Mjöllnir - 1.5" porting Handheld Piston Hybrid

[MrCrowley]

Have been thinking about it, I probably could get one done where I got the barrel welded. Was even thinking of giving my high school tech teacher a call to see if I could use the lathe or if he could make one for me.

Guess it would be made from aluminium, not sure what a better alternative would be.

[SpudBlaster15]

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[MrCrowley]

Sounds similar to how my valve has always functioned.

Thank fûck!

Kinetic (or dynamic) friction occurs when two objects are moving relative to each other and rub together (like a sled on the ground). The coefficient of kinetic friction is typically denoted as μk, and is usually less than the coefficient of static friction for the same materials.[15][16] However, Richard Feynman comments that "with dry metals it is very hard to show any difference."

Seems to follow what you said, good thing I lubed the freakin' shit out of the piston and housing.

[Juggernaut12121]

I'm a little late to the party but I was looking to build a piston valve hybrid sometime in the future (probably within one or two years based off of my financials(I have none ) )
Anyway I keep seeing yours and it looks amazing! I was wondering how much you paid for the whole setup after all the modifications and things (I saw you stated over $300 but that was when you had the nuts and bolts piston and the ABS barrel), thank you in advance!

[MrCrowley]

I'm a little late to the party but I was looking to build a piston valve hybrid sometime in the future (probably within one or two years based off of my financials(I have none ) )
Anyway I keep seeing yours and it looks amazing! I was wondering how much you paid for the whole setup after all the modifications and things (I saw you stated over $300 but that was when you had the nuts and bolts piston and the ABS barrel), thank you in advance!

Hmm, good question!

It will all depend on where you live, really. In the US, you can get parts a lot cheaper. I live in New Zealand and things are often a bit more expensive. I think I paid about $100USD for the galvanised iron fittings. I got the stainless steel barrel for about $30USD and welded a fitting on to it for $20USD. The barrel is stainless steel tube leftover from someone's handrail project, I bought it on an auction website similar to eBay. The original nut and washer piston could be built for about $20USD (in NZ) and then throw in another $10 for some araldite epoxy. The aluminium piston was machined for free by a kind member of the forums here but could be made for under $40 if you had access to a suitably sized lathe or a machinist friend. I looked at getting one machined by a local place and they wanted $70USD an hour. The piston wouldn't take long to make but that's still fairly expensive. I've spent quite a bit on the ignition circuits, maybe $100 or so because it took a lot to get right. The stun gun circuit was bought for about $15USD or so from a member of this website who used to have an online store. Other electrical components like switches, project boxes, and relays could be had for about $30USD total where I'm from. If you plan it right, you could make a decent ignition circuit for $30USD. The fuel meter can be expensive unless you buy smart and secondhand. I got a manifold fitting for $5, a 0-15PSI pressure gauge for about $10, a 0-145PSI gauge for $5, and a Norgen air regulator (not required but prevents over-pressurising the 0-15PSI gauge) I had left over from a previous project. The propane bottle and fitting can be bought for about $30. This is more expensive than usual because you have to get the propane bottle with the torch fitting. The torch fitting threads on to the propane bottle and can be modified to work with normal BSP/NPT brass fittings. The torch fitting is important because it opens the propane bottle valve when threaded on and has a flow regulator to control the propane flow. These torch kits may be cheaper elsewhere but cost me about $30USD in NZ.

I think that's about it. So I think a cannon like this could be built for $300USD, depending on your country and the availability of secondhand/cheap parts. In reality, I probably spent closer to $500USD as I had to do a lot of tinkering and what not.

[Juggernaut12121]

Wow alright, I was wondering about price differences but I didn't think some of the stuff would be too far off. Thank you! This was quite insitefull, I'll have to keep an eye out for some of the things like the fueling manifold and fittings and things on to go on sale.