b'RUBBER BOUTIQUEULTIMATE BENCH TEST!Much pie is spake about elastic! We get proper scientifi c and set up a pukka test rigY ou think catapult shootersdogs reviewing doughnuts. fame to make me some more band sets. are the most obsessive aboutScience at its best is obvious and aboveNot the epic ones he made to go with the their elastic? You are wrong!all, reproducible. So experiments are bestfull 152cm-draw rifle, but ones made to fit Its aeromodellers in F1D classkept simple and with as few variables asme. T he active length was 19cm so I had rubber-band powered planepossible. Then the results di erences arejust over 4x elongation. Not too much for contests! Their flimsy balsa-and-membraneall and only about the thing you really wantany worthy elastic. I used 9.5mm steel planes can fly indoors in circles for half anto know. In this case, the oldest question.balls.hour. The best rubber was made in MayWhat is the best brand of elastic? We know energy dissipates as heat and of 1999, according to this video. https:// By best we mean least pull weight forthat rapid release gives you best speed but youtu.be/sVaDvS33Z5Q They discuss andfastest projectile speed. To test this wefor consistency, each ball was fired after measure this stueven more than us. need a lot of things to be the same. Tothirty seconds of being cocked. And here is Likewise there have been many shootersstart with we need a test rig. In this case,the kicker.who have decided to set up a chrony andthe Chrony F1 speed measuring deviceWe had eleven varieties and all do lots of testing of slingshot elastics. Theseand a tripod with the slingshot rifle seenat 0.60mm thickness! So any speed tests are usually all about di erent tapersin this issue. Set to my draw length ofdi erences have to be the elastic as the and thicknesses and ammo and are all80cm (31.5in) so the results were as if Ibands are all the same taper and thickness about the speeds attained. Yet every singlehad shot them, but without my variation.and at the same draw length. A set of one that I have seen has been blindinglyI then asked the redoubtable RichardBrowning digital strain gauge fishing scales too complex and as scientifically rigorous asRogers of Handmade Catapult Bandswas used to measure draw weight.Richard Rogers cut - 18mm to 13mm taper, 19cm active and 0.6mm thick. Three sets each of eleven kinds!Another busy chrony testing day.Adapted Hegarty band jig, clamped to table for pull testing.1Precise Gen. 1 green:Draw weight @80cm: 8lb 10ozAverage 205.72 fps (5 shots) CONCLUSIONS2Precise Gen. 3 natural:Draw weight @80cm: 7lb 13ozAverage 200.7 fps (5 shots) 1)Elastics of the same nominal 3JustShootIt pink:Draw weight @80cm: 9lb 5ozAverage 196.56 fps (5 shots) thickness can vary absurdly.2)Draw weight is proportional to 4Sheshou white:Draw weight @80cm: 9lb 10ozAverage 216.42 fps (5 shots) energy stored.5 Draw weight @80cm: 11lb 12oz*Average 238.06 fps (5 shots) 3)There are e iciency di erences in Celtic Catty black:6Celtic Catty blue:Draw weight @80cm: 6lb 4ozAverage 184.04 fps (5 shots) draw weight conversion to ammo 7 Sumeike turquoise:Draw weight @80cm: 8lb 9ozAverage 206.54 fps (5 shots) speed but they will only be relevant 8 Gnol Kinetic Energy red:Draw weight @80cm: 9lb 8ozAverage 212.56 fps (5 shots) for these actual batches of elastic. 9SoBong black:Draw weight @80cm: 10lb 11ozAverage 220.48 fps (5 shots) And Celtic Catty black is hench, while Sumeike Turquoise is really 10100% Slingshot black/green:Draw weight @80cm: 9lb 4ozAverage 215.20 fps (5 shots) e icient.11 100% Slingshot natural:Draw weight @80cm: 8lb 3ozAverage 201.06 fps (5 shots) *Highest draw weight and speedLowest draw weight and speed049 SlingshotWorld 049049 SSW005 rubber tech.indd 49 29/11/2021 10:44'