"In the world of spuds today"

[farcticox1]

I sorta thought you would have all seen his stuff but I guess it's not that old. I like the marble machines 8)

If I build one I'd large it up a bit

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[hectmarr]

Style refined in aesthetics and a fantastic weapon. I like very much! :bounce:

[farcticox1]

I have been looking around for some possible safe to use indoor ammo, Nerf darts/balls, foam balls etc. Got some 20mm darts and 22mm foam balls coming, 3/4" Sch 40 PVC
Found a site selling balls for an airsoft grenade launcher, surprised to see how tight a fit they are

Material: High Density Foam
Dimensions: 50mm diameter for a superior air seal in a 40mm launcher.
Application: Used as a projectile for Airsoft M203 and other similar Airsoft Grenade Launchers.

[Zeus]

Stealing my contest idea boy! Better not be touching oxygen....

Quite curious about your results with it though

[farcticox1]

No worries, I'm judging

[jackssmirkingrevenge]

20mm PCP custom build from Finland...

[youtube][/youtube]

I believe the barrel is from a 20mm cannon

Build Log on the GTA forums

[hectmarr]

uhhhh !!! awful! it sounds beautiful! :bounce: :bounce:

[Zeus]

ITWOST, V1 didn't have the giddyup I needed, time to go over to a conventional(ish) hybrid cartridge. Hopefully my welding skills are sufficient. I expect 12ml at 28x should give me the required gas volume. If not, I'll be tapping gas from before the projectile for extraction.

[jackssmirkingrevenge]

oooh... watching this space.

[Zeus]

Yeah, I tried PVC and an atmospheric pressure propane/O2 mix, but between turning the fittings narrower and you know, PVC, I had splitting problems and it wouldn't move my bolt simulator far enough. Stress testing on the fill valve/spark gap tomorrow (I hope). Built it in a threaded fitting so I can inspect it.

[hectmarr]

Yeah, I tried PVC and an atmospheric pressure propane/O2 mix, but between turning the fittings narrower and you know, PVC, I had splitting problems and it wouldn't move my bolt simulator far enough. Stress testing on the fill valve/spark gap tomorrow (I hope). Built it in a threaded fitting so I can inspect it.

What do you use to test O2?

[Cthulhu]

I realized last night I need to stop whining about not having a lathe and just use what I've got...
So I shoved a nail in my drill and turned it with files.

I tried to make a nice dart for my blowgun, and I even attempted bluing the tip. Anyone have advice on getting a better color throughout the piece?

[hectmarr]

Try heating the metal to pale red, (obviously, before inserting the plastic), and immerse it in dirty engine oil. There remains, the metal, a blackish color. For the plastic, paint it, simply. Your darts are very nice.

[Zeus]

I just used a series of 3/4" (20mm) PVC fittings, but to work in my device, I had to make them smaller. Unfortunately the fuel mix was a bit too powerful

[farcticox1]

I think this 3/8 solenoid valve will work nicely when triggered by the manual button

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