CAD/CNC Tips & Tricks

[SpaceJockey]

There seems to be a fair amount of interest here in the Luthier's Corner in computer aided designing and machining.

I did a search and didn't come across any threads that are dedicated entirely to this topic, so I figured I would start one. My hope is that this thread will serve as a repository of knowledge for those seeking to dabble in the dark arts of 3D modeling and CNC as they relate to luthiery.

I am only just getting my feet wet with CAD. Currently I use Autodesk Inventor & Fusion 360 to model my designs.



I chose this program because
1) Wide variety of online tutorials both from Autodesk and 3rd parties
2) its free (sorta, the free version lets you design stuff but locks some functionality needed for exporting files or machining).That being said, the paid version is much cheaper than comparable CAD packages like Solidworks, for example.

There are lots of other free options out there of course, but I am not familiar enough with any of them to make a recommendation.

A good starting point for Fusion 360 is Lars Christensen's YouTube channel.

Another YouTuber, Austin Shaner has a fantastic series of videos dedicated to designing Guitars in Fusion 360.

If you have knowledge on the topic, please feel free to share it here.

 

[Barticus]

What CNC machine are you using?

 

[SpaceJockey]

What CNC machine are you using?

I haven't yet invested in one, but I have access to them through a friend and my former employer. Part of my reason for starting this thread is to gain the knowledge to make an educated purchase in the near future. I have a budget of about $3k.

Love your builds by the way! Really beautiful work.

 

[rudy4444]

I use CAD a bunch, no CAM though. On the forum I provide full CAD drawings for my detailed build topics.

 

[NedRyerson]

Awesome idea. I eventually want to head down this path myself. Thanks for starting the topic!

 

[Barticus]

I haven't yet invested in one, but I have access to them through a friend and my former employer. Part of my reason for starting this thread is to gain the knowledge to make an educated purchase in the near future. I have a budget of about $3k.

Love your builds by the way! Really beautiful work.

That’s a good baseline budget for a smaller unit… make sure you plan the rest of the gear you’ll need for your build out like cabinet, dust control, lights etc. as part of your budgeting as those costs will mount up as well.

 

[SpaceJockey]

That’s a good baseline budget for a smaller unit… make sure you plan the rest of the gear you’ll need for your build out like cabinet, dust control, lights etc. as part of your budgeting as those costs will mount up as well.

Any recommendations you can make? What are you using currently?

So far, I've looked at options from Shapeoko, AvidCNC, Openbuilds.

I'm hoping to have a complete system with tooling built out for under 5-6k, including everything you mentioned.

 

[Barticus]

Any recommendations you can make? What are you using currently?

So far, I've looked at options from Shapeoko, AvidCNC, Openbuilds.

I'm hoping to have a complete system with tooling built out for under 5-6k, including everything you mentioned.

After spending a lot of time doing research and playing with some of the different options in person I decided to drop my money on the OneFinity Journeyman. In my opinion it was the best value and closest to commercial grade in a prosumer line and offered many advantages that were attractive to me (it's built like a tank too)... I also added the 14w diode laser too (already have the D1 10w and D1 Pro 20w diode lasers) for larger engravings. I'm using Fusion 360 (bought on 40% off sale last fall) and considering picking up VCarve Pro too.

 

[tr4252]

I have a small shop with a couple of CNC machines; a 3 axis vertical mill and a 3 axis router I built from scratch. I use a Microkinetics controller and a software program called Millmaster Pro. I write my programs a block at a time in G Code, and use a CAD software called TurboCad. I used Autocad professionally for about 20 years, but as a retired guy buying out of pocket it was too costly for what I'm doing. I use the CAD program for design work and it gives me the coordinates to write programs, of course. I do mostly metal working, on a smaller scale than instruments though.

I'd be happy to share any dirty tricks I've learned as a designer/machinist over the years.

As SpaceJockey has said, supporting equipment and tooling can add up pretty fast. It sounds like the o.p. will be working mostly or entirely with wood, which I've found to be fun after working with high carbon steel, stainless, etc. Carbide end mills work good on wood.

You can import programs, but I'd suggest you at least become familiar with G Code. It will give you a basic idea of what's going on and is useful in troubleshooting a program.

I looked at the OneFinity Journeyman online and it looks OK.

