Shopsmith Forums

I'll start addressing software backwards -- starting with the CNC machine itself.

Motion Control:
There are two primary contenders in this area: EMC2 for Linux, and Mach3 for Windows. Mach3 is more full-featured, easier to set up, and arguably more robust. EMC2 is free and requires a 400mhz or better PC. Mach3 is $175* and requires a 1Ghz or better CPU. Both require a desktop PC with a parallel port. Laptops have energy saving circuitry that can interfere with critical parallel port timing.

Standard USB to parallel adapters will not work. There is a $150 USB adapter called "Smoothstepper" with drivers that are still considered Beta. It only works with Mach3. Some have had success, others failure with this adapter.

While there do exist other options in this area, you risk lack of compatibility. Both of these programs interpret "G-code," the native language of CNC. However the g-code definitions leave a bit of room for interpretation, and no two controllers handle it exactly the same. Therefore it is important that your CAM (Computer aided manufacturing) software know what machine control software you have. Most have support for both EMC2 and nearly all have support for Mach3.

Since your choices here are limited, this is the easiest software selection to make. Most people will make their decision about machine control based on budget, CPU power of their host computer, and/or preferred OS.

Mach3
EMC2
Smoothstepper
KCAM - A less expensive Windows option with a limited free mode. Check compatibility with your other software before buying

*Don't run out and buy Mach3 before you have made your decisions regarding CAD and CAM. Many CAD/CAM vendors will bundle Mach3 at a discount.

CAM

CAM software is what takes your part design and converts it into "G-code" which can then be run on your CNC machine (via Mach3, EMC2, etc). Most are capable of reading several industry-standard file formats, the most popular of which is DXF (Document eXchange Format).

The options in the CAD and CAM world are overwhelming. The information I am going to provide is just a small portion of what is available. Programs start at about $100 while the top end software can be ten thousand or more dollars a copy. A common "feature" in the CAD/CAM software world is that customer support is sold separately, and with a yearly licence. Called a "service contract" this can easily cost as much as the software itself. For that reason, I have stuck with software that has a large following and good user-user support in the CNCzone forums.

Also, I am using Windows. I know very little about Linux options, and even less about Mac. However, it is my understanding that very little (nearing none) CNC related software is available for the Mac. Linux users might start at the EMC2 site for information regarding other software options.

There are free software options, but you will pay the price in time, configuration, fiddling, and in my opinion, frustration. The place to start is http://cnc4free.org/
Although I opted against the free software angle for the reasons above, there are some good utilities at this site that are useful tools for everyone involved in CNC work.

When looking at CAM, there is a huge jump in cost (with one notable exception) when going from 2.5D to 3D. For example MeshCAM, a highly regarded low-cost CAM, sells for $175 (bundled with Mach3 it is $325) but the 3D capable version sells for $500. And those are the inexpensive programs!

Popular 2.5d CAM programs include:
Meshcam
Sheetcam
DolphinCAD/CAM (an integrated system)
CamBam (also has limited 3D support)
Vectric Cut2D

Dolphin sells for about $1000, but if you call or email informing them that you are a hobby user, you will get a SIGNIFICANTLY lower price. Dolphin is a capable CAD and an excellent CAM, but is beginning to show its age. It has the look and feel of its Win95 heritage. On the plus side, it can run well on less powerful machines. If you feel you will never outgrow 2.5D, Dolphin can't be beat. Dolphin does extend 2.5D to include what they call "profiles" which can be used to make simple curved edges, but nothing complex.

CamBam is an interesting beast. It is still in beta, and an older version is still available for free. It is not as elegant as the highly regarded Cut2D, but is more powerful and allows you to tinker in the world of true 3D.

Vectric Cut2D is the market leader in this category. Its claim to fame is amazing ease of use and reliability. Vectric has a full range of CAM offerings, and a purchase of Cut2D will give you a discounted upgrade on some of their other offerings.

I started with Dolphin and at first regretted my decision. The learning curve is steep, and the user interface is not very tolerant of beginners. However once you get your mind around it, it is a very capable system. I still use it when I am doing a simple 2.5D design, as it is the fastest path from concept to part.

I now also use CamBam because of its incredible flexibility and power, along with the ability to do 3d. However, CamBam is not the most polished of products, and even though it is still in Beta, the latest version costs more than Cut2D to register.

