Calibration Part 2

I retract my statement of yesterday.  Calibration is NOT straightforward.  I only thought so.

Last night, over a movie on TV, I sleeved the two PTFE tubes, my wife commented that this is the single most difficult part of the printer so far.  I disagree.  I have probably spent 6 to 8 hours trying to calibrate the printer and am pretty much where I started.

I can follow the flowchart, get the Theta arm to be parallel and perpendicular to the front of the machine with the M360 and M361 commands, and the angle between the arm joints to be 90 degrees with the M364 command.  In the process I have adjusted the steps per degree (M92 command) and the home offset position (M206 command).  Now the printer thinks that X0 Y0 is sharing space with the drive shaft and tries to jam the head into the copper pipe.

I cannot convince the printer to reset the 0,0 position with the G92 command (no effect), and manually adjusting the M206 values to what the book describes it to be, causes the printer to try and break it apart.

Moving the head by clicking on the +X or +Y buttons in Pronterface causes the head to move in approximately the right direction, but slightly diagonally and also not in a straight line.  So, even though the calibration procedure completed as described, the printer is clearly not calibrated.  This was the reason I claimed calibration posed few problems (I only completed the procedure last night, did not experiment further).

Even the M360 command from the home position tries to move the print head through the drive shaft, I have to issue M361 BEFORE M360 to force the head to take a more circuitous route to the Theta arm 0 degree position.

Good news is that the Bowden tube and extruder seems to work, and I convinced a thin strand of blue ABS to come out of the head last night!  The bed was lifted by approximately 15mm this afternoon, so now the platform can lift the bed to against the print head with a few millimeters of lead screw left.