Upgraded extruder assembly to a 2.5S But with MK2 BED  

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

This may have to do with the position of the pinda on the mk2.5 extruder compared to the mk2 extruder (referring to distance from endstops).

What firmware are you running on it?

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Hi !

I've tried with the latest MK2S firmware and latest MK2.5S firmware without any success...
I guyss i need to modify the FW somehow?

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

the Mk2 Printer used a Mk42 heatbed
the mk2.5 printer uses a Mk52 12volt Heatbed. 

the Calibration sense pads are in different positions

can you fit the Mk52, 12 volt heatbed and use the latest Mk2.5 firmware?

Joan

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Hello I don't have the MK52 12v heatbead. I have the original one from MK2 build and i still would like to use it together with the MK2.5S extruder assembly. I guess i need to modify the firmware for this to work?

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

If you want to use  the new extruder with the old heatbed, you might get away with using the Mk2 firmware, and revise the  E Steps setting,  the reason for this are that the mk2 extruder uses a smaller hobbed gear to drive the filament, and with the newer larger Mk2.5 hobbed gear, you will be over extruding on the base firmware. 

there is information in this thread https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-prusa-i3-kit-archive/calibrate-extruder-e-steps/#post-30216

regards Joan

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Ok but i've tried to do an XYZ calibration with the MK2S firmware with no success, note that i've installed the pinda probe V2 same as the 2.5S extruder assembly.

Also i want to use the MK2.5S fw as it has some usefull features for e.g. the filament sensor...
I guess i need just to adjust where the calibration points are in the code for the mk2.5s fw?

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

you are trying to run a hybrid printer on stock firmware, that's going to cause issues... 

you would be best adjusting the firmware, however you may be unable to use mesh bed leveling without the Mk52 bed.

good luck,

I chose not to revise the firmware when I fitted the Mk52 bed to my Mk2 MMU1 printer,

regards Joan

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Hi you have to comment this two lines out:

https://github.com/prusa3d/Prusa-Firmware/blob/9a60dd259bb69b14cc821c9db81acb59bd69254b/Firmware/variants/1_75mm_MK25S-RAMBo13a-E3Dv6full.h#L27-L28

as far i understand the firmware then the printer should use the mk42 routines.

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

https://www.dropbox.com/s/kcmzs83dcr2a49j/Firmware.ino.rambo.hex?dl=0

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Posted by: @sorav-g

https://www.dropbox.com/s/kcmzs83dcr2a49j/Firmware.ino.rambo.hex?dl=0

is this firmware is for mk2.5 with hotbed mk42?

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

I would like mk2 mmuv1  firmware for a 12 volt mk52 heatbed!

regards Joan

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Works for me with a MK42, MKS gen 1.4, Pinda2 probe.

I didn't check the filament sensor. But i am also not using it on my MK3.

After upgrading to a Standalone geared BMG extruder i removed it completly. 

https://github.com/cimoalpacino/Prusa-Firmware/tree/MK2S_MK25_3.9.1_RAMPS

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

@danielkrah

I attempted to commit out the two lines you suggested, but the compiler will not compile because it breaks the code. I am afraid there is a lot more that has to be done for this firmware to work with the mk42 heat bed. 

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

I don’t know if anyone still cares about this topic, but last night I successfully modified the mk2.5S firmware to work with the mk42 bed! I can post a compiled .hex file if anyone cares! I might just make a new forum post and link all of the mk2.5/S .hex files depending on your setup.  

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

@hillinator

Cool! I did this awhile ago before upgrading to MK 2.5.  As I recall, the MK 2.5 PINDA mount is in a slightly different X-Y location than the 2S , so it failed the XYZ setup. What I did was to alter the frame geometry a little so that the PINDA could find the sense points.  This method reduces the available build volume a little bit, so the firmware fix is probably better.

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

@hillinator

Can you advise what changes were necessary to make the mk2.5 firmware work with an mk42 heatbed?

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Posted by: @hillinator

I don’t know if anyone still cares about this topic, but last night I successfully modified the mk2.5S firmware to work with the mk42 bed! I can post a compiled .hex file if anyone cares! I might just make a new forum post and link all of the mk2.5/S .hex files depending on your setup.  

Any chance you ever made that post about the changes you made. I am doing a similar setup and I'd love to get a jump on the necessary firmware changes.

