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Re: Community Project #1 - Handheld, High Mix, Hybrid

Unread postPosted: Mon Aug 02, 2010 11:42 am
Author: Gun Freak
jackssmirkingrevenge wrote:If you find a way to reliably fuel small volumes, let me know!

It's not called a community project for nothing :roll: :D

Re: Community Project #1 - Handheld, High Mix, Hybrid

Unread postPosted: Mon Aug 02, 2010 11:58 am
Author: SpudBlaster15
jackssmirkingrevenge wrote:If you find a way to reliably fuel small volumes, let me know!


At 300x, it's not exactly going to be a small volume of fuel. :lol:

Finding a fill valve and building a sufficiently robust chamber would be a challenge at such a small scale... Perhaps we should adopt the Mythbusters' definition of a pen. :D

[youtube]http://www.youtube.com/watch?v=NAW_KPac-H8[/youtube]

Unread postPosted: Mon Aug 02, 2010 12:03 pm
Author: Gun Freak
Well... there are some pretty big pens out there... :D

Unread postPosted: Mon Aug 02, 2010 12:38 pm
Author: clemsonguy1125
And if thats still to small

Unread postPosted: Mon Aug 02, 2010 1:10 pm
Author: jackssmirkingrevenge
Riddle me this, imagine I have a closed chamber with the correct amount of propane for a 3x mix, and I use a pump through a schrader to pressurise it to 30 psi. Would the propane flow back into the pump through the schrader?

This could be one of the reasons why my hybrid cartridgefailed to ignite.

Unread postPosted: Mon Aug 02, 2010 1:31 pm
Author: Lockednloaded
Well I believe that if you're are pulling the pump shaft out to fast you could be losing a minute amount of the mix; when I pump with my larger pump on smaller chambers I can really see this happening, the needle jumps back as I reset the pump. good thought, could've been your problem. Its easily fixable as long as your HPA reg is highly adjustable

Unread postPosted: Mon Aug 02, 2010 1:33 pm
Author: Mr.Sandman
Pssh penguins are child's play. Rubber duckies are where it's at :lol: What would impress me would be a 300x cane gun firing 10 gram slugs at mach 2.

Re: Community Project #1 - Handheld, High Mix, Hybrid

Unread postPosted: Mon Aug 02, 2010 2:27 pm
Author: SpudFarm
jackssmirkingrevenge wrote:If you find a way to reliably fuel small volumes, let me know!


Premixed chamber of a bigger volume?
Then perhaps connect it to the "pen gun" and pump oil in on the bottom of the premixed tank to displace the propane/air mix into the chamber. Should be a easy way to reach high mixes.

Re: Community Project #1 - Handheld, High Mix, Hybrid

Unread postPosted: Mon Aug 02, 2010 2:56 pm
Author: jackssmirkingrevenge
SpudFarm wrote:Premixed chamber of a bigger volume?


This is the only solution that would properly work in practice, I can picture using say a soda bottle with the correct amount of fuel injected, then pressurised in one go with a compressor in order to avoid backflow, then decanting into cartridge.

If you use say a 2000mL soda bottle to decant into a 5mL cartridge the difference in volume is enough to say fill 10 cartridges with relatively the same mix.

Or... say 2mL butane in a 50mL syringe, then use the syringe to inject the mixture under pressure into a smaller volume syringe...

Unread postPosted: Mon May 09, 2011 4:49 pm
Author: jackssmirkingrevenge
I realise it's been several months since this thread died down, but some good ideas had been thrown around and now may be a good time to revive it, mainly because there has been some level of spudfiles member cooperation in recent weeks, as illustrated by the "long range" thread.

Also, things have come a long way since my post above when I had no clue how I was going to get a small hybrid to work ;)

Unread postPosted: Mon May 09, 2011 5:35 pm
Author: Zeus
Well I've just read through the thread and have a few ideas.

ijahman made a very nice pump action combustion that should be within most people's abilities, but I don't understand why some are so concerned about compressing a mix in a hand pump. If a burst disc is in the pump head it'll only make a loud noise.

But how often do internal combustion engines ignite for no reason? If a sensible compression ratio is maintained, it is incredibly unlikely that ignition would occur.

Unread postPosted: Mon May 09, 2011 6:00 pm
Author: saefroch
If you're referring to autoignition...

You do make an interesting point... there hasn't yet been a hybrid whose chamber is manually compressed before firing to increase mix number.

Unread postPosted: Mon May 09, 2011 6:26 pm
Author: mark.f
saefroch wrote:You do make an interesting point... there hasn't yet been a hybrid whose chamber is manually compressed before firing to increase mix number.


Well, daccel's hybrid fueling pump would technically be what you're describing. The "chamber" being manually compressed would be the chamber the torch is allowed to flow into and the pump would compress it into the hybrid's chamber. He achieved ignition on test with a very small chamber, I might add...

Unread postPosted: Mon May 09, 2011 7:10 pm
Author: saefroch
I guess that's pretty close...

Unread postPosted: Tue May 10, 2011 12:03 am
Author: jackssmirkingrevenge
mark.f wrote:Well, daccel's hybrid fueling pump would technically be what you're describing. The "chamber" being manually compressed would be the chamber the torch is allowed to flow into and the pump would compress it into the hybrid's chamber. He achieved ignition on test with a very small chamber, I might add...


That does put a dent in my cartridge dreams but good point...

That system + piston hybrid might be the way to go.