Official Luthiers Forum!

Hi all,

I'm currently planing an eventual new bigger shop, and amongst the different new tools I would like, a CNC machine might be on the list. Now since I absolutely never been even close to a CNC machine, I thought I would ask a few questions here, if you don't mind.

So, given I would like to be able to use my CNC manily for inlays, and potentially neck carving:

- How much should I plan on spending for the machine itself? (I'm not going to build it, by the way, no time...)
- What software do I need and how much should I plan on spending for it as well?
- What is the average learning curve I should expect from myself before actually being able to use my CNC productively?

I hope these are not too generic questions.

Thanks in advance for your help!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

The first question really isn't my domain, though if you do ever hit the point where you're comfy with building a machine I might be able to offer some advice on re-building them. The major part of my new machine is showing up here on Tuesday, but it's a used industrial router (7K lbs, fixed bridge) that I'm rebuilding. Cost me less than a K2, though

On question 2, I'd say the best deal you can get is some combination of Rhino, MoI3D, Visual Mill, and Madcam.

Rhino is around 1K, and works with both Visual Mill ~1K(aka RhinoCAM) and MadCAM ($750)
MoI3D is $300 and only works with Visual Mill

I think that Rhino is the way to go if you're going to get really serious about CAD, but that MoI3D is still the second best CAD option under 1K and probably the best dollar for dollar value. MoI is a lot more than 1/3 as good as Rhino, it's most of the way there.

On learning curve, I'd need to know a bit more about your background. Learning CAD is a lot easier if you have a scientific, technical, or engineering background. Mathy people can learn both CAD and CAM 'by the numbers' pretty quickly, and having any background with software in the same genre makes things much faster. The level of technical expertise you're going to need matters, too, as you can learn everything you need to know about both CAD and CAM to do inlay work in a weekend but how to model and cut a guitar neck is orders of magnitude more difficult.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I'll pretty much echo what Bob said.

The cost of machines can vary all over the map depending on how complete a system you're getting in to. I built a machine from a kit for roughly half price of an equivalent K2 but it took several months to get from writing a check to cutting parts. It's not as refined as the K2 but it has some advantages as well. For a reasonably sized machine for guitar work (20x30 work area, 24+ x 36+ would be better) plan on anywhere from $4k-ish for mostly home made to $10k+ for a good turn key package.

As to software, this is the trickiest part and the part you should start on. To cut your parts, you must be able to draw them in whatever CAD package you decide to go with. I would highly recommend to set aside a week or so to download trial versions of the software you're considering and sit down and actually do the tutorials and try to design some of your own parts. If you struggle with this, you'll need to somehow figure out how you're going to become proficient.

Actually running the machine itself isn't all that hard but like everything else, there's a learning curve. Work holding is one of the most difficult challenges for CNC work and usually one has to spend some cash on that as well.

Good luck!

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Thanks guys!

Regarding my own technical background, I'm pretty confident. Although I don't have an engineering degree, my previous job for 9 years was software engineering. And more precisely, in a Electrical CAD domain, where we had to couple our software with major 3D software such as CATIA and Solidworks. I haven't actually had to digg my hands in these 3D apps, but I had to understand the major concepts.

So around 10K for a standard machine... Ok. That is pretty hefty. And does that include the software to control it? I hope so... I may have to plan for a home made one, given the difference in price...

Regarding software, if I understand correctly, I need to master some 3D CAD software, which will export/import stuff in the CNC software that controls the machine. Is that correct? I assume once the design in imported in the CNC sofware, I have to work some more to define stuff, like tool paths for example.  Am I correct on this as well?

I would have more questions, but I'll stick to those for now... lets take things one by one!

Thanks again!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

There's three basic steps:

CAD - design your parts (e.g. Autocad, Rhino, Catia, Solidworks etc.)

CAM - Generate tool Paths and output G-code (e.g. MasterCAM, VisualMill, Madcam etc.) Some CAM software is a plug-in to the CAD software (e.g. RhinoCAM) and with some you export a file from your CAD software and import into CAM.

Controller - interpret G-code and actually run the machine. Mach 3 is probably the most popular for small time operations and runs on a PC. Industrial machines typically have a dedicated controller .

It's really hard to comment on pricing because there's such a range of products and capabilities. Mach 3 only costs $150 but you do need a PC to run it. From there you have things like k-flop, Flashcut etc. etc and costs increase.

