Skipping first 4 lines of print HELP
in Bug Reports
Hi.
I have a home made cartesian style printer with a stationary ext0. RAMPS 1.4 with Atmega 2560. X and Y have min endstops NC. Z has max endstop NC.
As a test print i just want a single wall .7mm thick by 10mm high by 30mm long. But i need it to be done in single passes for each level so i am using Repetier Host with Slic3r because i cant figure out how to make Cura slice single passes.
Everything works as expected and works normally with most prints except this simple straight wall. I know, I know... dont print the wall then... lol... but this basic design is part of what i need to do.
So what happens is:
- start print.
- bed homes xyz.
- bed moves to 5mm below ext0 (ie G1 Z5 F1000)
- once finished this move and temperature is achieved, its like it just pukes out the rest of the code up to layer number 4. Host's preview of the print shows 4 layers as the bed moves into position. By the time it gets to the bed center to start the print its already at layer 5 where it tries to start printing.
The code appears sequential as it pukes it out so i can't see whats causing it. Ive even tried writing pauses (G4 P2000) in between each step to troubleshoot. This works until the last pause is executed ( i wrote pauses up to layer 2) but then it just pukes out layers 3 to 6, and the machine starts trying to print layer 7 directly after layer 2.
I've tried changing communication settings down to 9600 baud with no difference. Changed USB buffer in steps to minimum with no effect.
It seems to be something with the hardware buffer? During the "puke" LCD screen "buffer" goes from 2 to 16 and pretty much stays at 16 through the print.
Ideas anyone?
I have a home made cartesian style printer with a stationary ext0. RAMPS 1.4 with Atmega 2560. X and Y have min endstops NC. Z has max endstop NC.
As a test print i just want a single wall .7mm thick by 10mm high by 30mm long. But i need it to be done in single passes for each level so i am using Repetier Host with Slic3r because i cant figure out how to make Cura slice single passes.
Everything works as expected and works normally with most prints except this simple straight wall. I know, I know... dont print the wall then... lol... but this basic design is part of what i need to do.
So what happens is:
- start print.
- bed homes xyz.
- bed moves to 5mm below ext0 (ie G1 Z5 F1000)
- once finished this move and temperature is achieved, its like it just pukes out the rest of the code up to layer number 4. Host's preview of the print shows 4 layers as the bed moves into position. By the time it gets to the bed center to start the print its already at layer 5 where it tries to start printing.
The code appears sequential as it pukes it out so i can't see whats causing it. Ive even tried writing pauses (G4 P2000) in between each step to troubleshoot. This works until the last pause is executed ( i wrote pauses up to layer 2) but then it just pukes out layers 3 to 6, and the machine starts trying to print layer 7 directly after layer 2.
I've tried changing communication settings down to 9600 baud with no difference. Changed USB buffer in steps to minimum with no effect.
It seems to be something with the hardware buffer? During the "puke" LCD screen "buffer" goes from 2 to 16 and pretty much stays at 16 through the print.
Ideas anyone?
Comments
Im not sure i can explain it better than i did. I'll try.
My printer is skipping the first 4 layers. It starts "trying" to print layer number 5 which is too far away from the bed. Repetier preview instantly shows the 4 layers already laid BUT the printer is just moving to the print start position.
By the time the printer gets to the start position, it tries to start printing layer 5 (each layer is 0.35mm high so 4x0.35=1.4mm). It skipped the first 4 layers.
When i watch the code and watch the repetier preview, i can see that the code is executing code line by code line (so no errors are encountered). Except all of the code, after the time it finishes G1 Z5 F1000 to the end of layer 4, happens in milliseconds. I'll cut and paste the gcode in the next post.
Sorry it took so long but the problem corrected itself!
I changed the PRINTLINE_CACHE_SIZE back to 16 from 5 (i changed it to troubleshoot) to try to get the code, but after i did... the problem was gone. Starts at layer 1 every time.
But if you can think of what would have caused this let me know your thoughts.
I was thinking about it after you said Repetier Host shows the print ahead of the actual print because of the buffers. Im wondering if my stepper was losing steps on the way up to the print start position. That would cause it to start printing off the plate. I dunno. At least its working again.
Thanks for your time!