[Rocco85]

Hi, I'm new around here, I've just started investigating the possibility of building a CNC router or mill. One of the first things that I've discovered is that it looks like I'm going to need a computer with a parallel port. My current computer is a laptop with USB ports only. I've come across the adapter card described below, will this work? And if not, what do I need?

PCMCIA CardBus DB25 Parallel / Printer 1-Port Adapter, RoHS Compliant
• Compliant with 32-Bit PCMCIA CardBus PC Card Type II standard
• Single DB25 Parallel connector
• IEEE 1284 compatible parallel port, supporting SPP, PS2, EPP and ECP modes
• Transfer rate: up to 1.5 Mbps
• 16-byte First-In-First-Out (FIFO) buffer
• Support Hot-Plug feature
• Work with Microsoft Windows 98/ME/2000/XP/Server 2003/Vista 32bit&64bit, Linux or DOS

[Dorsal]

Probably not.
A CNC controller card needs signals on 16 of the pins, as I recall - and the VAST majority of those adapters only support data output on enough pins to run a printer (6 pins of data). I investigated it myself a while back, and decided to buy a SmoothStepper card to run my 3-axis CNC from my Dell laptop. Although the laptop actually has a parallel port, there is a file in the root directory of Mach called drivertest.exe that showed the signal quality from that port could never run the CNC controller card. The SmoothStepper runs from a USB port but outputs to a DB25 port which you then connect to the controller card. The SmoothStepper is designed for running CNC machines, and it costs only $20 more than a good, usable PCMCIA-Parallel card was going to cost.
Go here: http://www.warp9td.com/index.php to read up on it and don't be intimidated by their "waiting list", the product is well worth the wait.

[Rocco85]

Thanks for your input. Anyone else confirm, refute or just comment?

[Zygoat]

im not going to say he is wrong, because i dont know for sure. but most of the manufactures recommend a second port if you need more inputs and outputs for your machine. i have to think that quite a few of the guys one here are running there machines on them. but like i said i have not confirmed this. maybe a source for your info?

i have been building computers for over a decade. never heard of it. but i wasn't running cnc's either.

[mkc2]

Hi all

I have used one of those cards to control my cnc router without having any problems, but they do recommend using a desktop pc over laptops.
Just my input.

Cheers Michael

[markcomp77]

Anyone else confirm, refute or just comment?

lpt via pcmci is possible (I checked this), but...
but especially laptop is not stable source of frequency

[Torchhead]

Virtually all PCI port expansion cards support bidirectional I/O (EPP or ECP) and work fine with MACH or EMC to generate pulses and do high speed I/O. We have used hundreds of cards (average cost about 20 bucks) that install and work perfectly. We typically shop for cards using the MOSCHIP chip set since their drivers seem to work with no problems on XP. The brand names change a lot but the boards all look the same that have the same chip set and use the same drivers. Spending more money on a port card will not insure it will work better or do anything the cheap one will do. The 14.00 ones on www.newegg.com work just as good as the 30.00 (

Another option is to consider a refurbed Pentium 4 box. For about the same cost as a Smooth Stepper you can own a 3Ghz Dell with 1G ram , internal Parallel and serial ports, and XP Pro loaded. There are several stores on EBAY that will ship you a desktop (mini-tower) for around 139.00 to 169.00 bucks. They make perfect CNC control PC's. The PC running your table should be considered "dedicated" to that task. Your design and CAM functions are better done on a separate computer and the cut files transferred to the Controller PC via Ethernet or Memory Stick. After losing 2 laptops to misfortune and shop dust we no longer use them for anything in the shop. Laptops are for working portable and are great for travel and field work.

PM me for links to sources for cards, and the refurbed PC stores.

TOM caudle
www.CandCNC.com

[markcomp77]

JITTER -->> measure of usefulness of pc-computer in cnc traffic control
http://wiki.linuxcnc.org/emcinfo.pl?Latency-Test

[Rocco85]

Okay, thanks guys, I think I'm going to take a $20 gamble and try one out.

Follow up question: once I've gotten the adapter, is there some Windows software available that I can use to assess it's suitability?

