Building the belt-fed Gun Turret perimeter?

[Peter34]

I have this factory I'm building, which I haven't looked at at all in about 10 days. It's going nicely, making red and green magic potions, and turrets, ammo and basic belts, and I'm inventing lots of stuff.

But the aliens keep attacking me, so I want an automated defence. I've opted for making a huge belt looping around my entire factory, with Gun Turrets along it, the belt feeding them ammo, which is produced by an Assembler Machine that in turn feeds the ammo to the belt.

But it takes forever to make that belt. Not so much manufacturing it, the Iron Plates -> Transporter Belts, but the manual process of running around placing it unit by unit. It's extremely tedious. I know once it's complete it'll actually be super nice to have, and enable me to add more Gun Turrets easily, on an as-needed basis. But actually completing it is painfully tedious, so I haven't actually completed it yet (notice how I said I haven't looked at all at the game in 10 days - this is why), and even more so I dread starting a new game, at some later time, because I'll have to build this huge-ass perimter belt again.

What am I doing wrong? Is my approach misguided? What do you people do in the early-mid-game phase to automatically defend your factories?

[Canyew]

Have two assembly machines making the ammo, set up a smart inserter that feed into a chest off your Science Pack 2 line, pulling transport belts off the line (As long as you have about 2 or 3 assemblers making belts this shouldn't hamper your science production at all. I was pulling transport belts off my line with a smart. So I can use 2 assemblers to convert them into fast belts. however I do have 4 assemblers making transport belts (6 assemblers making green science packs)

[DaveMcW]

the manual process of running around placing it unit by unit

You know you can hold down the mouse button to place transport belts while running?

[Align]

Is your defensive line very unevenly shaped? Or are you also including the inserters for the turrets in the tediousness? That could get old fast...

[Xterminator]

the manual process of running around placing it unit by unit

You know you can hold down the mouse button to place transport belts while running?

^ This. It sounds like you are placing belts one by one, in which case, yes it would be extremely slow and tedious. :p If your walls are straight, you can just hold down the mouse button to place the belts, and just walk along the wall and it will do it as you walk. Hope this helps! Don't give up yet.