Bandsets - Balancing performance with longevity

My first homemade bands were crude affairs. They shot lead balls and I loved them. However, before long. I went off on a quest for the ultimate in velocity and energy. I made some extreme bandsets that pushed the envelope in every direction: lighter, faster, thinner, more tapered. I spent a great deal of time experimenting, designing and re-testing. I found to my disappointment that while they were indeed faster and more efficient, they had the life expectancy of a mayfly. While I was experimenting, it was no bother, but when I settled on one design or another, it really annoyed me that I had to keep recutting bands and carry a spare bandset and ties with me. Most purchased bands lasted bit longer than mine, but with the possible exception of Hunter Bands, nothing lasted longer than about 200-250 shots.

What I needed was a bandset that struck a balance between performance and longevity.

Performance

A reasonable level of performance was not hard after all my experimentation. I started with double Thera-band Gold 230mm with an 18mm-12mm taper. That's a pretty typical formula just a bit beefier than the legendary Express Bands. I then squeezed a bit efficiency more out of it, with the slightest curve to lighten the back end. I used folded double bands so I wouldn't leave a flapping end that contributes noting but inertia. I made my pouch thin and narrow. I tie my pouch with a very small amount of elastic. All in all, I think they are pretty zippy. They shoot medium weight lead shot about as fast as a set of Hunter Bands because Hunter Bands are optimally efficient for really heavy shot. Shooting a medium weight (8-9 gram) shot, they expend most of their energy overcoming their own inertia and internal friction. At 16lb draw, they are only half the draw weight of Hunter Bands and at 7.3kg (16 lbs) I can still hold my hands steady with no shake and with minimal shock on release. A lighter band would be weaker and require a lighter pellet, but wouldn't be more accurate. I settled on this basic formula and devoted myself to addressing longevity.

The bandset showing the profile and pouch ties




Longevity

An engineer will take a good design and then go about reinforcing weak points until there is no weak link in a chain. Bandsets comprise of a pouch, bands and whatever ties are required to hold them together.

I had already minimised the weight of the pouch as much as I dared. I compensated for this by using high grade chromium tanned top leather. Top grain leather does not degrade as fast as split. I do not mould the leather for the same reason. I use round punches for the holes and I make sure the holes are not too close to the edge. When tying my bands to pouch to pouch, I tension each side at about 14kg each to pre-stretch and stress-test these critical areas.

Bands tend to tear wherever there is a weak point:

• Where the bands are more taught than the rest of the band, such as over the tip, under a tie, where the band is narrowest, or if one band is under more tension than the other;
• Where there is a sharp edge, or contact with a taught or inflexible tie band that causes constant rubbing; and
• At a nick in the edge or a hole, bubble, scratch or surface tear, or an area where it has perished of adhered.

Therefore, I spent a lot of time addressing:

• The ends of the bands where they are tied, to eliminate all but the most gradual transition from slackness into tension;
• A source of the best quality, most consistently manufactured, and environmentally robust bands; and
• The evenness of the bands in length, width and profile;
• Spatially separate the weak points so that they do not coincide with each other at any one point.

The next challenge was to design a balance of these features that do not exact too great a toll on performance. A good engineer may build on prior art to an extent, but he should also improve on their mistakes and weaknesses:

• Many band makers are turning to Thera-band Black or Blue for a performance boost. Although only slightly thinner than Gold or Silver, they tear or split much more readily. To compensate for the light draw of a thinner band, most use wide single ribbons of these thin bands, but any nick or tear will quickly propagate across the whole band. I use double bands because a failure of one band will not propagate to the other adding a little safety.
• Many band makers are experimenting with longer butterfly bands. These need to be narrower, can be hard to aim and are more likely to get tangled. Relatively shorter, stouter bands are more durable. Depending on how they are tied, my bands can be shot semi-butterfly, but they are designed for a traditional anchor-point draw length.
• No band makers that I have heard of are willing to make bands that involve multiple curves and complex shapes. My tapers are optimised so that the band is always pulling on the same proportion of band in front, the tapers go to full width at the tip of the tip and continue down the tip at constant width.
• At the pouch my bands are flared to full width. They are rolled over 2-3 times and the excess forms a pad that cushions the structural part of the bands from the inflexible edge of the pouch. Under the pouch tie bands, they are at greater than 90% of full width. Nobody else's tapered bands are so wide at these likely failure points.
• I tie my bands at the pouch with elastic not string. I leave enough stretch in these tie bands for them to flex, but not so much that they will slip.
• Very few makers are willing to make double layered tapered bands that are made from one continuous band folded over at the pouch. This leaves a flap of surplus elastic and can unbalance the bands. My bands are folded over in the middle and the resulting weight saving means that the extra width of the flared end is actually less mass than the usual ties. I also make my pouches thin and narrow for the same reason, but this discussion is about band durability.
• No other custom maker uses die cut bands that produce perfectly symmetrical, perfectly equal length bands with no nicks in the edges from bad cutting.
• No other maker includes a precise indicator mark that shows the person tying the bands to the pouch exactly where the midpoint of the doubled bands is. Tying doubled individual bands means one side is wrapped around the other and so the maker has to compensate for this by tying one loose end shorter than the other. If the maker holds the ends together compensates by making the motive end of one band shorter than the other, the bands will be unbalanced.
• The coated fabric ensures a gradual draw-out and protects the bands at the tip on both draw and release from shock, sharp edges and adhesion to each other. This works even better than the carved and polished solid teflon tips that I used to use and it can be attached to almost any for tip designed for flat bands.

