CNC Recommendations

[j. Kinnaird]

I’m pretty sure this is not the right place to pose this question but I wanted input from luthiers and non luthiers alike and well, that’s who reads this forum.

I want to get a small cnc machine with a budget around 5 or 6 k. Anybody out there have any recommendations. My plan is to use it for decorative touches, rosettes, etc, and perhaps have it hog out neck blanks and blind slotted fingerboard. Nothing too heavy. Perhaps carve out the top and back for a mandolin or fiddle.

[Tim McKnight]

Hi John,
We have a Shop Bot machine called the “Buddy”. It has a 24” x 32” cutting area with an 8” Z axis. I did a lot of research and the reason we settled on this brand is because of the support network. Shop Bot has a huge presence in our local Vo-Ag, Tech-Prep and vocational schools so getting help “locally” is very easy. They also put on “Shop Bot Camps” where you can meet other owners, network which has been very helpful for me because I did not have a prior background in CNC. They also have a tremendously helpful on line forum where you can post questions and usually get answers in minutes or a few hours at the longest.

My original machine came with a 3HP Porter Cable router which worked well for many years but the down side is noise, LOTS of LOUD noise while cutting parts. Routers are the most inexpensive way to go. About 5 years ago I upgraded to a 3HP water cooled spindle which is nearly silent when its running but you do get some cutter noise but it doesn’t always require hearing protection whereas the router does require constant hearing protection.

When roughing necks you will need a minimum of 6” Z axis travel to cut the heel so keep that in mind.

Some machines come with a PC while others require you to provide one.

LMI, Stew Mac and at least 4 other luthiers I know personally own Shop Bots so they have a presence in our craft.

The most difficult part of using a CNC is trying to figure out how to fixture the part to prevent it from moving while cutting it. I made a vacuum surface table for my cutting bed which has been very beneficial Holding parts. You need to hold the part from sliding because the cutting bit exerts a sideways force on the part. Vacuum works very well to prevent flat parts from sliding. I also use double stick carpet tape to hold small parts like bridges and finger boards adhere to larger flat boards which the vacuum holds.

Make sure that software comes with your CNC and that the OEM will support that software when updates are released. Shop Bot does both.

I seriously considered building my own CNC When I was researching them. There are plans out there to build CNCs using 80/20 “erector set” materials. However you have to consider your time invested in research, assembly, debugging and adapting third party software, steppers, drivers, ball screws, etc... it may not be worth it to you, which it wasn’t for me.

Sorry for the long winded post but hopefully you will find something useful here amongst the rambling.

[gr81dorn]

Adam at Circle Strings sings ShopBot's praises here:
He makes parts for his lines, Creston guitars and other guitar makers with that machine.

I work in a big manufacturing facility with a lot of equipment and work with lots of folks in lots of industries who have lots of other stuff..I am not sure pricing on a lot, but we use ShopSabre CNCs which are exceptionally accurate and high quality and very affordable compared to other things comparable - most of which come from Italy, Germany and Asia. We chose ShopSabre because they are made close by and they had a lot of of the higher end features tons cheaper and we haven't seen any downside to the quality. We have their top of the top of the line, but I've seen ShopSabre CNC's in some small guitar shops.

Preston Thompson has a small ShopSabre: at about the 5 min mark you see it.

Fadal, Haas and similar "vertical machining center" types are geared a little more toward making metal and plastic stuff. Jim Olson uses his Fadal to make jigs and tooling primarily, but I think he makes some parts and pieces in there. Taylor uses Haas if I recall when I've been in there, and I think martin uses Fryers...can't remember...haven;t been in there in awhile. Those VMC style CNCs aren't big flat-bed woodworking machines like the others, but can handle with as much accuracy but since it can make other stuff, has some cool flexibility, just a little different in size, shape and capacity of what can go in there.

I am sure the Taylor and Martin equipment is extremely expensive, but a lot of those CNC makers do have small, more affordable (simpler) machines that might meet your budget and needs. Many don't advertise prices, so it's hard to know what the price points are, so sorry if I'm waving Porche's in your face ;-)

I would definitely look at Shopbot and ShopSabre, but don't necessarily discount the possibility that a VMC might be more flexibile if you want to make other things, too. I have no idea who makes more affordable versions of any of these things but there are more out there now than ever.

My only takeaway from personal experience and lots of anecdotes from customers/partners - if you can swing it, pay for the ball screw mechanism vs rack and pinion systems. Reliability, accuracy and long-term value all favor ball screw driven machines.

