Official Luthiers Forum!

Who has a CNC machine and which one and why did you choose it?

_________________
https://www.instagram.com/fostinoguitars/
https://www.facebook.com/PuraVidaUkuleles/

I wonder how many Northwoods folks came way wanting to do this or 3D printing, we did too.

I have the Next wave shark
first thing is what are you going to make? there are so many things I learned so while I do like the shark they have some limitations in the software.
if you want to make necks you need minimum 3 D so aspire is the software you want. The Next wave has good customer support.
Also knowing how to fixture the work , so know what your getting into.

mine came with a 1.5 KW water cooled spindle and when the died after about 4 years I did upgrade to a 2.2 KW with a ER 20 collet.

it is good to ask people so you understand what your getting into. Learning how to use the software and understand how to draw on it , takes time.

I still make my bridges by hand since I am often remaking older bridges that were hand made to begin with so I have to match footprints. You will find the more you understand the machine the more you can do.
I chose this as it was made in America and it was complete. The stuff off china is cheap and often missing a few important things. I would call this a good entry level piece. There is a company near woodstock NY that makes a better machine and has tool changer in the design. So understand they are not plug in and go you must learn how to use this equipment .

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I use an Axiom Precision AR8 Elite - https://www.axiomprecision.com/elite/el ... l?___SID=U

I have been working with CNC in the building process for 3 years now. You can scroll my Instagram to get a sense for how I use it. http://www.instagram.com/cbcguitars

Top things to consider in my opinion:

- Z height: if you want to cut necks you’ll need the right Z clearance. Imagine it this way, if you have a 4” heel height you need that much clearance x2 to allow for a tool sticking out. The machine I referred to above has 7.48” which is just barely enough.

- Motors: servo motors are more desired. They are more accurate and you can drive them harder.

- Gantry: you want something rigid that won’t flex, especially if you’re making any tooling or jigs where it needs to be highly accurate and repeatable.

- Bed size: this is less critical for luthiers IMO because we aren’t processing sheet goods, making signs, etc… but you want to have at least 48” travel in the Y if you want to make things like outside molds, workboards, etc….

It depends on what you want to do with it, but I would stay away from hobby level machines if you think you’re going to invest a lot of time in moving your workflow to CNC.

I’m happy to chat more if you want to reach out or during the OLF Roundtable I’m happy to share what I know. My entire workflow is fully integrated with the CNC.

I’m really hoping Andy chimes in here as he can give the production shop perspective. I’m a weekend warrior.

Here is a bridge I made yesterday: https://youtube.com/shorts/iagi9Sv7QRY? ... TCbKKnemQ-

Brad


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

John, Brad, and future posters in the thread—

In addition to describing your CNC systems, could you also tell us the financial, physical space, and setup/learning time expenditures associated with your systems?

I stay interested and I see the value, but I’m choosing to be a “by the slice” consumer of CNC services for now. My current perspective is that getting into production of things myself with CNC tooling (instead of buying those things as I need them) would cross a cost threshold I am not ready for, on all three types of costs I identified (financial, physical space, and setup/learning time). But knowing your estimates of those three costs would help me (and maybe others) make future decisions with real life data. I appreciate the input!

This is a good point. I put a link to the machine I use so the cost and footprint are there. However, the time investment is a great question.

I have 1000+ hours in learning software and machine time making test cuts and eventually actual products. It’s not an insignificant undertaking. Be ready.

Every year, around February / March, the CNC Facebook groups are flooded with retirees whose wife bought them a CNC for Christmas and they have yet to make anything with it. John talked about it above, but be prepared to spend significant time learning the software. Too many folks have a picture in their minds of CNC being like a oven. You put a log in one end and out the other comes a finished product. Robbie O Brien just released a course for CNC and I’m so glad he did it the way he did. It’s not a course about 3D modeling, it’s about using the software that comes with a lot of machines, Vectric Vcarve, and putting it to good use making guitar parts and tools. This is the way!

BTW: on the topic of 3D modeling, if you’re looking to make necks, go with Fusion 360 or Rhino, which is a much steeper learning curve but the right way to approach it. I’m learning Fusion myself now but not trying to apply it to building until I get much further along.

Brad


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

Great info.

Hesh I'm definitely more curios about the 3-D printing for making jigs. That headstock break repair jig was amazing.