Romaxx has some almost turn key packages for under $5k http://romaxxcncrouters.com/cnc-router- ... t=10142350 but it's also not a high performance machine. It will still do a lot of work though. On the other hand, that same $5k will build you a much higher performance machine but you have to deal with building it.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

I always recommend downloading Rhino and playing with it for awhile to make sure you can get the hang of it. You can download it for free, with a limited number of saves. This gives you a great tool to learn with, for free.

If you find that you are able to draw what you need to (in 2D and 3D), then you're in good shape to get a CNC and to start learning that part as well.

However, you can save thousands of dollars by first verifying that a) you can do the CAD work to design the parts you want to cut and b) you enjoy it and want to do it! It takes a good bit of time to become proficient with the CAD part alone.

You could also draw your parts, and then sub out the production to some other poor slob who has used all of his brownie points with his significant other to purchase a CNC machine. You could then use your brownie points for other important things like fly rods, guns, boats, etc., etc...

Trev

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http://www.PeakeGuitars.com

You can still spend a ton of money on a home-made version as well...

Other CAD/CAM options are BobCAD/CAM and Dolphin CAD/CAM. They are somewhat less costly, but give a lot of bang for the buck. I have BobCAD and like it a lot. It once had a lot of issues but those have mostly gone away. Their newest version looks great, but requires a more powerful computer than I currently have to run. The nice thing is that the CAM package is built in to the software, so you have both options in one software.

Of course then you also have to decide between steppers and servos... which is another conversation.

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Thanks a lot guys! That is really great information.

I will try to download Rhino and give it a try.

Thanks for the link to romax Andy. What do you mean by "not a high performance machine"? How long would it take to carve a neck, for example?

Since many of you seem to have built their own machine, I"m starting to consider it. Is it that much of a challenge? How long should it take? And do I need tools I may not already have (milling machine?)

Thanks again!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Before buying. Rhino V5.0 will be out soon with x64 bit OS support. If you can wait? Don't know when it will release. Earlier they had said 2012.

Just a thought.

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Rick Hubka
Chemainus BC Canada

Alain,

The Romaxx is a fine machine but it's designed to keep the price down. e.g., he uses house made linear bearing components which while they work, they don't compare to an industrial profile bearing. It's an all aluminum machine but I think the uprights are 1/2" or maybe even 3/8" aluminum so there are compromises to keep the costs down.

On the other hand, it's ready to go. Add a computer, load the software and you're off and cutting.

If you look at the speeds, he says you can cut at up to 160ipm with 220ipm rapids. My typical cutting speeds pretty much start at 150ipm with rapids at 400ipm on my slow axis. When I'm cutting a fretboard, I'm actually cutting at 400ipm.

How that translates into how long it takes to cut a part is difficult to say but e.g. cutting fretboards the way I do, it would probably take close to double the amount it takes me.

If you decide to build your own, I would highly recommend going with a proven kit or at least a proven design. I hang out on CNCzone.com a lot and there's a lot of beginners that get sucked into re-design and re-re-re-design etc. because they just don't know what they don't know. I went with a kit which helped a lot of that but there were still issues I had to deal with (e.g. way long delivery time with associated heartburn). I'm a fan of the kit format, at least for your first as it can shave years off the process!!

One other recommendation is to buy a small used industrial machine. They often can be had for the price point of the Romaxx but usually require some re-working of some of the stuff. That's a very economical way to get going and if I decide to upgrade in the future, that may be the way I go.

One of the issues for us is that a tremendous amount of the "proven designs" are rack and pinion and although I don't really have any experience with those, they just don't seem like they'd cut the mustard for the types of things we're doing. I'd go for a ballscrew/profile rail machine and there's not a lot of plans for that.

Get an account on CNCzone.com and start checking out the build threads in the woodworking forums. You can see some of my threads on there too (I'm bandurier on there). That will give you a good idea on what's involved.

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Thanks again for this detailed information, Andy.

I will definitely go and take a look at CNCzone.com.

And I assure you I don't plan on re-re-redesigning! Just want to get the most efficient machine for the money I can put on it, as fast as possible.

For now I have plenty to chew on, but I assume I'll be back shortly with a few more questions. Stay tuned!

Thanks a lot!

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)