Great video again, Tomek. Thanks for sharing your knowledge. Two comments. 1) I check the level of my plank to hull attachment pretty much the same way you do. One thing I have noticed is that the garage floor level will sometimes have an impact on the results. Fact is that most garage floors are not level as one wants water to drain out or into a well. While this is not a bad thing from a garage floor point of view, it will make DN plank to hull alignment more challenging. Point being this is something worth keeping in mind and point being try to find good (level as possible) spots on the floor. 2) Plank to hull attachement can have huge impact on ones sailing performance. A few years ago a hole in the ice caused my plank to rip of my hull at a training session just before the WC and EC regattas. I fixed the problem, but never properly checked that chocks where level after the fix. I had the worst WC ever. Before EC I had to figure out what was wrong. And indeed. My reglued plank to hull system was the problem. At that time I had the Swedish attachement system with 4 x6mm bolts attaching the plank to the hull. Quick fix was to simply ad one washer in between the plank and the hull at one of the four attachment points. Chocks where level again and racing results where back to normal again. Point being: One simple little washer strategically placed made a huge difference !!! This last example shows us how important your video is.
John, thanks for valuable comment. I agree to both. My floor is leveled ;) I like the part "simple little washer strategically placed made a huge difference". You can't imagine how many people are redefining ther alignment now!
Great as always Tomek. How do you consider the influence of front spring compression? And the negative bend on the plank with higher pressure? Then the boat is going uphill on the ice. I have always measured this with load in the boat due to these two parameters, but I can’t say that I am correct doing so. It would just be interesting to have your point of view.
Good point David. Last year I filmed my front chock post while sailing in different conditions. When spring is strong enough then compression is marginal. Shock absorption is sufficient and influence on the angle little to none. And you are right that hi load on the plank will casue plank to tilt more than you could simulate while calibrating. Soft planks will tend to bend almost all the way down. My personal opinion is that alignement should be performed with 60-70% of max load. Simply because this covers a wind range where all three runners are engaged and are same important. Once you get more load on the plank it also means that wind is substantaily stronger and windward runner is of less importance because it is only touching the ice. And if it is not working this way then you will never sail in top of the fleet ;)
I agree with most of what you say. In my own personal opinion 60-70% of max load may be a bit on the high side. Reasoning is exactly the same as yours. Runner alignment is most important in light winds, in tacks and in gybes. All situations where the DN is not fully powered up. There fore I have reasoned that I check my alignment with skipper weight (in my case 80-82 kg) + 20 kg. Also. The game we play is a game of apparent wind speed. We need to get over that initial hurdle to get the boat going fast. So again alignment is crucial before we hit full speed. Obviously it is not a bad thing is runners stay well aligned at full speed too. But if you have to choose between full speed and low speed alignment I think most of us will prefer the latter. Regarding Davids question about spring load I think the angle of the front steering post will have an impact on what kind of spring is suitable. Some DNs have 0°, other builders prefer 4° and over the years some have had as much as 7° (from what I hear...). With a tilted front steering post you have the benefit of the steering runner tilting when you turn the tiller. This gives your steering runner added grip when for example rounding the bottom mark. As we know this can be an advantage in some conditions. However. The down side of the tilted front steering post is that when sailing on a straight line on bumpy ice the tiller will feel restless in your hand. When you hit a bump spring will compress and as the front steering post is tilted in combination with a non tilted back post the distance between them will vary depending on stiffness of the spring. Therefore a soft spring can result in a tiller that feels restless in your hand and ultimately your DN will track badly with the hull nose jumping here and there. Solution is of course in such cases a stiffer spring or one with a shorter working area. In my mind the effect of the spring on runner alignment can be neglected. But while we are on the topic of nose hight a more important factor is what kind of front runner vs back runners you are using. A Plate runner is higher than a Insert, which in turn is higher than a T-Runner and an Angle runner. I do my plank to hull calibration with a insert runner in the front as this runner is in height in between my plate and my T-Runner. And more importantly the insert front runner is the one I use most of the time. I have never actually measured plank to hull configuration with my alternative front runners. But I have checked it by eyeballing chocks to the ice. And I can tell you you can actually notice the difference in how the chocks lines up to the ice. (sorry for the long text. Hope you guys didn't fall asleep :-) )
I made some platforms with adjustable feet to level the hull prior to checking if the chocks are level. Is this necessary? Or is it overkill in that you can simply level the hull using the flat hull bottom to make sure the hull is level. Some hulls are not level but I believe mine is. Thanks again for helpful videos. I have subscribed!
First thing tomorrow, calibrating! Thanks a lot for all your helpful information. Regards.
Excellent videos. Thanks for share all these tricks of the trade.
This was so very helpful. I was so confused about this and now I understand. Thank you!