[j. Kinnaird]

Tim and gr81 Dorn I really appreciate you both taking so much time with your explanations. Very helpful indeed.
Thank you

[iim7V7IM7]

John, why not give luthier John Buscarino a call? He is nearby to you in Franklin, NC. He made the same transition that you are asking about some time ago. I think you would find it enlightening.

[j. Kinnaird]

Originally Posted by iim7V7IM7

John, why not give luthier John Buscarino a call? He is nearby to you in Franklin, NC. He made the same transition that you are asking about some time ago. I think you would find it enlightening.

Thanks for the suggestion. I will certainly do as you suggest.

[cleanheadsteve]

i bought a used bobsCNC for $600. it's 24" x 24" and does amazingly well for a cheapie. but ... if i had a budget of 5k-6k i would definitely buy something else. my buddy bought a shapeoko that handles 18"x36" and he is extremely happy with it. it was about half the cost of your budget. however, my favorite part of my system is the Aspire software. its over $2,000 but will open native adobe illustrator files with no issues. so i was able to get started with almost no learning curve

[Bruce Sexauer]

Don't do it. IMO, of course.

[charles Tauber]

As you are probably aware, in using a CNC router, there are three separate "stages" to going from idea to finished object. These are digitally modelling/drawing the object to be made, creating tool paths and, finally, fixturing/tooling and actual machining. Each one of these stages can have a steep learning curve. If you are new to the CNC world, don't under-estimate the amount of time and effort required to enter into it. Also, allow in your budget not just the cost of the basic machine but also any relevant costs for software, fixtures and tooling.

There are now so many different makes and models of CNC gantry-style routers that it is difficult to chose one. John's suggestions are very good regarding the Z-axis capacity, much quieter water-cooled spindle (router) and having good support and an active community to draw upon can be very important.

The starting point is to talk to people who are doing what you want to do and understand how they got there, and what choices they made - and why - along the way. Sounds like you are already doing that.

There is a new entry into the CNC field that holds some interest and promise. It is the Shaper Origin: https://www.shapertools.com/en-us/. Essentially, it is a hand-guided router that continuously corrects your guiding to accurately cut the desired geometry. It will not carve guitar necks or 3D contours and might well not be what you are looking for. On the other hand, it is potentially much more accessible for those not wanting to get too far into the "weeds" of CNC design and manufacture and will probably handle well things like rosettes, fret slots, etc.

[j. Kinnaird]

Originally Posted by Bruce Sexauer

Don't do it. IMO, of course.

Bruce you are such a purest. Part of the mystique.

[j. Kinnaird]

Originally Posted by charles Tauber

As you are probably aware, in using a CNC router, there are three separate "stages" to going from idea to finished object. These are digitally modelling/drawing the object to be made, creating tool paths and, finally, fixturing/tooling and actual machining. Each one of these stages can have a steep learning curve. If you are new to the CNC world, don't under-estimate the amount of time and effort required to enter into it. Also, allow in your budget not just the cost of the basic machine but also any relevant costs for software, fixtures and tooling.

There are now so many different makes and models of CNC gantry-style routers that it is difficult to chose one. John's suggestions are very good regarding the Z-axis capacity, much quieter water-cooled spindle (router) and having good support and an active community to draw upon can be very important.

The starting point is to talk to people who are doing what you want to do and understand how they got there, and what choices they made - and why - along the way. Sounds like you are already doing that.

There is a new entry into the CNC field that holds some interest and promise. It is the Shaper Origin: https://www.shapertools.com/en-us/. Essentially, it is a hand-guided router that continuously corrects your guiding to accurately cut the desired geometry. It will not carve guitar necks or 3D contours and might well not be what you are looking for. On the other hand, it is potentially much more accessible for those not wanting to get too far into the "weeds" of CNC design and manufacture and will probably handle well things like rosettes, fret slots, etc.

Good advice. Probably the more expensive software is the easiest to use.

[j. Kinnaird]

Originally Posted by cleanheadsteve

i bought a used bobsCNC for $600. it's 24" x 24" and does amazingly well for a cheapie. but ... if i had a budget of 5k-6k i would definitely buy something else. my buddy bought a shapeoko that handles 18"x36" and he is extremely happy with it. it was about half the cost of your budget. however, my favorite part of my system is the Aspire software. its over $2,000 but will open native adobe illustrator files with no issues. so i was able to get started with almost no learning curve

I want a water cooled spindle, good accuracy ease of operation and durability. Who should I see?

[charles Tauber]

Originally Posted by cleanheadsteve

...however, my favorite part of my system is the Aspire software. its over $2,000 but will open native adobe illustrator files with no issues. so i was able to get started with almost no learning curve

One needs to be very clear about what one is going to use one's CNC router to do. Illustrator is not capable of producing 3D models of the geometry one wants to create: it is a 2D graphics tool, rather than a 3D mechanical design tool. The 2D Illustrator files can be imported to "seed" the 3D models, but you'll still need to construct 3D models if you want to cut 3D geometry.

