Nerfhc: PVC is very inconsistent on the ID. So sometimes it will work great, sometimes it will completely fail. I recommend 1/2" EMT (steel tubes), as they are more slippery, more consistent, and a hair looser than PVC. Home depot definitely sells it (it's usually in the electrical section), and it's about as cheap as PVC. A hacksaw can cut it just fine, but do be careful to clean out all of the metal chips after you do so--I recommend blowing a wet piece of toilet paper through the barrel a few times. EMT isn't perfect, but it has about 10 times less of the "dart-fart" misfires that plague long barrel tagger blasters.
edit: Also, sheath your barrels people. Nothing sharper than 1/2" PVC should be the tip of your barrel.
This is the HAMP I made. @Happy burnination, it fires streamlines just fine using cpvc. Also, my plunger head eliminates the need for yarn, at least until you start making HAMPs with 1.5" dia. plungers ( but i got something for that too ).
What you made is not really a HAMP. It's a manual plunger, but it's got the same airflow as a SNAP. So it's really a LAMP (Low Airflow Manual Plunger). More importantly, you used a tight, lubricated seal. So, your blaster follows the rules of springers, not HAMPs, which is why it uses CPVC well. Although lubricated rubber seals can be used to make manual plungers of any size, finding the right components to fit can be tricky, and it will require an unreasonable amount of lube. Also, springer-fit HAMPs are harder to aim than loose barreled HAMPs, because the manual resistance varies as the pressure builds and is released.
Most CPVC is WAY too tight to fire slugs/stefans/streamlines out of a traditional HAMP, unless the foam is exceptionally thin. Apparently, in some regions the local foam and cpvc supply make for a loose fit, but generally it won't work with a yarn seal.
So, what would be the ideal size then? Also, my (apparently) LAMP has no problems with aiming and iv'e found that 2-3 squirts of WD-40 down the tube works fine and I know it has petroleum distillates in it but i haven't seen any rubber deterioration like with PJ.
There is no ideal size. Larger plungers with long, loose barrels are quieter, and in my experience, much easier to aim. Smaller plungers with shorter, tighter barrels are much more compact, and since they build pressure before firing, can achieve the same range as their larger cousins with a shorter barrel. Personally, I hate dealing with lube, and have no need to make my blasters smaller, so the yarn seal works for me. But, I think Wes was the one that observed that a LAMP would make a great integration for a long ranged, accurate blaster. So, the short story is, it depends on what you want from your blaster. I just don't like people telling everyone that CPVC works great for a HAMP barrel, when the yarn seal (which is the most unique feature of the classic HAMP design) is not usually compatible with tight barrels.
Edited by KaneTheMediocre, 25 October 2010 - 11:16 PM.
