Super Soaker Central forums

Silence · 04-22-2006, 10:22 AM

@ wetmonkey442:

Yeah, Cerberus appears to be a bit too complex, but hopefully, it will expand the soaker community's knowledge of WBLs

.

PVC really weakens in cold conditions. I haven't researched its temperature capabilities yet, but I know that it's a poor choice if the temperature is too cold. There have been problems with people using weak PVC "catapults" to hurl snowballs because the PVC cracks too easily--and now we're talking about at least 100 PSI (probably more--I haven't been following this too closely). A heater is an okay idea (assuming it's for this purpose), especially since the concept is already complex

, but I just wouldn't use a WBL or any soaker in cold weather.

wetmonkey442 · 04-22-2006, 12:41 PM

It's really not good to have a soaker fight with the temperature below 40 degrees (F). Even if temperatures aren't freezing, if you become wet you can develop hypothermia alarmingly fast. If joannaardway is using her WBL at any temp above 40 degrees she shouldn't really need a heater. I use all of my WBL regularly in the winter to shoot snow balls, at 100 psi. I've never had a problem, because I understand the limits of the piping I'm using. Never, ever shoot any pneumatic cannon outside when the temperature is below freezing.

Silence · 04-22-2006, 10:52 PM

I don't think "below freezing" is the perfect temperature at which to draw the line--unless, of course, water has entered any imperceptible cracks in the PVC and freezes, destroying the pipe like potholes destroy roads. Otherwise, the PVC will probably reach its limit long before the temperature gets that low.

Besides, anybody who wants to have a water (or should it be snow?

) war at 40 degrees Fahrenheit is insane!

joannaardway · 04-23-2006, 09:45 AM

The point is that the temperature in the chambers will drop.

However, my previous calcations about temperature do not cover certain aspects - when you estimate, nothing that extreme is needed - however, temperature control would not be a bad concept.

This is estimated barrel temperature (used for every shot). Reservior temp is currently unknown (used for 1/3 of shots).

Yes, the point about Cerberus expanding knowledge about water balloon launchers is part of my intent. The processor (if in the end there is one) will be set up with multiple sensors, and is intended to take and store data about each launch to use to use at a later date.

Cerberus will only run at a maximum of 100 psi, except in very rare cases.

Hellhound will be able to achieve 6 shots - given that it will be pressurized at >100 psi to begin with, the chambers will drop to around 24 psi for the last two shots.

I put together spare parts over the last few days. I have created a pneumatic launcher (not for water balloons though) using about 35" of 3/4" pipe.

Given that this is powered by the pressure bottle for my 3xA and is only reaching about 15 psi, with a less than perfect valve setup, and a projectile of scaled mass (a grape), it fires this projectile at about 150 ft/sec, for about 250 ft range.

Despite the fact that this prototype launcher probably holds the record for cheapest launcher ever to break the 100 mph limit (cost about £4 [$7] max), is built from odd parts and is ridiculously simple, it tells me more than I need to know.

Aside: This launcher is also legal in the UK - it only achieves about 3-4 ft/lbs (about 10 with something like an AA battery)

Hellhound will be at much higher velocities than this, so I think that my plans are more than accurate there.

Silence · 04-23-2006, 11:08 AM

I'm glad to see that you've obtained good test results

.

When you're making scale conversions, make sure that you convert areas, volumes, etc. properly--it's not a simple "multiply by a scale factor" issue. Just to let you know (I'm sure you're considering these anyway)

.

joannaardway · 04-24-2006, 05:39 PM

On experiments with higher pressures, I'm currently upgrading the bottle to increase it's leak resistance for an estimated cost of about - nothing.

I'm using the casing of a free pen I got somewhere - actually, the same type of pen that fixed my 3xA trigger and provided the concical nozzles for my CPS 27K - (all hail the wonder pen!) - the only real cost is the glue.

Although I've had the bottle up to 100 psi before, it sprang some impressive leaks spraying water in most directions, and given that water is less leak prone than air, when I get up to high air pressures, the bottle dumps it so fast I can't use it.

This is a bit like a CVF in effect. The mod itself doesn't improve performance - it makes it possible to reach higher performance levels.

These will be reached by pressurizing the bottle to the afore mentioned 15-20 psi, and then pumping in water to bring the pressure up to around 100 psi. The feed hose will then be drained of the water in it, so that just air is being fed into the barrel.

