computer spec to run MACH 3

[paulkane1]

i am new to all things CNC, and i would eventually like to build my own CNC MACHINE, i want to buy all my equipment over a period of time , because of money shortage, and i want to buy my computer , and MACH 3, software,and some CAM\ CAD software, to get me started. i would like a working area of about 4 feet x 4 feet, and i would like to engrave on wood, faces , logos, etc. could someone tell me , what basic computer spec do i need to start me of ?i need to know all the spec,HARD DRIVE, MEMORY, GHZ, operating system to run MACH3, is it WINDOWS XP, OR PRO XP ? what CAM\ CAD SOFTWARE , would i start of with ? is there any links to a free software programme ? is this the best way to start of , for a novice like myself ?get myself used to mach 3, and cam\cad software first, then go onto the mechanical side later of building the machine ? does it have to be a dual parallel port ? i would be very grateful for any help that anyone could give me. as i have said, i am a complete novice,and at times it seems a massive task that i am taking on , to build my own machine, i hope with the help of this forum , i will find it easier to finish the project. yours kindly paul

[wildwestpat]

Hi Paul.

Take this in small step but before you even start decide what you want to make. Size under the cutting head + material to be cut + accuracy + repeatability (Note accuracy and repeatability are different and unless you are going to supply parts or use parts made on other machines it is the repeatability that is important not the absolute accuracy.) Then the surface finish and dust or chip control.

Join the club where cash is king!

1. Mach3 runs most of its features from the free download edition. Pay only when you have got your machine running and need the extra features provided by the licensed software or are going into paid work on the machine.

2. Mach3 in not a heavy user of computing power but it requires real time control over the parallel port. (There are some fancy USB and Ethernet adaptors but these cost money and expertise to use.) There is advice on the type of computer on the Mach3 website. Must have Microsoft Windows operating system go for XP or Win 7 although Vista will work if you remove all its party tricks.) You do not need the high performance features so base versions from Microsoft are OK. Best to avoid lap tops as they use peculiar settings that may be difficult to inhibit as they are designed to save power and slow down when lightly used but since most laptops don't have a parallel port anyway that rules them out. I suggest a low specification desk top possibly a cast off as the demands are very low in terms of processor power. The shared use of RAM by the graphics can cause problems so an Intel mother board will be good but not one that uses the S3 graphics chip. The amount of RAM needs to be enough to run Windows + a bit fro running the program so a minimum spec machine is all that is required. It is possible to use a mother board kitted out with Ram and processor + a low capacity hard disk these are often available as a clearance bundle from electronics outlets but by the time you have bought Windows a second hand machine is a very attractive option. And you will need a display VDU or LCD.

3. Look at the Linux CNC software EMC2 as this is free and is well thought of.

4. Calculate or copy and existing known good design for motor size and gantry construction.

Rough out your design and price up parts for alternative drive mechanisms and keep an eye on eBay and any local sources including skips!

Read the many threads on the CNC Zone as it is a good source of both information and help.

Above all have fun as there is much enjoyment to be had but do stay safe as any machine tool can turn nasty when abused. Regards - Pat

[paulkane1]

thanks a lot pat for your help, there is a computer for sale here in belfast, the spec is as follows:- PENTINUM 4, 1024 MB MEMORY, 40 GB HARD DRIVE, WINDOWS XP, would this spec be suffice to start me of ?i get the impression from this forum, that MACH3 , seems to run better on WINDOWS XP, than on some of the other programmes, ? what is your opinion on that pat. what kind of CNC MACHINE do you have yourself ? did you make it yourself, and what kind of work do you produce . would you be fairly advanced on all things CNC ? would you mind if i keep in touch with you,on this forum, as i say i am a complete novice on all things CNC, but i am determined to have a go at making my machine. hope to hear from you soon, yours kindly paul, from belfast

[michaelthomas]

That computer would be more than enough to run Mach properly.

[ger21]

Mach3 will run a machine just fine on a 1Ghz Pentium III, but the interface may be a little sluggish.

It'll run on Windows 2000, XP, and 32 bit versions of Vista and 7.

