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A long sad tale...

Posted: June 12th, 2019, 4:56 pm
by jhansx
I have a Chinese clone of a Tront p802ma printer that came with a proprietary board software based on Marlin. I've had it over a year have about eight good prints. I decided to change the board to a ramps with an Arduino which I did and have reached the point where I have a ramps 1.4 on an Arduino mega 2560.
From this forum deserves the Croix liquor for helping well beyond the Call of duty as I have been trying to get this to work. The present problem is the x-axis home's find the y axis homes fine but the z-axis have no fire. With 12 volt power supply to the board driving off of a 30 amp power supply I get a vref of point6 on x y and e 0 and I get a 1.2 on Z. I've tested the connection for the Z motor they are plugged in the same way as X and Y which work. Attached are photos of the board as it is currently configured and a video of the homing failure. I use Reptier to communicate. Also have attached my Marlin 1.9 bug fix that is currently flat. Any input and help would be great. I seen similar problems that took countless trial and errors to get running. I'm not sure if I have a failed board or a bad driver plug-in although I'm not sure how that could happen if I have a good vref. I do have an oscilloscope that I can used to evaluate the output of the driver if necessary.
Cliff certainly as I say deserves a medal for service above and beyond these last several weeks.

Re: A long sad tale...

Posted: June 12th, 2019, 7:34 pm
by Roberts_Clif
It could be a bad Driver, Bad controller, Bad Stepper Motor Cable, it could be a Bad Stepper Motor.
It could also be the Z-Axis feed rate as you have recently upgraded firmware to Marlin 1.1.9BF

#define DEFAULT_MAX_FEEDRATE { 300, 300, 5, 25 }

Got jhansx here and now going in circles could use help to get his 3D Printer Printing...

Re: A long sad tale...

Posted: June 12th, 2019, 10:20 pm
by GrueMaster
Not seeing a video. Aside from that, some simple tests: Since X & Y work, try swapping X or Y with Z. After swap, just move the two axis independently. This will eliminate a lot of possible issues (cable, motor, controller, etc). Don't try to do full range motion, just 10 mm or so, away from 0 (so as not to break anything).

Re: A long sad tale...

Posted: June 13th, 2019, 2:22 am
by jhansx
Video. Sorry it didn't UL.

Re: A long sad tale...

Posted: June 13th, 2019, 7:58 am
by Roberts_Clif
GrueMaster wrote: June 12th, 2019, 10:20 pm Since X & Y work, try swapping X or Y with Z. After swap, just move the two axis independently.

This is one that usually skips my mine as my Controller do not have removable Stepper Motor driver Modules.

Though I will be remembering as I just Purchased a Arduino with the Ramps 1.6

Re: A long sad tale...

Posted: June 13th, 2019, 9:27 am
by LePaul
jhansx wrote: June 13th, 2019, 2:22 am Video. Sorry it didn't UL.
If you upload to YouTube, you can copy the YouTube link and the video will play within the forum

Re: A long sad tale...

Posted: June 13th, 2019, 9:28 am
by LePaul
GrueMaster wrote: June 12th, 2019, 10:20 pm Not seeing a video. Aside from that, some simple tests: Since X & Y work, try swapping X or Y with Z. After swap, just move the two axis independently. This will eliminate a lot of possible issues (cable, motor, controller, etc). Don't try to do full range motion, just 10 mm or so, away from 0 (so as not to break anything).
Swapping drivers would be a good first test. If it works, you know you have a bad driver. If it persists, the digging continues.

Re: A long sad tale...

Posted: June 13th, 2019, 11:17 pm
by jhansx
No Joy.
The new code doesn't change the zero movement on Z axis.
I switched a driver but can't see how a driver could be bad if it gives a good V ref?

Re: A long sad tale...

Posted: June 15th, 2019, 7:51 am
by Roberts_Clif
The voltage is a result of the 3.3volt supply an R1 Trim pot on the 3.3v supply this reference voltage an could exist, Vref could still be adjusted with a bad driver Chip.

Sample of a DRV8825 Driver module

0J4222.600.jpg

Re: A long sad tale...

Posted: June 16th, 2019, 6:35 pm
by Roberts_Clif
Have not head from you @ jhansx

How is this build going, we are waiting to see how it working.

Re: A long sad tale...

Posted: June 17th, 2019, 10:07 am
by Roberts_Clif
E-Mail From @jhansx

As far as the Ramps 1.4 is concerned I must have a bad board. The driver from the Z slot works just fine in any other slot. I don't get how I can get a good vref and still have a bad board. Thinking critically about it though, this should allow an approximation of where the failure is to be made. Keeping in mind that a perfect logical argument which proceeds from a false premise is invariably errant.

My plan:
1) study the pin tracings with the oscilloscope on a working driver as it performs.
2) conduct this study on all pins with an output
3) repeat for the bad driver and attempt to isolate the failed pin
4) locate the board component responsible for the failed output pin state

Assumptions:

since the driver functions in another slot it is likely not the problem
the input from the board itself to the driver must be the issue
once the pin or pins with faulty output are identified the board component or trace responsible for that output can be identified and examined
the faulty component n the board can be swapped out or the trace repaired
introduction of high quality scope probes to monitor the circuit will not disrupt the function of that circuit (in this case)

Forgot one test you can do, swap the cable for the Z-Axis stepper motor.

I have purchased a replacement for my Arduino, Ramps 1.6 plus A4988 drivers.
Will be troubleshooting my Arduino, Ramps 1.6 plus A4988 drivers, this should prove interesting for me.
Though I believe that I killed some IO's pins of the Arduino mega 2560 R3 as no stepper motors work.
After a simple mistake I made while testing the already working controller setup.
This will give me a complete set of new boards which I can compare signals on to verify what I believe.

When you are measuring the Arduino with an oscilloscope, be very careful not to touch two pins at the same time this will surely blow a running Arduino IO's pins.

If only the Z-Axis on the controller is bad you could simply edit "pins_Ramps.h" to swap the E1 extruder and make it the new Z-Axis shown Below.

Code: Select all

//Disable dead Z-Axis
//#define Z_STEP_PIN         46 
//#define Z_DIR_PIN          48 
//#define Z_ENABLE_PIN       62 
//#define Z_CS_PIN           40 

//Swap pins here to enable the New Z-Axis on E1
#define E1_STEP_PIN        46 //Old 36 
#define E1_DIR_PIN         48 //Old 34
#define E1_ENABLE_PIN      62 //Old 30
#define E1_CS_PIN          40 //Old 44
Then remember to plug your Z-Axis into E1 which is the New Z-Axis
This should work if extruder 1 is not dead, and the board is not working as programmed.
Remember that your Z-Axis has dual stepper motors so adjust V-Ref for dual stepper motors .