Bondtech MK3S
Ok, so I have installed the bondtech mk3 extruder on my mk3s and physically the parts work perfectly, went through a few bits that got damaged in the swap and am ready to print... or so I thought. I am unable to find a functional firmware for the setup I currently have and the issues are as follows:
1. The extruder drive is reversed due to the 3:1 gearing
2. The 3:1 gearing is not accounted for in the firmware though I believe I can do some gcode trickery in the way of M92 E 830 to adjust this (pls correct if I am wrong)
3. The Z height calibration fails due to the extruder being taller than the stock and requires a change of expected travel.
4. My final issue (as far as I can find) is that I cannot figure out how to compile a modded firmware correctly. I understand tech pretty well but have failed 11 (and counting) times in this task. Not to mention that I have no way of knowing if my altered parameters are even correct.
I am hoping to hear of someone who has either decent experience modding this firmware or has already done so to either share some wisdom in what I should make sure is right to successfully compile a firmware or maybe even send me their modded file.
(P.S. I do know that I could swap the two outer wires on the motor connector but do not feel comfortable doing so as tiny wires and I are not very good friends)
Re: Bondtech MK3S
Did you read the information in the Bondtech manual regarding "Set new E-step value"?
Bear MK3 with Bondtech extruder
Re: Bondtech MK3S
Reverse motor direction, you fix by swapping the wires of one motor coil. If the wires were numbered 1, 2, 3, 4 at the EINSY plug, you would swap #1 and 2 with each other. Just use a sewing needle to life the little plastic locking tab holding in the contact pins. The pins should slide right out. Then reinsert them in swapped order.
You could can obtain a pre-compiled firmware from
https://github.com/bgiot/Prusa-Firmware-BMG/releases
Or follow my instructions and 0.9 degree motor branch if you wish to learn how to compile firmware successfully. I found the Prusa supplied instructions less helpful.
https://github.com/guykuo/Prusa-Firmware/blob/0.9-Degree-Stepper-Support/README.md
You don't have to use 0.9 degree motors to use my firmware branch, just comment out the 09 degree motor defines that don't apply.
I don't know if you are using a 0.9 degree motor on your Bondtech extruder, but if you are, the defines would be...
/*------------------------------------
AXIS SETTINGS
*------------------------------------*/
//Uncomment def(s) below for 0.9 degree stepper motors on x, y, e axis
//Motors used should be 1 amp or lower current rating to avoid overheating TMC2130 drivers in Stealthchop.
//My recommended 0.9 degree motors for X, Y, or direct drive E are Moons MS17HA2P4100 or OMC 17HM15-0904S
//#define X_AXIS_MOTOR_09 //kuo exper
//#define Y_AXIS_MOTOR_09 //kuo exper
#define E_AXIS_MOTOR_09 //kuo exper
//Uncomment below for BMG Extruder
#define BMG_EXTRUDER //kuo exper implements changes based on Chris Warkocki BMG firmware mods
Yes, you still need to send g-codes to your printer to set e-steps.
Re: Bondtech MK3S
Make sure that you plugged it in properly. The black cable needs to be pointing up and it's hard to visually tell the difference between the bottom dark blue cable and the black cable in poor lighting.
Next to the picture in the instructions it says:
I'd start by checking that the cables are plugged in correctly.