Inner Tubes

Build a homemade water gun or water balloon launcher and tell us about it.
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Neongreen
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Inner Tubes

Post by Neongreen » Tue Sep 26, 2006 7:30 am

Hi all,
Until now, I've noticed that everyone has been using bicycle inner tubes!

I didn't know any better until I wondered onto my local auction website, and found 4mm thick motorbike innertubes that can stretch up to 4-5 INCHES. Imagine six layers of this - a solid INCH of rubber tubing!

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Drenchenator
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Post by Drenchenator » Tue Sep 26, 2006 10:40 am

Everyone does not use bicylcle inner tubes. Most use latex rubber tubing, which can stretch about 3 times in diameter and about 8 in length. It can be ordered in various thicknesses and diameters. Some use balloons but that is a cheap method in my opinion. Most people only use inner tubes for extra layering.
and found 4mm thick motorbike innertubes that can stretch up to 4-5 INCHES. Imagine six layers of this - a solid INCH of rubber tubing!
Stretching 4 to 5 inches is not too impressive, but a solid inch of tubing would be. Most of the power of the latex rubber tubing probably comes from its elasticity, so you may still not get much power out of this stuff because it simply does not stretch enough. I don't know, you probably should try it out and tell us how well it works, I just don't think that it will.
Last edited by Drenchenator on Wed Sep 27, 2006 8:39 pm, edited 1 time in total.
The Drenchenator, also known as Lt. Col. Drench.

Neongreen
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Post by Neongreen » Tue Sep 26, 2006 7:57 pm

Yup, I mainly am posting it here for those who do not have access to LRT. Two innertubes(21" each) would allow you to make an 8" PC with a solid inch of rubber.

How much does LRT cost compared to this? This is approx $15 USD for a 21", 4mm thick inner tube.

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Silence
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Post by Silence » Tue Sep 26, 2006 11:21 pm

LRT is fairly cheap, and it comes in many sizes for layering. You can get it from various manufacturers (I think) online for a low price; but most people who actually make [cheap] CPHs buy it in smaller quantities from McMaster-Carr.
Drenchenator wrote:Everyone does not use bicylcle inner tubes. Most use latex rubber tubing, which can stretch about 3 times in diameter and about 8 in length. It can be ordered in various thicknesses and diameters. Some use balloons but that is a cheap method in my opinion. Most people only use inner tubes for extra layering.
Slight mistake there, I think. As far as I know, LRT stretches to 8.5X its original ID (inner diameter), and elongates to 3X its original length.

Neongreen
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Post by Neongreen » Tue Sep 26, 2006 11:23 pm

McMaster-Carr - yeah... however, I don't really like the idea of a $50-60 USD shipping fee to NZ ;)

EDIT:
Not to mention several weeks of waiting.

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Silence
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Post by Silence » Tue Sep 26, 2006 11:32 pm

Well, manufacturer's websites often sell LRT for even cheaper. Do a Google search of LRT and New Zealand or Australia...

Alternatively, you could get all your otherwise expensive PVC also from McMaster-Carr...and there's a chance they'll have free shipping for expensive orders. You might have to seek advice beyond this...

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SSCBen
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Post by SSCBen » Wed Sep 27, 2006 12:49 am

$15 for one less than two foot tube is really expensive. For comparison, two feet of the same cheap LRT I've been buying would cost $5.24 and would be 4.77 mm thick. Much cheaper, but not even in bulk, and direct from the manufacturer is even cheaper (but a little less convenient).

Bike tubes also use less resilient rubber because they are not designed to expand. Per thickness that does mean they'll be a little more powerful because they are harder as far as I know (put a force gauge on the tube and stretch it to test because I really have no idea), but they also hold substantially less water. They're good if you have no access to anything else, but much more expensive. It would be better to have a LRT center and then stack bike tubes over that because most LRT manufacturers can not make a tube with an ID over 1 inch.

From what I know Primeline Industries, which has a 3/4" x 3/8" tube (231BA/BB) in the bulk tubing section, sells cheaper than McMaster-Carr and nearly everywhere in the world (including New Zealand). I asked at their LRT forum about the force of tubing, and both ID and thickness matter, so the 3/4" x 3/8" tube they sell should be the most powerful single layer available. I actually was saving that information for the new website update, but it's too good to keep secret.

I've also been thinking about finishing my LRT expanding machine which should allow for more layers than anyone had previously used.

Primeline Industries is run by a real nice guy and you should email him about getting tubing in New Zealand. They should have a local operation there from what I've read.
Last edited by SSCBen on Wed Sep 27, 2006 1:02 am, edited 1 time in total.

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Drenchenator
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Post by Drenchenator » Wed Sep 27, 2006 10:47 am

Slight mistake there, I think. As far as I know, LRT stretches to 8.5X its original ID (inner diameter), and elongates to 3X its original length.
Elongation: 850%
It elongates 8.5 times according to the McMaster-Carr page. And from testing (looking inside the pressure chamber of my homemade it gets at least 3 times larger in diameter (maybe even four, this chamber is a bit restrictive).
The Drenchenator, also known as Lt. Col. Drench.

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Silence
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Post by Silence » Thu Sep 28, 2006 2:08 am

I never quite noticed that, but whatever. The CPS Physics article on the site, as well I believe as a few of Ben's posts, suggest that the tubing only becomes 8.5X wider and 3X longer. I couldn't quite find the posts, but using Google instead of the vB search will probably be better.

You could be wrong for all I know (your brother would probably know), but I thought it would just be better to point it out. Thanks.

Neongreen
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Post by Neongreen » Thu Sep 28, 2006 9:10 am

Note: I read through the beginning of the thread and see that I worded my first post poorly. Everyone is using bike inner tubes instead of motorbike inner tubes, which promise to be much thicker.

Also, that inner tube you mentioned there Ben, it is only available on orders of 200 feet+ :/ Currently getting prices on alternatives.

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SSCBen
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Post by SSCBen » Thu Sep 28, 2006 10:36 am

That's weird because the bulk tubing is supposed to be random lengths of tubing chosen by the customer. I suppose it differs from place to place. Try other tubes.

Neongreen
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Post by Neongreen » Thu Sep 28, 2006 10:38 am

Yeah, I emailed the guy with about 4-5 suitable tubes, let's see what he says.

I've also come up with a new RangeBoost technology which will be implemented into my next gun.

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SSCBen
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Post by SSCBen » Thu Sep 28, 2006 8:58 pm

RangeBoost? Please explain. I'd be interesting in knowing how it works.

Neongreen
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Post by Neongreen » Thu Sep 28, 2006 9:01 pm

I need to build a working prototype before I even consider disclosing it.

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Silence
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Post by Silence » Thu Sep 28, 2006 10:50 pm

I completely respect your right to keep the technology a secret, but I'm interested now. I'm happy to make some suggestions if applicable, and it's not like you need any more credibility than what you've already earned :cool: . And chances are good that speculation will rise until your plans are revealed...

Anyway, I'm excited to see what's cooking, and no pressure. Feel free to post more information, though!

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