In slalom training in Moscow (that is, on small hills with a height of 50-55 meters and a slope length of 250-300 meters), we sometimes put DYI timing system. The gate at the start and photocell at the finish, and the clock. Communication between start and finish over the air (radio). It so happened that we call the timing system for ski as “omega”. So, our omega broke – the radio channel stop working. So the idea arose to assemble a new one based on the Arduino, i.e. can say that without a soldering iron. In a series of notes I plan to cover the progress of work.
Approximately 10 years ago, “Arduino” – platform for do-it-yourself of automation projects appeared.
I’m afraid to make a mistake, but about 20 years ago, microprocessors reached the level of “single-chip computer”, that is, in addition to the processor, the microchip has memory, the ability to load programs and of course keep input-output facilities. Nevertheless, until Arduino this area remained for specialists.
Arduino gives an opportunity to engage non-specialists in automation, that is, it is not necessary to be able to program at a low level, to use a programmer. And in general, you can not know “for what end to hold a soldering iron” 🙂 For all this, a single-board computer is provided. This computer is programmed via USB, using a “normal” computer on which the programming environment is installed. Various sensors and modules can be connected to the I/O of the board, and this can be programmatically linked using the “libraries” from the Internet.
In this section, for convenience, links to all notes on the topic: “DIY timing system for ski with Arduino” are collected.
Continue reading Timing system for Alpine skiing based on Arduino
The results of the competition in alpine skiing (for example) are recorded in the form of a protocol in which the participants are separated in accordance with the times shown. Despite the high accuracy of measurements, these are relative results (as opposed to 100 meters running or high jumps). That is, the participant can only assess their gap with respect to the leader, in seconds or as a percentage. However, not everyone is “chasing” with the leader, they more often look at their position relative to the familiar participants.
At the next competition everything will be different, other times shown, another leader. Another deviation is possible with respect to the leader and friends.
Is it possible to transfer these indicators: an accurate measurement of the times and the relativity of deviations from familiar participants into absolute indicators, as in the race for the one hundred meters? Yes! And pretty simple.
Continue reading Absolute classification time for analyzing competition results
At the end of the previous turn, the skis go more or less across the slope. Then the next turn begins, in which you need to try to load the skis as early as possible so that they start carving, that is, writing out the arc. On this topic on the site there is a series of notes with the tag “Loading skis at beginning of turn“. After carving the first half of the arc, skis in a short moment go exactly down. This season (2019) found out that is scary to continue to load skis in this phase, so the instinct of self-preservation does not allow to do it. That is, when the skis go exactly down, you have to let to stop press on them, and then when they turn to the beginning of moving accros slope, press it down again. From the side it may not be noticeable, and if it is noticeable, then it is clear seen that the skier presses on the skis twice in a turn instead of one. In the note I will understand how to deal with it.
Continue reading Ski loading in “exactly down” phase of turn
Stiff slalom skis go faster, of course, if you can control them. This is not an axiom, and indeed quite a controversial statement. But observing the trends of the past four years allows for such a conclusion. Let me clarify, this is not about the World Cup, but about amateur slalom 🙂
Stiff skis can be different: “like oak”, “shooting (at the end of the turn)”, “hard but elastic”. Soft skis are probably more like each other. Yes, and more friendly, easier to turn in and goes out of the turn without the “surprises”. The result of passing the slalom course is often determined by a couple of turns from a couple of dozen (slalom course in Moscow). Friendly ski usually allows you to go through key turns better. But a stiff ski can also be friendly. It is only necessary to neglect the FIS limitation of 165 cm (for men), if you cannot fully control skis with such a length.
Continue reading Stiff slalom skis go faster
Traditionally, it will be about the top slalom skis Ogasaka Triun SL, this time the 2019/20 model year (hereinafter I will call this model year as 2020). Judging by the catalog, the geometry of the skis has not changed, that is, the same as on skis 2019 and 2018. Therefore, the expectations were, like last year, the ski will remain the same. However, the test on the snow showed a noticeable difference, and for the better. Skis have become more tenacious and active. The difference is really small, but noticeable. According to information from Iwamoto san Ogasaka engineers reworked the design of the tip of ski.
Continue reading Ski Ogasaka Triun SL 19/20
Among the possible damages of the bicycle tire are those in which the replacement of the tube does not help. In the note I will share experience of bicycle tire sidewall repair. More exactly – repairing the side of a bicycle tire Michelin Pro4 Service Course V2. Continue reading Bicycle tire sidewall repair
The bicycle chain is part of the transmission, located in the open air. Therefore, on the one hand, the bicycle chain must be maintained in a lubricated state, and on the other hand, dirt adheres to the oil, turning it into an abrasive. It is best to solve the problem by placing the chain in a container that is protected from dirt. I saw this decision at Kickstarter, but it could not collect the funds for starting production. Therefore, we have to look for a compromise, as the producers of lubricants for the chain write about. That is, an oil is created, which is where it needs lubricates, while where is no need not attract dirt. I can not say that I tried many greasings, but those who came across still pretty messed up the chain. In the note I want to share usage of two liquids. The oil lubricates, and the paraffin film protects against dirt.
Continue reading Bicycle chain and liquid paraffin
It is difficult to say exactly why, but when carrying out slalom training gloves “burn”. Whether it’s form drill when drilling a snow, or a key for slalom poles, or simply when setting up a pole. Gloves are strong, leather. First there is a little “rubbed”, which can be sewn. Although this is already unpleasant, the glove looks still like new. And then it’s useless to sew it up. Then you can wrap your fingers with reinforced tape. This season I even saw such wrapped fingers on a World Cup participants 🙂
With the use of AliExpress it seems that there is an opportunity to solve the problem drastically. Because gloves can be bought for such a price that they could be replaced immediately.
Continue reading AliExpress for alpine ski. Gloves for slalom course
I took the idea to buy small things for alpine skiing from AliExpress from Sergey Kuznetsov. In January 2018, he ordered there a diamond files for the sharpening the edges and shared link on ski forum. I, as thought, have such files, still quite working and did not planned updating. But the price on the link was so attarctive that start to think. And not not only about diamond files. In the note I share Sergey Kuznetsov’s experience.
Continue reading AliExpress for alpine ski. Diamond files