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  #1  
Old 10-14-2017, 07:49 PM
ADK ADK is offline
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Question Possible CNC electric guitar build

My FIL bought a CNC machine recently and has been making some very cool wood items. He's been woodworking for many years.

He sent me a link to some electric guitar plans. He's offered to work with me on a project. I know nothing about it, but he's very handy. It could be fun.

Has anyone done this type of build? Any advice on the best way to proceed?
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  #2  
Old 10-15-2017, 01:40 AM
mirwa mirwa is offline
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Cnc files are pretty easy to draw up yourself, if he has a cnc likely he will have a drawing program that outputs Vectors.

Using the cnc to cut pockets and pickups and profile cutout is the best use of the machine, using it for doing the curvature of a les Paul body is extremely time consuming compared to just hitting it with a belt sander.

For that reason you don't need to buy rendered body shapes.

I like doing things by hand as it connects you with the job, but cnc is a tool of the future, embracing it and using it is something modern luthiers have to do to make money. I have for note 3 cnc routers, 1 cnc lathe, 2 cnc lasers, 2 cnc plastic printers.

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Old 10-15-2017, 10:24 AM
Truckjohn Truckjohn is offline
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My best advice is to know yourself before you start..

Are you a project starter or a project finisher. There is a huge amount of work and money between "wood parts" and "Playable guitar". The "hobby guitar" universe is littered with the carcasses of half finished guitar projecgs.

Are you pretty handy? Are you already doing some woodworking or metal craft work now? How about electronics? Have you done some soldering and electronics wiring? How about "guitar tech" work - making nuts and saddles, setting intonation, fretwork, etc?
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Old 10-15-2017, 10:51 AM
Brent Hahn Brent Hahn is offline
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You can buy complete, finished bodies and necks from Warmoth for only a little more money than those CNC files would cost you.
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Old 10-15-2017, 11:53 AM
charles Tauber charles Tauber is offline
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Those new to computer numerical control (CNC) work need to understand that there are three stages to such work, with the exception of laser and plasma cutters that effectively have two.

The first stage is creating a digital version of what is to be produced with the CNC machine. For simply outlines, this can be 2D drawings in computer aided design (CAD) software programs or it can be a simple drawing in a "drawing" program such as Corel Draw or Adobe Illustrator. For more complex 3D shapes, the geometry of the object to be made must be modelled as a 3D object in a 3D CAD modelling software. This first stage requires at least moderate proficiency in the 2D drawing or 3D modelling software. For many 3D modelling software, there is a steep learning curve to be able to successfully model the desired geometry. Many fail at this stage.

The second stage is that the 2D outlines/3D geometry must be processed to produce code that can drive the CNC machine to produce the desired outline, depth and geometry. Typically, with modern machines, this is "G Code", the most common language for driving CNC machines. Part of creating the G code is assigning appropriate tooling (e.g. cutters, router bits, drill bits, etc.) as well as spindle speeds and feed rates, which require knowledge of machining and of materials. Creation of G codes is a second significant hurdle for those new to CNC machining. G codes are often created in a second software, though some drawing/modelling software will produce G codes, and some G code software has some drawing/modelling capabilities. (2D outlines can be sent to a laser and plasma cutters using what are effectively print drivers and don't require G code be produced, making laser cutting much more accessible to the inexperienced.) Raster images can also be converted into 2D outlines for cutting purposes, such as reproducing a photograph in a chosen material.

The third stage is the actual machining process in which material (e.g. wood, metal or plastic) is held in the machine, the machine zeroed and the shaping/manufacture actually occurs. This requires at least rudimentary knowledge of how to position and immobilize the work piece during the machining process as well as cutting tool/material speeds and feed rates. Keep in mind that there is an entire occupation that has traditionally been dedicated to this stage of the process: a machinist.

All that to say, it isn't as simple as having an idea and having it magically appear at the other end of the machine.

Having looked quickly at the OP's link to the "CNC files" for guitar shapes, it appears that the supplier is offering two formats of 2D drawing files - DWG and DXF - and one 3D format, STL. Their website states that they do not offer the service of modifying the designs, but that you can change the 2D format drawing files yourself on an appropriate CAD system. They offer to supply the 3D files in a number of common formats, if requested, to allow you to make changes to the 3D models in your own CAD system.

To be clear, the supplier is not supplying CNC-ready files. They are providing "stage 1" files. For example, they state clearly that pocket depths are left to the purchaser of the plans to set: the files are 2D outlines that do not specify depth. The purchaser is then required to generate G codes on their own.

If you want to save some hours in creating 2D outline drawings, it might be worthwhile to purchase their plans. Just be aware that, unless using a laser or plasma cutter, these aren't ready to just feed into a CNC machine and cut wood. The capabilities of the CNC machine that the OP's FIL has might also come into play. (Some entry-level woodworking CNC machines only process raster images, rather than vector geometry.)

