Home v. Origin - How to Resolve?

I have a Prusa I3 style printer (Aurora A3).
So it's home position is off the print bed - to the left and forward about 40mm x&y.
It's print area is 190x190 square
If I print something at 0,0 it is actually offset left and forward by 40mm.
My original solution to this was:

G28 X0 Y0 ;move X/Y to min endstops
G1 X40 Y40 ;Move to print origin
G92 X0 Y0  ;Set this coordinate to 0,0

But this appear to just shift Home position so now nothing will print within 40mm of the front or left of the print bed.

So, just now I tried:

G28 X0 Y0 ;move X/Y to min endstops
M206 X40 Y40 ;Add these offset to move commands

But somehow that allowed it to print outside the print bed!

Doing this was bad, very bad:

G28 X0 Y0 ;move X/Y to min endstops
M206 X-40 Y-40 ;Add these offset to move commands

Hope someone can help, I've run out of idea.

So how can I set my printer up so that HOME is outside the print bed, but the Print Origin is on it?

Thank you for any help/assistance/suggestions.

I would try

G28 X0 Y0 ;move X/Y to min endstops
G92 X-40 Y-40 ;tell the printer where it really is

G1 X0 Y0  ;move to 0,0 to test it

Actually I would put this in firmware in configuration.h

#define X_MIN_POS -40
#define Y_MIN_POS -40
#define Z_MIN_POS 0
#define X_MAX_POS 190
#define Y_MAX_POS 190
#define Z_MAX_POS 200

Thanks for the suggestion!

I tried the "G92 X-40 Y-40" and it did the same thing (see photo). But even stranger, as the print head was passing through the negative positions it moved REALLY SLOOOOW and almost sounded like it was grinding.
Once it got to into positive positions (past 0,0), it sped up to normal speed and proceeded to print incorrectly like before.

Is there anyway to read what is stored in the firmware for those values now?

I've been avoiding updating my firmware 'cause I just know I'll muck something up and end up with a doorstop



P.S. Here's what these commands production (maybe this'll help?)

Send: M115
Recv: FIRMWARE_NAME:Marlin V1; Sprinter/grbl mashup for gen6 FIRMWARE_URL:[github.com] PROTOCOL_VERSION:1.0 MACHINE_TYPE:Mendel EXTRUDER_COUNT:1 UUID:00000000-0000-0000-0000-000000000000
Recv: ok
[...]
Send: M360
Recv: ok
[...]

Edited 1 time(s). Last edit at 09/05/2016 03:25AM by DaHai8.

OMG!
I'm a COMPLETE IDIOT!!!
I just wasted a whole day and everyone's time who looked at this an scratched their heads.
I'm sorry Dust, I'm a dunce.
The model has a straight side right there and is not rounded.
I think I'm going to just hide under a rock for the rest of eternity.

Sorry everyone. This is resolved: PEBKAC