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Post by Deleted on Jul 22, 2010 10:44:02 GMT 10
I've now started on the water video analysis of my rig using a gopro surf HD video cam. I mount it on the aft corner of my deck and tilted down it shows how hard I'm not hiking while tilted up it views the entire rig sort of side on (when on stbd tack) and looking up the leech (when on port tack). Really useful for showing up diferences between 2 diff sail designs on the same mast and the effect of main tension, cunno and outhaul alterations on sail shape. You can integrate this with data from the velocitek speed puck and very quickly determine what a fast sail shape is and what tensions the various sail controls should be at.
Both the speed puck and cam can be brought together for less than the price of a new sail and I would suggest provide a much greater performance gain.
Anyone else trying anything similar?
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Post by Glenn AUS 719 on Jul 22, 2010 14:51:21 GMT 10
Your timing is perfect, I only sent off last night to Sportscamera.com.au for info on a camera with a remote trigger that I can rig off the mast tip. yet to look into the speed puck but I guess that would be in the equation. The other point is you need to record all the details for each shot, settings, waves wind strength, speed etc. Lots of people will be wondering why go to this extreme and for myself it is simply because I sail mostly on my own so comparing rigs and settings needs to be more of a one man band style.
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Post by Glenn AUS 719 on Jul 22, 2010 18:34:21 GMT 10
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Post by Deleted on Jul 23, 2010 6:43:54 GMT 10
Must admit I don't see it as extreme. To me it's interesting and makes solo training sessions a lot more fun. The results you get are also extremely cost effective in the long term. Strongly recommend getting a speed puck, sometimes what looks fast actually isn't and this instrument tells you that pretty instantly. Prob 80% of my training is actually not done with other oks but against my mate in his laser radial. It's good for him upwind and good for me downwind.
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Post by Glenn AUS 719 on Jul 23, 2010 16:33:10 GMT 10
This is not a direction I intend to follow (the high tech) I am more interested in getting a better understanding of how the sail works dyanamically with varying conditions and settings. More for my own education then anything else. At the end of the day I can improve mostly by just getting out on the water, which is what I do. I guess when you are out there by yourself you start coming up with these ideas. Presently looking into the velocitek puck, if they ever reply.
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Post by Deleted on Jul 29, 2010 7:29:47 GMT 10
This isn't a criticism of anyone, (because I can see that some people might think this is too much of a professional attitude to have) but I was thinking about this the other day in the shower at the club waiting for my feet to thaw out after training (as you do ;D). And I thought well you wouldn't see a keelboat crew going out training with no speed instruments, and no AC boat would train without taking pics of their sails.....so why would we? Especially considering the equipment required to do so now is lightweight/dependable and can be brought for the price of less than a new sail. We all stand around boats on the ramp pull the sail in and then walk around looking at the sail shape, well a camera lets you do this out on the water where all the extra dynamic force effects of body movement and seaway can also be seen on sail shape. I think when you go out training you've got to look beyond the square of just sailing and enter the sphere of information gathering as well. At the end of the day it makes it more fun (esp when you sail by yourself) and the benefits are huge. Training with the velocitek last season played a big part in my sail/mast selection and so how fast I was going. Information I gathered from that before the Kalmar Worlds, at the Kalmar Worlds (while out training) and immediately after the Kalmar Worlds let me sort through my exisitng sails and determine what was the fastest type shapes for each of my masts. Consequently where many people were buying new masts, modifying masts and buying new sails my total campaign costs from Kalmar to Wellington were only 3 new sails ie less than the price of a new mast. Wellington was by far the cheapest worlds campaign I've ever done in the OK. The velocitek in the medium term saved money and a lot of guesswork.
Now with the video cam I've analysed my current newer rig and can see improvements which will be made to my existing sail designs. You don't have to be a sailmaker to determine what a fast shape is, all you have to do is gather data from different shape sails you already have and combine that with what the boat feels like to you to sail....you then start formulating ideas of what is fast for you (not the herd), which are then passed onto your sailmaker to put into your next sail. It isn't rocket science, it isn't even high tech, it's just a little extra hardwork and commonsense I reckon. There will be people who might say this is all to time consuming, well the actual information gathering is done while you're sailing and I'd estimate I would spend say 2 hours max on average per week analysing the data from the previous weekends training sessions. Hardly very much time I think. And best of all it's fun and you learn heaps! For instance you learn very quickly that the difference between hiking hard and not hard is 0.5knots.....a new sail won't increase your speed by that much.
