Yes, Moss, you can use a bicycle pump on it. The best would probably be the foot-pump kind, with a pressure gauge, as it will take a while to fill & you want to know the pressure.

As for calibration with pressure and height, I achieved 150 ft. with 1.5" diameter, 5 ft. barrel PVC with a 12 oz. shot pouch on orange polyethylene slickline, at 110 PSI. I believe it could be calibrated for different heights, but it will need some more testing. 60-70 PSI is more than enough for trees around here,where we're lucky to find 50 ft. anchors nearby. If we take a road trip North, we can find 120 ft. plus in about 2 hours.

I'm sure I'll be experimenting with many different materials, sizes and designs & will keep you posted.

Thanks TreeTramp, for the wise words about PVC. We experimented with all kinds of PVC devices when we were kids, & it's probably a miracle we're all here. I'll take your advice, and the next phase will probably incorporate a _meta_l pressure tube, with its own pressure gauge etc. Glad you and your son weren't hurt by the PVC exploding.

Climb (and launch!) safe, and have fun, too

I have thought about building another PVC cannon with a design that eliminates end caps. The physics of the stress on the ends makes me think that they all be built without end caps at all.

Two parallel 2" PVC pipes with elbows at each corner would form a rectangle or a square. Then halfway along both opposite pipes have two tees connecting one side to the other with a third tee pointing up. Using a 2" tee with a 1" female threaded side port will allow you to screw on _meta_l pipe nipples for the valve and barrell asembly.

The rectangle could be made in a size that will also be used as the ground _base_ so the barrell is already standing tall like a flag pole. Make the barrell tall enough so no idiot could look down the barrell to see if it loaded. Air it up and tip it to aim.

The 12 volt air pump and battery could be mounted on the _base_ and all kinds of gauges and relief valves could be positioned well.

Using a 1" lawn sprinkler valve and a Radio Shack push to close button wired to the battery makes a deluxe cannon.

All that is left is some kind of sound supressor to rid your shooting of that annoying pipe organ tune when you fire.

When I was shooting potatoes the sound brought out all of the neighborhood kids.

Good luck and safe hunting.
Dan

SRT-Tech,
I like the modification ideas. If I try PVC again, I'll definitely incorporate a no-end-cap design. I've thought about trying the flexible pipe used for LP gas also (any thoughts?). Pressurized PVC makes me nervous too, especially when it's cold. I still like the _meta_l designs you mentioned before, except for the weight-factor.

All in all, I see why people like cross-bows, lol.

Since you mentioned shooting potatoes, have you ever heard of pumpkin-chucking? There's a serious sub-culture of pumpkin-chucking cannons in the area. The local competition has cannons that fit on a semi-tractor trailer bed and shoot a serious distance. Maybe I could just climb in one and launch into a huge tree, lol.

Safe launching,
Ogham