Messages

71

General Mach Discussion / Re: Only X-axis motor is working

« on: March 28, 2018, 12:17:12 AM »

Weird. I don't see an edit icon. I would have edited the above post.

I felt that I should check the cable more and discovered that pin7 didn't connect to anything.

The cable is in the garbage now.

72

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 11:57:37 PM »

Ahhhh ...
I am not entirely sure I understand your diagram. If it really means that you got continuity between p21 at the left side and pin4 at the right side, then I am boggled. That is NOT a DB25 extender cable!!!!!!! I dunno what it is!

That is exactly what it means. I got continuity between pin 4 and 21.
I can't reassign that.

If I couldn't get another cable tomorrow, I'd split the cable and manually rewire it all for a test. For now I'll wait.

73

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 11:29:48 PM »

Pin 2 on the parallel port emits on pin 3 on the cable.
HANG ON!
Where are you getting your pin numbers from?
The pin numbers seen on a ribbon cable connector are NOT the same as the numbers we use for I/O pins on the PP. In particular, pin 2 in CNC numbering scheme is pin 3 on a ribbon cable.

Cheers
Roger

It was a simple continuity test.

Here's where I stopped

74

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 10:21:01 PM »

Here is one absolute that I got from my diagnostics.

Pin 2 on the parallel port emits on pin 3 on the cable.

It's a brand new cable and it's bad.

I suppose I could use a multimeter and map out the cable to find out if all the pins are off one or if they are all connected or whatever and then remap the program based on the outputs.

Or I could buy a new cable.

75

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 03:40:50 PM »

Hi,
sounds like the parallel port of your PC has 3.3V output levels.

Is the BoB you are using 3.3V capable? If it is expecting 5V inputs it might describe your situation.

Craig

That's a good point.
I should look into that further.

Thanks for pointing it out.

76

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 10:03:07 AM »

It appears those pins are setup as direction pins.
If you move those axis in the other direction the
pins will change state.

olf20 / Bob

I was just doing what the video was saying to do. It was only to check to see if I was getting proper responses from the output pins on the parallel port.

I discovered that I can get all of the 8 "data" pins to function properly. I also discovered the left and right arrows on the X axis don't control both directions. Left controls the minus movement but "X" key on the keyboard controls the plus movement.
Likewise for Y and Z
Down arrow controls minus on Y and the "Y" key controls the plus.
Page down controls the minus on Z and "Z" controls the plus.

So, the parallel port is verified as functioning properly. Tonight I check the parallel cable the same way. If the parallel cable is working normally then I have verified that the BoB is the culprit.

77

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 01:12:52 AM »

So, here's where I am.

I took a look at this video
https://youtu.be/uglCm_qsojk

Then I did what the video said.
I hooked the ground to pin 25 and then the positive on the multimeter to pin 2. It was reading 3.3V
I checked pin3 and it read zero. Then I pushed the up and down arrow and the output changed to 3.3V
I checked pin 4 and it was zero. I used the page up and page down and the pin read 3.3v.

The interesting part was that, once the pin went high (3.3v) it wouldn't go low again.

Still trying to figure out why X will work, though.

I only tested pins 2,3,4 this way. If they don't go low then there appears to be a problem in the computer.

78

General Mach Discussion / Re: Only X-axis motor is working

« on: March 27, 2018, 12:09:14 AM »

Hi,
blue LEDs have a forward voltage drop of about 3.3V and so with a what may be a 3.3V port the LED
would not light reliably. A red LED has a forward drop of around 1.2V and is suitable.

Craig

Red LED made no difference in the diagnostics.

79

General Mach Discussion / Re: Only X-axis motor is working

« on: March 26, 2018, 11:19:30 PM »

OK, here's what I did, knowing I'm not sure of what I'm doing.

I disconnected my printer port.
I took a blue LED (I can switch a red one in if needed) and added in a 680 ohm resistor in series.

Using this image as a reference



I connected the cathode to pin 25 on my printer port.
Then connected the resistored anode to pin 2.

Using Mach3, I tried to cycle the X-axis. The LED didn't change.

I reset the X-axis pin2 to low and nothing changed on the LED.

Bottom line is that I don't know how to check the data output on the pins on the Parallel port with success.

80

General Mach Discussion / Re: Only X-axis motor is working

« on: March 26, 2018, 09:39:24 PM »

Oh.
May I interpret that as meaning that you could not get any signals from the Parallel port connector itself, except from the X axis pins?
If so, then I make the following deductions:
Mach3 and the parallel port driver are correctly installed and able to drive the X axis.
The other parallel port pins are not working, although you could check this further by trying to move the X axis onto some other pins.

All of which means, to me at least, that the parallel port chip on the computer motherboard may be damaged. If so, this is not recoverable (unless you replace the MOSTEK chip on the motherboard).
 If correct, then your next choice is to buy an external pulse engine. I strongly recommend against a USB version as they are very prone to noise interference. Buy an ethernet one.

Cheers
Roger

I don't have the tools necessary to check the parallel port pins. I suppose I could monkey rig something but I'm too lazy today.
What pin in the parallel port provides a +5 signal and which one provides ground?