Good luck!

Tom

 

[Jazzdogg]

For those of you running CNC, which routers are you using? Have any of you invested in water-cooled routers?

 

[shodan]

Umm, how did you get Autodesk Inventor for free? Other than a 30 day free trial? Or student?
BTW, NanoCAD does have a free version.

 

[Barticus]

I have a small shop with a couple of CNC machines; a 3 axis vertical mill and a 3 axis router I built from scratch. I use a Microkinetics controller and a software program called Millmaster Pro. I write my programs a block at a time in G Code, and use a CAD software called TurboCad. I used Autocad professionally for about 20 years, but as a retired guy buying out of pocket it was too costly for what I'm doing. I use the CAD program for design work and it gives me the coordinates to write programs, of course. I do mostly metal working, on a smaller scale than instruments though.

I'd be happy to share any dirty tricks I've learned as a designer/machinist over the years.

As SpaceJockey has said, supporting equipment and tooling can add up pretty fast. It sounds like the o.p. will be working mostly or entirely with wood, which I've found to be fun after working with high carbon steel, stainless, etc. Carbide end mills work good on wood.

You can import programs, but I'd suggest you at least become familiar with G Code. It will give you a basic idea of what's going on and is useful in troubleshooting a program.

I looked at the OneFinity Journeyman online and it looks OK.

Good luck!

Tom

Can you mill headless headpieces and bridges if a design and specs are provided?

Are you running a spindle or router on your CNC?

 

[mikewalker]

Just putting this out there... is anybody here currently doing CNC on Linux?
So many decent-powered machines are going to be pushed to linux in 2024 when Win10 support ENDS ( lots and lots of very good hardware is not supported by Win11!) I have three very serviceable i7 machines (8-core, 32GB DDR4) that microsoft would prefer us to consign to the dustbin)

Just stumbled on this: LinuxCNC

 

[tr4252]

Can you mill headless headpieces and bridges if a design and specs are provided?

Are you running a spindle or router on your CNC?

Hi Barticus.
I probably could machine the parts you mentioned. What material(s) would you like to use and how tight do the tolerances need to be? How about quantities? If you have fairly well detailed drawings and specifications I could give you an estimate.

My 3 axis mill has a standard spindle with a tapered bore for collets, etc. My router uses a modified panel trimmer which has a typical router chuck.

Tom

 

[kalmar]

We had a guy in our Makerspace, who was running LinuxCNC and would never use something else.

For Fusion exists a AddIn to export DXF. Makes CNC and Laser easier.

 

[Barticus]

Hi Barticus.
I probably could machine the parts you mentioned. What material(s) would you like to use and how tight do the tolerances need to be? How about quantities? If you have fairly well detailed drawings and specifications I could give you an estimate.

My 3 axis mill has a standard spindle with a tapered bore for collets, etc. My router uses a modified panel trimmer which has a typical router chuck.

Tom

Okay, I’ll PM

 

[Barticus]

Just putting this out there... is anybody here currently doing CNC on Linux?
So many decent-powered machines are going to be pushed to linux in 2024 when Win10 support ENDS ( lots and lots of very good hardware is not supported by Win11!) I have three very serviceable i7 machines (8-core, 32GB DDR4) that microsoft would prefer us to consign to the dustbin)

Just stumbled on this: LinuxCNC

Hmm not sure I understand what you mean I have an i5 and 3 older i7s (16gb) ALL running Windows 11 without issues for the last couple of years. That’s what I’m running Fusion 360 and Adobe suite on (also run Mac for all the same software). And while I have run Linux for other specific functions (firewalls, dev, etc) for many years, I have no plans to convert any of my design machines as I prefer to use them as tools, I don’t want to spend tons of time working on the machine itself.

As far as ‘driving’ the equipment (CNC, Lasers, etc) this all depends on the actual device… you’re typically not connecting directly to the device, you’d generate the G-code from the design software and then run from the head unit (USB or WiFi). For lasers it’s typically like connecting to a printer (with device specific drivers) and run from inside the design software or just create PNG/SVGs for laser engraving and cutting and run from that device’s app (eg - Lightburn) from Windows or Mac via USB or WiFi.

