# Tube Size is Deceptive !



## wll (Oct 4, 2014)

Ran some numbers on the REAL width of my tubes, and was surprised;

Diameter x 3.14 (Pi) = circumference or width.

4.5mm OD = .555

5m OD = .615

6mm OD = .741

1/4 OD = .785

5/16 OD = .979

And then you figure in that most has a wall thickness or .055 to .062 ..... you end up with some powerful rubber in a small tight package.

Ever wonder why even the smaller tubes in a looped config have so much power ? .... looped 1745's give you 1.11 inches of width, and .055 wall thickness, that is a lot of rubber

Just me pondering,

wll


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## bigron (Nov 29, 2012)

Wii

have you always been a numbers guy,i'm not being a jerk i am just curiuos


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## M.J (Nov 1, 2010)

If you want to do a more direct comparison between any type of rubber you can use the cross section area. That allows easier and more accurate comparisons, especially between flats and tubes.


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## Jacktrevally (Feb 14, 2011)

Yes a lot of rubber!


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## pgandy (Aug 15, 2011)

Good observation Wll. It would be more meaningful if you calculated in the area of the rubber involved, i.e. (OD-ID)π. But then to be fair one would have to know the thickness of the flats involved in order to make a just comparison.


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## Jacktrevally (Feb 14, 2011)

The sectional area is an indication of how much rubber is present but it doesn'tbgive you any indication of the retraction!

You can have similar areas or less area, this doesn't imply that in both cases they are going to shoot as fast!


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## M.J (Nov 1, 2010)

pgandy said:


> Good observation Wll. It would be more meaningful if you calculated in the area of the rubber involved, i.e. (OD-ID)π. But then to be fair one would have to know the thickness of the flats involved in order to make a just comparison.


The following chart lists cross section for most popular tube sizes. Cross section for flats is found by multiplying width of the band by the thickness (also shown in chart).










Edit: The pic won't get bigger :iono:

Find it here: http://slingshotforum.com/topic/13848-dankung-tube-sizes-explained/


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## wll (Oct 4, 2014)

On my OP I was just giving an observation of the width of rubber compared to flats, I have no idea the retraction speed and if a tube hinders that or not. It was just interesting to me that two little 1745 tubes had 1.11 inches of width, with .o55 wall thickness.

Bigron said:

wll

have you always been a numbers guy,i'm not being a jerk i am just curiuos

Ron I've always been a guy who wants the facts, not opinion as much as I can get. Been this way since I was a young kid, always tinkering, finding out what works the best, always trying to make things as simple as possible ... I could go on and on.

wll


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## Wingshooter (Dec 24, 2009)

wll said:


> Ran some numbers on the REAL width of my tubes, and was surprised;
> Diameter x 3.14 (Pi) = circumference or width.
> 
> 4.5mm OD = .555
> ...


I compared 1745 tubes against I inch .030 latex flats and found for all practical purpose's they shot pretty close to the same in my stump shooting forays. That is one reason I shot them for so long. And still do on occasion. I didn't realize until now that there is almost twice as much rubber in the tubes to get what is basically the same results. Interesting indeed.


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## POI (Dec 5, 2014)

Thinkin outside the math box.... equal length cuts of any type of material placed in a liquid with the displacement measured will tell you the materials volume comparatively speaking. and again with no real world retraction info...


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## POI (Dec 5, 2014)

Wingshooter said:


> wll said:
> 
> 
> > Ran some numbers on the REAL width of my tubes, and was surprised;
> ...


and don't that offer some reason for the general accepted notion of durability.


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