i broke the hinge of my DS phat and lost the piece that came off. i wanna fix it, but without buying a new shell.

Well, its an original DS.. thats pretty much it i guess.

Re-design7 years ago
You could try building up the area where the piece is missing out of fiberglass cloth and resin then shaping it and coloring it to match but it's always going to look like a patch.

Look for a dead DS phat on ebay and get that to replace your shell.
I have this exact damage to a phat hinge - the far side of the cylinder snapped off, and this is the part that holds the detent clicky that keeps the screen at a given angle.

Repair is an option but not a good one since its such a structural part - I second Re-design's idea of either find another broken one, or get a replacement shell.

You can't beat www.dealextreme.com for replacement parts - just check the reviews and make sure a given item is perfect.