John I was just thinking hmmmm it doesn't take all that long to make a bridge. Im just going to make small parts for now and cut out figs nd templates.

Don I was thinking something similar. I can have Andy Birko make me a bridge for $10-$12. A decent machine costs roughly $6,000-9,000. Not to mention that Im getting old so it's going to take me a long time to figure out how to use the thing. lol

Brad I.m still undecided on how far to go with CNC,

_________________
https://www.instagram.com/fostinoguitars/
https://www.facebook.com/PuraVidaUkuleles/

FWIW I built my first DIY CNC machine to support my guitar building in 2008. I've replaced or rebuilt it five times since. I know my machine, and what is available out there in painful detail. I sometimes think that my true hobby has been this amazing, exciting, infuriating, frustrating, machine --not actually making guitars.

I use my CNC almost exclusively for hobby building guitars. I'm not a production shop, and I don't sell time on my machine. I've also never worked in aerospace and am not a retired machinist. That's my perspective, so take what I say with a grain of salt.

First, more is sometimes less. I wanted to make a full sized acoustic guitar neck in one carve, just like the big boys. That means that a machine has to be able to clear a 4" blank sitting on a .75" vacuum jig to hold it. Using a .5" x 6" extra long ball nosed bit to do the final finishing path means I needed the tip to be able to move 4.25" top to bottom. For other operations with a normal bit sticking out only 1" I need the z carriage to travel approximately another 5". Realistically that is a 12" z travel on a gantry that sits at least 6" above the spoil board. That requires a VERY rigid machine with an unusual amount of Z travel and clearance. As a reference, see the popular professional CNC from Avid CNC. They don't recommend going beyond the 8" clearance/8" travel on their $12,000 floor model (but they do offer 12/12). Most hobby machines have about 3" of clearance or less, because more would require a very different design.

Guess what? I eventually decided it didn't make sense to try to make the neck and heel all at once like the pro's do. I could make the neck out of a 1" blank and a heel out of a 2.5" stack and glue them together later. This is what the machine really excels at, very precise alignments and very intricate cuts. It is lousy at hogging out lots of wood or cutting large pieces. Now my machine has about 4" of clearance and 5" of travel (still A LOT for hobby machines) but is much more rigid and I have less problems.

The point of the story is that using a hobby CNC is different than a full production machine that might cost $20,000. You won't be using it the way Taylor factory uses theirs or probably even how Andy Birko uses his. And you probably don't need the size you think. If I build myself another, it may only have 18" x 6" x 3" travel. But I'll make it rigid enough to mill metal. Big enough to do inlays, bridges, rosettes, and brass parts, and no more. On the other end is a CNC large enough to cut a sheet of plywood, but is more or less limited to sheet goods. Sure, that would be nice to have but probably not worth the floor space or cost. A machine that can mill brass and aluminum, cut an acoustic guitar neck in one go, hold a rotary axis, cut dovetails into a vertical board, cut a sheet of plywood in full depth pass at 200"/min, etc. is a beautiful dream. But I neither have the budget nor the floor space for something like that. AVID gave this guy a machine like that, but I'm not a famous YouTuber with millions of views: https://youtube.com/playlist?list=PLZqh ... XrqelVUTv-

Second, rigidity is THE consideration. Not power. This is wood we are cutting, not steel. You don't need a massive router or spindle. because you are never going to do a 1" deep cut. Your limiting factor will always be rigidity over power. A 1.1Kw spindle or laminate trimmer is plenty powerful to take a 1/8" cut in wood, but a cheaply made router on rubber wheels with a 1/4" belt driven gantry won't be able to handle it at anything other than snail speeds. You don't even need particularly powerful stepper motors (Yes, stepper motors. Servo motors are industrial options that may offer power and performance you will probably never use). For machines like the ShapeOKO, Onefinity, FoxAlien, or LongMill, the limiting factor will ALWAYS be rigidity, not power.

So what would I recommend? I know we all want to, at a minimum, be able to cut a fender style neck and make a Tele body for a friend, so things like the very capable but small Nomad is out of the picture. For machines that fit in your guitar shop and do some good things. ShapeOKO, Onefinity, FoxAlien, or LongMill all offer versions that have linear rails. I would skip their less expensive versions. Of the four I mentioned, ShapeOKO PRO and the Onefinity ELITE both have some limitations but are good overall machines. You can do a lot with both of them.

