Lj's USS Texas(BB-35) SJS 3D Print complete Kit build

I’m building this as a fast gun. Also, I only use four cannons.
I didn’t know about HPA being lower in capacity.

Thank you for your insight. That drives my confidence in HPA over CO2

Update

I did just order a 4500 psi HPA Compressor I thought about doing an another bigger tank as a refill bottle but the guy said it might be better to just get a portable HPA compressor. I figured out it is more cost effective too. The price for a bigger bottle and then getting that bottle to give its contents without equalizing was going to drive the cost up too.

 

This is not accurate.

The cylinder that I sell is simply a pressure vessel, it can hold whatever you put in it. It is rated for CO2 per the manufacturer, DCEC cylinders in Taiwan. It is rated for a working pressure of 3000psi, which is liquid CO2 pressure, not the 4500PSI of HPA compressed air. Pressurizing one of my tanks to 4500psi is over 1500psi in excess of their rated working pressure.

IRCWCC does not specifically allow or disallow HPA. You will get less usable gas out of the tanks I sell if you try to use HPA instead of CO2, as the tanks store liquid CO2 not gaseous CO2, which then expands. Whereas HPA is just that...high pressure gaseous air. It will also take a considerable amount of time to fill an HPA tank with any sort of small portable compressor, far too long to be ready between IRCWCC sorties after you've exhausted your initial fill up. This is one of the main reasons why we have not adopted it. CO2 is not "going anywhere" per say, while paintball and whatnot may have embraced HPA due to their lighter spun fiber tanks and such, CO2 is extremely easy to get from any industrial gas supply store. Think more welding gas and less paintball store.

I caution against listening to advice from alternative formats, ie big gun, or alternative hobbies, ie paintball, when trying to build for IRCWCC. You can test fire your guns using an HPA tank and compressor, or even just any $60-80 pancake air compressor from home depot. But actually battling the boat is done with CO2.

I have been extremely busy with life and things, but have been making an effort to be more present on the forum and such to help out. If you need guidance, the best people to ask would be @Kevin P. @Beaver @Anvil_x @Lou @bkoehler @Renodemona and possibly more, active, IRCWCC captains who are more than willing to show and help with questions.

 

YOUUUUUUU RAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAANG!?

also yeah double tap all the above, especially re: HPA vs. CO2 and rated pressures

Safety First!

 

So what do you mean? CO2 in battle but then HPA off battle?

 

Can me setting everything up as HPA cross over into CO2?

 

I don’t know where to get liquid CO2 and get more besides my tiny bottle

 

If you attend a battle, there will be co2 at the battle. If you want to refill your co2 tank outside of a battle you can buy or rent a 5 lb or 20 lb co2 tank from a local welding supply store. here is a link to air gas which is a large supplier

https://www.airgas.com/Gases/Carbon-Dioxide/category/605
Then you need a co2 fill station which connects the big tank to the little tank, something like this https://www.ebay.com/itm/306425715950

to test the guns on the bench, you can use a small air compressor. I battle a lot and only use an air compressor to test guns. 110psi is fine

https://www.harborfreight.com/3-gal...lFpAKB4oZ_PI9pOdKKp2hXI6-3dt1ELxoCxv8QAvD_BwE

 

I do the same as Kevin with a pancake compressor. they work great and it's way less of a pain to deal with when you're bench testing things

 

I suppose that depends on what compressor you get... I have a pretty good one but I don't think it has ever taken me even ten minutes to fill a 48 cubic inch bottle to 3000 psi. After you you consider the time for pre-chilling a CO2 bottle and nonsense with scales there isn't a ton of difference in the refill time. The lower capacity is a potential deal breaker for some ships/people. Besides, the HPA compressor automatically turns off. So it can be filling while I am doing other things nearby.

However, I agree that you should take the advise of the people who you will be battling with - they are the ones you will be looking to for support.