Many users buy used P4's to use with Mach3. It's one of the most cost effective options.

[wildwestpat]

Hi Paul
That sounds OK if the price is right! May be you can strike a deal by putting up some bit of wall in exchange. Old PC's do not have much value so it would be a small wall! Check that it has the printer port - the big long socket with 30 odd pins. Also check that the video chip is not one of the S3 type as these can cause problems. Right click on the screen background and look at the video adaptor and see that it is not mention SIS or S3. With a P4 this is not very likely if it is a commercial built machine.

Suggest you try and get the Microsoft Windows CD as this should have been with the machine when new. It may also be a partition on the hard disc. IMO it is best to reload Windows if you are going to use Mach3 and not go with Linux and EMC2.

If you have questions stick with this thread and ask as there are a lot of people with experience of all sorts of different aspects of machine building and use.

Since you ask I am a retired engineer, I am currently converting a small mill and lathe for CNC control as I want to automate the small scale production of clocks. I got into CNC some fifty years ago when it was all punched paper tape or cards but that is history!

Good luck and keep posting in this thread.

Regards - Pat

[paulkane1]

thanks a lot for your help pat, can i ask you one question, why is it important to have the long 30 pin or so ,printer port at the back of the computer ?and why is it important to get the original OS CD , for microsoft windows,if it is not with the system, is it a major problem ? again thanks a lot for your kind help. yours kindly , paul

[paulkane1]

thanks a lot ger21, for your kind help.it is greatly appreciated. what i am picking up is that the best system for to run MACH successfully , is a P4,with windows XP , or XP PRO.thanks kindly for your help. yours kindly paul

[wildwestpat]

Hi Paul

Q. why is it important to have the long 30 pin or so ,printer port at the back of the computer
A. Because the printer port is a simple way of interfacing to the stepper motors. The signals on the printer port (LPT) are under real time control from the processor this is important as other output sockets have built in buffers which cause a delay and this is unacceptable to a CNC system. There are special adaptor boards that will interface between the USB socket and the CNC but these are another ball game and carry a price tag. That LPT is also bidirectional so it will support limit switches etc.

Q why is it important to get the original OS CD
A Since this is a second user machine and may have had programs installed that have only been partially removed. My recommendation for CNC is to re-install the operating system and to use either a new hard disk or reformat the existing one. For this you need the CD. Yes you could use a friends CD if it is for the same operating system and use the 25 character product registration key for your machine NOT theirs! This brings us to the really important issue - is the Windows on the machine genuine? If so it will pass the on line registration check.

Have a look on the ArtSoft web site where there are videos and documents galore. ArtSoft USA - Video Tutorials

I hope the price is not hard to pay as you people say in NI. - for a good deal.
Regards - Pat

[paulkane1]

thanks a lot for your quick reply pat, greatly appreciated. as i say i am a novice to all things CNC, so i am going to take my time , and learn as much as possible, some times it seems a daunting task, to grasp all the information that is flying about on this particular subject. just treat it as if i am back at school. i will keep in touch with you, if i need any other help. yours kindly paul

[ger21]

FYI, a parallel port is 25 pins.

[atypicalguy]

I am cutting wing-shaped female tools from MDF using Rhino and MADcam. I was testing a new toolpath today with some high rapid speeds and the stepper action was reasonably smooth until the machine tried to cut a complex arc at each end of the wing while roughing. With the feed speed cranked up on the X and Y axes, like 90ipm on the long axis and 50 on the short axis, the machine would get extremely jumpy, seeming to stop and start several times per second trying to cut the path.

I'm wondering if the computer simply cannot drive the thing that fast, so the motors have to stop and wait for the next instruction from the computer, then restart, then stop again, etc. It is an old Dell OptiPlex 110 with 450 Mhz or so. Pulse train looks fine at 25000 on the test.

Is there a simple way to exclude this? The path runs fine when I slow it down. I don't think I am exceeding the ability of my motors as they are 1200 in-lb and the machine can go 600 ipm. It was rapiding just fine at 200 ipm on this file on one axis.

Thoughts appreciated. Thanks.