Fallout 3 Big ?

How many self made weapons are there, where do you get the schematics for them, and how do you get the acheivment?

There are 7 weapons. Bottlecap mine, dart gun, death gauntlet, Nuka Grenade, Railway Rifle, Rock it Launcher, Shishkebob. The schematics are located all over the map. Some you can buy, some you have to find or get as quest rewards. You have to build 1 of each to get the achievement.