Software that uses the Parallel port of a PC

[rgillard]

Hi Guys,

I have decided to build a very small prototype of my CNC Plasma machine before I take the plunge with the finished article. I have experienced with previous projects that building the machine of your dreams without any experience is usually biting off more than I can chew. My plan is to use some parts from old printers and steel to build up a mock unit that will draw the parts onto a sheet of paper. This will give me a much better grounding for when I go try build an 8 X 4 machine. I was hoping to use the parallel port to drive these small stepper motors.

Anyone know of a program that can output through this port?

Thanks

Ronan

[samco]

Few that I can think of off the top of my head...

Turbocnc http://www.dakeng.com/turbo.html
mach http://www.machsupport.com/artsoft/index/index.htm
EMC2 http://www.linuxcnc.org/ <-my fav

[rgillard]

Thanks Samco for your reply.

I have downloaded a version of Mach3 to my pc. Looks like an excellent tool.

In order to build my prototype cnc machine I have stripped down an old printer as my Y axis which has a built in bipolar motor.

I will build the X axis with a unipolar motor i have lying round and most probably a belt and some linear guides like weldtutors. I have an old motor controller board that I was hoping to drive the unipolar motor with. (rs 217-3611)

Datasheet is as follows.

http://www.rs-components.hu/ds/425_6241.PDF

My motor is a http://www.nisiki.net/Catalogues/Motors/NMB/PM55L.htm

I am a bit unsure of how to connect this motor up, partly as I do not want to blow my motherboard to shreds ( I have a breakout board in the post) but I would like to try and get things moving (well really turning).

I am getting signals out from mach3 on ports number 4 and 9 (stripped a spare printer cable)
about 3.6V for direction
and a pulsing for the step (cant actually see it on the multimeter but its slightly lighing up a LED when the X axis in Mach3 is moving)

What signal do I need to supply for the clock signal to the board.

Do I connect the step signal from Mach3 to the Full/Half Step port on the control board.

If anyone can point me in the right direction I'd really appreciate it?

Sorry if this post is in the wrong forum.

Regards,

Ronan

[Torchhead]

You can't drive a motor directly off the parallel port. First the max drive current for a parallel port is about 15ma (.015 Amp) and it's at 3.3 to 5 VDC. It's made to drive a MOS chip inside a printer. Even some motor drives need more current than that to operate.

All parallel port from software (EMC, MACH3, TurboCNC,) use Step and Dir signals. The Step would be considered the "clock".


You are going to spend a lot of time putting together a table that will in the end be worthless (except for entertainment). Few if any of the parts will be usable in a bigger design and bigger designs with bigger motors will need different gearing, slides and linear motion components. You will end up going a lot of it twice...true you will learn from the mistakes, but if you invest an equal amount of time reading and studying this forum and the hundreds of machines users here have built it will be like going to CNC college.

Tom Caudle
www.CandCNC.com

[rgillard]

Tom,
Thanks for your input. Its great to be getting advise from a CNC Guru. I hope to do a deal with you in the future on a plasma set up if you will ship to Ireland?

The main reason I want to build a small prototype is to learn. I am worried about spending 5000Euro on building a machine and making a mess of it. At the moment I cant even drive a stepper motor using Mach3 let alone try and control 3 axes and a tool. Id really like to gain some experience in simply controlling motors to start with. One step at a time and all that (no pun intended)

On the point of the small prototype I already have a Y axis..Straight out of a printer. I reckon I can make the X axis in one day out of scrap steel lying around. The way I learn is by reading something and then manually doing it. Its usually during the manual part that things start to click in my head. The prototype will not be extremely precise. I am just looking to move an x and y axis and try and get it to draw basic shapes to start. I have been reading the forum for about 6 months now and am just starting to get brave enough to try a table for myself. The other point is that I can work on this in my house rather than my cold workshop because it is so small.

With regard to connecting my current setup as discussed previously:

If I connect a 24V power supply to the stepper control board,

Connect the direction signal from the parallel port (Mach3) to the direction signal on the stepper control board

Connect the Step signal from the parallel port(Mach3) to the clock input on the stepper control board

Set the full step/half step input and the preset to 0. So I should be in half step mode .

Do I need to connect the ground of the parallel port to anywhere?

Do the signals from Mach3 need to be amplified in any way?


Thanks again for your help.
Ronan..

[Torchhead]

For your driver card:

A lot of your questions are specific to the driver card you have. The amount of drive current needed (from a parallel port) is determined by the inputs on the drive card. Some require no buffers, others may not work off the low current lower voltage outputs of recent parallel ports.

Your driver card may have an 'enable' pin that needs a logic signal (high or low?) to let the signals through.

No ground to the motor card = no signal. You have to have a ground return for the logic signals. On some cards/drivers the common is a +5 (supplied externally in most cases) and the step and dir signals are active low, meaning they are the ground return.

Sometimes trying to use poorly documented or poorly supported electronics can end up in a long learning curve that will cause frustration and often stops the project.

Tom Caudle
www.CandCNC.com

[millman52]

You might be interested in a learning kit that is avalible on ebay. Do a search for a store named "Hubbard CNC" Once you find the store look for educational or similar titled sub heading.

I'd highly reccomend you use at minimum a opto isolated break out board for your experiments. It will go a long way toward protecting your parallel port on your computer.

[rgillard]

Hi Guys,

Its been a while since I got time to spend on my CNC dream machine. I am still hoping to build a small prototype machine that will draw out shapes with a pencil first, before I plunge into the real machine. I got an hour or two of this test rig started tonight.

I cut two lengths of 42mm pipe that I had lying about.