GGDT estimates the velocity will roughly double over the standard pressurization (so about 200 mph with a grape)- range with a grape can be estimated at around 600 ft (using my own range estimator - it's actually accurate to about 0.5% error given current test data)

This velocity is actually not techically legal at about 20 ft/lbs with a grape (the legal limit being 12 [at least for an unlicensed air weapon]). However, I believe that breaking 200 mph for £4 isn't bad going at UK prices.

In theory, this concept could easily be carried over to a larger bore for an auxillary water balloon launcher for a 3xA - I don't imagine I will though.

The mass scaling incorporated factors such as barrel length, area, volume and friction - it's not an ideal match, but it will do.

Silence · 04-24-2006, 06:03 PM

GGDT? I'm starting to get lost...but I have to go now.

joannaardway · 04-25-2006, 09:50 AM

GGDT - gas gun design tool. It's generally considered to be the best pneumatic launcher modelling tool out there.

Errors on speeds are usually less than 2% if all facts are entered correctly.

I have posted my launcher on spudtech, if only to be interesting - if you want to take a look, it's in the finished launcher section and is called "Lancer"

I would provide a link but the word filter keeps on turning part of the link into "Instead of checking whether this was spelt correctly...." or however it goes. (It's an asp link and has a question mark after the s and p meaning that the word filter sees "s p ?")

Silence · 04-25-2006, 04:57 PM

So that's why I keep on seeing that annoying message, "(Instead of checking to see whether this was spelled correctly, I opted to take the lazy route)." I thought it was just some fad. Ben, can you please remove this?

I'll visit spudtech now. I had heard others talk about it (and Nerf sites), but I didn't really care then.

04-22-2006, 10:22 AM	#46
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	@ wetmonkey442: Yeah, Cerberus appears to be a bit too complex, but hopefully, it will expand the soaker community's knowledge of WBLs . PVC really weakens in cold conditions. I haven't researched its temperature capabilities yet, but I know that it's a poor choice if the temperature is too cold. There have been problems with people using weak PVC "catapults" to hurl snowballs because the PVC cracks too easily--and now we're talking about at least 100 PSI (probably more--I haven't been following this too closely). A heater is an okay idea (assuming it's for this purpose), especially since the concept is already complex , but I just wouldn't use a WBL or any soaker in cold weather. __________________ Forum rules

04-22-2006, 10:52 PM	#48
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	I don't think "below freezing" is the perfect temperature at which to draw the line--unless, of course, water has entered any imperceptible cracks in the PVC and freezes, destroying the pipe like potholes destroy roads. Otherwise, the PVC will probably reach its limit long before the temperature gets that low. Besides, anybody who wants to have a water (or should it be snow? ) war at 40 degrees Fahrenheit is insane! __________________ Forum rules

04-23-2006, 09:45 AM	#49
joannaardway Do not adjust your TV set Join Date: Feb 2006 Location: SW Hertfordshire, England Posts: 875 UserID: 549	The point is that the temperature in the chambers will drop. However, my previous calcations about temperature do not cover certain aspects - when you estimate, nothing that extreme is needed - however, temperature control would not be a bad concept. This is estimated barrel temperature (used for every shot). Reservior temp is currently unknown (used for 1/3 of shots). Yes, the point about Cerberus expanding knowledge about water balloon launchers is part of my intent. The processor (if in the end there is one) will be set up with multiple sensors, and is intended to take and store data about each launch to use to use at a later date. Cerberus will only run at a maximum of 100 psi, except in very rare cases. Hellhound will be able to achieve 6 shots - given that it will be pressurized at >100 psi to begin with, the chambers will drop to around 24 psi for the last two shots. I put together spare parts over the last few days. I have created a pneumatic launcher (not for water balloons though) using about 35" of 3/4" pipe. Given that this is powered by the pressure bottle for my 3xA and is only reaching about 15 psi, with a less than perfect valve setup, and a projectile of scaled mass (a grape), it fires this projectile at about 150 ft/sec, for about 250 ft range. Despite the fact that this prototype launcher probably holds the record for cheapest launcher ever to break the 100 mph limit (cost about £4 [$7] max), is built from odd parts and is ridiculously simple, it tells me more than I need to know. Aside: This launcher is also legal in the UK - it only achieves about 3-4 ft/lbs (about 10 with something like an AA battery) Hellhound will be at much higher velocities than this, so I think that my plans are more than accurate there. __________________ "Over the hills and far away, she prays he will return one day. As sure as the rivers reach the seas, back in his arms again she'll be." - Over the Hills and far away, Gary Moore "So many people have come and gone, their faces fade as the years go by. Yet I still recall as I wander on, as clear as the sun in the summer sky" - More than a feeling, Boston

