I have 3d printed myself a T4 quad.
I mistaken the back for the nose so I positioned the gps and flight controller to be pointing towards the back.
Because of the all the cabling is now too short and there are connections that have to be desoldered then resoldered.
What affect does mounting it backwards have on the copter?
Is there a way I can flip it around in software for now.
From your picture I can see that it is installed correctly with the yellow arms being the front. Also the fact that is flying means it is the correct orientation, otherwise it would flip over. I think what you need to do is reverse the pitch channel, 2. This is standard for copters. Check your radio calibration again. Read the last tip in this wiki about ch 2 being reversed.
Sorry I didn't make that clear. that isn't my copter. Mine inot nearly as neat and tidy. Plus one of the belts slipped whilest printing so the frame is alittle wonky.
So what effect will it have if I mounted the flight controller and gps in the oppersite direction? surely the controller has no idea it's mounted the wrong way? If so why did the original designer and everyone else mount it similar to whats in the image.
What happened with mine was it appeared to gain altitude but then it flew off in NE direction then hit the deck. After that accident it bent the prop mount quite badly. I'm waiting for new motors.
Did you set the orientation of the primary (external) compass accordingly?
I'm guessing I didnt. how do I do that?
Also in mission planner there are three compasses. How can I be sure which is one is my gps and which is the one inside the pixhawk
Number 1 is in the GPS. Number 2 is in the Pixhawk
If I understood your right in your initial post right: both the flight controller and the GPS pointing to the back. In that case you should have not a compass inconsistency, except you haven't calibrated them. You and Chris are right, but i have the feeling I either misunderstood you, or there is some more going on.