firmware change doesn't change my accel, jerk, ect

So I'm new to this forum (first post), and I normally try and figure everything out on my own, but I have came across a problem I cant for the life of me figure out.

So far I have a prusa I3 and that thing rocks. I have never had any problems, i print only PLA on it, and it just keep going and going. it went so smoothly I decided i wanted to build a kossel.

I have the folger tech kossel, and they were pretty good at supporting me, but now im stuck on something that just doesnt make sense.

In the config i am trying to change my jerk and accel settings but not matter what i do my jerk is 20 and my accel is 3000. I have looked everywhere trying to find another location in the marlin firmware to make this chage, but im just lost i guess. Below is what i cut and pasted out of my firmware, however when i load the firmware i do not get the accel and jerk setting i specified below

i thought about hard coding a m205 as a work around, but it just bugs me that i cant seem to change this

also what kind of number do people normally run for a kossel machine? yes yes i know its depends on the particular machine, but I'm sure there are some closer default values than what i had to start with

Thanks in advance is anyone has an idea as to what my problem is.


#define DEFAULT_ACCELERATION 8000 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000 // X, Y, Z and E max acceleration in mm/s^2 for retracts

// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
// The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
// For the other hotends it is their distance from the extruder 0 hotend.
// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
// #define EXTRUDER_OFFSET_Y {0.0, 5.00} // (in mm) for each extruder, offset of the hotend on the Y axis

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 500.0 // (mm/sec)
#define DEFAULT_ZJERK 500.0 // (mm/sec)
#define DEFAULT_EJERK 500.0 // (mm/sec)

okay, what am i doing wrong? I also found that the stock numbers for the folgertech kossel made my parts slightly to large, after investigating this i noticed that the printer actually had 189/2.25 for the steps per unit which comes out to 84, however with the 20 tooth pulley it should be 80. I made a change in the firmware and my LCD still reads .084, and also my accel and jerk havent changed. Im so frustrated what am i doing wrong?


#define DEFAULT_AXIS_STEPS_PER_UNIT {80, 80, 80, 100}
#define DEFAULT_MAX_FEEDRATE {300, 300, 300, 300} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {1000,1000,1000,1000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for skeinforge 40+, for older versions raise them a lot.

#define DEFAULT_ACCELERATION 8000 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000 // X, Y, Z and E max acceleration in mm/s^2 for retracts

// Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing).
// The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder).
// For the other hotends it is their distance from the extruder 0 hotend.
// #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis
// #define EXTRUDER_OFFSET_Y {0.0, 5.00} // (in mm) for each extruder, offset of the hotend on the Y axis

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK 500.0 // (mm/sec)
#define DEFAULT_ZJERK 500.0 // (mm/sec)
#define DEFAULT_EJERK 500.0 // (mm/sec)

Does your RAMPS setup make use of the EEPROM to store the machine settings etc? If so, you can reflash the thing as much as you like but until you ask it to reload the default value and save them to the EEPROM it'll keep using the old settings.

Last night after my post i started to look at EEPROM thinking that may have something to do with it. to be honest i don't know what I'm doing and I just try and read through the code to find the changes i need to make. How would I reload the default values and change them? would i need to do this on the printer itself? is there any ways i can change my firmware in case i have a board go bad?

Thank you for the help

M502 loads default values, M500 writes to prom.

M503 displays what is in the prom, and M501 recalls it manually.

So, an M502 followed by M500 will allow the settings you compiled in the take effect.

- Tim

Edited 1 time(s). Last edit at 07/27/2015 02:28PM by tadawson.