Attempting to print on an old Printrbot custom from back in 2014 and using the fallowing G-code

G28 X0 Y0
G29 ; Auto Level
M212 Z0.1 ;Set the Z-Gap -.2
G1 Z5 F5000 ; lift nozzle

how ever no matter what i set the “Z-gap” to the head does not seem to get any closer or further away from the print bed that i can see. i have checked the auto-leveling sensor is working correctly and it works perfectly when its homing it self the filament even sticks but once it start to do the actual print the head stays so far away from the print bed the PLA just globs up and fouls the first layer. successive layers work just fine but with the first laying being messed up it inevitably messes up some where else along the way and total ruins the print even when using a raft.

Does any one have any idea what the issue could be and/or a solution?

Change your homing gcode to match the one in the pic… You are missing the home z line

m212 should not be part of your start code…

it it needs to be entered into the console followed by M500 to save it before you start a print…

i suggest starting at 0 and working down until it is calibrated

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M212 is a setting that gets stored on the board. After you send the command “M212 Z0.1”, you then need to send “M500” to save. Once it’s saved you don’t mess with it unless you have to change it so you don’t need M212 in your start code. Also you can send “M501” at anytime to see all the current saved settings. REMEMBER, unless you send “M500” after, the setting is not saved. That’s why your start code had no effect.
-Jesse

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VERY IMPORTANT:
One more thing. Just to be clear, those settings are ABSOLUTE not RELATIVE. It’s very dangerous to mess with those setting without knowing what the current settings are. I mentioned the “M501” command. You should use it to check the current settings BEFORE you change them so you have a base line. For example, if you want to lower the z by .1mm and M501 says the current setting is “M212 Z -0.2” you would need to send “M212 Z -0.3” and save(M500). I recommend always following this with another M501 to verify the changes were made and are correct.
Hope that makes sense. You might even want to take a screen shot of your current settings as a back-up just in case you need to go back or have a reference.
-Jesse

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I second this