Last edited by charles Tauber; 10-15-2017 at 12:03 PM.
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Old 10-15-2017, 06:13 PM
mirwa mirwa is offline
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Quote:
Originally Posted by ADK View Post
It could be fun.
Has anyone done this type of build? Any advice on the best way to proceed?
What body shape are you looking at making

Steve
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  #7  
Old 10-15-2017, 06:25 PM
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Quote:
Originally Posted by mirwa View Post
What body shape are you looking at making

Steve
I don't know. This is all very preliminary. It wasn't on my radar until FIL sent me the link a few days ago. He's very excited about getting into new projects, though I understand making a (playable) guitar requires more precision than most other projects. That is to say that this could be frustrating for he and I both.

The point about those plans being stage 1 is the kind of insight I'm looking for. Thanks.

I'm really busy with other things, so am leaning against taking this on. Knowing what I know now, it just doesn't seem like something I'd enjoy.

Thanks again.
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Old 10-15-2017, 07:25 PM
mirwa mirwa is offline
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One of the easiest bodies to make is a tele style unit, its flat on both sides.

If you want to get your friend started with punching one out, I can draw one up in about 10 minutes with all toolpaths to suit their machine and send it to you vee pm. (No cost)

Let me know

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Old 10-28-2017, 09:19 PM
LouieAtienza LouieAtienza is offline
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As a guy who has carved archtops on guitars, using many methods ranging from table saw to Lancelot tool on angle grinder, to building different router jigs, I will say I prefer to CNC them.

Here's the dirty secret about STL files - they contain no parametric data. They're basically a bunch of interconnected triangles. Meaning you cannot easily manipulate them. This is done to prevent reverse-engineering of course. But if you look online you'll find real 3D CAD files, and you'd want IGES, STEP, SLDPRT, 3DM, X_T (parasolid)... You could reverse-engineer a STL file with a program such as SpaceClaim, but that software costs $2500, then you have to buy the STL edit module which probably costs another $1000. And it's totally worth it if you're a manufacturer or engineering firm.

Here's the other dirty little secret - you're limited as to how you can machine a STL file. Because there is no parametric information, you're limited to either raster milling (moving back and forth at a certain direction and constant Z level) or waterline machining (offset machining around). However you can get around this and use 2D paths to do the pockets. This is provided the STL of the body does not have the pockets drawn - otherwise the CAM will just blindly cut the pockets in the raster fashion, and you're left with pretty rough pockets that have to be cleaned up later.

Quote:
Originally Posted by Charles Tauber
(Some entry-level woodworking CNC machines only process raster images, rather than vector geometry.)
Even the cheapest import CNC with the horrendous TB6560 chipset can do simultaneous 3-axis movements. It is up to the control software, which in the hobby-DIY realm is Mach3/4 or LinuxCNC (and now UC CNC, EdingCNC...) It's more the CAM software you're using. I have complete control of every aspect of machining, direction, speed, etc. in my CAM system... but then again it cost more than my tabletop CNC router and CNC mini mill combined. But I use the run-of-the-mill (pun intended) Mach3 as the control software.

Which brings up another dirty secret - The machining WILL require post-processing in terms of sanding to remove mill marks. Machining contours requires the use of ball endmills which invariably will leave scallops that have to be removed. And if you work of an STL, since it's made of a triangle mesh, it will leave facets all over that have to be removed, however I enjoy sanding...

Quote:
Originally Posted by mirwa
One of the easiest bodies to make is a tele style unit, its flat on both sides.

If you want to get your friend started with punching one out, I can draw one up in about 10 minutes with all toolpaths to suit their machine and send it to you vee pm. (No cost)
I'd agree the Tele body is the easiest one. But he'd need a neck too!

Quote:
Originally Posted by Charles Tauber
To be clear, the supplier is not supplying CNC-ready files. They are providing "stage 1" files. For example, they state clearly that pocket depths are left to the purchaser of the plans to set: the files are 2D outlines that do not specify depth. The purchaser is then required to generate G codes on their own.
A 2D DXF file does not have any pocket depth data. But this is ridiculously simple to handle, since all you would have to do is specify a pocketing strategy for whatever contour you pick, then tell the CAM software what depth you want this pocketed to. It's pretty brainless actually!

I posted a mini-tutorial thread on this a while back, but unfortunately PhotoBucket has decided to hold photos hostage. I have the pics still, so when I get the chance I'll put them back up.

Last edited by LouieAtienza; 10-28-2017 at 09:32 PM.
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  #10  
Old 10-28-2017, 09:27 PM
LouieAtienza LouieAtienza is offline
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Quote:
Originally Posted by ADK View Post
I don't know. This is all very preliminary. It wasn't on my radar until FIL sent me the link a few days ago. He's very excited about getting into new projects, though I understand making a (playable) guitar requires more precision than most other projects. That is to say that this could be frustrating for he and I both.

The point about those plans being stage 1 is the kind of insight I'm looking for. Thanks.

I'm really busy with other things, so am leaning against taking this on. Knowing what I know now, it just doesn't seem like something I'd enjoy.

