the nanites have to be connected to the projector and the blueprint you want to build has to be touching the projector and everything has to be set to be owned by same player,something i learned recently as well could that be it?

Yeah, it was my bad, turns out I misunderstood projectors and their uses. I got it working after moving the projection to touch the projector.

The projection can touch any part of the ship that has the projector on it. It doesn't have to be touching the projector itself (though it can and is easy to use that way), it just has to touch a block somewhere on the same ship as the projector.

Sorry to Necro this thread, but im afraid to say I'm having a head scratching time. I'm trying to get the Factory to craft me some drones/piloted ships, but i cannot for the life of me work out how to make the connection from station to small ship with a projection. I read that it wont work through landing pad/strut/foot, so I've spent a couple of hours trying work out how to connect a small grid connector to the large grid connector so that i can then attack power and projector unit to that. and I'm afraid im completely stuck. Am i trying the right thing the wrong way or am i completely wrong, Could you give me the 'idiots' guide please.

How I got the nanites to build a small ship for me :
1. drop a connector on the same grid as your factory. It doesn't need to be connected to anything, just dropped it on an armour block. Power it off for now.
2. Beside this I placed a small landing gear to start my small ship.
3. Build a pillar of blocks approx 5-6 blocks high then extend it out over the connector you placed already.
4. Build a connector on the small grid directly over the other connector.
5. Build a battery/solar panel/small reactor on the small ship.
6. Add your projector and project your ship.
7. Get it all offset and lined up the way you want it.
8. Grind away the landing gear.
9. Turn on the connector.
10. If everything is lined up the way it should be you should now be able to lock the connectors together.
11. As soon as you lock them the nanites should start building.

This was just a quick and dirty way I did it today.
I'm gonna try and design a more permanent solution that I can reuse, for example building a box of blocks around the connectors so I dont have to keep eyeballing to make sure its all lined up.

Maybe you can try this mod from BiggLou55: https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=660736134

I rebuilt it for the work in space and it works fine.