If one is wanting to "carve" guitar necks and arch top instrument plates using a CNC router, one requires a 3D model to do so.

Originally Posted by j. Kinnaird

Good advice. Probably the more expensive software is the easiest to use.

I wish that were true. In the 3D world, mostly, more expensive gets one the functionality to perform more complex geometry. Some of the better/more expensive computer aided design (CAD) softwares do provide functionality that makes it faster and take less effort to create some elements.

As a mechanical engineer, I spent 25 years teaching engineers, designers and draftsmen to use CAD software. Don't underestimate the steepness of the learning curve: the more complex the geometry you want to create, the greater the functionality the software must provide, often at greater cost. There are, however, some software packages that are free to use for non-commercial use. For "makers", One of the most popular of those is Fusion 360, an Autodesk product. One of the things that makes Fusion so popular with many who make things is that the software also includes the ability to generate tool paths (G code). Many furniture makers use Sketchup, originally designed for architectural use, but it is not a mechanical CAD tool and isn't well suited to using its 3D models for generating tool paths. (The free version of Sketchup doesn't really provide functionality for creating 2D drawing, useful for cutting 2D profiles, such as cutting out a guitar top or back.)

Originally Posted by j. Kinnaird

I want a water cooled spindle, good accuracy ease of operation and durability.

AT least for the novice, there really isn't a lot that is easy about the process.

Many cities have "maker spaces", which are open-to-the-public workshops that people join - with monthly or annual fees - to access tools and workshop space. What equipment maker spaces have varies from one to the next. A well-equipped maker space will have traditional woodworking tools - table saw, band saw, drill press... - as well as laser engraver/cutter, CNC router, 3D printers, etc.

A friend of mine was heavily involved in Canada's largest maker space. What he found was that, for many novices, having to learn how to create a 3D model of the object they wanted to cut/make was a huge impediment, one that many couldn't get beyond. The most often used tools in that well-equipped shop were the laser engravers/cutters: they require only a 2D outline - or photo/image - of what is to be cut, an outline that can be created in inexpensive/free 2D CAD or graphics programs, such as Inkscape, Illustrator, Corel Draw and others. (Lasers are, essentially, 2D: no neck carving, or archtop carving.)

It might be worthwhile to take a step back and look at the nature of computer numerical control (CNC) machines, in general. Each has, at its core, a motor for each axis that drives a "head" along, commonly, three axis - X, Y and Z. Such a machine is referred to as a "three axis" machine. (For more complex geometry creation, there are four, five and six axes, that introduce rotation about each axis.)

There is a controller that tells the motors what to do, interpreting instructions, "G code", that provide the machine with where and how fast to move the head, in what sequence with what tool. (The instructions (G code) are created by a designer or machinist based on the geometry to be created - a 2D drawing/graphic or 3D model: software is need for that. One of the things that one does when preparing G code is to select and specify the cutters/tooling that are going to be used, in addition to their speeds and feed rates.)

This is essentially the same arrangement regardless of what is attached to the moving head, be it a router, a laser or a nozzle for 3D printing. (The laser and 3D printer don't require G code: one can usually "print" the geometry directly from one's computer to the machine.) The reason that I bring this up is that there are an increasing number of machines available that will do all three: router, laser, 3D printing. Each of these technologies can bring some very interesting options to the table. Yesterday, for example, I cutout on a laser engraver the replacement bridge plate for a guitar repair that I am currently doing. I also cut out the gluing caul on the laser. Had I chosen to, I could also have cut the holes in the bridge plate at the same time.

It can be a rather daunting task to familiarize oneself with the three technologies - all CNC - their capabilities, and what options they bring to one's work. Youtube videos can be helpful for that.

[BEJ]

I don't know if you already have one, if not a carving duplicator can do a lot of the things you want to do for a lot less money and no need for software. One can buy one or make their own, with your skills making one should be a walk in the park and could be custom made for specific guitar building in mind.

Bruce,

[Guitars44me]

My brain hurts just from reading all this!

I can not imagine the tech skills needed to get going with a lot of this.

But John probably has them, after teaching science to gifted students so long.

Whether or not to spend all the time, effort and moolah is the question, I suppose.

For me the cachet of hand made takes second (or fifth) seat to the tone, volume, comfort, playability and beauty of John's guitars.

Have FUN whatever you choose!

Off to play the OVERLORD....

PAUL