SIEG KX1 Mach3 advice needed please

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Mike Ginn

Well-Known Member
HMEM Supporting Member
Mar 5, 2020
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I have a SIEG KX1 CNC mill running MACH3 R3.041. MACH3 has been configured for the KX1 and I don’t know what that means. MACH3 runs on a very old Dell under XP Pro. The interface to the KX1 is via a parallel port.

I was advised at purchase by ArcEuro that MACH3 should be run under XP with no AV or internet connection due to the way the interrupts work. A built in parallel port was essential eg not a USB to parallel converter.

I will very soon need to change the computer. Very few (none?) have the old parallel port. I believe MACH3 will run under Windows 7 or maybe Windows 10.

Can anyone advise on running MACH3 under W7/10/32/64bit and how to “generated” the parallel port which is compatible with the KX1.

I should add that the system is currently working fine and I would be happy to stay with XP but the computer could die due to shorted capacitors (known Dell fault) and I would then be really stuck.

The KX1 is no longer supported in the UK but ArcEuro have spares but no technical support. I have not been able to extablish if there is a replacement board for the KX1 providing a USB interface.

Thanks in advance for your help

It is very likely that your new computer will have a PCIE slot onboard so you can get a parallel port for that. Verify that the new computer does have the PCIE slot and talk to the supplier about the parallel port.
I'm told that there are issues using the PCIE slot with MACH3. I agree that for most applications the PCIE would work BUT has anyone any experience of using the PCIE/parallel port board with MACH3/SIEG?
My KX3 connects by a factory fitted USB (newer mill) but still need to run on XP so just adding a port may not suit as it is getting harder to find XP machines.

Not sure what is needed to rum Mach3 on a newer computer but it can be done, CNC4YOU sell W10 laptops with Mach3 installed but not sure what they connect with so may be worth asking them
Thanks Jason
I spoke with ArcEuro who couldn't supply the USB board for the mill. I do know that MACH3 will run under W7/10 but I believe that the 32bit version is needed. Most computers which run W7 can run XP. As I said I am very happy with XP - its just the parallel port interface which is my issue - and I don't understand what the issue really is.

In my worst dreams (nightmares) I think about the cnc cutter flying of to x0,y0 and destroying the part due to errors in the interface!

I have a self built LMS 3990 (Sieg X2) CNC that uses a newer laptop and a PMDX-411 SmartBOB USB port. I'm running Mach4 but am guessing it might also run with Mach3. I bought the PMDX at Cabin Fever here in PA several years ago. The guy who was there was really helpful. I'm sure if you reached out to him via their website he would be willing to help you solve your problem. PMDX.COM - Products for CNC and motion control applications

Followup - I just checked on their forum. Unfortunately looks like the PMDX-411 doesn't work with Mach3. They offer a hobby version of Mach4 bundled with the PMDX. If you don't want to go that route it still might be good to reach out to get their recommendation.
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Mach 3 will run fine with windows 10. I would recommend the Ethernet Smooth Stepper (ESS), and an inexpensive break out board from CNC4PC. I have the board that breaks out 2 ports and uses screw type terminals. I use one of the small 6x6 in square x 2 in thick mini PCs with my setup. the computer takes little space, has HDMI video so I needed an adapter from HDMI to VGA. Has plenty of USB ports for keyboard, mouse and memory sticks for holding programs. I added a microSD card to save settings and such. Has ethernet and Wireless connections, Ethernet is hardwired to the ESS and the wireless is turned off unless I need to get access to the internet for downloads or updates. This is all running on a Sieg KX3. Use it for a couple small production jobs.
and I'm doing pretty much the same as kf2qd is except under win 7. The Ethernet Smooth Stepper with three different machines running under Mach 3. Those are my Grizzly G0704, Sherline mill and Sherline lathe. Each machine has its own parallel port, which is called out in the Mach 3 setup so I can't run three machines at the same time. Changing from one to the other was never something I tried to do quickly. To change machines, I just quit the Mach 3 I'm running and open the other installation.

Since Win 7 is out of support, either never connect to the internet or connect and get off the net as quickly as you can. I leave mine off the net all the time. Gcode files or anything else I need goes out to the shop on a thumb drive.
You will be pleased to know I have solved the problem!

Thanks for all the suggestions. I couldn't see how to apply most of them within my setup which is fixed ie the KX1 interface and the need for a parallel port. The suggestion of using a PCIE slot was a good one but I have an issue with this - I don't have such a slot! Let me explain:- I have limited space and the PC is mounted above the mill. It's a very small format Dell SX270 running XP and hanging under the shelf using the Dell bracket/foot. There are no expansion slots on the mother board - only the parallel port and USB ports. I really would like to keep to this size PC and I am happy with XP BUT the computer is about 19 years old which is not good. The mill was purchased in 2011 I think.

