CNC vs hand... The gap in closing?

[Mark Hatcher]

Well this all seems to be devolving into the differences and mind sets between the manufacture of factory guitars and guitars made by small shop luthiers.

I like factory guitars. I think all the affordable guitars and the large marketing budgets they have serve as a gateway for my future guitar sales.

I’m a one man shop and I frankly don’t pay much attention to quick and cheap processes especially if they come at a cost in quality. I don’t hate powered tools I just don’t use them if I can improve the quality by doing it by hand. So I do it by hand when it is the better choice.

I like to gain my speed and efficiency by improving my skill as a luthier.

I also try to eliminate the use of jigs in my shop. Once you make a jig to route or shape, say a bridge, that design dies. It no longer evolves. It’s too easy to just use these clone bridges and not adjust them for weight or strength or be doing adjustments for response verses sustain.
I use a profile template and trace that onto the block of wood. From there It’s freehand. Yes, I use a spindle sander to rough it out. I use a beautiful refurbished 1956 eggbeater hand drill to start the peg holes. The hand drill doesn’t burn the holes into the wood like a power drill does.
I do this because I will be putting the typically wedge shaped bridge pins in there and a burned hole is more likely to split.
There have been obvious improvements over the years in the design that still starts with the same template. Improvements that just evolved over time without me even consciously trying. I really like that.

It’s a different world building being the only one in the shop building individual guitars. I wish I knew where to get fairy dust that I’ve been told everyone wants. For a one man shop I don’t think the answer is automation or some kind of woo woo. It’s work and experience.

[Driftless]

Originally Posted by Rickenbacker1

CNCs have been making parts correctly for years . A hand built part can vary quite a bit . But once the program is set correctly on a CNC machine every time the part will be the same . Another thing is tooling ,most Chinese factories have first class tooling . Where these manufacturers seem to screw up but caught by quality control is not following the machine routing as what happens with a hand
machined part. I don’t care how it’s built as long as it’s right ,but automated machines have made items of quality and affordable.

This isn't really correct. Even with modern manufactured materials (much less wood!) the part will not be the same every time. There are many variables that a human has to account for. A human absolutely can use manual machines to make things just as precisely as a CNC machine, it just takes longer.

When I'm manually machining I am watching the same variables as when I'm using CNC machines (I mostly use CNC). And there is always a way to make something to any spec with only the simple machines of physics that hand tools represent.

I think the idea that CNC works like a magic copy machine is at the root of the notion that CNC can make perfect guitars cheaply, and also the notion that it removes some undefineable spirit in the wood left by old timey hands. I think both notions are not just wrong, but also miss what's actually special about guitars, and the real abilities of people who make good ones, no matter what tools they use.

[Bluenose]

I think CNC machines are used for cutting out parts aren't they? IMO part of the guitar building process that requires the least amount of skill. If you ever have the good fortune to own a guitar that was made by a true master you'll know that something so artful and unique could never be produced by a machine or even in an assembly line factory.

[Mycroft]

Originally Posted by Mark Hatcher

Well this all seems to be devolving into the differences and mind sets between the manufacture of factory guitars and guitars made by small shop luthiers.

I like factory guitars. I think all the affordable guitars and the large marketing budgets they have serve as a gateway for my future guitar sales.

I’m a one man shop and I frankly don’t pay much attention to quick and cheap processes especially if they come at a cost in quality. I don’t hate powered tools I just don’t use them if I can improve the quality by doing it by hand. So I do it by hand when it is the better choice.

I like to gain my speed and efficiency by improving my skill as a luthier.

I also try to eliminate the use of jigs in my shop. Once you make a jig to route or shape, say a bridge, that design dies. It no longer evolves. It’s too easy to just use these clone bridges and not adjust them for weight or strength or be doing adjustments for response verses sustain.
I use a profile template and trace that onto the block of wood. From there It’s freehand. Yes, I use a spindle sander to rough it out. I use a beautiful refurbished 1956 eggbeater hand drill to start the peg holes. The hand drill doesn’t burn the holes into the wood like a power drill does.
I do this because I will be putting the typically wedge shaped bridge pins in there and a burned hole is more likely to split.
There have been obvious improvements over the years in the design that still starts with the same template. Improvements that just evolved over time without me even consciously trying. I really like that.

It’s a different world building being the only one in the shop building individual guitars. I wish I knew where to get fairy dust that I’ve been told everyone wants. For a one man shop I don’t think the answer is automation or some kind of woo woo. It’s work and experience.

How about for the body? I know builders who do it both ways.

Don't you need an owl to have woo woo?

