CNC: Lining up the ducks. Asking software questions...

Ray C

Ray C

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All,

I've been thinking more about CNC for milling and like many other things, the hardware is half the issue and software is the other half. I'd like to get folks opinions about controller software. I downloaded the user manual to Mach3 -easy to understand and I see what it does. Can folks recommend other packages? BTW: I'm looking to do my homework up front and get a package that's mature, has growing room built into it and works with minimal fuss. Professional software development is part of my real-life job and I have no interest in playing games with half-baked freeware etc... Now in the next breath, I don't wish to spend thousands of $$ and would estimate my budget for the software part at/around 500-700 (USD). Either Windows or Linux is fine with me.

Also, if anyone cares to share their experiences about why they switched form one package to others over say, the last few years, I could probably gain some insight about what to watch for.

FWIW... For CAD software, I'm using Alibre Professional but, I haven't updated to the latest version which came out a few months ago. I'll get to that soon. Also, hardware-wise, I'm thinking of the Precision Matthews PM45-CNC variable speed machine as the starting hardware -only because, I'm completely familiar with that style manual mill -and I trust the daylights out of Matt.

This overall endeavor will probably be my fall and winter self-improvement effort and I'm starting the homework process now.


Ray
 
You may want to peruse the "CNC Basics" sticky in this forum, we covered some of what you are asking, but maybe not all.

I think the 2 most common PC based controllers are Mach 3 and LinuxCNC. Here is an interesting writeup op a survey over at CNCCookbook

http://blog.cnccookbook.com/2012/08/02/cnc-control-market-shares-what-are-the-most-popular-controls/

Personally I use LinuxCNC, and have been very pleased with it. It is free, and very solid. I don't have much experience with Mach3, mainly due to the fact that I don't much like running windows, and I take other options when I have a choice. There are a lot of "flame wars" about which is better, but for any small machine with up to 4 axes, I don't think it matters.

Some things to keep in mind

* Mach has a free demo, so you can play with it (not sure if there is a "simulation" mode)
* Linux CNC is free, and has a bootable CD so you can play with things.
* The main thing I find annoying about LinuxCNC is that you cant' "touch off" in the middle of a program, unless you use a probe. I understand that Mach can do this. I have worked around it
* Linux CNC supports rigid tapping (which I got working recently.. and is awesome). I am not certain if Mach can do the same thing, or if this is an issue.
* LinuxCNC cannot use any of the available usb based control boards. Keep that in mind when purchasing hardware.
* If you go with LinuxCNC, I recommend the hardware boards from Mesa. They don't make it very easy to figure out what you need, but I have gone through the pain, and can provide some guidance. The boards were cheaper than I thought, and were much easier to wire and configure than a simple parallel port breakout board.

I think Mach only runs a couple hundred, so that leaves you a bit of cash left in your budget. If you don't already have a CAM package, you will have to consider that. I currently use AlibreCAM, and it works, but is quirky. I know others have used some sub $300 packages with some success. There is also a free version of the MECSoft CAM suite called "FreeCAM". It's kind of a "one trick pony" in that it only does 3d contouring (and only one type of 3d contouring at that). This would be very slow if you are doing mostly 2.5d stuff.

I would also recommend getting a license for GWizard if you have money left in your budget, I find it very useful, especially for looking at tool deflection.

I think the XX45 type machine is well suited to CNC. If I had it to do again, I think I would start with that type of machine rather than a knee mill.

I would also recommend looking at Syaminab's GCode course [thread]12278[/thread]. Even though I have a CAD/CAM package, certain things are still easier to just code by hand.
 
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I'm using Mach3 and I like it. In between the CAD source and Mach3, I'm using D2nc. It has it's limitations. Go to their web site and check out the list of things it will not do, like ellipses and filets. I've been able to work around these, but it takes more time in CAD. Do your homework on the intermediate software and find something that will do everything you need.
 
I would vote for Mach 3. When I built my CNC in grad school, we tested several options, and we all agreed on Mach 3. Mainly for the great support!

