Disabling Endstops/Defaulting to Certain Coordinates?

I'm working on a project that involves using a Ramps 1.4 board, and Marlin as the firmware. I've figured almost everything out, but have one thing to work out: How can I disable endstops?
The concept of this device is that instead of being limited to a a certain area, the device can be placed on the ground, and will draw whatever is sent to it via bluetooth (Note: This isn't a 3D printer, but rather a 2D plotter using the same concept of a 3D printer. Instead of printing multiple "layers," it only prints one, with a pen/pencil/chalk/etc.)
What I would like, is that when the device turns on, or a print is started, instead of physically travelling to the min/max endstop positions, it simply locks the motors, and identifies its current location as min/max/center/whatever we define it to identify as.
The point of endstops are to prevent anything from crashing. However, this device is capable of going indefinitely in the X and Y axis. The only axis we would need homing on is the Z, as the "hotend" will still need to touch the ground.
So, How can I disable the need of endstops, and have the device default to certain coordinates upon starting a print?
Or would this be something defined in the slicing software?

I guess another way of looking at it would be, "How can I manually home the printer, and not need hardware endstop confirmation?"

Thanks!

G28 Z
G92 X0 Y0

That will do the trick, as I also have no endstops in my CoreXY yet.
You can also place jumpers between gnd and the X/Y endstop pins to fake an imidiately triggered endstop. Then you can use "G28" for all axis.

Quote
o_lampe

G28 Z
G92 X0 Y0

That will do the trick, as I also have no endstops in my CoreXY yet.
You can also place jumpers between gnd and the X/Y endstop pins to fake an imidiately triggered endstop. Then you can use "G28" for all axis.

Yes thank you. I figured out that removing G28 from the slicer prevents homing. Does the G92 line force the printer to believe that those are the current coordinates? What happens if I don't use it? What does it default to?
Shorting the signal and ground pins was actually what I originally did. I started the print with a jumper connecting all signals to ground, and once the printer "homed," I removed it. It became kind of a hassle, as I had to time it and everything. Thanks again!

Quote
o_lampe

G28 Z
G92 X0 Y0

That will do the trick, as I also have no endstops in my CoreXY yet.
You can also place jumpers between gnd and the X/Y endstop pins to fake an imidiately triggered endstop. Then you can use "G28" for all axis.

Yes thank you. I figured out that removing G28 from the slicer prevents homing. Does the G92 line force the printer to believe that those are the current coordinates? What happens if I don't use it? What does it default to?
Shorting the signal and ground pins was actually what I originally did. I started the print with a jumper connecting all signals to ground, and once the printer "homed," I removed it. It became kind of a hassle, as I had to time it and everything. Thanks again!

Quote
o_lampe

G28 Z
G92 X0 Y0

That will do the trick, as I also have no endstops in my CoreXY yet.
You can also place jumpers between gnd and the X/Y endstop pins to fake an imidiately triggered endstop. Then you can use "G28" for all axis.

Yes thank you. I figured out that removing G28 from the slicer prevents homing. Does the G92 line force the printer to believe that those are the current coordinates? What happens if I don't use it? What does it default to?
Shorting the signal and ground pins was actually what I originally did. I started the print with a jumper connecting all signals to ground, and once the printer "homed," I removed it. It became kind of a hassle, as I had to time it and everything. Thanks again!

Quote
o_lampe

G28 Z
G92 X0 Y0

That will do the trick, as I also have no endstops in my CoreXY yet.
You can also place jumpers between gnd and the X/Y endstop pins to fake an imidiately triggered endstop. Then you can use "G28" for all axis.

Yes thank you. I figured out that removing G28 from the slicer prevents homing. Does the G92 line force the printer to believe that those are the current coordinates? What happens if I don't use it? What does it default to?
Shorting the signal and ground pins was actually what I originally did. I started the print with a jumper connecting all signals to ground, and once the printer "homed," I removed it. It became kind of a hassle, as I had to time it and everything. Thanks again!

I used marlin without endstops for years without one single crash. So I was disappointed when at some point (1.1.0 RC7) the homing procedure became mendatory.
I asked the developer on github and he showed me a firmware workaround that helped me get rid of this stupid homing. Yes, I hate it. Especially Z homing.

This is what he wrote
thinkyhead:
Marlin now tracks whether it has been homed with G28 as a safety feature. It also requires re-homing for some commands if the steppers go to sleep. If you need support for a machine with no endstops, it will need to be added as an optional feature. For the time-being, just add the following to

setup()

in your personal copy:

LOOP_XYZ(i) axis_known_position = axis_homed = true;

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