I cut four pieces of 80mm x 3 box section which will be used to hold the pipe. (similar to weldtutors machine).

I made up two trucks for carrying the gantry

I also stripped down an old printer that I had. There is a bipolar stepper motor in it and I am going to use the printer ink head carraige as a Y-axis. I need to buy a bipolar stepper motor driver for this motor. Is there any way to find out what Voltage and current this motor needs to operate properly. It is an epson EM-293 8X0905A. I have searched Google on this and not found anything useful... Is there any test I can do to find this out. I also have to go and buy a DC power supply so I would like to buy one that will run these motors.I was looking at a triple power supply which outputs 5V and 12V @ 0.5A and 0-30V with adjustable current up to 2.5A Because this is only a test rig I wasn't going to buy top of the range control boards. If anyone could advise me I would be most appreciative.

Regards,
Ronan

[MonoNeuron]

Hi,
For the size 17 steppers that you have there all you need is an old PC computer power supply. It has the 12 volts for the motors and 5 volts for the controller supply. (if you need it). The more voltage you have the faster the motors will go but there is a trade off on torque which drops off considerably with speed and 12 volts is ok.
I built a small router a while ago using size 17 steppers and PC power supply to test how good they were and also try out some model plane 3 phase motors and they are surprisingly powerful for their size. I still had to gear them down a bit, about 3:1 , but they perform admirably. It took about 14 days to build with a lot of head scratching. :-)
Here is a link of it on YouTube.
http://youtube.com/watch?v=-cOkD-4wF2I

If you buy a driver then get a microstepping one with 8 or 10 steps per step. Don't go for the full step or half step unless you have a 5 phase drive and motor which give you 500 and 1000 steps per rev respectively. Half and full step on a bipolar motor is very jerky and adds to vibration and noise.
Have fun with the build.
Rich.

[rgillard]

Hi Guys,

I have bought myself a bipolar microstepping control board. I want to use this control board to move a epson 600 stepper motor. Even though this will be a microstep with a small stepper motor it will be a big step for my CNC Dreams. I have taken a power supply out of an old PC. There is 12V and 5V outputs. I hope I can use this to run the motor.

But before I go blowing up stuff I wanted to show how I'd set it up and then if there are any major mistakes maybe they will be pointed out before I make a mess of things.

Ok so in Mach3 I have set the outputs for the x-axis to

ENABLED has a green tick
STEP PIN# 3
DIR PIN# 2
DIR LOWACTIVE has a red x
STEP LOW ACTIVE has a red x
STEP PORT 1
DIR PORT 1


So I will connect my parallel cable from my pc to my breakout board and the step signal should be in pin 3 and my dir signal should be in pin 2. On my breakout board there is a 5V input and a ground. There is also a VDD (it looks like that anyway) and a ground. What am I supposed to connect to this. Im not sure whether I got literature with the board but I cant locate it if I did.

On my motor control board I need to give it a ground and +VE Input voltage. I was going to use a 12V input from the power supply . On the power supply (see pics) it gives the DC output voltage and currents. The model is PS-230WRE. Is this a 230W power supply? If so there is a +5V which gives out 23A, +12V which gives out 9A, -5V which gives out 0.5A and -12V which gives out 0.5 V. Which 12 V am I looking to connect to power the motor? 9A seems like a lot for a small motor and the board is rated for 2.5A 30 V Output drive Capabilites. I have kind of answered my own question there but clarification would be nice. Just for interest sake does anybody know which PC components run off which voltages? Also on the control board there is a pot which needs to be adjusted for VREF. How do I find out the Motor Current for the motor in the printer. The table is TAble 2 in the pic..I have looked for datasheets on them before and could not find them... There is a pic of the table included.

Wiring up the motor coils and step and dir should be straight forward after that.

Hopefully someone can tell me whether im on the right track or not...

Best Regards,
Ronan..

[rgillard]

Hello All,

I finally got home from China to do a little work on this project. I tried last night to jog a motor using Mach 3. Firstly I connected the breakout board to the PC and gave it the +5V from an old PC Power supply. I used some LED's and resistors on a breadboard to firstly make sure I was getting a signal to the breakout board. For the direction signal I got a voltage of 5V when the x axis was moved in a negative direction and approx 0V when the motor was moved in a positive direction. For the Step signal I got either a constant 5V or a constant 0V depending on whether the the active high was enabled or disabled. I was happy enough that I had signals to this point.

I then used the 12V output on the PC Power Supply to power up the stepper driver board. The green light came on and there was no smoke. I connected up the motor properly and the step, direction and ground connections. I left the enable input empty. When I powered the board up with the motor connected the motor locked up and I could hear a high pitched noise. However, when I tried to move the motor the signal from the breakout board was now only 1.8V (not enough to cross the 2.9V minimum high signal). Can anyone tell me what I am doing wrong. There are 2 inputs into the breakout board (see doc) Both Are 5V. On the power supply there are many connectors. I picked one randomly and took 1 ground and two 5V(red) cables off that one connector. Do I need to take the 5V from two different connectors?

If anyone can point me in the right direction I'd really appreciate it.

Ronan

[MonoNeuron]

Hi Ronen,
Make sure you have the pin on the emergency stop in Mach3 shorted, or set up, as this will stop the pulses from the program from being sent. (Pin 10 I think????) You have had it running so I think you already know this.
Also check you parallel cable to see if all the wires have the same resistance. I had one once that was different on some of the step pins which caused the step signal to go high or low whenever it felt like it.
Watch the set up videos on the ArtSoft web site to get some more insight on the program and how to set up the relevant pins/ports.
Also check for ground loops. Don't connect both ends of your shielded cables to ground etc.
I hope this helps.
Rich.