I am a beginner at making nerf homemades... so bare with me.
Hacksaw, Dremel, pipe cutter, or anything else that can cleanly cut PVC (NOT CPVC)
Hot glue gun and hot glue
(Optional) Flat, heavy weight
PVC cement (I also used a primer which I highly suggest)
Lazer level (or just use a lazer or a ruler)
DUCT tape (NOT DUCK TAPE)
Lots of E-Tape (electrical tape)
2" inch PVC about 2 feet
(1) 2'' inch PVC coupler
1.5" inch PVC about 3 feet
1/2" inch PVC about 6 feet
(1) 1/2'' inch PVC ''T"
(2) 90 degree 1/2" inch PVC elbows
As many bushings as it takes to get from 2" inch PVC to 1/2" inch PVC
Nerf darts, Screamers work the best (Streamlines kinda don't work)
Some sort of Plastic/ Tape friendly Lube
Step 1: Body and Plunger
The body (2'' inch PVC) should just be just long enough so your non dominant hand can still stretch forward a good 10 inches (look at the photo)
I used a black 1.5'' inch piece of PVC
Cut on the longer side of your piece of PVC about three fingers down
Step 2: Cut Body and Plundger
Remember, wear eye protection and always cut in a vice if you are using a hand-held saw.
Step 3: Sealing the Plunger
Step 4: Glueing the Plug Together
Do this by glueing one to another, squishing it with a weight until it's dry, and glue another one on top and squish it with a weight until it's dry. Repeat until all four are glued together
I used a giant, concrete book-end (look that up on google) to squish them all together
Step 5: Glueing and Sticking the Plug on the Plunger
Once you have done that cover it in DUCT TAPE so it is Uber held on.
Step 6: Create the MASSIVE O-ring
Step 7: Bushings
The problem with the bushings is that you have to use a coupler to join the bushing to the 2'' inch PVC
Step 8: Glueing Bushings
Finally primer and glue the coupler with all the bushings sticking out of the opposite side to the end of the body of the H.A.M.P
Sorry, no pictures.
Step 9: PVC U (sounds Funny I Know)
Simply glue one of the 1.5 inch long, 1/2'' inch pieces of pipe inside the two elbows, but make use the elbows are totally vertical (I did this by pushing them, on their side, on a flat surface) JUST LOOK AT THE PICTURE IF YOU DON'T UNDERSTAND.
Primer and glue in the other section of 1.5 inch long, 1/2'' inch PVC piece into an end of a elbow.
Step 10: Barrel
I wrapped mine in some e-tape so it looks cool.
Step 11: Barrel Wobble Prevention
To modify one of these (yes I know mine is not a "T" but oh well) you need to take out the old dremel ( or you could use a small file but that would take FOREVER! !!) and use a sanding bit to get rid of the ridges on the inside that prevent you from pushing one pipe all the way through. Once you have triple checked that some 1/2'' inch PVC will easily slip into the modified "T" it is time to mount it.
I am fortunate enough to have a lazer level (basically a fancy lazer with a level) so i just marked where I wanted the modified "T" to go and made sure it would live up with the PVC U we made earlier. I realized the "t" would be too low so my barrel would bend, so I put a small section of 1/2'' inch PVC in the "T"
To make sure the PVC that will go in the T will stay in place i ground down the bottom so it was the same as the surface of the Body.
I AM TERRIBLE ABOUT DESCRIBING THESE KINDS OF THINGS SO PLEASE FORGIVE ME AN TRY TO BARE WITH ME :(
I used super glue to bond it to the body, after the super glue dried T filled the empty hole at the top of the 1/2'' inch PVC nub that fits into the "T" with lots of PVC glue
Step 12: Decoration
Step 13: LUBE!!!!!!
Step 14: How to Fire + a Firing Test
Small H.A.M.P (Firing test done with homemade stefans)
Average: 20 feet
Regular H.A.M.P (Firing test done with "Whistler" darts)
Average: 80 feet