I do personally encourage you to test on the bench with same supply you will use on the water. If you go CO2 then jump in with both feet. If you cannot find somewhere local to refill CO2 bottles then you can buy a refilling setup online and get 20 lb. tanks from your local AirGas supplier. Then you will be able to refill CO2 bottles at home as needed. Depending on how much you test before meets maybe just buying a few extra bottles will be good enough to hold you over... The members of your club should be able to help you there.

 

So this is the compressor I own.
https://a.co/d/5KCyNBR

It 6mins from start to finish on my tank from Will.
Which if I want this to be even better I should order another tank

 

I have used both. HPA is preferred in paintball circles because there is no phase change involved, which allows them to dump tremendous amounts of gas without freezing their system. CO2, on the other hand, is stored as a high-density liquid that boils into gas as it gets used. This gives much greater energy density (effectively shots per unit volume) than HPA, allowing us to use much smaller, lighter bottles. Couple of questions. First, what pressure are you running your HPA tank at? Some tanks are rated for 4500PSI, but many are only good for 3000PSI. Also, what size tank do you have? Gotta make sure it's actually big enough to meet your needs. The general rule of thumb is a bit over 1oz of CO2 per offensive unit for most cannons. I don't know a great conversion between HPA and CO2, but one tank I have is rated for 5oz of CO2 or 13cu.in. of HPA. Then consider HPA is about 1/2 to 1/3 the per-shot efficiency of CO2. So that bottle which would be good for 4-5 cannons with CO2 would only be good for roughly 2 cannons.

I didn't know that high-pressure compressors were that readily available or fast to fill. I may have to look into HPA again for some of my bigger ships.

 

My bottle is rated for 3000 psi. I have 4 cannons.

 

Really!? I am surprised by this... I always assumed that fast gun cannons used a lot less gas than big guns cannons do. I used to be able to completely empty my BB HMS Lion's cannons and still have a ton of CO2 left with a 20 ounce bottle... I think that was ~1200 quarter inch rounds... maybe I remember that wrong. In any event I never ran a 12 ounce bottle on Lion but I always expected that I could have.

I am still only experimenting with HPA so I cannot speak with confidence exactly how well it compares... other than by observation it is a ton lower capacity. Completely by observation, I would be shocked if it was 1 ounce of CO2 to 3 cubic inches of HPA that you suggest... I would give good odds it isn't even 1 ouch to 4 cubic inches.

Someone more knowledgeable than I am about HPA can help here hopefully but from what I have seen the metal HPA bottles are all 3000 psi. The 4500 psi bottles are carbon fiber (etc). I am suspicious that the fiber bottles will not take impacts well so I have only been testing with metal bottles.

The 48 cubic inch metal HPA bottles are a bit bigger than a 20 ounce CO2 bottle. They are probably close enough to the same size for many builds. However, I would be very surprised if they have the equivalent gas volume of a 12 ounce CO2 bottle... probably more like a 9 ounce bottle.

[I guess I should sit down and test this one day lol]

 

hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahaha

I run a 5 oz CO2 tank for 2.5 units of cannon. High-flow cannons are total hogs but they really get the message across in a way that low-flow just can't do.

nothing says "My Sidemount is gonna score belows" quite like "The water between my cannon and your hull is totally displaced and my rate of fire is going cyclic"

 

Yeah, I sometimes forget the high rates of fire you all use and the speeds you all run at. We dump a ton of gas all at once but then don't do it again for six or eight seconds... and often longer because after a few shots it takes time to come around for another pass.

 

So what does all this mean for my boat and situation?

 

It means people just wanna talk sometimes. As for your TX, looking good so far, good luck, and keep at it.

That, and do check out your local welding supply, CO2 is so handy.

 

Also, don’t forget to check Home Depot. They sometimes carry the smaller 20lb cylinders as well. They’ll be in a cage outside in front.

 

I’m concerned about the weight of my boat. Right now, I have put in all the absolute items and it’s flirting at 30lbs.

 

Can you send a picture of all the items laid out? That seems a bit excessive.