Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: stankern on November 28, 2008, 12:34:01 AM
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i seem to have a problem that cannot be resolved .With the cnc machine powered up, turning on the computer (win xp) during booting the cnc machine drives the z axis down by 2.5 to 3 inches( loss of control ).
I have changed all the settings on the parallel port ,changed the cable to the gorilla cnc and tried 3 computers ,problem does not go away and i'm afraid to use the machine as it could damage the z axis or the gantry.i have been shutdown for a week so far.
I don't know what to do
http://www.youtube.com/watch?v=EngUvy3YKAE
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Check all of you shielding is properly grounded to one single pointand that none have come loose, especially the step/dir wires to your drives
Hood
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Thanks for the tip checked all that and its ok.But........
Well i found out that this is the way it is,if the cnc is powered up during computer boot up it will move, manufacturer says its how the parallel port works on some computers .I have tried 5 computers and they all drive the machine crazy dangerous.The gorilla people suggested a charge pump board that will stop this at a cost to be about $300.00,I'm starting to learn that this machine has no stops ,no preventions, its minimal for looking after a mistake or glitches and could cause serious costly trouble.
The manufacturer says its mach3 working through the parallel port if it was usb this would not be happening
I never knew this from the start and its less than 1 year old
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You could get a SmoothStepper for $150 which works through USB. All you would then need to do is plug your PP cable into the SmoothStepper (if you order the ribbon to parallel port cable)
You could also probably just get a decent breakout board that has the chargepump already and that will be a lot cheaper than $300, I have PMDX 122 and like them, think they are around about $80.
Hood
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300.00 for a 25.00 safety charge pump? criminal.go to cnc4pc . download the instructions. or, you could install an on/off switch on the power to your breakout board. turn it on only after the computer has booted up.
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all the ideas are good except the power switch as you're forgetting ,if the machine was doing a 3 hour job and it had a computer glitch and re-booted
and drove the router/spindle into the table especially where the steel support beam was it would be a disaster.
I feel the machine should have had some safety protection to protect itself.
Some ideas here are good and i will look into them ---thanks
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As you've found out this is a problem with booting a computer while your machine is on, the post and OS send signals to the PP, so as has been said use a charge pump, this will stop that happening.
I will add though that you should be using a UPS on your control computer, this will help with most computer problems and is a must when controlling expensive equipment.
Steve
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i have never had mach3 shut down or reboot during the execution of a part. while i dont do 3 hour single jobs,my plasma cutter has cut
hundreds of 12'x6' steel nested parts files of up to 25 minutes duration each. mach has never failed , as compared to the shopbot controller that would fall on its ass several times a day. put on the charge pump. it will shut off the power to the breakout board if mach goes wonky.
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thanks I will add the charge pump and I'm also going to try a pci lpt port add on , some say this cleans up the lpt port.
I tried 5 different computers and they all cause this whether they are new or old
I appreciate the help.
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thanks I will add the charge pump and I'm also going to try a pci lpt port add on , some say this cleans up the lpt port.
I tried 5 different computers and they all cause this whether they are new or old
I appreciate the help.
That would suggest to me your real problem lies outside the PC - something about the way your drive electronics are setup that causes an high noise sensitivity....
Regards,
Ray L.
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I'll also add that I've used my mach 3 controller several times with 3D files that have taken 8-9 hours on a medium sized mill cutting Brass and Aluminium at 300mm/min and Mach has never failed mid file.
Steve
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Gorilla CNC User,
Adding an additional PCI parallel port wont stop the problem you are having.
What is causing the issue is intentionally built in to the BIOS and operating system.
It is not a matter of a defective P.C. or parallel port
First the BIOS on the motherboard polls the port or interrupts
Secondly Windows also polls the ports and interrupts during startup.
The only solution is to add a charge pump and wire it so the motor drivers are disabled when Mach3 is not running.
Jeff...