One last comment -- Those using Mach3 will get a free CAM with it called LazyCAM. Development was dropped and it is an unfinished but workable product. The problem is that it assumes you already know a LOT about CAD/CAM and CNC. It is poorly suited for the beginner because of lack of good documentation, and the more advanced user has probably outgrown its capabilities. However, there are some out there happily using LazyCAM.

I recommend that this little primer be only the starting point for your investigation into what software might be right for you. The options and price ranges are seemingly endless.

A couple well-regarded higher end systems to look at for comparison:
ArtCAM
MasterCAM

Next up.... CAD

Question -- is any of this at all understandable/helpful?

paulrussell wrote:Question -- is any of this at all understandable/helpful?

For me? Mostly understandable! Good explanations!

Useful? Maybe! Will have to see what the future holds. If ever my physical health gets compromised CNC would become a stronger possibility.

Your efforts certainly have given me a better understanding of CNC machines! Thanks, Paul!:D

Yes it 's understandable Paul, I just wish that the interface was updated to USB, since most new PCs aren't even coming with parallel ports any longer.

tom_k/mo wrote:Yes it 's understandable Paul, I just wish that the interface was updated to USB, since most new PCs aren't even coming with parallel ports any longer.

I understand your frustration. As I mentioned, there is the Smoothstepper usb option for Windows, and there are also parallel cards you can add to a modern computer.
As I understand it, USB, in order to be as versitile as it is, has very loose timing standards. There is no guarantee that data will be sent at a particular time. This won't work for CNC which needs coordinated timing of three axes sending data for both direction and motion.
I suspect Smoothstepper uses some level of buffering and adds time stamps to the data stream in order to put the data back together and send out the needed parallel motor control signals.
So in effect if CNC electronics were updated to USB, they would need something like the Smoothstepper built-in, and this would roughly triple the complexity of motor control electronics (with corresponding cost increase).
Unfortunately, hobby CNC is currently a small market making do with low end pro gear or simple solutions designed by fellow hobbyists.

paulrussell wrote:I understand your frustration. As I mentioned, there is the Smoothstepper usb option for Windows, and there are also parallel cards you can add to a modern computer.
As I understand it, USB, in order to be as versitile as it is, has very loose timing standards. There is no guarantee that data will be sent at a particular time. This won't work for CNC which needs coordinated timing of three axes sending data for both direction and motion.
I suspect Smoothstepper uses some level of buffering and adds time stamps to the data stream in order to put the data back together and send out the needed parallel motor control signals.
So in effect if CNC electronics were updated to USB, they would need something like the Smoothstepper built-in, and this would roughly triple the complexity of motor control electronics (with corresponding cost increase).
Unfortunately, hobby CNC is currently a small market making do with low end pro gear or simple solutions designed by fellow hobbyists.

I've been in the market for a laser engraver. They're basically an XY milling machine with a laser beam instead of a dremel bit for a cutter. The Laser uses variations in wattage to get the Z axis. They work with USB. I have a Roland vinyl cutter which is basically an XY gantry device with the Y axis being the roll feed, and it uses a USB connection. It could be though that both of these devices have built in buffers.

tom_k/mo wrote:It could be though that both of these devices have built in buffers.

I supect so. The electronics hardware most people use for CNC are brain-dead simple.
But I'm sure as old pcs with parallel cards get harder and harder to find, neccessity will again become the mother of invention. For the time being, an old pc costs about the same as Smoothstepper, and keeps your main computer free of sawdust.
Now I'm off to enjoy "Beer tasting for wine lovers" in hopes of finding a beer my wife will like.
Tomorrow: You CAD!

CAD Software

This is the area with by far the most options and variety. There is no way I can even begin to cover a fraction of the offerings, but I will tell you what I've tried, and what I ended up buying.

First off, there is Sketchup, of which the free version though capable, does not export to the standard DXF file format. However, since the time I made my initial evaluation, there has been an explosion of Sketchup plugins, including a DXF export plugin, and plugins for export to various CAM packages.

Since I've not used Sketchup extensively, I can't comment on how well it works for CNC work. I've read that it is capable, but not the best choice.

Many people also use CorelDraw, which does have native DXF export capability. However the Corel DXF has compatibility problems with many programs, and the $59 add-on DXFtool is often required to circumvent these problems.

