calculations

[dyldo]

does any one know or could point me in the driection of calculations for optimum barrel length/chamber size?

i wish to make my next cannon as small as possible

thanks for any input

[wblteen]

Search the wiki for a program called GGDT

[rna_duelers]

It's not sizes that are optimum it's more Ratios C:B ratios Chamber:Barrel.A .8:1 is the optimum for an advanced combustion wiht propane injection,mixing fans and stun guns.But for a spray gun there is a number of 1.5:1 C:B that people seem to stick wiht for spray n shoot combustions.

[Freefall]

RNA, this is the pneumatic section.

Dyldo, listen to wblteen and look for "GGDT", Dave Hall's Gas Gun Design Tool. Pick some design points and use GGDT to figure out the rest.

[jackssmirkingrevenge]

-=download it here=-

[dyldo]

downloaded it very detailed to many realy im unsure of some of the options like seat diameter, vent diameter. but all i realy want to know is roughly how much bigger in volume should i make the chamber compared to the volume of the barrel?

[Freefall]

... And that's what GGDT will tell you once you put in the numbers.

Tell us a bit about your valve, and we can help you with the inputs.

[dyldo]

piston valve about 18mm or .7 inch in diameter i think iv got it though
now to make it and see how it works