The bandset showing the coated fabric under and between the bands



The result of all of this is that the bands out last conventional bands by many times. The only times I have ever seen these bands break is when I have tied the tips so tightly that the ties cut right through the bands. Forum member shot in the foot has about 5,000 shots on his bands and despite an offer of a replacement set when these go, he says they are still in as-new condition. I think this result is exceptional and unextected, but band life of over 1,000 shots is quite possible if the bands are used properly and not abused or dry-fired. There are several other bandsets in the hands of members around the world and I've not yet had any reports of failure.

The die cutter




So Where's the Balance and Compromise?

The idea of finding balance is identifying the point at which you get less incremental improvements and start to pay an increasing penalty in other areas. Do not keep going when you have already reached a level where further improvements are unnecessary.

• I could have made the bands faster. I could have made them thinner, longer, a little more tapered and specified a lighter shot weight. This would all degrade the duty cycle.
• I could have made the bands heavier to pull. This might have extended the life and offered more kinetic energy, but it would have affected accuracy.
• I could have made the bands last longer. Reducing the taper, adding a bit of additional protection here and there, I could increase the life still further, but latex has a finite shelf life and in any case, who wants a bandset that lasts forever but won't shoot fast and accurately?

Should I Complain to My Supplier If His Bands Only Last 150 Shots?

Well, 150-250 is about the industry standard for bands and tubes. Some do a lot better, others do worse. It'd be unreasonable to say that the standard has been raised. I wouldn't complain that a pair of low profile sport compound tires only last half a year on my car, but users will decide if they are content to play $3-5 plus shipping every weekend and spend the first few minutes of a tourney tying and breaking in new bands and shooting a bandset that they didn't actually practice on. I would encourage makers to lake a good look at their designs and work out what can be improved.

I like to consider that this bandset as described is my own intellectual property, but it would be impractical to enforce that and unreasonable to expect that other makers wouldn't adopt some of the features to improve their bands. I hope that people will apply their own intellect and inspiration and make bands that are better than mine. If you are keen to try out my bands (for use rather than to reverse-engineer for profit), read my blog entry on trading/barter and then drop me a PM. I don't ask for much in return for the bands and certainly good value compared to making your own.


What's Next In Band Development?

I've sunk investment into the die cutting mould and I'm pretty happy with how these bands have come out. Right now, I'll just keep on making more exactly the same. I bag them up in a sealed pouch and store them away from direct sunlight. I'm spending more time looking into how to make slingshots faster and cheaper without losing the charm and quirkiness of a hand-made product. There are however, a lot of avenues for further bandset exploration.

• The weakest parts of the bandset remain the pouch at the sides of the punch hole and the tie-points. I will eventually work out a better design.
• Site Vendor Flatband sent me a virtual treasure-trove of new elastic materials to test. Some of these incorporate multiple layers elastic with high elongation elastic sandwiched between abrasion resistant elastic. Others use surface textures to improve elongation and reduce hysteresis. Any of them may lead to a new bandset design.
• I'm investigating the use of rubber glues, vulcanising compounds and other pouch attachment methods.
• I would like to make a quick change attachment for for tips that doesn't require tools or impact the feel, performance or longevity.
• I want to make the coated fabric less prone to slipping about on the fork tip so that I can tie the tips with less tension.

That's all just off the top of my head. There's lots of avenues to explore.