Thanks again.
I say, make a Tele body, buy a neck from Warmoth or MusiKraft, and hardware and electronics to taste. This alone is ambitious, but very doable. Then if you like the process you can try learning how to do the neck. Remember this can be a great learning experience for your buddy as well...
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Old 10-28-2017, 09:29 PM
LouieAtienza LouieAtienza is offline
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Quote:
Originally Posted by Brent Hahn View Post
You can buy complete, finished bodies and necks from Warmoth for only a little more money than those CNC files would cost you.
You can find real, useful files for FREE online. Which are far superior to any STL file. Great for 3D printing though...
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  #12  
Old 10-28-2017, 09:49 PM
mirwa mirwa is offline
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As mentioned above, a lot of hand finishing goes into the job after basic machining.

Far left - customers drawing
Middle - my 3d rendering of their wishes and email discussions
Far right - Job after couple of hrs hand sanding and shaping the contours up after the bulk of the shaping was done with the cnc

Tele is far easier



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Old 10-28-2017, 09:56 PM
mirwa mirwa is offline
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This was at completion of cnc, its good but many many tool marks

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Old 10-29-2017, 09:49 AM
charles Tauber charles Tauber is offline
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As this is neither a Computer Aided Design (CAD forum) nor a Computer Aided Manufacturing (CAM) forum, I don't want to get too far into these things.

The point of my previous post was simply to point out that the "CNC Ready" files being sold in the OP's link were not "CNC Ready" and that, for someone entirely new to the CAD/CAM world, as the OP stated he is, it isn't as simple as pressing a button. One can't simply walk up to a machine and say, "body, 2" thick, Tele" and have a Telecaster body come out the other side. Believing one can is surely to result in disappointment. I'd wanted to help the OP avoid that disappointment by giving him a brief overview of the typical steps involved from computer-aided design to manufacture.


Quote:
Originally Posted by LouieAtienza View Post
Even the cheapest import CNC with the horrendous TB6560 chipset can do simultaneous 3-axis movements. It is up to the control software, which in the hobby-DIY realm is Mach3/4 or LinuxCNC (and now UC CNC, EdingCNC...) It's more the CAM software you're using.) Mach3 as the control software.
At woodworking shows aimed at hobbyists, there are often several models of CNC machines that are offered as turn-key tools. They are small, portable planer-sized machines that come with software. As provided, those only process raster images. It might well be that one could use different software with them - as CAD, G-code producers and controller software - but doing so is likely well-beyond the knowledge of those purchasing such machines. The OP's FIL's machine might be such a machine and the OP ought to find out what capabilities/requirements his FIL's machine has prior to spending hundreds of dollars on "CNC-Ready" files, per his OP.


Quote:
A 2D DXF file does not have any pocket depth data. But this is ridiculously simple to handle...
It is for those with experience. For those without experience, it might well be the difference between success and failure.
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Old 10-29-2017, 10:41 AM
LouieAtienza LouieAtienza is offline
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Quote:
Originally Posted by charles Tauber View Post
As this is neither a Computer Aided Design (CAD forum) nor a Computer Aided Manufacturing (CAM) forum, I don't want to get too far into these things.
OF course. However this is the way things are headed toward, so I thought it be of interest to discuss

Quote:
The point of my previous post was simply to point out that the "CNC Ready" files being sold in the OP's link were not "CNC Ready" and that, for someone entirely new to the CAD/CAM world, as the OP stated he is, it isn't as simple as pressing a button. One can't simply walk up to a machine and say, "body, 2" thick, Tele" and have a Telecaster body come out the other side. Believing one can is surely to result in disappointment. I'd wanted to help the OP avoid that disappointment by giving him a brief overview of the typical steps involved from computer-aided design to manufacture.
Agree, and was just echoing that sentiment by discussing what's actually involved, from someone who actually does CNC electric guitars, for myseld and as a "shadow" builder...

Quote:
At woodworking shows aimed at hobbyists, there are often several models of CNC machines that are offered as turn-key tools. They are small, portable planer-sized machines that come with software. As provided, those only process raster images. It might well be that one could use different software with them - as CAD, G-code producers and controller software - but doing so is likely well-beyond the knowledge of those purchasing such machines. The OP's FIL's machine might be such a machine and the OP ought to find out what capabilities/requirements his FIL's machine has prior to spending hundreds of dollars on "CNC-Ready" files, per his OP.
This may have been true 10 years ago, but for the most part today's DIY CNC crowd are pretty sophisticated, and you can get high-end CAD/CAM like Fusion360 for free. Just like anything, there is a learning curve.

And I agree with the cost of those "CNC-ready" files, that anyone can get for free, with better quality, and editable, online. Which is why I made that point.

Quote:
It is for those with experience. For those without experience, it might well be the difference between success and failure.
Here it is in a nutshell. Click on a curve - for example, a pickup pocket. Go to the toolpath menu and pick pocketing. Select tool cutter size, how deep per pass, and final depth. Click OK. Done. It really is that simple.
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