3 replies to this topic

[CooledWhip]

Well I am modding my AT3K, and I saw that online, people use petg, I used petg for my BBB and it didn't work very well, the dart didn't shoot out. I got some CPVC, but from what I saw online, my CPVC is different than others'. They can just slide their dart in like in actual nerf blaster, when I have to twist mine in, I can't just push it in from the tip. Is the barrel I am using bad? Do I need slicker barrels? Thanks

[Carbon]

Your CPVC fit sounds like a typical springer fit barrel. My darts don't slide in easily, but I get good performance with SNAPs. For an AT3k, you may want to try .5" Sch80.

Anyway, barrel recommendations are a rule of thumb sort of thing. They usually work for most people, but it depends on the foam you're using and what supplier your barrel source uses. Take some darts to the hardware store and see if you can find a decent fit (typically a sliding fit for airguns, and a tighter fit for springers.)

Edited by Carbon, 08 September 2013 - 12:11 PM.

[Mully]

Generally the consensus with barrels is that loose fitting barrels are used for air guns (PETG) while tighter fitting barrels are used for springers and other such blasters (CPVC)
3k's are a lot weaker than 3b's, the reason PETG probably didn't work out on your bow, is because Big Bad Bows simply don't have enough air volume to make a dart fire out of PETG. (Depending of course on dart fit, type of dart, and the length of the barrel)
Your CPVC is probably the same type we all use, I know I'm using the same kind almost everyone else uses, and I have to use a ramrod to get streamlines into it, and twist and turn taggers and whistlers when I'm loading those. Where did you get your CPVC?

Also, you might have already seen this, here's a great series of videos made by NoM, detailing the building process of a 3k.

Part 1

Part 2

Part 3

Part 4

Edited by Mully, 08 September 2013 - 02:22 PM.

[azrael]

The basic idea is that we use tight fit barrels for springers because we need the system to build up enough pressure to generate enough kinetic energy to break the coefficient of static friction.

In an air blaster, the tank stores air, meaning that the air in that system is already at its maximum pressure. A loose fit will take the most advantage of this stored energy.