SOLVED Running Z axis using ext1 driver - Help with missing steps

[Juliogdiana 3]

Hello guys,

I have a problem with my UM2 board, the Z driver just stopped work, it doesnt move the motor, it just shake the motor like a mad and make load noises, I think it is gone.

I am trying to find a solution without having to buy a new board, so I decided to use the EXT1 driver to run the Z axis.

I went to pins.h at Marlin and I did it:

motherboard 72

#define Z_STEP_PIN 49 //37

#define Z_DIR_PIN 47 //39

#define Z_STOP_PIN 29

#define Z_ENABLE_PIN 48 //35

#define E1_STEP_PIN         37 //49

#define E1_DIR_PIN          39 //47

#define E1_ENABLE_PIN       35 //48

It is great, worked, now my Z axis moves up and down, do homing without any problem, however when I start to print something, looks like the Z axis is moving only a half way as it should move, example, I did a dry run with a 200mm high object and the build plate only moved about 100mm down.

I have played with this values #define DEFAULT_AXIS_STEPS_PER_UNIT   {80.0,80.0,200,282} but in any way I increase or decrease the steps per mm for Z axis, it still moving only half as it should be.

What do I am missing here guys?

I have looked at the code and I cant find nothing where I can fix it, any help will be acceptable.

Edited October 28, 2017 by Guest

[gr5 2,210]

Can't you just change it to 80,80,400,282? That should fix it.

The Z axis has a jumper roughly in the center of the board that can switch the Z between 8 microsteps per step or 16 microsteps/step. By default the jumper is off and that makes for 200 steps/mm.

But you are using the second extruder stepper which is always 16 microsteps / step. So you need to set the steps/mm to 400 instead of 200. Easy. You can do this with gcode commands if you don't want to rebuild marlin.

[Juliogdiana 3]

Yes, like I said I have played with this values already, I have used 400 and even 100 but it doesnt make any difference.

I wonder if the ulticode flavour has a play on it? As a standard it is configured for 1/8 microsteps for the Z axis, is there anyway I can change it on Cura?

[Juliogdiana 3]

I dont think a UltiCode has a play on it as I have tried a print with Standard RepRap Gcode and it still the same.

[tinkergnome 927]

Yes, like I said I have played with this values already, I have used 400 and even 100 but it doesnt make any difference.

 

DEFAULT_AXIS_STEPS_PER_UNIT is only used after a factory reset...

In all other cases the stored value from the EEPROM is used. As @gr5 said, the stored value can be changed with gcode M92.

Or change the Configuration.h, upload the firmware and perform a factory reset.

Good luck!

[Juliogdiana 3]

Thank you tinkergnome, I did the factory reset with 400 steps/mm and on calibration the build plate crashed into printer head, tried the calibration again and still the same.

Looks like too many steps now.

I cant get the Pronterface to connect to my printer, is there any other software that I can run the "M" commands?

[tinkergnome 927]

Thank you tinkergnome, I did the factory reset with 400 steps/mm and on calibration the build plate crashed into printer head, tried the calibration again and still the same.

Do you have changed something else? Perhaps "Z_MAX_POS"?

I cant get the Pronterface to connect to my printer, is there any other software that I can run the "M" commands?

I know Octoprint and Simplify3D, but there are probably more. I think, former Cura versions (choose 15.04.6) had a simplified pronterface dialog too - (not sure)?

[gr5 2,210]

You should be able to get pronterface to work. It's a little tricky but not too bad. Basic overall steps for a PC - plug the cable in and listen for the "da dunk" sound indicating you plugged in a USB device. Then go to device manager and locate that device. If there is no device then install the arduino USB driver. It's part of the cura install and also you can get it from the arduino people.

Once you see the device in device manager it should show up as a COM Port for example COM7 or maybe COM13 or whatever. Then go to pronterface and have it use that port. The baudrate I believe is around 115k. The baudrate is also specified in the configuration.h file.

[tinkergnome 927]

Right. Once the COM port is identified, any serial terminal program can be used to send gcode commands to the printer. For example Putty or RealTerm. The default baudrate for UM2 is 250000

[Juliogdiana 3]

Thank you guys, got sorted, I had changed the Z max on firmware to 270, thats why it was hitting the build plate.

Everything is running perfect now.

Thanks again for the crucial tips.