Mach 3 Post processor?

[Howley]

I have seen postings from people that have used the Mach 3 post processor as opposed to the one that comes with your Shopbot.

1. Why?
2. What are the advantages?
3. What are the disadvantages?

If I'm reading the web page right, Mach 3 is only a $150.00. Not a lot to spend if there are advantages to be gained.
Are there additional hardware modifications to the bot that have to be made?

Any insight would be appreciated, or I'm I completely misunderstanding what I'm reading.

Thanks, John

[donek]

Mach3 is a completely different control software than the Shopbot Control software. I have a machine that runs on Mach3. While Mach3 may be extremely versatile, in my opinion it's garbage as a router control software.

A post Processor is part of your CAM software. It is what tells the CAM software how to format the code it generates for a specific machine. Much of what is generated for a mach3 machine will be recognized by the shopbot control system. While you might be able to use a Mach3 part file, there's very little reason to generate mach3 code to run a shopbot. If someone has created a part for a Mach3 machine and only has that code, you could try using it to cut the part, but that would be the only reason, as far as I know, for running a Mach3 part file with the shopbot control software.

[cnc_works]

Sean, I would be very curious as to the negative experience you had with Mach to describe it as garbage. I'm not defending Mach, though I use it. Just thought I might profit from your experience.

[dana_swift]

The Vectric software that comes with a bot can only output through the ShopBot post processors. If you want to output to Mach3 you have to purchase VCarvePro or Aspire, both of which come with Mach3 post processors as well as the ShopBot posts.

My assumption is that there is a contract issue between SB and Vectric that is being enforced to get the software tools included with the bot purchase.

The vectric software is a big incentive to purchase a Bot over brand X which runs Mach3, as its included in the purchase price. Shopbot is subsidizing that software cost, so that appears to be why the Shopbot versions only output ShopBot SB3 control codes and not G codes, or any other type.

If you use Mach3 (FYI, I have only heard great things about it! The above is the first negative review I have ever heard, wonder why?) Just purchase the full versions of the Vectric products, the post processors you get are fully documented and you are free to edit the posts to adapt to specifics of your applications. Not only that they have a post processor for just about every CNC mill or router under the sun. The list of supported equipment is very very long.

Vectric can be reached for more specific support questions, email always works well when I have contacted them as its a "long distance" call. They reply very quickly. Same thing with SB as everyone knows

D

[donek]

Sean, I would be very curious as to the negative experience you had with Mach to describe it as garbage. I'm not defending Mach, though I use it. Just thought I might profit from your experience.

I will restrain myself and limit my comments to the 4 biggest issues I see.

1. Any piece of software that crashes so frequently that the author includes a reset button on every screen is not ready for commercial distribution. Shopbot has never included such a button. They have demonstrated that it is not necessary to include one.

2. This is the shopbot screen


below are 4 of the 6 screens that are necessary to accomplish the same tasks that shopbot has cleverly incorporated into one screen.


If you believe that it is difficult to learn CNC try starting with the Mach3 interface. As a 14 year veteran , I still don't get the majority of the stuff on these screens or why they are even required.

3. If you don't or can't position your limit switches where mach3 requires, it is impossible to get their soft limits to work. This is the feature that prevents the machine from running into the dead stops, or right of the rails if no dead stops exist.

4. This may not necessarily be Mach3's fault, but G-code is not a language that is user friendly. There are a hundred or more commands all assigned a number. There is no intuitive logic to this language, so the beginner or expert is left needing a written table of commands and an explanation of what they do. The shopbot language is not only intuitive, it is built off the menus at the top of the control console, so it's not even necessary to open a book or look at a help document to discover what a command does.

While I will continue to use this machine run on mach 3 and I am endeavoring to develop an stripped down simple screen set for the CNC router user, I don't believe Mach3 is a useful beginners tool. Mach3 is the most commonly used control system for CNC machines, because it is relatively inexpensive. It is, however, the source of most new users frustration.

[Brady Watson]

There was a time when there was no such thing as a 4G board using microstepping drivers on a non-Alpha tool. Some decided to convert from running SB software to Mach for greater choices in motors and drives, which resulted in smoother cutting. This had nothing to do with the control software; It was about hardware choice. When the 4G came out, running Mach was a moot point because you could run any step and direction drive you wanted. Why people still want to run or convert to Mach on a SB is beyond me. It kills the resale value of the tool. To each his own I guess.

-B

[danhamm]

John, getting back to your question, is there any advantage to "you" converting to mach3, ( no) you would have to butcher your machine, meaning, remove the control board and replace it with a board capable of running mach3. and then have the fun of rewiring to that control board.

System controllers and software there are many, Shopbots, wincnc, candcnc,precix,and Mach3 and now mach4, these are just some I have used, all have there highs and lows and all do pretty much the same thing.
The thing with mach3 is most of the control software is open to oem's building there own front ends and some front end control operations.
I at present run Mach3 and am very happy with it, I use 2 different setups one for 3/d and another for everyday use.
That said consider it the...Ford versus GMC versus Dodge scenario.

[donclifton]

One should not knock what one doesn't understand. I have converted several shopbot and other routers to use Mach3. One could have both if they wanted by just disconnecting the motors from the shopbot controller and connecting them to a mach built system. In Mach I can build a screen just like the one that shopbot uses with all the same inputs and outputs. I'm in no way knocking shopbot but I just want to let you know that in mach you can write your own macro's to do just about anything you want, design your own screen, and buttons that call scripe's or macro's. You can do Tangentail cutting, run a lathe, Mill, Hotwire cutter or any other piece of cnc equipment you want. I have mine with a semi automatic tool changer, Laser center finder. Mach might not be for everyone but if you like to customize your setup mach is for you.
thanks
Don

[adrianm]

If you're able to customize Mach3 to that level then you can do the same with the ShopBot software as well. I run a completely custom written touch screen interface for my ShopBot. The only thing that anyone used to SB3 would recognise is the red panel. All the same macros/programs can be written in SB3 as well.

It definitely is horses for courses though. I used Mach3 for years to and didn't have a problem with it but I found the ShopBot software far easier to customise and modify (although I did write my own screensets and several macros for Mach3) probably because of the software languages I favour rather than any failing with Mach3.

IMHO SB3 is a much more user friendly control software out of the box compared to Mach3. Software designed for one purpose is always going to be easier to use than something meant for multiple purposes.

However if I had multiple computer controlled machines (not necessarily routers) then I would almost certainly be running Mach3.

[sam_harbold]

I ran Shopbot software for the past 13 years until I was forced to switch from Shopbot to MACH about a year ago. The switch to MACH was easy about a 1/2 a day including hardware changes. From time to time I get a job that requires me to hand write the code. I have written the code for jobs in both Shopbot and Gcode and to be honest I didn't find one harder than the other. As for the reset button on each screen it's not there to reset the software (I have never had Mach crash in the year I have been using it) but is there to reset an E stop activation. I can say the biggest difference with Mach is my machine is a lot faster and more reliable. My max jog speeds under Shopbot control was 3-4 IPS on the x & Y and .5 ips on the Z. With Mach max jog is 10-12 IPS on all three axis. The Z axis was a real problem under Shopbot control move speeds of .25 IPS were unreliable in that after several z moves I would be cutting either too deep or not deep enough. Cutting a 3D file was out of the question. With Mach I have gone as high as 4 IPS move speed on the Z and cut numerous large files including 3D files and the Z axis has remained constant.

Sam