Don't forget that you need an intermediate program to generate the G-code from your drawing. These are generally called translators, or CAM programs. The drawing that you generate from Alibre, generally a DXF (2D) or STL (3D), would be imported into the translation program, where you set the options for the machine. This is where you specify the feed rate, machine work area, and a host of other options. This program will then generate the G-code file that Mach, or another machine controller software, will use to control the machine.

We ended up using two different translator programs, Vectric Cut2D, and SheetCAM. Our machine was dual purpose, router and Plasma. We used Vectric for the router, and SheetCAM for Plasma. SheetCAM was really made for torches, plasma or otherwise, and has a variety of options for pre-heat, dwell, lead-ins, etc. You obviously won't need these features for a mill though.

If you plan on doing lots of 3D work, look at Vectric 3D, or if you REALLY want to get fancy, RhinoCAM. ($$$)

How are you planning on motorizing the Mill? Steppers or Servos?

Good luck! Building a CNC is a really fun and difficult process, but amazingly rewarding when you see it move the first time.

-Cody


http://www.vectric.com/index.html

http://rhinocam.com/index.shtml
 
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Mach3, cambam and cutviewer for me. I strongly advocate getting a simulator regardless of which CAM package you go for - It can save a lot of aggravation. All of these packages have unrestricted evaluation modes and there is a good deal on cambam + cutviewer. CAMBAM has a large following and a good forum.

If you don't have any exposure to CNC, I suggest joining a local makerspace (if there is one near you) and getting some exposure to CNC there.
 
My Tormach has Mach III and in the two years I've had it, all I have ever done is run it. I work in stages. Some weeks I'll work 70 or 80 hours, then some weeks I'll work 3 hours a day. It just depends on what I feel like.

I use GibbsCam to program by machine, and so far, so good.
 
Guys,

I'm in the office today -can't talk too much right now. Here's few more thoughts...

I've programmed in computer assembly language, micro-code and machine code for a good long while. I'm also proficient in "C" programming. I'm old-school computer guy. Point peing, G-code does not scare me one bit. -Just another computer language...

I have Alibre Professional CAD and consider myself at "intermediate skill". It has some CAM plugins but not sure which ones. Alibe just went thorough a re-vamp -fortunately, I paid the maintenance fee. I don't know much about the CAM part of the equation. For starters, I have no reluctance to writing my own G-Code.

I just want to avoid the pitfalls of software packages that don't work and play nicely together.

The PM-45CNC is out of the box ready for CNC. Has all motors, controllers etc. I don't know much about it but will find-out. My heart is not set on that machine but, since I already know the non CNC version, it's a natural starting point for me. http://www.machinetoolonline.com/PM-45M-CNC.html

My reason for digging this up is because I understand Mach4 is coming out (already available). Want to know if this is a good time to adopt it or switch to something perhaps better... Also, I need to start getting up to speed and getting my head wrapped around this and need to "get conversant" with you guys.

Ray
 
One more thing. Alibre CAD (now called GeoMagic) is partnered with MecSoft and SprutCam. See link here: http://www.alibre.com/company/alibresolutionpartners.asp

There are no prices listed for these CAM plug-ins... -You know what that means! If you have to ask,you can't afford it. So, anybody know about these packages and roughly what they cost?


Ray
 
You can check out Tormach's pricing for an idea (they are probably going to be a little lower than going direct.. but you never know). I think I payed about $1200 for my copy of AlibreCAM.
 
Ray C said:
I don't know much about the CAM part of the equation. For starters, I have no reluctance to writing my own G-Code.
Ray
Click to expand...

If you are capable of writing your own G-code efficiently, there is no reason to invest in anything other than a machine control software like Mach.

I guess it depends on what you are making, but writing G-code by hand is laborious. Anything besides simple circles and squares gets complicated quickly, and even these simple shapes require calculating the offset for the bit size and shape.

I would HIGHLY recommend a CAM software. It takes the CAD drawing you have doubtlessly already generated, you tell it about the machine, tooling, etc, and it makes all of the calculations for you. It is a HUGE time-saver, even for simple items, and practically mandatory for the commercial environment.

These programs aren't extremely expensive, not sure about the Alibre plugins, but the software I use is ~$150 per seat (Vectric). And it even has rudimentary CAD built in!

-Cody
 
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