I built Oblivitus's UP3, it is a great knex pistol that uses minimal parts and depending on the amount and type of rubber bands you use shoots quite well but i decided to make it even lighter while not reducing its power and stability. Here is what i got, btw this is my first instructable and im assuming that you have already made the UP3 so im just posting pictures of the final product but i can add better ones if requested.
The barrel is built like the UP3 but shorter and lighter.
The handle is also similar.
The trigger is the same.
Step 1: The Barrel
If you have built the UP3 the barrel is the same idea but uses the lightest possible pieces and is of course shorter because i found the extra length added unnecessary weight. most of the blue spacers are not required however by removing them you will reduce the barrels stability, The only blue spacers that are necessary are the ones that are by themselves.
Step 2: The Handle
The handle is also the same idea as the UP3 but again made lighter
Step 3: Trigger/Assembly
The trigger is also the same as the UP3.
The gun goes together the same way as the UP3 so if you have built it you should have no problems. Thank you for taking the time to view and possibly make my mod to Oblivitus's UP3 and I hope you enjoy.
Note that my gun works great so if yours does not please make sure you have put it together properly before posting here, thanks =)