[pvfederico]

I've never understood the big deal about "hand made guitars." For years we've had automated equipment that is much more precise than any human hand tool.

In the near future, the best guitars will be made by robots, because they will have perceptions way beyond those of any human -- including those needed in the selection of wood and assembly.

There is a strong possibility that we will see higher quality for much less money.

[Guitars44me]

Originally Posted by pvfederico

I've never understood the big deal about "hand made guitars." For years we've had automated equipment that is much more precise than any human hand tool.

In the near future, the best guitars will be made by robots, because they will have perceptions way beyond those of any human -- including those needed in the selection of wood and assembly.

There is a strong possibility that we will see higher quality for much less money.

I am wondering if you have actually played any high end human built guitars, perhaps by any of the luthiers who are AGF sponsors?

If perfect visuals are what you seek, perhaps you are correct… but if TONE is your goal, so far some human built instruments win EASY for my ears, at least

Remember, the coveted pre war Martin and Gibson guitars were made by humans, too!

I am finding this thread discouraging…. But I find modern life often the same.

Off to play some music. Too much screen time yields unhappiness

Cheers

Paul

[redir]

I'm building my 72nd guitar right now and never used a CNC machine. I'll probably build another 70+ guitars God willing I make it that long and have no plans on using a CNC. I have zero issue with anyone who uses a CNC but am kind of surprised by the comments that suggest most small builders do or would at least like too. Most of the ones I know don't. CNC is really for the production shop not the builder that makes 5-10 guitars a year, or more probably.

Having said that I, as a fan of science fiction, have no doubt that our machine overloads will take over one day and it's looking to be sooner rather than later.

[Bluenose]

I agree with Guitars44me.

If you play the guitar you are a guitarist and if you build guitars you are a luthier. Do all guitarists have the same level of skill and are able to produce music of the same quality?

The same can be said for luthiers. I personally believe that a master luthier can handcraft a guitar using some modern power tools that will have something a little special in it that AI/machine cannot and will not be able to duplicate.

That's just my opinion but I do own a handcrafted guitar that is just amazeballs that wasn't really that expensive and the luthier is/was an anonymous Chinese person. I think time will prove me right and I hope I'm still around for it.

[gr81dorn]

Originally Posted by redir

I'm building my 72nd guitar right now and never used a CNC machine. I'll probably build another 70+ guitars God willing I make it that long and have no plans on using a CNC. I have zero issue with anyone who uses a CNC but am kind of surprised by the comments that suggest most small builders do or would at least like too. Most of the ones I know don't. CNC is really for the production shop not the builder that makes 5-10 guitars a year, or more probably.

Having said that I, as a fan of science fiction, have no doubt that our machine overloads will take over one day and it's looking to be sooner rather than later.

A former employee of mine recently retired. He'd been around our plant for decades and engineered some of the most impressive material handling systems you've ever seen. He left about 20 years ago to be a full time custom woodworker and built an incredible shop on his property. No one was more meticulous and skilled than him. Insane joinery skills and an attention to detail that few possess. He got a CNC machine a few years into being on his own to open the door to more opportunities and eventually came to rely on it more than he ever could have imagined. His rationale was simple "I trust that the computer's math is better than mine will ever be". He's right. He'd later rely more on its speed and consistency. Ultimately, the CNC machine allowed him to work probably 10 years longer than his body could have and output a lot more stuff over that time, to boot. It, ultimately, all depends on your goals and aspirations. As I've said before, a CNC machine is just another power tool...a more capable and expensive one, but it's just a tool. You still have to be a craftsman and have skills to make it work for you.

I believe if you had a CNC to do some of the busy work and some of the precision work for you, you might really appreciate that if you wanted to make more instruments. If you enjoy the process, the time and the output of using other methods and machinery, then it wouldn't really make much sense to invest in equipment like that. Definitely not for everybody.

My primary argument for CNC use is the consistency part. I've had a number of instruments made for me over the years. One particular builder has made me 5. He is old school and no CNC. "I want the neck profile on this one to be exactly like the 12 strong from last year"...it was sorta close, but noticeably thicker shoulders and less pronounced V shape. He tried and used the same gauges and template, but it was pretty different cuz hand-scraping and sanding will do that. There's beauty in that, by the way.

Conversely, I have bought necks from Warmoth for 20 years....all pretty much exactly the same, one to the next.

[rllink]

I do believe that for some people that minimalist hand tooled approach is appealing. For several years my brother used to make hand hewn furniture and peddled them at Renaissance fairs and Buckskinning events. I will agree that there is intrinsic value for both builder and buyer in some cases but I don't buy into the notion that it results in a better and more beautiful guitar unless all that heart and soul image plays into the buyer's experience.

