So, enough of the theory for a moment, on to the practice! Can knowing about all the technical stuff that I’ve been talking about in these uniBlogs – CGs, CPs, static margins, yaw wavelengths, MIs, etc, - really be of practical use when designing or choosing a dart? Well, now you can judge for yourself because the first two concrete realisations of all this theory are now available to you the dart player. UniLab and Sigma darts have (albeit slightly belatedly!) hit the market.
I will be talking more about uniLab in future uniBlogs, so all I’m going to say about it this time is that it uses all of the theory I’ve been explaining (and even more that I haven’t yet covered) to help you get the most from your Unicorn darts. To see how it does this, just click the uniLab link at the top of the Unicorn website. I hope you enjoy using it and find it helpful. Unicorn isn’t claiming it’s perfect as yet, but, with the help of your feedback, they plan to keep upgrading and improving it until it is!
And now for my main topic, Sigma darts, which, shaft and flights included, have been designed using uniLab to operate as an optimum aerodynamic unit and be the most technologically advanced darts available. Personally I don’t think they look bad either!
Firstly, at the risk of sounding like a sales catalogue, let me describe the three dart types that make up the Sigma range. There is the One soft tip, which is only available in 19gms, and there is the Pro and One steel tip, which share identical 97% tungsten barrels made in 21, 23, 25 and 27gm versions. The difference between the Pro and the One versions is purely the shaft and flights they are supplied with, the former using part-titanium side-loading shafts of the SlikStik type with delta-shaped flights and the latter polycarbonate-aluminium matrix end-loading shafts with enhanced delta flights. Perhaps a bit confusingly, but for an excellent reason which I shall explain later, the slightly more expensive Pro is also supplied with spare One shafts and flights.
Now on to how Sigma has been designed. The first problem that was faced was that the optimum dart barrel is obviously a matter of personal preference. Some people like a comparatively smooth, fine grip, for instance, others prefer coarse. Some players hold their darts like javelins and need a long barrel, others perch them delicately between forefinger and thumb and are happy with a short one. To cut to the chase, no one design of dart can satisfy everyone’s ergonomic and bio-mechanical requirements.
But finding the optimum dart for a player with strong individual preferences on barrel type is the realm of uniLab, so Sigma darts can address a slightly different question.
And that question is, given a player without over-riding preferences as to grip, length and shape, what design of dart barrel would be best from a scientific point of view? And the answer is one that, whilst being long enough for most players to grip properly, has the lowest possible MI (moment of inertia). The reason for this is simple – it allows the most scope for designing a shaft and flights that give the best aerodynamics without having to worry too much about their MI.
Those of you who have been reading these uniBlogs will know that, to minimise MI, it’s best to have a fairly short barrel with the mass concentrated as much as possibly near where the CG (centre of gravity) of the complete dart will be. This consideration led to the very slightly rear-biased “torpedo” shape of the Sigma barrel and the use of the high 97% tungsten alloy, which helps by giving more weight for less length (and diameter, of course – so there’s plenty of room for three in the treble twenty!).
To allow a player a choice of steel tip barrel weights whilst preserving the in-flight characteristics, the MIs of the different weight barrels were matched by judiciously varying the profile, which was also chosen to aid consistent grip location. This resulted in the slightly unusual circumstance of the heavier barrels being fractionally shorter – an anomaly that has already provoked some comment on internet fora!
The last Sigma barrel design question to be addressed was what grip finish to use? A coarse grip can feel more secure, especially in hot venues or when the pressure’s on, but it can also sometimes hinder a smooth release. Fairly fine grooving was therefore used around the barrel’s maximum diameter (and the dart’s CG position), with the “wedge” effect of the barrel narrowing toward the rear being relied upon to aid the achievement of positive throw acceleration without a need for over-tight gripping.
And so on to the choice of shaft and flights. I’ll talk more about this next time, but for the moment it suffices to say that the Pro shaft and flights are chosen to give maximum accuracy for top players whilst, for the improving player, the One shaft and flights provide a highly-stable, impact-angle optimised dart (which is also best for soft-tip boards, which is one reason why there isn’t a Sigma Pro soft-tip).
And that explains why One shafts and flights are supplied as alternates with Sigma Pro barrels. As the Big Boss at Unicorn HQ (who’s good with analogies) says, for even a top driver of road cars to step straight out of a hatchback into a Formula 1 is a big ask – it can but help having a Formula 3 handy to practice with first!
Finally, why are the darts called Sigma? Well, that was the Big Boss again. The Greek letter Sigma, in upper case (Σ) is used in mathematics as a symbol for the sum of all the parts, which neatly describes the concept behind Sigma darts. I’m not sure if he also knows that, in lower case (σ), it’s also used to indicate the “standard deviation” of a distribution, which could easily make it a measure of the accuracy of a dart.
All in all, I’ll think we’ll give him the benefit of the doubt on that one – it’s never a good idea to undervalue the Boss in writing!
Q & As!
Damon and Phil Taylor’s darts:
Last time I talked to Phil he was using his Purist Gold 24 gms (cat no 10405) with the longer XL Ti titanium shafts (cat no 78570) and Maestro Slim flights. But, as I was showing him some rather interesting uniLab results, who knows if he still is…..