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

So, I upgraded my MK2S to MK2.5S+ (prints R4 and R5) with two missing options:

1. I still use the old MK42 12V Heatbed. It works, money is tight at the moment.

2. I still use the PINDA version 1, I never had version 2 and SuperPINDA ist to expensive for me at this point.

I already printed with a slightly modified 3.2.3 Firmware. The sole change was

#define Y_PROBE_OFFSET_FROM_EXTRUDER 5  // MK2/S 9

Then I changed the firmware to 3.10.1 with minor changes to test most functionality:

- Added Configuration.prusa.h from MK2.5S variant
- Added TACH1 in temperature.cpp, pins_Rambo_1_3.h for a 5V tacho print fan

The printer works and fans cycle in self-test with autofantest. Calibration and other stuff failed obviously.

So I changed the necessary values in mesh_bed_calibration.cpp (I never noticed until now the misspelling of levelling 😉 )

const float bed_ref_points_4[] PROGMEM = { /* changed */ 33.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_X, // 33 - 2 - 23 - 0 = 8 + 4 = 12 17.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y, // 17.4 - 9.4 - 5 + 4 - 0 = 7

236.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_X, // 236 - 2 - 23 - 0 = 211 + 4 = 215 17.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y, // 17.4 - 9.4 - 5 + 4 - 0 = 7

236.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_X, // 236 - 2 - 23 - 0 = 211 + 4 = 215 213.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y, // 213.4 - 9.4 - 5 + 4 - 0 = 203

33.f - BED_PRINT_ZERO_REF_X - X_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_X, // 33 - 2 - 23 - 0 = 8 + 4 = 12 213.4f - BED_PRINT_ZERO_REF_Y - Y_PROBE_OFFSET_FROM_EXTRUDER - SHEET_PRINT_ZERO_REF_Y // 213.4 - 9.4 - 5 + 4 - 0 = 203};

and mesh_bed_calibration.h

#define BED_X0 (9.f - BED_ZERO_REF_X) // 12 - 4 + 1
#define BED_Y0 (11.4f - BED_ZERO_REF_Y) // 7 - 4 + 8.4
#define BED_Xn (212.f - BED_ZERO_REF_X) // 215 - 4 + 1
#define BED_Yn (207.4f - BED_ZERO_REF_Y) // 203 - 4 + 8.4

Additionally I had to tweak a few things in xyzcal.cpp, because the 32x32 calibration matrix would run out of the printers travel boundaries and lock the X and Y axies (loose steps, no calibration possible). To much to publish here, but I changed the xyzcal_scan_pixels_32x32_Zhop() function, so that it would initialize the pixels[] variable with zeros and only measure pixel/position 4-28 in X and Y direction. This finally gave me the new 32x32 scan calibration feature, without loosing steps.

Also, since the changes on the hotend change the printer head geometry the furthest point left (= X_MIN) is not outside of the print bed coordinate system, but already at 2-3 mm right of the MK2/S zero pint. This means, that the available printer size shrinks in X direction to 0-246 mm, so you will loose 4 mm and the printer will always start at +4mm X axis with every print. So to stop the printer to go out of bound set the travel limits in Configuration_prusa.h

#define X_MAX_POS 246    // was before 250

You could manage to print at position [3, Y], but then the X end-stop is already depressed, so you should avoid that.

With these changes the self-test runs without problems, nice calibration point maps are measured, calculated and send to the terminal. Also, mesh bed levelling with 3x3 measurement points works flawless (cold and hot), obviously without steel sheet the 7x7 option doesn't. I have a variance of 0.69. Since I still use the PINDA version 1 probe I think there are some problems with the mesh bed levelling, because my first layer calibration looks horrible, but I still haven't made enough tests yet. Obviously the PINDA version 1 uses different correction factors, PINDA version 2 ist actively corrected with a thermistor readout and SuperPINDA has a less variance correction table or even none. So this (and a bed straightening with washers) is on my ToDo list.

So, happy modding.

RE: Upgraded extruder assembly to a 2.5S But with MK2 BED

Hey. Sorry about the late reply. Life has been busy and it’s been a very long time since I’ve messed around with this. If I have some free time on my hands soon I’ll try to get a thread made with the changes I’ve made.