I would find it very difficult to install a larger PC format.

So my solution is to purchase another old SX270 as a possible replacement/spares. When I receive the SX270 (in the post!) I will load all the S/W and keep it as a standby.

Happy days!

Again thanks for your support which actually brought me to this conclusion.

At some point you will have to do an upgrade. Investing in 20 year old parts will not keep you going for long...
Hi Mike I got given a Dell Optiplex i3 PC which I have upgraded Win7 to Win10 & I am now running Win11 on it. Although it does not have a parallel port it does have a RS232 Serial port. Can you use a serial to parallel cable to interface with Mach3? Cheers Peter from OZ
I don't think I can make use of a serial port and I really do need a very small format PC. The OS and processor are not important - XP will carry on working and the processors seem to have a long life. The main weakness of the SX270 and all PCs are the smoothing capacitors which can be changed but its not an easy process.

Long term I might need to bite the bullet and switch to a larger format PC - and also generate the space for it. I could then make use of PCIE slots which the SX270 does not have

Thanks for your interest

Hi mike, the Dell optiflex 790 I have is about 12" x 12" x 3.5", but I have in the past had a similar HP. They called Small Form Factor (SFF) PC's & mine has a 2 x PCIe slots. Hope this helps. Peter
I could see that working. Some time ago I found a HP PC of the correct size which did have a parallel port. Needs further investigation.
Many thanks
Those old Dell Optiplex computers are mostly quite reliable; I have two 780 models, one for my lathe and one for my mill. But like all old computers with a spinning hard drive, it's not a matter of "IF" the hard drive will fail, but rather "when" will it fail, so I pull out the old spinning hard drives and replaced them with solid state drives: SSD. I live in Thailand, so I used a company based here,...there are lots of these hard drives to chose from, so shop around for what works for you.
Hi Toymaker
I agree. SSD are the way forward and really speed up old (and new) computers. I have to say I only use the Samsung brand and find their data migration software excellent. For MACH3 and a few other programs the small and cheaper SSD are sufficient.

If you haven't changed to SSD then you are missing of on speed performance - we are comparing (approx) microseconds to milliseconds in access time and of course they are solid state.

I have a Dell Optiplex 745 and have just bought a second-hand HP Pavilion Elite... because the Optiplex told me only 67% of my hard drive is good... It tries to self-repair but cannot.
The 745 is slow compared to the newer HP.
Is it worth buying an SSD hard drive for the Optiplex? - or will the processor still be very slow?
Do I need the old computer anyway?
Suggestions on a postcard please...
K2-TTI (Totally Technically Incompetent!)
Here is my virtual Postcard!

My main issue is the lack of a parallel port on modern/small format computers.

It is always worth installing a SSD. This is because the main speed limitation is the access time on a mechanical HD. The other improvement you can make is to increase the RAM to at least 4Gb. The processor is less of an issue. I run MACH3 on a Pentium 4 with 2Gb of RAM and a mechanical HD - shortly to be replaced with a SSD - it works just fine mainly because I don't have any of the microsoft baggage running and there is no AV or any other s/w to slow things up.

Most SSDs come with software which allows the complete operating system and data to be transferred to the new SSD.

I have a Dell Optiplex 745 and have just bought a second-hand HP Pavilion Elite... because the Optiplex told me only 67% of my hard drive is good... It tries to self-repair but cannot.
The 745 is slow compared to the newer HP.
Is it worth buying an SSD hard drive for the Optiplex? - or will the processor still be very slow?
Do I need the old computer anyway?
Suggestions on a postcard please...
K2-TTI (Totally Technically Incompetent!)

If you only use your Optiplex 745 to run one of your CNC machines, then you don't need a very large (memory size) hard drive,...I suspect your old machine's hard drive is much less than a Gigabyte, which means you can replace your failing hard drive with the smallest SSD you can find. The smaller the drive, the lower the price; the drives I bought cost less than $20 each.
Thanks Mike, sounds like I can do a sensible upgrade if I decide to keep the Dell 745. I'll probably replace the Jumbo jet sounding Cooling fan as well. But I don't have any CNC machines to drive from the computer.... Strictly hands-on stuff! - Turning hand-wheels and reading off dials, etc... (because I enjoy that stuff!).
But I thought it may be a suitably bigger (safe?- not sure?) back-up for the wealth of photos and documents I have. - Or is a simple back-up external hard drive just better?