach.

EDIT: That's not to say I'd ever go back to doing it the old way. :-) Carving a plate with planes and scrapers might be meditative. But I get my meditative moments watching a well-refined program running on a tuned-up machine.

[mirwa]

I'm one of those. I'd be happy to share details if anyone is looking to build a 24" x 48" machine for under $3000. Rapids at 1000 inches a minute, cuts at 300. That's fast.

Good to see, I built my first cnc router 7 years ago, I dont think people who buy them off the shelf and through ebay appreciate them as much as those who actually make them.

[j. condino]

Or, how about the supposed Holy Grail when it comes to tone??
The Loars sure maintain a certain suspicious consistency that points to a pattern carver, with not a lot of tweaking after-the-fact....

Go Bruce!!!!

The real question is does the builder how to build a great mandolin????? I know a lot of folks who write great code, but clearly don't have a clue about how a great mandolin works or how to go about building one. Many of the best known builders in the world utilize cnc technology in their building process, they just don't go around bragging about it. If Stradivari were alive today, do you think he would build 1100 instruments the same way he did in the 1700s?

Even though I feel like a complete sissy as a mandolin builder talking about cnc machines, as a double bass builder I lust after one almost every day!

J.
Www.condino.com

[sunburst]

One of the things I've acquired with advancing age (and aching joints) is; if it makes me a sissy to "farm out" the wood wasting portion of mandolin plate carving to a CNC machine, I don't care! It's sort of like wearing shorts with no sun tan or wearing sandals with socks. Past a certain age, we just don't worry about what other people think (especially the young ones, what do they know?...).

[Michael Lewis]

All this over a couple Kentuckys. This shows the range and depth of the folks that come here.

The CNC stuff is interesting, and I almost that way several years ago but didn't. Now my fingers and knuckles are protesting, hopefully I can get a couple more good years from them before I retire. Now I fully understand Hans Brentrup's retirement, as arthritis got to him too soon.

Now we've gone and got all philosophical about this, new folks will come up and the elders eventually fade out, and the process goes on.

[mirwa]

What is interesting, is whats next.

I know when I started out it was chisels / sandpaper / profile gauges. Even today I feel it still in my wrists when I start sanding

Then came the duplicarver, wow what an invention and time saver that was

Then came the cnc, it speaks for itself

Whats next,