MechMate CNC Router Forum

Go Back   MechMate CNC Router Forum > After Building the Beast - Operating , Troubleshooting and Maintenance > Troubleshooting
Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Reply
 
Thread Tools
  #1  
Old Sat 28 March 2009, 04:47
martin77pl
Just call me: Martin #39
 
Wroclaw
Poland
There is some change in the motor reaction and lights on the geckos. But still nothing close enough to wha it should be. When pressing arrows on the keyboard the motors are buzzing or wibrating. They do not turn just vibrating. I did change the jumper to be grounded for the gecko on the pmdx. There is red light on the gecko together with the green one. Maybe the power is not sufficient enough to power up the motors? When I press tab on the keyboard and there is 100 % slow jog motors buzz. I changed that to 60 % motor started to turn slowly but still vibrating. Any ideas what might be wrong?
Attached Images
File Type: jpg Picture or Video 005.jpg (68.5 KB, 157 views)
File Type: jpg Picture or Video 007.jpg (75.2 KB, 156 views)
File Type: jpg Picture or Video 009.jpg (71.7 KB, 157 views)
File Type: jpg Picture or Video 010.jpg (71.7 KB, 158 views)
File Type: jpg Picture or Video 011.jpg (67.8 KB, 158 views)
File Type: jpg Picture or Video 015.jpg (92.2 KB, 157 views)
File Type: jpg Picture or Video 016.jpg (116.5 KB, 159 views)
Reply With Quote
  #2  
Old Sat 28 March 2009, 06:08
Richards
Just call me: Mike
 
South Jordan, UT
United States of America
How have you connected a power supply to the PMDX-122 card? Page 4 of the PMDX-122 instuction manual lists the three different ways that a power supply can be connected to the board. (In your photo, I don't see anything connected to any of the three power supply inputs - to the USB connector, to the J11 coaxial jack, or to terminals on J8.)
Reply With Quote
  #3  
Old Sat 28 March 2009, 12:17
martin77pl
Just call me: Martin #39
 
Wroclaw
Poland
I have it connected via usb from a computer. The picture does not show that but chose this way of powering the pmdx.
Reply With Quote
  #4  
Old Sun 29 March 2009, 09:33
Richards
Just call me: Mike
 
South Jordan, UT
United States of America
Let's do some basic trouble-shooting. Check the voltage on the PMDX-122 J5 connector. Verify that you have 5VDC between the +5 and the GND terminals. Then, with your meter connected to the +5VDC terminal on J5, verify that you have 5V when you touch a probe to J1-Common, J2-Common, J3-Common and J4-Common.

The actual voltage may be slightly different, but +4.75V to +5.15V is acceptable for most TTL type circuits.

If the voltage test passes, then you'll need to use an oscilloscope to check the actual pulses being sent to the G203v stepper drivers. All that the PMDX-122 board does, as far as step and direction, is to buffer (amplify) the signals. Whatever signal is sent through the parallel port to the PMDX-122 is buffered and then passed on to the G203v. If you connect the 'scope's ground lead to GND on the PMDX board, and then touch the probe to J1-Step you should see pulses being sent to the G203v. The voltage of the pulses must be at least 2.5V (they will probably be about 5V). The width of the pulse must be at least 2uSec (which you can set in the Motor Tuning section of Mach 3).

At this point, as long as you have a Green light on the G203v stepper driver, pulses sent through the PMDX-122 to the G203v should make the motors turn.

A very crude test can be made my connecting two fresh AA batteries in series (so that you have about 3V). Connect the (-) end of the batteries to the Common on the G203v and then tap the lead from the (+) end of the battery to the Step terminal on the G203v. The pulses will cause the motor to turn. It will take 2,000 taps to make the motor's shaft turn one time, but you will at least be able to verify that the G203v is working.
Reply With Quote
  #5  
Old Sun 29 March 2009, 14:53
martin77pl
Just call me: Martin #39
 
Wroclaw
Poland
I checked the voltage. It shows 4.9 VDC on the pmdx +5 and ground on J5. I also tried J5 +5 and common on J1 J2 J3 J4 and again it showed 4.9 VDC. I used tuninig settings in mach3 and managed to have the motors turning nice and smoth for 30 seconds or so. Then they stop and the red light appears on the gecko next to green one. The green and the red are lit together. I think it might due to the wire I used for the kitchen project. The trouble shooting page in the gecko user manual there is something abouth not using short circuit. I cut wire which is a meter long and used it to connect the geco and the motor.
Reply With Quote
  #6  
Old Sun 29 March 2009, 17:17
bradm
Just call me: Brad #10
 
Somerville(MA)
United States of America
Hmm. Two thoughts:

Check this: http://www.mechmate.com/forums/showt...07&postcount=2

And, from the Gecko manual:

ERROR LED: The RED ERROR indicator is lit when:
1) During power-on reset for 1 second when power is first applied to the G203V.
2) While the DISABLE input is active.
3) When there is a short-circuit on any motor output. Momentarily activate the DISABLE input to reset.
4) During over-temperature shutdown. The LED automatically resets when the drive temperature drops.

Obviously it's not case #1. Since you motors did run for 30 seconds, it probably isn't #3.

So I think you should:

A) take a measurement on your disable input pin
B) Double check that issue with GND it the referenced post above.
C) Double check your current set resistor values by measuring them.
D) Double check for a thermal problem. Are your geckos warming up? Are they heatsinked well?
Reply With Quote
  #7  
Old Sun 29 March 2009, 18:37
Richards
Just call me: Mike
 
South Jordan, UT
United States of America
Let's look at the wires from the motors again.

- Have you taped each unused wire so that it cannot short itself to any other wire?

- Are the current limiting resistors about 40K?

- What is the temperature of the G203s (Room temperature, warm or hot)?

- Is anything at all connected to the Disable terminals on the G203s?

Assuming that you've used an extension cable between the G203 and the stepper motor, are the wires electrically insulated from each other?

My G203v drivers are all heatsinked on a large piece of aluminum, but I don't think that even unheatsinked drivers would overhead in 30 seconds from motors that only pull 3A maximum. When I run my PK296B2A-SG3.6 motors, the G203 drivers hardly ever get much above room temperature.

I'm thinking that you have mistakenly miswired the drivers to the motors somehow. If possible, connect a motor directly to the G203.

-Wire the motor's BLACK wire to coil A (Terminal #3).
-Wire the motor's YELLOW wire to coil /A (Terminal #4).
-Wire the motor's RED wire to coil B (Terminal #5).
-Wire the motor's WHITE wire to coil /B (Terminal #6).
Reply With Quote
  #8  
Old Sun 29 March 2009, 23:32
Lex
Just call me: Johan #56
 
Empangeni KwaZuluNatal
South Africa
Hi Martin,
I had the same problem with my test panel. I checked every wire to the motors for continuity. I found 4 bad crimpings. Fixed them and everything worked! Problem was that only one coil was working making the motors to oscilate. Good luck.
Reply With Quote
  #9  
Old Tue 31 March 2009, 11:36
martin77pl
Just call me: Martin #39
 
Wroclaw
Poland
Hi everybody, I used your advice and connected motors directly to the gecko. I did it and it turned out to be excelent idea. Well I tried with only one connected and it run smoothly and continously without any interruption. It seems there was a a problem with the wire I used for connecting the motors to the gecko. Anyways, I hope all of them will work fine just like the one I tested. I thank you guys for your advice. It was awesome experience to see the motor turn and change direction without a problem.
Reply With Quote
Reply

Register Options Profile Last 1 | 3 | 7 Days Search Today's Posts Mark Forums Read

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 11:48.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.