CNC Router - New PC Parallel Port Pickle!

Hi everyone!

I've been driving my self nuts of late trying to fix this problem, so I thought id ask here for help please.

Ill try and put in all the info, to frame the problem correctly..

I'm a home CNC enthusiast, I like to just make stuff

CNC wood router
Old PC (HP) died of old age so got a new PC - HP medium format running Icore5 Windows 7 32bit - DB25 coming off the motherboard pins (checked voltage 3.4vdc) Fresh installation.
Gecko Drive G540 (just serviced as I thought it was at fault)

Mach3 loaded and running sweet, until randomly the machine sometimes it just does a slow x,y,z plunge which i cant stop from Mach3, I have to press the off button on the CNC Machine. This has happened whilst doing nothing or worse it's happened during a project which ruined it.

I ran the same code 6 times and it happened once (6th time) the only difference was I'm pretty sure it happened while i was going between tabs on Mach3.

I found that I could replicate the fault on demand which is a break through really, If I have everything on, M3 running and click file Entib or Merlino the machine will do a slow x,y,x dive that i can only stop by killing power to the machine.

I can also make it happen sometimes by opening another program while M3 is running at idle (autocad)

I dont think its M3 I think it might be something with the PC.

Sometimes when every thing is just sitting there doing nothing, the machine will shudder and sometimes start an x,y,z dive, while doing nothing at all, while diving the DRO dont show any movement, if i unplug the DB25 it still moves....


No idea what to do next, was hoping with lock down to get back into this.

Would be grateful for any help, happy to set up teamview session if needed.

Thanks in advance
Darian

The simple answer is to NOT do ANYTHING else while Mach3 is running.
Don't run other programs, don't open other files, don't change screens in Mach3.

Hi

Yeah I'm guessing that, but it seemed fine on last machine, but it doesn't solve the fact that it just does it randomly when M3 is just sitting there?

thanks though

D

I moved to LinuxCNC to avoid problems like this. Have not had any ghost in the machine type behaviours on LinuxCNC.

This is one of the reasons I moved from Mach3 to UCCNC.

I found I had to be move computer savvy with Mach3. I would go into MSCONFIG and disable any non-essential start up programs. I'd disable all sorts in Task Manager (programs/processes/services). I'd even remove programs that came installed with Windows. Basically I wanted nothing running in the background that was not essential to Windows.

UCCNC uses an external motion controller and all the step/direction signals, etc are sent to the motion controller board before they are actually needed, i.e. they are buffered. The real timing is done in the motion controller board. Mach3 on the other hand, when using the parallel port, is very sensitive to any interruptions from other services suddenly deciding to do something.

Hi

Thanks, i get what your saying.

Trying to make what i have work while in lock down..

Ill look into the UCCNC though

thanks for for the reply

Darian

I had to uninstall Autocad from my system to prevent random movements. Never had another random movement. I read somewhere that Autocad is trying to take control of the parallel port, thus causing the problem. Regardless if Autocad is open or not, it is running in the background. My computer is now solely for running the cnc system with Mach3 and Flashcut loaded.

Hello

I followed your advice and it still doesn't work as it should. For now i have revamped the old CNC PC and use that just for Mach and use the new PC for CAD/CAM. I'm now looking at the differences of the two machines in terms of driver & BIOS versions etc...

thanks very much

D

I have read a lot of talk about earthing the spindle and shielding the cables. I have not experienced earthing problems, but apparently this can cause similar problems. I do know that not all Chinese spindles are earthed inside the spindle. The 4th pin is just that and not terminated inside, that is if you are lucky enough to have 4 pins and not 3, which are definitely not earthed. Just a thought.

Hi

Thanks for that, Ill try it. At the moment using the old PC is working, so i have just been cutting out projects and having some pleasure rather than project out of the machine!
It is a Chinese spindle on the machine, again it's off the old PC works fine and the new one does not....


thanks very much for the reply.
D

Let's go back a few steps.
What was the old computer, an XP?
I assume you are using a parallel connection on the new win7. If so was it an original factory install setup you are using? Or is it a add on accessory parallel port card?
I have found identical computers can run very different in reality.
I have been through a dozen xp's and only found 2 that would run my routers. All have been reformatted first.Interestingly my friends router runs on an XP that won't run my computer and vise versa. We swapped computers and both have no operating problems.

Trying to run Mach3 through a parallel port, with or without an add-on card, is unreliable to say the least. This is KNOWN.
The problem is that Mach3 needs a special driver to make the XP O/S work with the parallel port, and W7 does not love (or even tolerate) this driver.
Actually, I am rather surprised you get anything from the PC at all.

If you are interested, read up on what Art Fenerty did with Mach2 and XP. He managed to create a port driver which displaced the Windows XP O/S from its top rank, pushing it down to 2nd. He had to do this because Windows, in any version, is NOT a real time system, and for controlling a CNC you MUST have real time operation. No choice.

