# tubular discussion



## colt (Jun 8, 2010)

I'd like to pick the collective brain of slingshot forum today and start a discussion on tubes. specifically on dimension ratios.

what started this thought for me was the fact that i love the simplicity and economy of a tube, but long for the power of flat bands. i continued thinking and started to consider dimensional ratios. it is generally known that with flat bands, thickness plays a big role in efficiency. with all things constant (draw weight and length, projectile, etc) theraband black will throw faster than gold. this shows us that rubber operates more efficiently spread thin. remember this is where the only difference is in material dimension ratios. for instance, lets say that to get the same pull weight, (making this up) you need to achieve a thickness to width ration of 1/80 with TB black and 1/40 with gold.

applying this to tubes, lets observe my observations. thinking i was a strong guy, i started making double strand Chinese style tubes from green Thera Tube. i could shoot it, but it was heavy so i ordered some TT red. i made identical bands and the pull weight was more manageable. the interesting part is that the TT red lost a disproportionately small amount of velocity compared to the red. i got a drastic reduction in pull weight and a marginal difference in velocity with the same projectile. the difference between TT green and red? they both have the same O.D. of 5/16", green's I.D. is 3/16" and red's I.D. is the larger 7/32" and thus we have a different OD to ID ratio. as of yet i have no capability to compare tube bands where the only difference is ratio. in fact, that would be hard to do. however, with this we can gather that like flat bands, the efficiency of tube bands affected to some degree by dimensional ratio.

what i would like to test at this point is some extremely thin walled tubing. and see how it performs. essentially, a tube with a very different ratio. 
for comparrison here are some ratios of commonly available tube rubber. numerator is OD, denominator is ID.
Chinese rubbers:
1745 -	2.6/1
1842- 2.3/1
2050- 2.5/1
other tubes:
5/16" x 8/32"- 1.66/1
5/16" x 7/32" (TT red)- 1.43/1
5/16" x 6/32" (TT green)- 1.25/1

any thoughts?


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## dgui (Jan 12, 2010)

Have tried various tubes and the one that suites me the best for accuracy speed and durability are the black 1845 one tube per fork, pouch to fork 6 to 6-1/2 inch works best for me. Best performing ammo for this is 5/16 steel ball. In addition to this if you use RayShots Mag Pouch then you will see the advantage in easy loading and better speed shooting. But, this is the combination that works for me.


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## shooter452 (Nov 6, 2010)

colt said:


> the interesting part is that the TT red lost a disproportionately small amount of velocity compared to the red. i got a drastic reduction in pull weight and a marginal difference in velocity with the same any thoughts?


I'm sure you are aware of this but it bears a reminder that a lot has to do with projectile weight. I've been learning (at least I think) that heavier bands will not shoot lighter ammo much/any faster than lighter bands but once the ammo gets past a certain weight the difference can be seen or measured. I know that I shoot mostly over powered bands for my ammo (which is really a waste) and suspect many do the same in the search for more power and speed. Just a thought that I hope is helpfull. I hope this thread leads to the better understanding you desire and I know I will be interested in the opinions and facts uncoverd.


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