 

[SpaceJockey]

As SpaceJockey has said, supporting equipment and tooling can add up pretty fast. It sounds like the o.p. will be working mostly or entirely with wood, which I've found to be fun after working with high carbon steel, stainless, etc. Carbide end mills work good on wood.

You can import programs, but I'd suggest you at least become familiar with G Code. It will give you a basic idea of what's going on and is useful in troubleshooting a program.

To start with, it will mostly be used for wood, plastic, and composite materials. Eventually I would like to be able to machine metals, but with my budget I'm not sure what my options are. Aside from instrument hardware, I've got plans to machine other objects, namely motorcycle and car parts, molds for creating composite parts, etc.

I know the rigidity of the machine and the router or spindle I use are factors to consider. From what I understand, cutting metals requires much slower speeds than wood.

 

[mikewalker]

Hmm not sure I understand what you mean I have an i5 and 3 older i7s (16gb) ALL running Windows 11 without issues for the last couple of years. ...

Well, you are one of the lucky ones! Windows 11 only officially supports "8th-gen" CPUs, and balks at some other things like lack of TPM support in the BIOS. There are some published 'workarounds" but they involve registry hacks, reinstalling all your apps after 'upgrade' and warnings about increased Bluescreens (remember those?) and future updates being denied... all in all not a rosy picture!

 

[rickwrench]

Your targeted $3K budget on the CNC itself is easily doable. Tooling costs are ongoing, of course.
You also need something stout to mount it on, a computer, and dust collection.

Make or break will be your CAD/CAM software. You can have the best machine in the world, but if you can't tell it exactly what and how you want something done, you're better off using saws and chisels. Remember that your robot apprentice is stupid. And always looking for an opportunity to turn a nice piece of wood into kindling.

I've got a ShapeOko 4xxl, but with my own waste board, and I'm using their stripped down router body. They were behind on their T-slotted waste board production when I ordered, and I prefer tape/CA/tape for holding stuff down anyway. So I got a deal, and used 1-1/4" sub floor as the waste board. Dead flat and a nice chunk of mass to keep things from wiggling. I used a 1" surfacing bit to skim it true. The CNC frame is mounted on a big heavy library desk which has a piece of 1-1/4" sub floor mounted on top of its 1-1/2" oak top. Handy drawers in front for tool storage.
I run the Carbide controller program off an older Macbook. The Macbook also drives a "cheap" 55" 4K TV I'm using as a shop monitor. I can see job progress from anywhere in the shop, pull up the design in Fusion if needed, etc.
The big monitor has also been very helpful for actually seeing the wiring diagrams I lay out while I'm working. Handy for watching baseball, too.
I have a decent sized (2000 cfm) dust suck-o-matic system for the whole shop, collector is outside, so, real clean air inside. I ran 4" flex/drop hose as close as I could to the sweepy fixture. The system is gated and runs the CNC leg direct. There is no mess, no dust, no chips, nothing. Also, the suck-o-matic + sweepy attachment draws massive amounts of clean air through the router body. It's usually ice cold, even after a long job.

Good things about the ShapeOko:
• Price/value.
• The extruded frame assembly is quite stiff. Even with the wider xxl gantry.
• The belts on the model 4 are wide and I haven't had to do any belt adjusting or tightening since assembly.
• The support has been fantastic.
• Carbide's controller software is good.
• Cuts aluminum and brass just fine (w/ a single flute cutter, and shallow cuts). But, RPMs are always going to be on the high side/edge with a router.

Issues with the CNC I've had during the last 2 years:
• Carbide's design software is fairly limiting. I gave up quickly and switched to Fusion360.
• I failed to remove and put a drop of blue Loctite on EVERY SINGLE BOLT during assembly (since solved).
• The limit sensors on the model 4 use spade connectors to plug into the wiring harness. They occasionally lost continuity from the all wiggling. This caused the machine to crash during calibration and return to home. They sent a couple replacement sensors, but, same issue, and I just snipped the spades and hard wired all the sensors. No problems since.
• Keep the belts clean. Good dust collection handles this task proactively.
• Getting the router/spindle axis 100% true/vertical takes shim stock, and some time. There is no adjustment mechanism on the mount (at least with my version of the machine). The gantry has some adjustments for level tracking, but they don't really address fine tuning the Z vertical.

And... it took me months to adjust to the "I can make anything" mindset.

Rick