As far as CNC, my brother, who has long been a woodworker, left the making of hand hewn furniture behind long ago and now has his own CNC machine in his shop. He's gone from primitive to cutting edge in his retirement and his new high tec image is as self gratifying to him as the pioneer craftsman image those many years ago did. At least my experience in going on shop tours with him, CNC machines are quite common these days with hobbyists.

[redir]

Originally Posted by gr81dorn

A former employee of mine recently retired. He'd been around our plant for decades and engineered some of the most impressive material handling systems you've ever seen. He left about 20 years ago to be a full time custom woodworker and built an incredible shop on his property. No one was more meticulous and skilled than him. Insane joinery skills and an attention to detail that few possess. He got a CNC machine a few years into being on his own to open the door to more opportunities and eventually came to rely on it more than he ever could have imagined. His rationale was simple "I trust that the computer's math is better than mine will ever be". He's right. He'd later rely more on its speed and consistency. Ultimately, the CNC machine allowed him to work probably 10 years longer than his body could have and output a lot more stuff over that time, to boot. It, ultimately, all depends on your goals and aspirations. As I've said before, a CNC machine is just another power tool...a more capable and expensive one, but it's just a tool. You still have to be a craftsman and have skills to make it work for you.

I believe if you had a CNC to do some of the busy work and some of the precision work for you, you might really appreciate that if you wanted to make more instruments. If you enjoy the process, the time and the output of using other methods and machinery, then it wouldn't really make much sense to invest in equipment like that. Definitely not for everybody.

My primary argument for CNC use is the consistency part. I've had a number of instruments made for me over the years. One particular builder has made me 5. He is old school and no CNC. "I want the neck profile on this one to be exactly like the 12 strong from last year"...it was sorta close, but noticeably thicker shoulders and less pronounced V shape. He tried and used the same gauges and template, but it was pretty different cuz hand-scraping and sanding will do that. There's beauty in that, by the way.

Conversely, I have bought necks from Warmoth for 20 years....all pretty much exactly the same, one to the next.

The only thing I am starting to find annoying now is cutting fret slots. Another think I have on my radar is an archtop guitar. I could totally see a use in CNC just to hog away the majority of the work before finely tuning it.

[Alan Carruth]

rickenbacker1 wrote:
"CNCs have been making parts correctly for years . A hand built part can vary quite a bit . But once the program is set correctly on a CNC machine every time the part will be the same ."

But the wood the parts are made of won't be exactly the same. In fact, even two pieces of wood cut back to back from the same piece can differ enough from each other to matter in the final sound. I know this because I've done the experiment. OTOH, even though it is probably not possible to make 'identical' guitars, even using 'the same' material, you can get 'arbitrarily close' using similar material, if you know what you're doing. The trick is to copy acoustic measurements, using your knowledge of how the guitar works, understanding the characteristics of this set of wood, and having the skill to compensate as you build. It's possible that a program could be devised to do this, interactively running a CNC machine. I don't think we're all that close to that point yet, although, of course, I could be wrong.

[RichardN]

If you're intent is to make each guitar unique then a CNC is not a good idea. The time it takes to program and test the program would wash out any time savings.

If you're doing a run of just a few guitars, maybe five or more, the CNC can't be beat.

If you're a highly skilled luthier and you believe your time is valuable you'll find the CNC can save you countless hours allowing you to focus your attention on more important parts of the process.

I own a custom design-build business that has several CAD machines and it is remarkable what we can achieve with them.

[Alan Carruth]

RichardN wrote:
"If you're intent is to make each guitar unique then a CNC is not a good idea."

Which was my point. Since every top (in particular) is a bit different you're going to have to vary things to get the best out of each one. Usually it's enough to alter the brace profiles a bit, but in some cases you'll need to go further than that. I don't think I've ever made two that were exactly the same, so for me using a CNC for things like braces makes little sense.

[RLetson]

Mr. Carruth: Almost on-topic. After years of reading your posts here and elsewhere, I finally got a chance to hear one of your guitars in the hands of Rachael Kilgour. Lovely looking-and-sounding instrument, lovingly played by Rachael (who loves the guitar). She told me that it was one of a pair that you built to test whether it is possible to produce two identical-as-possible instruments and have them sound and play identically--and that your (and her) conclusion was that every guitar is going to be itself, no matter the care exercised in controlling the variables.

FWIW, that's also the conclusion I came to after talking to quite a few builders and restoration specialists during the dozen years I wrote for Acoustic Guitar magazine.