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Post by Glenn AUS 719 on Jul 29, 2010 21:20:01 GMT 10
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Post by tim on Aug 4, 2010 15:47:00 GMT 10
Hi Karl,
Can you explain a little about how you use the speed puck. Obviously it gives you a visual display of your speed that you use while sailing, and the data logger lets you analyse your training session on the computer, but how do you measure variables like windstrength and shifts, waves etc (these could effect your results).
How do you record / analyse the results so they can be compared with future training sessions.
Where on the boat have you mounted it? Also do you switch it off when racing?
Thanks,
Tim
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Post by Deleted on Aug 6, 2010 11:09:50 GMT 10
Hi Karl, Can you explain a little about how you use the speed puck. Obviously it gives you a visual display of your speed that you use while sailing, and the data logger lets you analyse your training session on the computer, but how do you measure variables like windstrength and shifts, waves etc (these could effect your results). How do you record / analyse the results so they can be compared with future training sessions. Where on the boat have you mounted it? Also do you switch it off when racing? Thanks, Tim I mount the speed puck on a stainless bracket which fastens where my tac tic usually goes. Here it is very visible on either tack (see attachment pic). Data is saved as a .vcc file which is played using gps action replay (a free downloadable program) or I think it's called speedplay which you can download from the velocitek site for a small fee. I use gps action replay because at the time I felt too stingy to shell out any more dollars. They supply a computer download cable. Using gps action replay you have to manually input windspeed and direction so that vmg an be calculated. The program shows a boat symbol moving along with instantaneous speed, vmg and bearing showing alongside it. You can zoom in and out to any scale you desire. You can also set a distance behind the boat over which an average speed is calculated and shown. I'll tend to sail say 1nm on one tack so a really good average speed can be calculated, this is the best way I think to pick up differences between rigs. The most variable component to the whole equation is actually your fitness. For instance when I started off 4.7knts was a great average speed. Just before the worlds using the same rig that average speed had become 5knts which then increased to 5.1 knts with my best rig on. You also have to be aware that the speed is speed over the ground so you have to be mindful of tide effects. Consequently I pick data from the cross tide tack for my analysis or slack water data if I'm sailing at that time. Probably the best feature of the device is the speed display while you're actually sailing. You can see your speed drop very quickly if you don't hike hard so it encourages you to sail harder. I have used it in club races which actually is a bit unfair as it shows you when a speed drop has occurred which you are unaware of. Consequently you may steer a fraction lower or change your sail settings to get your speed back up. It makes a big difference whereby you immediately gain a few boatlengths on your opposition. The more you sail with it though the more aware you become of those situations requiring an adjustment and they become automatic without having to see the puck. I also brought rechargeable batteries for mine as it is the least expensive option. Typically the 3 AA batteries will last abt 2-3 3 hour training sessions. After sailing with it a few times a "feel" is developed whereby you know what speed you should be doing on any given day and small differences attributable to changes in rig and sailing technique can be recognised. Attachments:
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Post by Deleted on Aug 6, 2010 12:29:49 GMT 10
Have also attached a snapshot of gps action replay showing displays you can put beside boat symbol. This was a session into the tide so 4.8 average pretty good. Actually started day off at abt 4.9 but dropped to 4.7 as I got tired. Attachments:
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Post by Deleted on Aug 6, 2010 12:38:02 GMT 10
Now if you interface that data with vidcam footage you also get to see what fast sail shapes look like. Here are a few vid snapshots taken recently...too bad abt sailing into the sun on one tack...but you get the idea. Attachments:
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Post by Deleted on Aug 6, 2010 12:50:24 GMT 10
another pic. Attachments:
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Post by tim on Aug 11, 2010 9:47:53 GMT 10
Thanks Karl,
I have emptied the pockets and bought a speed puck. I've used it a few times now and can certainly see it's value as a training tool. As you say, you can see when tiredness starts to slow you down and you start to pinch a bit. Also it's great to have records to keep track of a days sailing.
The camera will have to wait a bit (low on brownie points at the moment). I did see the youtube footage, any chance of of some more video?
Thanks again,
Tim
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Post by Glenn AUS 719 on Aug 11, 2010 17:32:36 GMT 10
Holding onto my pennies as I cannot see how I would be able to get consistent readings on the river.
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Post by Deleted on Oct 7, 2010 10:40:36 GMT 10
Thanks Karl, I have emptied the pockets and bought a speed puck. I've used it a few times now and can certainly see it's value as a training tool. As you say, you can see when tiredness starts to slow you down and you start to pinch a bit. Also it's great to have records to keep track of a days sailing. The camera will have to wait a bit (low on brownie points at the moment). I did see the youtube footage, any chance of of some more video? Thanks again, Tim Here you go..... www.youtube.com/watch?v=RBybd_6GEVA
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