04-23-2006, 11:08 AM	#50
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	I'm glad to see that you've obtained good test results . When you're making scale conversions, make sure that you convert areas, volumes, etc. properly--it's not a simple "multiply by a scale factor" issue. Just to let you know (I'm sure you're considering these anyway) . __________________ Forum rules

04-24-2006, 05:39 PM	#51
joannaardway Do not adjust your TV set Join Date: Feb 2006 Location: SW Hertfordshire, England Posts: 875 UserID: 549	On experiments with higher pressures, I'm currently upgrading the bottle to increase it's leak resistance for an estimated cost of about - nothing. I'm using the casing of a free pen I got somewhere - actually, the same type of pen that fixed my 3xA trigger and provided the concical nozzles for my CPS 27K - (all hail the wonder pen!) - the only real cost is the glue. Although I've had the bottle up to 100 psi before, it sprang some impressive leaks spraying water in most directions, and given that water is less leak prone than air, when I get up to high air pressures, the bottle dumps it so fast I can't use it. This is a bit like a CVF in effect. The mod itself doesn't improve performance - it makes it possible to reach higher performance levels. These will be reached by pressurizing the bottle to the afore mentioned 15-20 psi, and then pumping in water to bring the pressure up to around 100 psi. The feed hose will then be drained of the water in it, so that just air is being fed into the barrel. GGDT estimates the velocity will roughly double over the standard pressurization (so about 200 mph with a grape)- range with a grape can be estimated at around 600 ft (using my own range estimator - it's actually accurate to about 0.5% error given current test data) This velocity is actually not techically legal at about 20 ft/lbs with a grape (the legal limit being 12 [at least for an unlicensed air weapon]). However, I believe that breaking 200 mph for £4 isn't bad going at UK prices. In theory, this concept could easily be carried over to a larger bore for an auxillary water balloon launcher for a 3xA - I don't imagine I will though. The mass scaling incorporated factors such as barrel length, area, volume and friction - it's not an ideal match, but it will do. __________________ "Over the hills and far away, she prays he will return one day. As sure as the rivers reach the seas, back in his arms again she'll be." - Over the Hills and far away, Gary Moore "So many people have come and gone, their faces fade as the years go by. Yet I still recall as I wander on, as clear as the sun in the summer sky" - More than a feeling, Boston

04-22-2006, 12:41 PM	#47
wetmonkey442 Super Moderator Join Date: Jun 2003 Posts: 256 UserID: 47	It's really not good to have a soaker fight with the temperature below 40 degrees (F). Even if temperatures aren't freezing, if you become wet you can develop hypothermia alarmingly fast. If joannaardway is using her WBL at any temp above 40 degrees she shouldn't really need a heater. I use all of my WBL regularly in the winter to shoot snow balls, at 100 psi. I've never had a problem, because I understand the limits of the piping I'm using. Never, ever shoot any pneumatic cannon outside when the temperature is below freezing.

04-24-2006, 06:03 PM	#52
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	GGDT? I'm starting to get lost...but I have to go now. __________________ Forum rules

04-25-2006, 09:50 AM	#53
joannaardway Do not adjust your TV set Join Date: Feb 2006 Location: SW Hertfordshire, England Posts: 875 UserID: 549	GGDT - gas gun design tool. It's generally considered to be the best pneumatic launcher modelling tool out there. Errors on speeds are usually less than 2% if all facts are entered correctly. I have posted my launcher on spudtech, if only to be interesting - if you want to take a look, it's in the finished launcher section and is called "Lancer" I would provide a link but the word filter keeps on turning part of the link into "Instead of checking whether this was spelt correctly...." or however it goes. (It's an asp link and has a question mark after the s and p meaning that the word filter sees "s p ?") __________________ "Over the hills and far away, she prays he will return one day. As sure as the rivers reach the seas, back in his arms again she'll be." - Over the Hills and far away, Gary Moore "So many people have come and gone, their faces fade as the years go by. Yet I still recall as I wander on, as clear as the sun in the summer sky" - More than a feeling, Boston Last edited by joannaardway : 04-25-2006 at 11:56 AM.

04-25-2006, 04:57 PM	#54
Silence Administrator Join Date: Apr 2006 Location: Virginia Posts: 3,285 UserID: 576	So that's why I keep on seeing that annoying message, "(Instead of checking to see whether this was spelled correctly, I opted to take the lazy route)." I thought it was just some fad. Ben, can you please remove this? I'll visit spudtech now. I had heard others talk about it (and Nerf sites), but I didn't really care then. __________________ Forum rules

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