3D printing is another entire can of worms. I have one of those as well. I built a Voron, for those of you who know. They are also a steep learning curve if you want to make useful tools out of them. If you want to make a plastic vase that changes colors, they are great right out of the box. If you want something that has dimensional precision and needs to withstand multiple use... eh. It can be done, but you aren't printing in PLA at 200mm/min.

I hope some of you find that useful.

Great info and one of the reasons I keep steering away from purchasing a CNC lol. I hate tools with limitations. This cracks me up every time I think about this I call Birkonium and order up some more parts lol

_________________
https://www.instagram.com/fostinoguitars/
https://www.facebook.com/PuraVidaUkuleles/

^—— that’s a lot of good feedback for you, David.

It’s a great point that necks can be done multi step. Even on their side in a two sided machining process.

Question for you rlrhett (sorry don’t know your first name), have you used any of the shapeoko or foxalien machines? I have some limited experience with both and they both felt like toys. Maybe the shapeoko pro is a different beast?


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

I used an original ShapeOKO from five (10?) years ago and a recent ShapeOKO Pro. Definitely different machines, and I wouldn’t call the recent machine a toy. I haven’t used a current ShapeOKO standard, so I can’t say. Nor have I used a FoxAlien.

That said, these machines are made from standard components. 15mm MGN rails vs delrin wheels. 8mm GT2 belts vs ACME threaded rod vs ballscrews. The frames are all aluminum extrusion. You could make your own machine, as I did, out of aluminum extrusión and the components you want. Machines with the same components will all perform roughly the same.

In my experience belts and delrin wheels is a very light weight machine that approaches being a toy. It barely will push a .25” bit through wood. The same machine with ball screws and linear rails on all axis will cut aluminum all day. Each of the pre made machines compromise somewhere.

Linear axis on the Z is bare minimum. On the Z and across the X carriage is pretty essential. Wheels on the axis the gantry rides on (usually called Y) is acceptable, but if you can afford it…

I would avoid belt drives, but as you can see the ShapeOKO pro used beefy 15mm belts. Ball screws are probably only necessary if you plan on milling brass bridges, aluminum jig parts, etc.

Like everything in life, you will want the upgrade for everything once you get started, but they are not essential. Ball Screws on all axis and 15mm Hiwin rails is my ultimate goal. But the ShapeOKO pro seems to be a good compromise for what a guitar hobbyist would need. My own machine uses 15mm rails on Z and X and wheels on Y. It has double Y motors and is built with aluminum extrusions and 8mm aluminum plates cut by a previos incarnation. All axis are driven by threaded rod.

I still have issues pushing a .5” bit in wood or a .25 bit in aluminum at reasonable speeds. But it will cut a slab guitar and Fender style neck with no issues. Delicate inlay is only limited by my greyware, not the machine. My next upgrades will be ballscrew on the X axis and 15mm rails on the Y.

Again, hope that helps.


Sent from my iPhone using Tapatalk Pro

Awesome. Thanks so much.


Sent from my iPhone using Tapatalk Pro

_________________
Insta - https://www.instagram.com/cbcguitars/
Facebook - https://www.facebook.com/cbcguitars

I definitely consider myself a beginner. I took a three or four night class at the maker space I belong to. I can pocket (i.e. cutting the recess for a rosette), and I can profile (i.e. cutting out the shape of the top), but I can’t do anything three dimensional like radius a dish, profile the top of a bridge, or radius a fretboard.

However, even with pretty basic skills, I’ve been able to cut outside molds, bending forms, etc. As long as you can generate dimensionally accurate files, I still think you can do useful things with CNC while you develop more advanced skills and problem solving abilities.

One thing that has helped me is drawing my geometry in an Illustrator-like program called Graphic, then exporting those drawings as dxf or dwg files to open in the CamBam or whatever to generate the tool paths. I’m much more comfortable using the drawing tools inGraphic than I am using CAD (at least the CAD programs I've seen). I can still generate dimensionally accurate files, and it’s much more intuitive to me, personally.

Watching Brad use his CNC has actually inspired me to draw some smaller projects lately, like this set of sanding blocks to help shape the cutaway and neck blocks for my florentine cutaways. This is an area I'd like to become more efficient in. The idea with these is that they'll be cut out of plywood or something, then layered together---just like an outside mold. The crosses are where I'd put a small 1/8" diameter pocket for 1/8" indexing pins to keep everything lined up for gluing. I look at this and think it's pretty basic---it's just cutting an outside profile---but it will turn into a useful little set of sanding blocks.

