SpudFiles

What kinds of tests does everyone want to see? Soon, I'll be doing tests on vortex and cloud strafers of the same size and barrel length, seeing their power, ROF, and air consumption, at 10 psi increments going from 70-110 psi. I also might do tests on how long it takes for PVC cement to cure (not that you should go against the time on the can). Another test I might do would be pressurizing Sch 40 PVC, Sch 40 cell core PVC, and cell core ABS, small chambers of the same volume, and seeing if they can hold pressure.
Any suggestions, post 'em here.

how are you going to figure out rof for a bbmg??

I heard, more accurately read, somewhere that if you put a magnet near the breach of the barrel it will increase power, when using steel or other ferrous metal projectiles of course. That would be something for you to test.

Clear chamber on cloud and film in slow-mo. That way if we see if there is anything to improve.

Same with vortex with clear block too.

OH! And Redo the gasoline effect on pvc test

Test all-purpose abs-pvc cement on PVC with abs endcaps.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras nec placerat erat. Vivamus dapibus egestas nunc, at eleifend neque. Suspendisse potenti. Sed dictum lacus eu nisl pretium vehicula. Ut faucibus hendrerit nisi. Integer ultricies orci eu ultrices malesuada. Fusce id mauris risus. Suspendisse finibus ligula et nisl rutrum efficitur. Vestibulum posuere erat pellentesque ornare venenatis. Integer commodo fermentum tortor in pharetra. Proin scelerisque consectetur posuere. Vestibulum molestie augue ac nibh feugiat scelerisque. Sed aliquet a nunc in mattis.

noname wrote:I also might do tests on how long it takes for PVC cement to cure (not that you should go against the time on the can). Another test I might do would be pressurizing Sch 40 PVC, Sch 40 cell core PVC, and cell core ABS, small chambers of the same volume, and seeing if they can hold pressure.
Any suggestions, post 'em here.

Those tests will only be useful for your specific pipe and circumstances. Chances are that the SCH40 pipe will hold up well over its pressure rating, the cell core pipe will probably hold a significant amount of pressure, and the glue will hold up to pressure well before the listed cure time. However, the recommendations for pressure are based on a statistical distribution of failure based on numerous tests and theoretical calculations. Where the "safe" limit is set depends on the chances of failure and cost of failure.

Say there is a 1 in 100 chance that a certain size of cell core pipe will burst 100 psi. You could do a ton of tests and still get no failure, but given that hundreds or possibly thousands of people make spud guns each year, and chances are a person will be standing right next to the pipe if it fails, is it really safe to use?

SpudBlaster15 wrote:Test the integrity of a chamber constructed using an epoxy such as JB weld as opposed to PVC cement.

yeah i want to make a gun using JB weld and that would be useful

How much pressure a standard 1" sprinkler valve can handle before it starts to leak/fail. You could try the common green one or loads of different types.

lukemc, I'd pour exactly 500 BBs and measure how long it takes to dump them all.
Judgment Arms, I could do that, give me some more details on how I'd set it up.
Benstern, I don't have a video camera or the funding for that, maybe someone else could do it. I'd provide the clear block, no problem.
Frankrede, it's possible.
SpudBlaster, sure, I'll try it.
Clide, "is it safe to use?" Those who read my tests and think it's safe might use it, those who still think it's unsafe won't.
Crowley replied as I was typing this one-fingered while eating a drumstick. I'll test that with a normal one, then with one of my soon to be seen "Modded Out the Ass" valves. This includes the valve's body, a custom metal diaphragm, a modded blowgun, and one of DR's valve lids.

noname wrote:l\
Clide, "is it safe to use?" Those who read my tests and think it's safe might use it, those who still think it's unsafe won't.

The problem is that the "test" caters to the unsafe, and in all likelihood will only serve as justification for those who are ignorant to the reasoning behind pipe ratings to continue their unsafe practices and misinform others. Somebody who doesn't know better will say, " this guy pressurized his cell core chamber up to 300 psi and it didn't blow, so there is no way mine will blow up at 120 psi." Next thing they know they are waking up maimed in a hospital room ready to become the next media figure for how dangerous these unregulated weapons known as spud guns are.

For a ROF test on a bbmg couldnt you just get a large sheet of paper, burst fire for 1 second, and count the holes?

it would be a little long....my ancient cloud BBmg shot a hundred BB's a second. (measured.)

SpudBlaster15 wrote:Test the integrity of a chamber constructed using an epoxy such as JB weld as opposed to PVC cement.

Using marine epoxy resin and PVC (properly mixed with the PVC suitable roughened to ensure proper adhesion) I've taken my designs to 400psi without failure, indeed the PVC will split before the epoxy will.

For a ROF test on a bbmg couldnt you just get a large sheet of paper, burst fire for 1 second, and count the holes?

Er... as opposed to just counting the amount of BBs in your chamber before you pulled the trigger compared to the amount of BBs after you let go of it?

They say a picture’s worth a thousand words: