SpudFiles

took a quick picture of a current build thats almost done. Wife was pissed that I left it on the counter though.

Moonbogg wrote:took a quick picture of a current build thats almost done. Wife was pissed that I left it on the counter though.

Someone likes solidworks

So is it a three chamber Burst disk pneumatic or a Hybrid ?

Moonbogg wrote:took a quick picture of a current build thats almost done. Wife was pissed that I left it on the counter though.

< Is suspicious of that picture.

Hey guys, I was wondering if you could throw some ideas my way.

For fathers day I'm planning on building dad a pneumatic inline 4 or v8 2 stroke motor to run on the compressor. The blocks will be made from pieces of delrin 2.5 cm wide (1"), 2 cm high and 10 cm long. Cylinders will be in increments of 2 cm along the 10 cm.

I'm planning on using this nice 1/2" drill I found on the ground (no joke, a very nise hss bit- new in pack. Turned it in and no-one claimed so it's mine!) to bore 1/2" cylinders (clearly) which should not need any liners. Then going to make pistons from some aluminum pipe which is barely shy of 1/2".

Schraders will be used as valves (think blowback hammer valve) which will be modified for 0 psi crack pressure + whatever pressure is behind them. They will also be cut down to expose the stem. They will be mounted in the head, which will be made from a sheet of perspex.

What I'm having issue with is the crankshaft, does anyone have any ideas? That's the only part I'm completely clueless on.

Btw, it will have onboard oil supply, electronic start, mounted on a nice wooden stand.

Any ideas on the crank? thanks guys.

inonickname wrote:
Hey guys, I was wondering if you could throw some ideas my way.

For fathers day I'm planning on building dad a pneumatic inline 4 or v8 2 stroke motor to run on the compressor. The blocks will be made from pieces of delrin 2.5 cm wide (1"), 2 cm high and 10 cm long. Cylinders will be in increments of 2 cm along the 10 cm.

I'm planning on using this nice 1/2" drill I found on the ground (no joke, a very nise hss bit- new in pack. Turned it in and no-one claimed so it's mine!) to bore 1/2" cylinders (clearly) which should not need any liners. Then going to make pistons from some aluminum pipe which is barely shy of 1/2".

Schraders will be used as valves (think blowback hammer valve) which will be modified for 0 psi crack pressure + whatever pressure is behind them. They will also be cut down to expose the stem. They will be mounted in the head, which will be made from a sheet of perspex.

What I'm having issue with is the crankshaft, does anyone have any ideas? That's the only part I'm completely clueless on.

Btw, it will have onboard oil supply, electronic start, mounted on a nice wooden stand.

Any ideas on the crank? thanks guys.

You could make a crank out of aluminium or brass disks say about 5mm thick cut from rod stock, but before cutting the disks drill a hole down the rod for a shaft. You can then solder the shaft sections in the center hole for each disk. An offset hole can be drilled in each disk to acommodate shaft sections for the big end bearings. I hope that makes sense

Subsonic Spud

That's pretty decent; thanks!

I'm most likely going to leave the crank to last; hopefully I'll have something good to make it with by the but it not may have to do some casting..

Oh you didn't fall for the pic? Damn, lol. Oh well, I only spent 12 hours on it. I had to make models of all the floor tiles and even the dog dish etc.
Its a triple something or other. I'll tell all when its a reality.

I'm thinking for the pressie I might just do it on the lathe/mill at school. I'm thinking of swapping the schraders for a rotating valve that opens at the top. I'll put a diagram up in a second.

The usual suspect in a render is it being suspiciously shiny

But it's looking interesting, not looking like a massive custom parts bill from this angle.

Hotwired wrote:The usual suspect in a render is it being suspiciously shiny

But it's looking interesting, not looking like a massive custom parts bill from this angle.

HEHHE! Was hoping i'd at least make someone do a double take haha. I am just starting to do actual renderings since I never really had a reason to. I will try to get them good enough to eventually fool you...even if only for a second

About the custom parts. Yes, none of that this time around . It should be pretty reasonable without sacrificing any awesomeness.

Did a quick drawing of the valve in question:

It should work well, though only has one issue. I wanted to do a messy, squiggly bunch of exhaust pipes. These valves are also much quieter though the power is epicly moar.

Gonna bring a chunk of delrin in to work the design over with and sort it out, then hopefully do one in aluminum.

I feel I am be hijacked! Help!

Hijacked? This thread is for everyone mate.

Though all credit to you, it is a very good image, not something I'd bother to go into that much detail with but still very nice. This one should be impressive..

Hotwired wrote:The usual suspect in a render is it being suspiciously shiny

The work is too perfect. Not a spot of fingerprints, glue, paint drip, oil, scratches. Look at the Star Wars movies to see stuff with the proper dings, grunge, and dirt to make it look real. When the rods with nuts don't have threads, or cut marks on the end, something is up. . A kitchen with dog dishes and not a spot of dog hair on anything was the other clue. Learn to make a mess now and then. At least my brazing job looks like a home project.

Did a quick drawing of the valve in question:

Nice rotary valve. It had to stare at it a while and follow the color legend. It's a departure from the typical steam engine. If you split the shaft, so the shaft is free to turn 180 independent from the crank, you can make it reversible. Start the engine either way, so the valve drops back and it will run that way. Stop the engine and turn it the other, and the valve will drop back 180 the other way and continue to run.

I have a model steam engine that has this reversing arrangement on the crank for the valve.

QUESTION: you know those pipe quick connect things. usually used on combustion breech systems. yea. what are they called? when I type "quick connect thingy" into the lowe's search bar nothing comes up. lol. and do they make them in 1"?

To attach the barrel to launcher?

They're called cam locks. One on the sponsors has em.