If I were as cool as Brad, I could probably figure out how to cut them out of one piece of wood and save the gluing hassle, but it shows how you can start basic while you get there.






Sent from my iPhone using Tapatalk

I got an X-carve (from Inventables) and its a decent starter machine. I liked it most because it was more affordable for my hobbyist needs. The Z-depth is pretty terrible, so carving heels on your necks isnt doable out of the box. Also, it's belt driven so it's a little less reliable (from what I have read) but I haven't ran into too many issues. If you are doing pretty light-medium duty work, it's a good machine.

_________________
-Marcus
http://www.bailieguitars.com
Instagram | YouTube

Building on James Orr's post, if you have any practical access to a CNC router _before_ you buy your own I would highly recommend trying out the CAD software side of things first and then making test cuts on a machine at your local maker space, at a friends, buying time at a job shop, etc.

Until you try creating some 2D, and then some 3D CAD objects and get a feel for that process and all of the pain points that come with it, your machine specs are very much a secondary consideration.

Once you have effective CAD skills and have seen some resulting test cuts or finished pieces from your CAD files then your priorities in terms of CNC machine specs will be way more obvious. You will accumulate experience and reference points to judge the value of things like frame stiffness, ball screws, servos, tool-changers and so on as previous posters have pointed out.


(I didn't necessarily follow my own advise as stated above, but if anyone can benefit from my hind site then great.)

I have a Stepcraft M700 with the ballscrew and aluminum table options. I bought it because the size fitted into the limited amount of space i have, and it is fully supported in Australia. Before that I had a cheap Chinese CNC that I used to dip my toe into the CNC world. That had all sorts of problems, but served it's purpose and convinced me that support is very important if you are going to spend what to me was a lot of cash on a bigger and much more capable machine.
The Stepcraft support has been first rate so no regrets on the decision. The experience with the small Chinese machine was useful because I learned to use the software, although the Stepcraft has made me go much deeper into the capabilities of the software. 90% of what I need to do with CNC is 2D, so I have not done anything in 3D yet. 3D is a lot more complicated, and many people start out thinking 3D and get into all sorts of trouble. If you are starting out, think 2D at first, forget about 3D things such as carving a neck. Some things just are quicker and easier to do by hand. Getting the CNC to do complicated custom 3D carving involves a lot of time modelling and debugging. Nothing ever works perfectly the first time, and only very simple things will work the second time. Debugging can take a huge amount of time, but once you get it perfect, then it will be perfect and accurate for as many times as you wish. So, the best approach IMHO is to pick tasks that the CNC is good at - things that need accuracy and repetition. One off complicated things do by hand. I use mine to do things such as inlays, pilot holes for tuners, bridge pin holes and slot, oval sound holes and rosettes, mandolin tailpiece covers etc. All difficult to do accurately by hand, but the CNC does a great job. I use Vectric software which is supported by the Australian Stepcraft distributer.

I have a Next Wave Piranha, 12 x 24 table. Picked it up for $1000 (barely) used. I use Vectric V carve software - it will cut 3D, but you can't really model 3D. You can import 3D files.

It's big enough to cut a Tele body in two operations. Does a good job on inlay. I've cut fret slots, roughed neck profiles, made a bunch of accurate tools.

I'm a manufacturing engineer by trade and have spent 30+ years in CAD/CAM/CNC, so the learning curve was pretty short.
I have access to modelling software through work when needed. Also a 3D printer at work which I've used for any number of handy little items.

It's another tool in the arsenal for my shop.

Having been involved in the multi axis cnc world for more years than care to admit, everything rlrhett stated is spot on. Rigidity is key. Not just rigidity in the axis' but also the spindle. So if you machine will use a hand held router for a spindle make sure the mounting arrangement is very rigid.
I cut the pyramid bridge and logos/pockets the other day on a little nomad machine I borrowed from a friend (good friend eh!).
So a small machine like that can only take cutters with a 1/8" shank. Max Spindle speed was 10K and it's a belt drive 70 Watt spindle. I obviously was successful with it.
For the bridge I used a 1/8" ball end mill for the bulk of it, spindle speed of 10K, a feed rate of 15 ipm and with a step depth of .030. The bridge came out great but it took an hour.
For the inlay I used a 1/32" end mill, Spindle speed of 10K, depth of cut .015 and a feed rate of 3 ipm. the pocket and the inlay matched well. A machine like this is pretty good for inlay but I would avoid it for much else. I believe this about a $3K machine. It's rigid but under powered on the spindle, but it's fine for tiny cutters.
My friend uses this machine for circuit boards, which I bet it excels at. Light detailed cuts, like inlay.
Anyway, just some ramblings on a small machine, which can work for some task.
I would really like to hear more about the stepcraft machine Peter Coombe is using.

