Marlin firmware fork for MakerFarm i3v w/ auto bed level & Roxy's enhancements

[AbuMaia]

Same, I think. It's the one I got from MakerFarm in their 8 inch i3 kit.

[Drone]

This issue is certainly beyond my paygrade to figure out then. I have no idea why there would be different behavior with the same hardware/firmware. I'm sure there is a logical explanation, I'm just not the guy that's going to figure it out. That being said though, I am very happy with the way ABL is working. I find the first layer to bed adhesion has dramatically improved for both ABS and PLA and now I don't use any tape, glue or hairspray for PLA at all and just glue stick for ABS. If I use glue stick with PLA, even after allowing to cool below 30c I have to use a blade to remove the part. Very happy with this.

[AbuMaia]

It tells me that the sled docking offset is likely a red herring, and the real bug is somewhere else, some setting that I have different or am not using at all.

[dacb]

This is interesting. So if you don't define it you get a build error or a runtime error?

[Drone]

This is interesting. So if you don't define it you get a build error or a runtime error?

No, it compiles fine and runs fine except it performs a G28 properly, including raising the Z probe at the finish and then does nothing when it should be starting the G29 routine. I had this same issue when setting up ABL a little over a month ago and found the answer in a thread where someone else had the same issue. He uncommented that line and everything worked from then on. I had the same behavior and the same fix worked for me also. I haven't altered any file other than the few changes required in your fork in the configuration.h and the issue was there again. I had done hours of searching over a month ago to find a solution, so applied the same solution and had the same positive result with G29 running normally. I had assumed this must be a common issue, but from Abu's reply I'm guessing this is not common at all. The only changes I made that may not have been standard in the configuration is changing travel limits after homing #define Z_MAX_POS 250 (your build had a value of 235) and commented out Z_SAFE_HOMING.

I have included my configuration.h if you want to look at it.

Configuration.h

[AbuMaia]

That might be the issue there. I have Z_SAFE_HOMING enabled. If I disable it, I have the problem of my Y axis moving while the Z raise before homing runs, which offsets the Y axis by the Z raise amount. It seems as though Marlin is unaware of the Y movement, as it doesn't change the Y current position number to reflect the move. I couldn't figure it out, so I just leave Z Safe Homing enabled to avoid it altogether.

[Roxy]

I can confirm that the September 15th release of Marlin required extra Pre-Processor commands in Marlin_main.cpp in order to compile clean if the Sled stuff was not enabled. The code needed to be modified as follows:

#ifdef ENABLE_AUTO_BED_LEVELING
#ifdef Z_PROBE_SLED
//
// Method to dock/undock a sled designed by Charles Bell.
//
// dock[in]     If true, move to MAX_X and engage the electromagnet
// offset[in]   The additional distance to move to adjust docking location
//
static void dock_sled(bool dock, int offset=0) {
 int z_loc;
 
 if (!((axis_known_position[X_AXIS]) && (axis_known_position[Y_AXIS]))) {
   LCD_MESSAGEPGM(MSG_POSITION_UNKNOWN);
   SERIAL_ECHO_START;
   SERIAL_ECHOLNPGM(MSG_POSITION_UNKNOWN);
   return;
 }

 if (dock) {
   do_blocking_move_to(X_MAX_POS + SLED_DOCKING_OFFSET + offset,
                       current_position[Y_AXIS],
                       current_position[Z_AXIS]);
   // turn off magnet
   digitalWrite(SERVO0_PIN, LOW);
 } else {
   if (current_position[Z_AXIS] < (Z_RAISE_BEFORE_PROBING + 5))
     z_loc = Z_RAISE_BEFORE_PROBING;
   else
     z_loc = current_position[Z_AXIS];
   do_blocking_move_to(X_MAX_POS + SLED_DOCKING_OFFSET + offset,
                       Y_PROBE_OFFSET_FROM_EXTRUDER, z_loc);
   // turn on magnet
   digitalWrite(SERVO0_PIN, HIGH);
 }
}
#endif
#endif

void process_commands()

[AbuMaia]

That is how my marlin_main looks. Looking at the marlin_main in the ericzalm zip file, it seems the changes are to add a
#ifdef ENABLE_AUTO_BED_LEVELING to the start of the code section, and its corresponding #endif at the end.

[Roxy]

Dacb, Right now the code says:

if((f_probe_bed_position == b_probe_bed_position) || (r_probe_bed_position == l_probe_bed_position)) {
SERIAL_ERROR_START;
SERIAL_ERRORLNPGM(MSG_EMPTY_PLANE);
Stop();
return;
}

Shouldn't this be changed to:

if((f_probe_bed_position >= b_probe_bed_position) || (r_probe_bed_position <= l_probe_bed_position)) {
SERIAL_ERROR_START;
SERIAL_ERRORLNPGM(MSG_EMPTY_PLANE);
Stop();
return;
}

If these values are wrong, other code breaks, such as:

int xGridSpacing = (r_probe_bed_position - l_probe_bed_position) / (n_points-1);
int yGridSpacing = (b_probe_bed_position - f_probe_bed_position) / (n_points-1);

[dacb]

Looks good to me. Have you tested this? If so, I'll make the change and publish it.