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Cannon seems underpowered?
Posted: Mon Dec 31, 2007 4:00 pm
by lemmiwinks
So I finished my pneumatic cannon, it has a modded sprinkler valve, 3' 3" diameter chamber and 3.5' 3" diameter barrel. I've tried shooting some different things like tightly packed snow and different balls, generally using newspaper as wadding. The stuff shoots far, but it seems like it should go farther... For example, a 3" by about 6" snow cylinder flew less than a block. What could be my problem here? Is my barrel too long, or is it just the diameter that's killing me? Any tips would be greatly appreciated, thanks.
Posted: Mon Dec 31, 2007 4:01 pm
by octane89
Snow might just be a bad projectile so try other items. Or try and 2" barrel around the same length.
Posted: Mon Dec 31, 2007 4:02 pm
by BigJon
What size is your sprinkler valve?
Posted: Mon Dec 31, 2007 4:03 pm
by octane89
Most are 1" or 3/4". Easy to assume its one or the other.
Posted: Mon Dec 31, 2007 4:05 pm
by BigJon
Well i have seen some bigger but you probly right octane.
Also what pressures are you using?
Posted: Mon Dec 31, 2007 4:07 pm
by elitesniper
how bout some pictures so we can see the problem
Posted: Mon Dec 31, 2007 4:08 pm
by jrrdw
The ratio is out if I read correctly. The barrel has more volume then the chamber. Should be the other way around. More chamber then barrel.
Posted: Mon Dec 31, 2007 4:13 pm
by mark.f
That, and the valve is horribly undersized. For a 3" barrel, I would suggest a piston valve, or burst disk.
Posted: Mon Dec 31, 2007 4:16 pm
by elitesniper
why dont you use the 3.5 to make the chamber?
Posted: Mon Dec 31, 2007 4:22 pm
by bluerussetboy
another thing to remember when just shooting snow is moisture content. a wetter/heavier/warmer snow will go farther than a dry/lighter/colder snow.
Posted: Mon Dec 31, 2007 4:24 pm
by elitesniper
warm snow? is there such a tthing? isnt that just water
oh i think i know the problem your snow cylinder you were fireing might be to heavy?
Posted: Mon Dec 31, 2007 4:32 pm
by dewey-1
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Posted: Mon Dec 31, 2007 4:35 pm
by elitesniper
yea but it depends on what psi hes running at
Posted: Mon Dec 31, 2007 5:08 pm
by bluerussetboy
elitesniper wrote:warm snow? is there such a tthing? isnt that just water
oh i think i know the problem your snow cylinder you were fireing might be to heavy?
there really is such a thing. for your amusement.
The following are standard definitions of snow types and their associated abbreviations.
Powder-PDR: Cold, new, loose, fluffy, flaky and dry snow which has not been compacted.
Packed Powder-PP: Powder snow, either natural or machine made, that has been packed down by skier traffic or grooming machines. The snow is no longer fluffy, but is not so extremely compacted that it is hard.
Hard Pack-HP: When natural or machine made snow becomes very firmly packed. The snow has never melted and re-crystallized, but it's been tightly compressed through grooming and continuous wind exposure. You can plant a pole in hard packed snow, but it takes more effort than packed powder.
Machine Groomed Snow-MGS: Loose granular snow that has been repeatedly groomed by power tillers so that the texture is halfway between LSGR & PP. Some of the snow is granular & has been so pulverized that the crystals are like powder sugar. It's neither LSGR or PP.
Wet Snow-WETSN: Powder or packed powder snow that has become moist due to a thaw or rainfall, or snow which was moist when it fell.
Wet packed Snow-WPS: Natural or machine made snow that has been previously packed and becomes wet usually because of rainfall.
Loose Granular-LSGR: This surface results after powder or packed powder thaws, then refreezes and recrystalizes, or from an accumulation of sleet. This is also created by machine grooming of frozen or icy snow.
Frozen Granular-FRGR: This is undoubtedly the most misunderstood surface condition in ski reporting. It is defined as a hard surface of old snow formed by granules freezing together after rain or warm temperatures. Frozen granular will support a ski pole stuck into its surface while ice will chip away and not support a pole.
Wet Granular-WETGR: Loose or frozen granular snow which becomes wet after rainfall or high temperatures.
Icy-ICE: Not to be confused with frozen granular, ice is a hard, glazed surface created either by freezing rain, ground water seeping up into the snow and freezing or by the rapid freezing of snow saturated with water from rain or melting. Ice will chip away and not support a ski pole when stuck into it.
Variable Conditions-VC: When no primary surface (70%) can be determined, variable conditions describe a range of surfaces that a skier may encounter. Parts of trails can be Loose Granular, partly Packed Powder, and parts Frozen Granular, for example.
Corn Snow-CORN: Usually found in the spring, Corn Snow is characterized by large, loose granules during the day, which freeze together at night, then warm up again and loosen during the day.
Spring Conditions-SC: This is the spring version of Variable Conditions. It is used when no one surface can describe 70% or more of the terrain open for skiers.
Windblown Snow-WBLN: Powder or granular snow which has been blown by wind into forming a base.
Posted: Mon Dec 31, 2007 5:13 pm
by elitesniper
so is there such a thing as cold fire? ha im jk