Great video again, Tomek. Thanks for sharing your knowledge.
Two comments.
1) I check the level of my plank to hull attachment pretty much the same way you do. One thing I have noticed is that the garage floor level will sometimes have an impact on the results. Fact is that most garage floors are not level as one wants water to drain out or into a well. While this is not a bad thing from a garage floor point of view, it will make DN plank to hull alignment more challenging. Point being this is something worth keeping in mind and point being try to find good (level as possible) spots on the floor.
2) Plank to hull attachement can have huge impact on ones sailing performance. A few years ago a hole in the ice caused my plank to rip of my hull at a training session just before the WC and EC regattas. I fixed the problem, but never properly checked that chocks where level after the fix. I had the worst WC ever. Before EC I had to figure out what was wrong. And indeed. My reglued plank to hull system was the problem. At that time I had the Swedish attachement system with 4 x6mm bolts attaching the plank to the hull. Quick fix was to simply ad one washer in between the plank and the hull at one of the four attachment points. Chocks where level again and racing results where back to normal again. Point being: One simple little washer strategically placed made a huge difference !!! This last example shows us how important your video is.
John, thanks for valuable comment. I agree to both. My floor is leveled ;) I like the part "simple little washer strategically placed made a huge difference". You can't imagine how many people are redefining ther alignment now!
Take it you use a front runner also with added height of jig channels in back? This bow angle adjustment also makes a big difference...
Best, CA
Chad, good point. Indeed I have steering runner resting on a wooden block representing height of a jig. I should have mentioned that.
Great as always Tomek. How do you consider the influence of front spring compression? And the negative bend on the plank with higher pressure? Then the boat is going uphill on the ice. I have always measured this with load in the boat due to these two parameters, but I can’t say that I am correct doing so. It would just be interesting to have your point of view.
Good point David. Last year I filmed my front chock post while sailing in different conditions. When spring is strong enough then compression is marginal. Shock absorption is sufficient and influence on the angle little to none. And you are right that hi load on the plank will casue plank to tilt more than you could simulate while calibrating. Soft planks will tend to bend almost all the way down. My personal opinion is that alignement should be performed with 60-70% of max load. Simply because this covers a wind range where all three runners are engaged and are same important. Once you get more load on the plank it also means that wind is substantaily stronger and windward runner is of less importance because it is only touching the ice. And if it is not working this way then you will never sail in top of the fleet ;)
I agree with most of what you say. In my own personal opinion 60-70% of max load may be a bit on the high side. Reasoning is exactly the same as yours. Runner alignment is most important in light winds, in tacks and in gybes. All situations where the DN is not fully powered up. There fore I have reasoned that I check my alignment with skipper weight (in my case 80-82 kg) + 20 kg.
Also. The game we play is a game of apparent wind speed. We need to get over that initial hurdle to get the boat going fast. So again alignment is crucial before we hit full speed.
Obviously it is not a bad thing is runners stay well aligned at full speed too. But if you have to choose between full speed and low speed alignment I think most of us will prefer the latter.
Regarding Davids question about spring load I think the angle of the front steering post will have an impact on what kind of spring is suitable. Some DNs have 0°, other builders prefer 4° and over the years some have had as much as 7° (from what I hear...). With a tilted front steering post you have the benefit of the steering runner tilting when you turn the tiller. This gives your steering runner added grip when for example rounding the bottom mark. As we know this can be an advantage in some conditions.
However. The down side of the tilted front steering post is that when sailing on a straight line on bumpy ice the tiller will feel restless in your hand. When you hit a bump spring will compress and as the front steering post is tilted in combination with a non tilted back post the distance between them will vary depending on stiffness of the spring. Therefore a soft spring can result in a tiller that feels restless in your hand and ultimately your DN will track badly with the hull nose jumping here and there. Solution is of course in such cases a stiffer spring or one with a shorter working area.
In my mind the effect of the spring on runner alignment can be neglected. But while we are on the topic of nose hight a more important factor is what kind of front runner vs back runners you are using. A Plate runner is higher than a Insert, which in turn is higher than a T-Runner and an Angle runner.
I do my plank to hull calibration with a insert runner in the front as this runner is in height in between my plate and my T-Runner. And more importantly the insert front runner is the one I use most of the time. I have never actually measured plank to hull configuration with my alternative front runners. But I have checked it by eyeballing chocks to the ice. And I can tell you you can actually notice the difference in how the chocks lines up to the ice.
(sorry for the long text. Hope you guys didn't fall asleep :-) )
I made some platforms with adjustable feet to level the hull prior to checking if the chocks are level. Is this necessary? Or is it overkill in that you can simply level the hull using the flat hull bottom to make sure the hull is level. Some hulls are not level but I believe mine is. Thanks again for helpful videos. I have subscribed!