If you are familiar with Sketchup and CorelDraw, you will recognize that Sketchup is a 3D design program, and CorelDraw a 2d. The two programs that I use are similar -- the first is 2d (actually 2.5d) and the second a true 3d cad design package.

The first I have already mentioned in my discussion of CAM: Dolphin Partmaster. Dolphin is a long-in-the-tooth program with its roots firmly in the Windows95 era. However, it is also an incredibly powerful CAM system with a decent CAD.

The CAD is a bit frustrating for a new user. Lines, arcs and other elements must be defined as to length, radius, and position when first drawn, and cannot be easily modified or moved. Usually it is easier to delete a line and draw a new one. Resizing an entire object can be a considerable chore unless a special "parametric" method be used when it is first drawn.

However, once you are fluent in its ways, Dolphin Partmaster can be your fastest way from an idea, to a part. Dolphin is advertised at about $1000, but a call or email indicating you are a hobby user will yeild a VERY significant reduction in price. (Mentioning my name "Paul Harker" won't hurt -- and no, I don't get a kick-back.)

Much has happened in the world of CAD since Dolphin first arrived on the scene. Believe it or not, $1000 CAD packages have until very recently been considered the low end of the market.

Today's standards in CAD include Solidworks, which even today costs $3999 a copy. However there is a CAD solution called Alibre which until early this year was selling for $1000 for the basic version. In January they reduced all their prices to 10% of their former levels. This is an incredible value! This is not a program which was overpriced at $1000 -- the hopes and dreams of Alibre is that in this tough market that they will be able to make their money selling online in volume rather than with high prices through resellers who take a big cut.

So far it seems to be working, and I am a VERY satisfied customer.

What is different about Alibre is that much like Sketchup, it is a parametric design tool, and allows you to design not only parts, but also entire assemblies. Here is a link to an interactive PDF (An Alibre feature) of a Brian Law clock I recreated in Alibre: Law Clock 1
Click on the PDF for zooming and rotating of the clock.

Alibre has an interface that is much more user-friendly than that of Dolphin. I should add that both Dolphin and Alibre have significant learning curves. Both companies offer demo versions and have online videos and tutorials. Alibre sells a tutorial book, and there is a less expensive book available on Lulu or Amazon called "Learn 3D CAD - An introduction to Solid Modeling" by Ron Bowes.

However, at about $1000, Alibre's integrated CAM is not so affordably priced, so I was in need of a CAM solution. As I wrote before, I selected CamBam because of its flexibility, price, and basic support for 3d. Another plus is a plugin called "Alibre to CamBam Bridge" developed by a fellow hobbyist, Spiked3 allows seamless integration between the two products.

A bit of disclosure: AFTER buying Dolphin and Alibre, I have been involved with both companies. I have worked with DolphinCAD/CAM USA to develop a procedure to correct installation and licensing problems.
On the Alibre end, after a series of questions to Ron Bowes, the author of "Learn 3D CAD - An Introduction to Solid Modelling," I became active in proofreading an upcoming revision supporting the latest version of Alibre.
My only reimbursement for the above has been promises of reduced price upgrade to the next version of Dolphin, and a PDF of the new book.

Links:
Sketchup
Alibre
Dolphin Partmaster
CamBam
DXFtool
Learn 3D CAD
Alibre CamBam Bridge

In closing this mini-series about hobby-level CNC: I've only exposed the tip of the iceberg in my posts. Become an educated buyer, start small and simple, or both. This can be an expensive hobby, and is very addictive. (For example I feel I've already outgrown and am looking to sell my Bluumax in order to buy and/or build a bigger, better machine.) Regarding the machines themselves, there are a few MDF-based plans out there that will yield very capable machines. The two most popular of which, with free plans and a huge support base are: Joes2006 and the JGRO. Active forums for both can be found at CNCzone.com

Good luck!!

Paul,

Thanks for sharing your experiences with getting started in the CNC router world. I'm planning on building a CNC router later this year, probably using one or more of the Solsylva (David Wright) designs. I'll definitely be referring back to this thread as I get closer for software and any additional wisdom that comes up.

Trying to learn the technologies and terms is a daunting task in itself, definitely not something you want to just jump into without a lot of research and ideally a mentor.

Thanks and have fun,
Roy