Now, you have two main choices: a) go back to XP with an LPT port on the motherboard, or b) got with any later version of Windows but using an external pulse engine such as an ESS or something from UCCNC. A third choice is to drop Mach3 and go for something else - LinuxCNC or another minor player.

So why won't some XP machines run Mach3? Because they do not have the original MOSTEK parallel port chip on the motherboard; instead they use an add-on card with a different chip which tries to emulate the MOSTEK chip. To be sure, those add-on cards can run a printer just fine, but they cannot handle the bidirectional traffic which Mach3 uses. There are other bits of hardware which also relied on that old chip: they too died at the time.

There was a big stink when MS went to W7 because of the loss of the old LPT facility, but MS did not care. They may not have even noticed our complaints. This is why the Smooth Stepper was developed.

Also, do not put your CNC PC on the Internet, and strip most other SW packages off it. Some of those other packages keep interrupting to try to access the Internet for updates and to give your personal info away to the vendors. The interruptions are long enough to crash the CNC.

Cheers
Roger

Quote:

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Trying to run Mach3 through a parallel port, with or without an add-on card, is unreliable to say the least. This is KNOWN.

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As a blanket statement, this is not true at all.
Mach3 was designed to work with the parallel port only, and tens of thousands of users (most likely a large majority) still use it with the parallel port, with no issues.
The parallel port was the only way to use Mach3 for many years.

Having said that, the parallel port works best with old PC's that were made when XP was still the most current OS available, or even older than that.

If you want to use a PC made in the last 10 years, You'd be better off using a motion controller than the parallel port.

Hi Gerry

To the best of my knowledge, Art Fenerty's LPT driver, which is a core part of the original Mach2/3, can not be loaded by versions of Windows later than XP. It does things to the OS which the later versions of the OS do not permit, pushing the OS down one ring so that Mach3 can over-ride it. That was the genius part of what Art did. So one has to use an external pulse engine and skip the LPT driver - which is a far better idea anyhow.

I may be wrong, but that is how I read Art's doco on the internals.

Cheers
Roger

Lots of people use Mach3 with 32 bit versions of Windows 7. That's the last version of Windows that Mach3 can use the parallel port.

Hum, yeah, I could have misunderstood the boundary a bit. I know that W64 won't run Mach3 through the LPT (I tried), but I have not checked the 32 bit version. So, consider me corrected, and thanks.

Since switching to a Smooth Stepper, and especially to the ESS, things have become a LOT more reliable and stable. I will throw in a recommendation for the latest ESS driver from Warp9 for Mach3 on a lathe: with a good encoder on the spindle the threading has become excellent. Suitable for light commercial use imhe.

Cheers
Roger

Quote:

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Originally Posted by chopper13

Let's go back a few steps.
What was the old computer, an XP?
I assume you are using a parallel connection on the new win7. If so was it an original factory install setup you are using? Or is it a add on accessory parallel port card?
I have found identical computers can run very different in reality.
I have been through a dozen xp's and only found 2 that would run my routers. All have been reformatted first.Interestingly my friends router runs on an XP that won't run my computer and vise versa. We swapped computers and both have no operating problems.

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Hello Sorry late in reply, Back at work after lock down and and CNC machine is low on the list.

Thanks you very much for taking the time to comment, here are the answers....

Old PC (old faithful)
PC- 32bit Windows 7
Onboard Parallel port (not a card)

New PC
32 bit windows 7
Onboard parallel port , got a ribbon cable from the pics in the mother board.
Identical set up to the old machine, but still has the issue


Old PC runs sweet!


thanks
D

See my post #12 re MOSTEK chip.

Cheers
Roger

I bought a knock off Chinese Mach3 LY-USB100 adapter. My initial test proved it to be next to useless on my old controller. Chinese black box controller.
However 2 years later I have retrieved it from the junk box and have it running with a TB6600 4axis breakout board. It runs all 4 axis, spindle start/stop and flood control. Reading the B/S that came with it it is apparently capable of running on Win10 64 bit.
I have yet to try that but will in time. I purchased the Warp9 ESS sometime ago and run that with my number 1 router. At present I'm fixing a small bench top router for a friend and that is why I used the LY-USB100. I was surprised it worked but it does. If it works with Win10 it will make trying to get a XP computer none essential anymore.
I still prefer the Warp9 as the USB adapter could have all the problems associated with Chinese wiring for all I know. I wanted something bullet proof for myself. Got tired of the 12 computers I tried to run my Black Box controller on with out success. Worth the initial outlay and a very good backup forum.

A lot of cheap Chinese adapters will drive four axes 'OK', but they can't handle more complex g-code like threading and touch-probes. It's a 'you get what you pay for' situation. And you rarely get useful English doco.
Might be useful on a little 3D printer?

Cheers
Roger