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Pressure distribution in selected curling brush heads
This research is joint work with Dr. John Newhook, Dr. Michel Ladouceur, and Dr. Ryan Frayne of Dalhousie University in Halifax. John is a Professor of Civil Engineering and the Dean of Engineering at Dalhousie, while Michel and Ryan are assistant professors in the Kinesiology department of the School of Health and Human Performance at Dalhousie. At the 2022 North American Conference on Biomechanics (NACOB) held the week of August 22-25 in Ottawa, we presented our initial work that compared a variety of commercial brush heads in how they distributed pressure across their pads in a static laboratory setup. Forces and pressures were recorded using two 3200E Tekscan (Tekscan Inc., Boston, MA) pressure sensors affixed to the top of an AMTI BP400600 force plate (AMTI Inc., Watertown MA), with the sensel areas abutted. CONFORMat Research software (version 7.1: Tekscan Inc.) was used to collect the pressure sensor data, which was recorded at a frequency of 100 Hz. Our results are
Does brushing with a brush turned to 90 degrees really work?
Recently I’ve received numerous inquiries regarding teams rotating their brush heads 90 degrees when attempting to “carve” a stone (accentuate curl). Some tour players, as well as commentators, have adopted the term “knifing” for this tactic. As of the date of this post – 26 March 2022 – I’ve probably been asked the question at least twenty times and so, rather than continue to respond individually to each questioner, I decided to post this short article. As usual, this post is joint work with my research colleague John Newhook of Dalhousie University in Halifax. Short answer The question isn’t, really, whether or not using a brush head turned 90 degrees “works”. Applying brushing forces – and hence thermal energy – to the ice on one side of a stone over the other is going to have an effect on a stone’s trajectory. The actual question to be answered is under what conditions is brushing using a brush head turned 90
Zeroing a PT-2 Smartbroom
Even though the PT-2 has been discontinued by Canadian Curling Tools in favour of their new “Smartbroom” device, a number of curling associations and individual coaches continue to use PT-2 instrumented brushes with their teams. A characteristic of the PT-2 that coaches must be aware of is the frequent need to “zero” the PT-2 brush to ensure that the force readings from the brush are as accurate as possible. The need for this is because the PT-2’s load sensors are cemented into the brush’s EQ brush pad, and over-tightening of the bolts that fix the brush pad in place can result in skewed measurements. As I’ve been asked a few times about the zeroing method for the PT-2 I decided to post this article. PT-2 documentation is no longer available on the Canadian Curling Tools website. To zero a PT-2 brush, follow these steps: Ensure that the brush head is plugged into the PT-2’s display unit, and the unit is
Visualization of stone rotations for athlete feedback
This article is joint work with John Newhook of Dalhousie University in Halifax. It is well known that the number of rotations given to a stone, particularly at guard or draw weight, will impact both the duration of the shot and the stone’s trajectory as it travels down the ice. Upon release, a stone will have its maximum angular, or rotational, velocity (think number of rotations per second). Just as the speed of the stone slows with time, from this point until it stops, so does the stone’s rotational velocity. A “soft”, or gentle, application of angular acceleration (torque) to the handle upon release, with a relatively few number of rotations, tends to cause the stone to curl more, and sooner. Often such a release will cause the stone to “dig in” and fall short of the intended target. In extreme cases – a “straight” or “lazy” handle – the stone can actually stop rotating completely before it comes to
Moving to OnForm from Hudl Technique
I’ve been a long-time (since 2014) user of Hudl Technique (originally a software product called UberSense) for doing video analysis. With the quality camera systems now available on various Apple devices (and on Android devices as well) there is little need to use a separate camera system for on-ice or off-ice video analysis, and moreover using one’s personal device is decidedly more convenient. Those of you who are Hudl Technique users should have received an in-app notification that Hudl Technique is being discontinued and, later this year, the back-end video storage for Hudl Technique will vanish. However, the good news is that Hudl Technique was acquired by partners Gear Fisher and Krishna Ramachandran, who was the original developer of the UberSense software, and their new product, called OnForm, is designed to offer better video analysis than Hudl Technique and in addition permit royalty-free sharing of video, images, files, and annotations to athletes on their own devices with integrated messaging. With
Brush head mass – a short survey
During my talk at the online Adapting/Thriving 2021 Conference presented by the Ontario Curling Council, and other provincial sport organizations, I made several statements regarding potential parameters to the selection of a brush, among them being the size of the brush pad and its contact area with the ice. Even though WCF-approved brush heads and pads all utilize the same Oxford 55 420D yellow nylon fabric, and are tested by the National Research Council for compliance with World Curling Federation specifications, there are differences amongst the available products. Some brush pads have an integrated design, comprising the base, foam, and fabric as a single unit, whereas other brush pad designs use separate components so that the Oxford 55 fabric can be replaced independently of the foam or base. Perhaps the most interesting brush to do this is the End Game brush from Madison, Wisconsin, where the replacement fabric comes simply in die-cut sheets of Oxford 55 nylon. With the End