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frustrated new guy
« on: January 30, 2008, 07:17:46 PM »
sure could use some help getting the steppers to do something besides lock up. here is the set up:

3 axis router w/ steppers
Mach 3 mill
Mdfly driver board
xp pro on dell 3.3V desktop
CNC 4u breakout C10 Rev 8.3/+5V from USB

Steppers will not run
Output on step pin (y=p4 for instance) when up arrow pushed and dro showing countup. Scope trace shows that signal (normally high,ether 3.3 coming
from port or 5 out of breakout board) low going pulses dropping 1v or less from high rail, not enough, certainly to trigger opto isolators on drive board.

I have uninstalled, including driver, Mach and reloaded. I have installed a second port and reconfigured.  Must be something to do with signal generation.


Why are the pulses not going rail to rail?

Thanks, Ralph Trimnell

Offline jimpinder

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Re: frustrated new guy
« Reply #1 on: January 31, 2008, 10:20:19 AM »
Ralph - dont get you ******** in a twist.

You are doing the big bang approach and something is wrong, You will not find the answer.

Disconnect any connections to your lathe/mill or the stepper motor drivers. The only thing you should have connected to your computer is the LPT1 cable and a breakout board. You will need to use your breakout board, because 3.3v out from your computer is not sufficient to drive the stepper drivers directly.

I suggest you use Mach 3 turn for these tests - it makes no difference.

Open Mach3 turn at the Manual page
Go to Config/Ports and Pins. On the Port setup and Axis selction page, ensure that Port 1 is enabled. On the Motor outputs page DISABLE all the outputs. On the spindle set up page, un-tick the Disable spindle relays. Enter Output 1 at Clockwise and output 2 at CCW.
Goto Output signals page and under OUTPUT#1, enter Port 1, Pin 1.

Check your breakout board and see what voltage is on Pin 1.
It should be 0volts (or very near) - If it is 5 volts or near have a look at Output Signals again and see if Output#1 is ticked as active low. If it is, untick it.
With your mouse, on the Manual Page of Turn, click the spindle icon.
The signal on pin 1 should now change to 5volts (or very near). Click spindle again, and it should return to 0v.

You can check all your pins in this manner and see exactly what is happening by altering the pin setting of Output Signals/Output #1.
The pin numbers you can use are on the page in front of you.

Once you are satisfied that all your pins are working correctly,
Go to Ports and Pins and enable the x axis, and enter port 1, pin2 and port 1 pin 3 on the step and dir positions (do not forget the ports)
Connect up your pin2 to the step input on your stepper driver card, pin 3 to your dir input and do not forget the signal ground connection, which can be any of pins 18 to 25. Connect a stepper motor to your driver board (with the appropriate power suppy) and see if you can control the motor using the jogging facility on the Manual page.

The rest is just more of the same. I used Mach3 Turn because it has a manual spindle on'off. The set up of Turn and Mill are identical.
If you have had any luck so far, you can change to Mill and try and set that up the same way.

Jim.






Not me driving the engine - I'm better looking.

Offline jimpinder

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Re: frustrated new guy
« Reply #2 on: January 31, 2008, 10:35:37 AM »
Re-reading this, you may be well ahead of me - (I don't have a scope) - but I remeber a post from a guy who was also using hobby CNC boards. The problem seemed to be with the earth, or more correctly 0volt line - and there were also some common lines that could be tied to either 0v or 5v.

The thing to ensure is that your computer has a good connection on the signal ground side, to your breakout board - i.e. one of pins 18 to 25 is tied to the 0v of your breakout board. There may be a jumper to do this if the pins are not readily available.

Best of luck - Jim
Not me driving the engine - I'm better looking.
Re: frustrated new guy
« Reply #3 on: January 31, 2008, 12:32:50 PM »
Ground is good, signals not mixed,
to simplify everything, I am measuring the pulses right out of the pci port, direction signals work fine so the port is ok but any pulsed  signal will not move more than 1 volt from logic high (or low if you reconfigure the logic) I am going to swap out computers to see if there is a problem with the pci chips not being able to handle anything at speed but this seems like a long shot. And I don'd see how the mach driver could tell the output port to put out a partial signal.  Still confused.

Offline Chaoticone

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Re: frustrated new guy
« Reply #4 on: January 31, 2008, 03:52:14 PM »
Quote
but any pulsed  signal will not move more than 1 volt from logic high (or low if you reconfigure the logic)

What are you checking the voltage with? I have sent you a personal message.

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: frustrated new guy
« Reply #5 on: January 31, 2008, 04:06:20 PM »
reading with hitatchi 20mhz scope and/or digital multimeter. I can see the puses just fine on the scope. it's just that they do not go full 
low (drop about 85mv below 3.3. This is not a logic signal.  I have switched computers but get the same results. Are there adjustment
controls for the driver to correct this? Ralph

Offline Hood

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Re: frustrated new guy
« Reply #6 on: January 31, 2008, 04:15:18 PM »
Shut Mach down and run the DriveTest.exe and see what it looks like, you will find it in the Mach3 folder.
Hood
Re: frustrated new guy
« Reply #7 on: January 31, 2008, 09:21:13 PM »
Yeh, that says everything is ok but now I cant even get the jog to work with the up down buttons.  I am not even at the stage of trying to get a real machine to work, but now there is no ouput to the port and I dont know how to fix it.  Think I can get my money back?

Offline Chaoticone

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Re: frustrated new guy
« Reply #8 on: January 31, 2008, 09:28:43 PM »
You want your money back or you want to get it runing?

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: frustrated new guy
« Reply #9 on: January 31, 2008, 09:36:12 PM »
More problems: driver test says "could not locate missing vectors". Like all stupid error messages, It does not give instructions for fixing the problem!!!!!