_________________
Jim Watts
http://jameswattsguitars.com

What would you like to know about it?

I bought it as a kit and assembled it myself, but you can get it fully assembled. Comes with a 3yr manufacturer warrantee even with the kit so they must be confident about the quality. Working space is 479 x 743 x 194mm. There are many machines available (including Stepcraft) 1m x 1m but that is too big for the space I have. I got the kit because I wanted to know how it was all put together so if any problems would be easier to fix. It took me about 15hrs to assemble, the kit has hundreds of parts, but they are precision made and everything fitted together perfectly. The assembly manual is over 100 pages long and is the best I have come across, so no complaints there. I was very impressed with the quality (made in Germany), bit it is not heavy super robust industrial quality designed to run continuously. I have had it running for 8 hrs continuously every day for a few days, but I don't use it every day. It is all aluminium construction, but Stepcraft have a custom made extrusion that is huge for the X axis and that greatly improves the rigidity where most cheaper CNCs fail. It is rigid, I can't move it when I lean on the spindle, but it only weighs a bit over 50kg and I have appreciated the lighter weight when I needed to move it. The M series comes with precision square rails and a precision ballscrew option so is not a toy. Other reasons why I like the Stepcraft is it is probably the most versatile small machine on the market. Stepcraft support a 4th axis, tool changer, 3D printing, laser, plus a whole other set of accessories such as a 3D probe. You can do all that on other machines, but the manufacturer of the machine usually do not supply and support it. It also had the biggest Z axis working space of all the small machines I looked at, and that has been appreciated. You can also remove the table and the Z axis will reach all the way down to the base. There is an extensive support network with lots of information available on the Stepcraft web site, and from on line forums. If you have any problem, usually you can find an answer reasonably quickly. I have not really used it to it's full potential yet, but am quite happy I made the right decision.

Problems - I had some software installation problem but managed to resolve that by searching the forums. It uses UCCNC and a customized version is supplied. Some parts are tricky to install, there are 2 springs in the Z axis limit switches that have a nasty habit of flying off across the room never to be seen again when you try to install them, but they did supply 2 spare springs which I did need. Found one spring but not the other which vanished forever. I also had a problem with the tool length sensor that would not work. That problem was resolved with the help of the Australian distributor. It was a hardware fault in the main circuit board which they provided a replacement board. I got unlucky, only one they have had with the fault apparently, but is now working perfectly.

With CNC machines, basically you get what you pay for, there are no bargains unless you spend rather a lot of time building your own, and then it is no longer a bargain. The other thing that drove me to buy the Stepcraft is that there have been many manufacturers of small CNC machines come and go. When they do go, all your support vanishes. I have been thinking about making the plunge for a long time and keep an eye out on what is available, and much of what was available 10 years ago is no longer there because the companies have gone under and vanished. Stepcraft have been around a long time, their M series is a relatively recent addition to their lineup, the D series have been around a very long time, but the D series are really hobby machines, they don't use square rails nor ballscrews.

Does that help?

I guess for one thing, what size cutters are you using and what are your typical feed rates and depth of cut.
Do you consider the machine rigid enough to be repeatable. I've seen some machine that are not repeatable, even to the point that they miss their home position by like an 1/8 inch after completing the program.
Thanks!

_________________
Jim Watts
http://jameswattsguitars.com

I have tested repeatabilty and it is spot on accurate. I zeroed it with a fine point cutter to a marked fine point, then ran a job where it moved around a fair bit and then went back to zero. It went back to zero exactly spot on. Stepcraft give some impressive specifications for repeatability with the ballscrew option, and after that test I believe them. I have mostly been using small cutters so far, 3mm or smaller. Smallest has been 0.5mm. Speed of cutting and depth of cutting depends on what bit I am using and what I am cutting. Cutting Spruce and cutting Ebony is not the same thing.