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Re: RAMPS 1.4 and Mega2650 upgrade problems

Posted: Sun Oct 21, 2018 10:26 pm
by JacobLindsay
Quick update. I've gotten the z axis working properly. I still can't get the printer to home. When prompted to auto home it doesn't move to find the endstops it just moves according to the travel limits set in configuration.h

Re: RAMPS 1.4 and Mega2650 upgrade problems

Posted: Sun Oct 21, 2018 10:56 pm
by JacobLindsay
Another quick update. The printer homes now by moving to the endstops (I inverted the logic for the endstops) but after it hits the endstops I wants it to move either to the center of the bed or just over the heat bed adjusting screw. Basically I want the nozzle over the heat bed so I can check nozzle height right after I home. How do I do this

Re: RAMPS 1.4 and Mega2650 upgrade problems

Posted: Mon Oct 22, 2018 12:11 am
by Stefan
Hi JL,

(Look up how to post code snippets in their own block form so it is easier to scroll past it - probably not a big deal here, but some forums would troll you pretty badly).

Ok, glad to hear you are making progress! Send a command like "G0 X100 Y100" after homing to get the extruder centered on the bed.

To get the extruder to heat properly WITH the fan on, we need to set the PID parameters. These values tell the machine how aggressively to heat and autocorrect the extruder temperature. Almost every machine will have different values. Send this command when the machine is cold: " M303 E0 S200 C8". This tells the printer to run a PID test for extruder 0 to a temperature of 200C a total of eight times. When it is done, it will spit out constant values: Kp, Ki, and Kd. Use these numbers and replace the ones in your current configuration.h. When you restart the printer, it should now use these settings. You can also do something similar for the heatbed (check configuration.h for instructions).

If you run your printer connected to a computer, I'd recommend Octoprint or Pronterface as a console. (Great for centering extruder, for example).

-Stefan