[Torchhead]

After the install open Windows Device Manager and make sure the port shows up as an LPT (number does not matter). Then open the resources tab for that port and write down the hex BEGINNING address for the card. Then configure the PORT in MACH to "look' at that address. If it's done right you should see the first 7 or 8 LEDs across the top of the RAW PORT BITS monitor in Diagnsotics tab ON (green). If they are all greyed out then MACH is not talking to the PORT address correctly.

You will need to have MACH setup to read the proper inputs so you can test. The assigned inputs on a simple BOB are pins 10, 11, 12, 13 and 15. Normally pin 10 is reserved for E-STOP so you have 4 inputs you can use.

Outputs are mapped in the Ports & Pins and Motor Outputs (for step & dir signals) and are typically pins 2-9. The other outputs pins 1, 14, 16 & 17 and are open for use with either functions. Often 17 is used for Charge Pump.

TOM caudle
www.CandCNC.com

[Rocco85]

I'd rather not do an install on MACH just yet, are there any small stand alone programs that'll let me test the port?

[mlabruyere]

There are also specific modifications you need to make tot he OS on the laptop. The reason is the power management functions used on the laptop may casue issues for you. Here are some of the details:

http://www.machsupport.com/forum/ind...ic,3378.0.html

[mlabruyere]

I'd rather not do an install on MACH just yet, are there any small stand alone programs that'll let me test the port?

Maybe but the one in Mach is looking for specific aspects and reporting them to you that other programs may not.

Why the hesitation on the install?

[Rocco85]

Why the hesitation on the install?

I'm still at the very early stages of my investigations and at this point, I have no idea if I'm going to be using Mach or some other software. I hate having unused software installed on my machine and I hate installing software only to uninstall it later so I'd prefer to wait with the install until after I've made some decisions concerning software.

[Torchhead]

Not sure I follow that logic train but ......the choices for PC CNC control software narrow down pretty quickly if you want to spend less than 500.00. IF you want to run with Windows as the OS then the list is even thinner. I don't know any better way to evaluate software than to load and use it (unless you believe the pretty boxes at the computer store).

You can download, install, run and test MACH from the DEMO program for FREE. It will let you run up to 500 lines of code. You can't use some of the advanced features like the built-in THC options but all other common functions work fine.

You don't even need a parallel port hooked up to demo MACH (especially if you don't have hardware to hook to it). I run a version on my desktop to use during phone support and to write software that has noting hooked to it but air.

TOM caudle
www.CandCNC.com
Totally Modular CNC Electronics

[Rocco85]

Be that as it may, I'd still prefer not to install the software until I'm quite sure I'm actually going to use it hence my desire for a small standalone program, are there any?

[hemsworthlad]

Hi Rocco, . . .Just my 2 cents worth.!!

Like Tom dont understand the logic regards Mach, it's not a registry destroyer, go for it because the time spent learing it's hidden talents now will be well worth the investment in time when you start cutting. . . . plus it's free. . . . .For now.!!

Regards the use of a Laptop over desktop, again Tom is right.
If you have the room and right atmospheric conditions in the shop then a dedicated desktop is best esp in monetry terms. . . .BUT . . . If like me you live in a damp climate then a laptop becomes a better option.
Tom i know from other post's doesn't seem to be a fan of the Smooth stepper but i can tell you from using 1 it's a great piece of kit and for me well worth the money because it allows me to use a laptop and still get a super fast and smooth pulse train that NO desktop using PP can match.
Plus it's like having 2 PP and lots more IO which is also nice, Yes it's not the cheapist way but if you want to use a LT it's by far the best IMO and takes away all the problems associated with LT's.

Well think that's enough said and good value for my 2c's.

Cheers
Dean.

[AJA]

I have a different situation which I think would benefit from a parallel port adaptor “T” plug.
I would like to access different pins in the printer cable for use with other hardware without going to the breakout board. I have thought about using an A/B switch and jumping the switch on the pins I need from the added hardware printer cable to the printer cable from the breakout board. A “T” plug adaptor at the PP at the computer would make it easier.
Is there such a plug available?
AJ