MK2 Z-Motors on MK1  

Re: MK2 Z-Motors on MK1

Jeremy

Yes, it will work, but you will have to change the Z steps per mm value. This can be done in 2 ways:

Amend firmware
Issue a M92 Z400 command (in GCode)

Both will work; the former will be more permanent, the latter can be included in the start GCode section of your chosen slicer.

Peter

Re: MK2 Z-Motors on MK1

Peter -

Thank you for your response. I am fairly new to this so any help I get is appreciated.

Are you able to amend the motor current in the start gcode?

I am more in favor of running a custom firmware. Any suggestions on a resource I could use to learn how to do this? Would it be possible to get someone to write me a firmware .hex file that I could try. I'm currently building up my hybrid at the moment and will be ready to test in a couple days.

Thank you again

Re: MK2 Z-Motors on MK1

Do you see any issues with using the other MK2 motors with MK1 firmware? I noticed the extruder motor is quite a bit larger on the MK2 and I'm probably just going to use the MK1 motor. However, the y and x axis motors seem to be identical between the two models.

Re: MK2 Z-Motors on MK1

Jeremy

I have already posted notes on how to amend the firmware; see my post here: http://shop.prusa3d.com/forum/software-f13/how-to-setup-arduino-to-compile-fw-on-a-mac--t1258.html#p9453

If you want to do this, you are on your own... Just make sure you have a few years C++ programming experience before you start, otherwise you can break things.

Why would you want to change the motor current? You have the Quiet & High-Power options in the firmware which gives good options for these motors.

Peter

EDIT: You cannot compare motors by looking at them; you will have to check the specs.

Re: MK2 Z-Motors on MK1

Jeremy

Just checked the firmware; for both Mk1 and Mk2 all the motors are set to the same current.

Peter

Re: MK2 Z-Motors on MK1

Thank you again Peter.

From what I recall, doesn't the MK2 motor run quite a bit more current to compensate for the larger lead screws?

If I can get away without changing the current I am ok with just changing the steps/mm in Sli3er as I do not have any programming experience.

If I have to go back to the full MK1 setup I will. I just wanted to take advantage of some of the improvements made on the MK2 like the integrated Z-shafts.

Re: MK2 Z-Motors on MK1

Jeremy

As I stated earlier, both Mk1 and Mk2 firmware use the same motor current for the Z motors. Check it for yourself here: https://github.com/prusa3d/Prusa-Firmware

Peter

Re: MK2 Z-Motors on MK1

Makes my life easier! Thank you so much Peter for all your help. It's very much appreciated.

Re: MK2 Z-Motors on MK1

Peter, this is the current difference I was referencing between the MK1 and MK2 variants

Re: MK2 Z-Motors on MK1

Apologies, you are indeed correct.

It seems that last time I compiled the firmware, was for the Mk1...

I think that you may be able to set that with M907.

Yup - Marlin.cpp:

case 907: // M907 Set digital trimpot motor current using axis codes.
#ifdef MOTOR_CURRENT_PWM_XY_PIN
if(code_seen('X')) digipot_current(0, code_value());
#endif
#ifdef MOTOR_CURRENT_PWM_Z_PIN
if(code_seen('Z')) digipot_current(1, code_value());
#endif
#ifdef MOTOR_CURRENT_PWM_E_PIN
if(code_seen('E')) digipot_current(2, code_value());
#endif

pins.h:

#define ELECTRONICS "RAMBo13a"

#define HEATER_0_PIN 3
#define HEATER_BED_PIN 4
#define FAN_1_PIN -1 //6
#define PS_ON_PIN 71
#define MOTOR_CURRENT_PWM_XY_PIN 46
#define MOTOR_CURRENT_PWM_Z_PIN 45
#define MOTOR_CURRENT_PWM_E_PIN 44

Peter

Re: MK2 Z-Motors on MK1

I really do appreciate you looking into this for me.

I'm not trying to bite off more than I can chew, just trying to understand how the system works a little better.

In your opinion, what would be the easiest method for achieving this? Execute a command in the start g-code ( is this possible? What would the syntax be for this line) or going directly to the firmware and recompiling?

Jeremy

Re: MK2 Z-Motors on MK1

I'm not quite sure if "digital trimpot motor current" is the same as "motor current". The first one is actually controlled by M907, but second one by M906, which is unsupported by Marlin: http://reprap.org/wiki/G-code#M906:_Set_motor_currents

Re: MK2 Z-Motors on MK1

Jeremy

As a software engineer, I have been "playing" with the firmware and making it suit my needs from a week or so after receiving the Mk1.

However, at the moment, the firmware is in a bit of a mess, with Mk1 firmware included in Mk2 branches and faulty/incomplete Mk2 firmware available.

If you are happy with a V2.2.4, which was a good stable Mk1 release, then it is very simple to amend that for your requirements (only 2 lines of code to change); you will of course also be able to make other changes which suit you - such as removing the Z_MIN of 0.23mm.

As long as you are careful, you should be OK.

Download the "Master" branch from here: https://github.com/prusa3d/Prusa-Firmware

Personally, I use Notepad++ for editing the firmware and the Arduino.cc UI for compiling and upload. The only problem with Notepad++ is that you do have to remember to close the file you are editing as simply closing the program does not commit any changes you make.

Questions: Which RAMBo version do you have, what filament diameter do you use and which extruder will you be using?

Once you let me know that info and you have set up according to my notes (previously linked), I can tell you exactly what to do.

Peter

Re: MK2 Z-Motors on MK1

Peter -

I am running a 1.75mm Rambo 13a E3DV6Lite.

Purchased i3 plus kit in May of 2016

Re: MK2 Z-Motors on MK1

You want to stay with the Lite6 or upgrade to the V6 (from the upgrade kit).

Probably easier to stay with the Lite6; the V6 is better for very high speed prints and temps over 240 degrees.

Peter

Re: MK2 Z-Motors on MK1

Jeremy

Attached is the firmware for a Mk1 with lead screws. I have edited the 2 lines you need changing.

Note this is for a 1.75mm Lite6 Mk1 with 8mm pitch lead screws for the Z axis.

Once you have downloaded, I will explain the changes.

Peter

EDIT: You need to download the ZIP and extract the folder "Firmware" - I use the desktop for this.

Re: MK2 Z-Motors on MK1

OK, this is what I have done:

Once you have the Arduino IDE downloaded and set up for the RAMBo, follow my instructions for compiling and uploading the the printer.

Peter

Re: MK2 Z-Motors on MK1

Again, thank you so much again Peter.

I am in process of building my printer back up. I will be in touch in a couple days!

Re: MK2 Z-Motors on MK1

peter -

I think i've got this figured out, however when I compile the file to binary i get a boot loader error (see attached). Am I better off just compiling and uploading instead of trying to make a .hex file? Am i missing something?

Thanks again.

Jeremy