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Offline joea

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usb to printer port
« on: July 17, 2017, 09:00:43 PM »
so I have a  win7 with 32bit computer with just usb outputs, no printer ports. Can I use a usb to printer port cable to get a working system?
I know there are devices like smooth stepper or ucc that can be used for a 64bit, but I want to use a virgin system.
...joe

Offline ger21

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Re: usb to printer port
« Reply #1 on: July 17, 2017, 09:52:00 PM »
No.
But if it's a desktop, you can add a PCI parallel port.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: usb to printer port
« Reply #2 on: July 17, 2017, 10:04:43 PM »
Hi,
no...a USB to parallel converter may be adequate for a printer but it will not work for Mach.

The original Mach uses a 'parallel port' but really its much more than that. The PCs own CPU is pressed into service to create accurately timed
pulse streams to drive steppers/servos. For various reasons a PC CPU is not very good at producing accurately timed pulses, it a real credit to
Art Fennerty that he managed to get it to work as well as it does. In any event the CPU is our 'motion controller' and now it has to communicate
those pulses to each driver simultaneously, so it switches the output pins of a DB25 parallel port on and off, and can do so simultaneously.

USB is a serial communication protocol and so it appends messages front-to-back and sends off chunks. The messages cant arrive simultaneously,
they have to be reassembled. Worse USB send packet every few milliseconds so any sense of accurate timing is absolutely shot. If we use the PC
CPU to create pulse streams we need a 'realtime' communication protocol to signal the drivers. USB wont do, in fact neither will Ethernet despite being
way way faster. There are such realtime communication protocols unfortunately such solutions that exist for X86 Windows PCs are very expensive.

What can and does work is to send 'trajectory' data from Machs Gcode  interpreter thru either USB or Ethernet to an external motion controller.
In this case the controller is most likely to be an FPGA, DSP or industrial microcontroller. All these ICs are optimised for generating pulse streams.
Note that the trajectory data can be sent serially, it gets assembled into a buffer table on the controller board. The pulse streams generated by the
controller chip turn output pins on and of simultaneously as is required for the motors to be co-ordinated.

As for your situation you have a couple of choices.
1) Install a PCI or PCIe card with a parallel port and use the PCs CPU as your motion controller.
2) Use an external motion controller, the cheapest and simplest are a UC100, a PMDX-411 or a PoKeys 57cncD25

A parallel port card is likely to be around $20. You may have to do a bit of research...not all parallel port cards are equal. Also because X86 Windows CPUs
aren't the best as motion controllers you will have to accept some limitations on speed, timing accuracy and especially sensitivity to other software running
on your PC.

The external controllers I've mentioned are USB and the output connection is a DB25, you might call it a USB to parallel converter, but they are in fact
way way too clever for that. They are around $100. Speed and timing accuracy is good. You can use either 32 bit or 64 bit OS. These devices all have Mach4
plugins if you want to see what all the fuss is about. There are even better and more capable controllers as well but at greater cost. If you budget allows
it I would recommend an external controller, I have used parallel ports but I wont be going back now!

Craig
My wife left with my best friend...
     and I miss him!

Offline joea

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Re: usb to printer port
« Reply #3 on: July 18, 2017, 08:17:54 AM »
originally I had a system win7 32bit, but I upgraded this machine to 64bit   so I could use fusion 360; but then could not use mach3. It seems I do everything wrong first before I get it right . In my local I can not find a win7 32bit with parallel port.
I did find a xp with pp but that won't let me load fusion 360.

I want a virgin system as a base  product as a comparison for future systems, i.e. ucc, grbl, etc.
Is there anywhere I can download a valid legal win7 32bit product?

...joe

Offline RICH

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Re: usb to printer port
« Reply #4 on: July 18, 2017, 09:19:54 AM »
Joe,
Should be able to purchase a Win7. I had two used computers, one lap top and a Dell tower which are dual boot ie;
have XP Pro and  Win 7 64 bit. Was worth every buck to just let them install the operating systems.
The only thing is that you will be limited in memory in that configuration.

Fusion only worked on the lap top using Win 7 as it was faster processor than the Dell.
Looking to the future, sooner or later, an external motion will be required. Hopefully the dedicated pc for CNC will outlast me!

The real PITA, is all that software one has that cost a small fortune and requires repurchase to function on new PC's.

Dated, :D

RICH

« Last Edit: July 18, 2017, 10:05:07 AM by RICH »
Re: usb to printer port
« Reply #5 on: July 18, 2017, 01:33:25 PM »
Hi,

http://www.mini-itx.com/store/

have plenty of boards with built in parallel port and for under $100.You'll still need 32 bit Windows and all the usual limitations of parallel
port motion controller apply. I bought a dual core Atom board about 3 years ago and loaded it with Windows 7 Embedded Standard 32 bit, WES7.
WES7 is a free download and if you register with MS free for six months. Buying a licence is not straight forward, you need to sign an agreement with MS.
Cost me $200 NZD, about $180 US at the time. Used the boards built-in port and another PCI port with Mach3 for 2-1/2 years, no problems.

More recently shifted to Mach4 and an Ethernet SmoothStepper with the same 'little baby Atom board'. The low computing power of the Atom runs
Mach4 fine but I would buy something with a bit more go if I were to buy again, i3 with 4 gig would be good enuf....

I would suggest that you need one PC to run your machine and another separate machine for CAD/CAM. Your machine controller PC should do nothing
else but control your machine. Anything else loaded on it like CAD/CAM, internet, networking etc just increases the chance that your machine will crash.
If you don't believe me just carry on and when bits of carbide are whizzing around your face after having exploded I promise you'll be convinced!

Craig
My wife left with my best friend...
     and I miss him!

Offline ger21

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Re: usb to printer port
« Reply #6 on: July 18, 2017, 01:56:20 PM »
If you go to a 32 bit version of Windows 7, you won't be able to use Fusion 360. You do realize that, right?
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline joea

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Re: usb to printer port
« Reply #7 on: July 19, 2017, 07:12:11 AM »
Yes I know about the fusion 360 restriction. The plan now is to use a 64bit laptop for design and cam. Then move the g-code to the mach3 machine; is that doable?
Is a post processor necessary or available?
How are people doing this?
I found a computer shop locally that will replace the xp system with win7 32bit; I'll bring the computer there today.

.....joe

Offline ger21

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Re: usb to printer port
« Reply #8 on: July 19, 2017, 08:04:49 AM »
Yes, the Mach3 post processor is in Fusion 360, and is used when you export the g-code.
I transfer my g-code over my network, but many people use a USB stick.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline joea

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Re: usb to printer port
« Reply #9 on: July 19, 2017, 08:46:46 AM »
just thinking. Can generated g-code be placed in the cloud i.e. Google drive and then run on the mach3 machine?

....joe