Snoring?
Noo. The occasional thud of one over wined , yes.
Chalk talks are fun and when your mind is overloaded, just leave!
goose the drawing sideslip forward
not sure about the prying one.
Sideslips work on ice but are unpredictable.
The classroom situation is working
Thanks, I feel better now. My earlier comments about putting the paddle forward of center, and even farther forward when the speed is greater, were based on both the prying sideslip and one that I call âwedgingâ where I push the paddle forward for more oomph (though with the second one, thereâs yaw which must be corrected at some point, either ahead of time or after), but not on anything else. It was canoeist11âs comments that made me stop and think that maybe other strokes applied in different spacial orientation would be different, and it was Glennâs comments that made it crystal clear. Anyway, Iâm glad to know the part I remembered for sure wasnât backwards from âyour realityâ. And on reflection, I now realize that I DO reach behind center for the drawing sideslip. I had to recall some specific difficulties that Iâve run into (and ârun intoâ would sometimes be the right words) for the details to come back to me.
Anyway, thanks to all.
Makes me feel a little better, too.
For just a little bit there I was wondering if I was suffering from paddling dyslexia!
My turn to muddy the waters?
Glenn and GBG, thanks for the very long and serious, but unnecessary explanations. I think if you re-read my somewhat sarcastic but well meant previous post you may understand my feeling. First, for those scholars out there, Center of Lateral Resistance was early on discussed by Thomas Moore in his 1928 âTraditional Model Yacht Designâ book and other centers in âShape of the Canoeâ by John Winters. It was applied by Pat Moore in the science fiction sounding âfulcrum rayâ term.
My point is that CLR (or CLP) in itâs application is more of an abstract idea for hull designers and not so much an applied science. Eric Sponberg, of Sponberg Yacht Design, Inc. states it thusly:
(abstracted for brevity) The center of lateral resistance (CLR) is actually a misnomer. It is also called the center of the lateral plane (CLP), which technically is a more correct name. That is, it is the geometric center of the underwater profile of the hull. Naval architects and yacht designers use the CLP for general design purposes because it is convenient and easy to calculate. In reality, the hydrodynamic forces do not really go through the CLP, at least not constantly, although they may do momentarily. It is actually quite impossible to calculate the precise center of the action of the hydrodynamic forces with any degree of accuracy because they are constantly changing as the boat moves through the water.
So one can see, to the applied scientist will give short shrift to the abstract approaches used in hull design and comparisons. In other words, get in your solo canoe and find the âSweet Spotâ.
No disagreement with that part
â Last Updated: Dec-19-14 3:13 PM EST â
I sort of tried to convey the impracticality of "knowing" exactly where that effective centerpoint is in pointing out that it's not always in the same place anyway (and this it's very different in function than the geometrical centerpoint to which you have chosen to shift the emphasis, via your quote), and in noting that blade position must be changed on account of its angle and direction anyway. So yes, you really do have to find the right spot by feel. Still, my main point was that a lot of things suddenly became a lot clearer to me, and made it possible to see the "how and why" a lot better than I ever had before, once Glenn clarified the actual mechanics of what's going on so that I could relate it to my normal understanding of combined forces. I'd never done that before. I'm certain that this new understanding will help me in doing less futzing around in figuring out where the paddle should be placed, particularly on braking/side-slipping strokes that require a very rearward blade placement (most of the other placements are pretty instinctive to me by now, but not the far rearward ones - I ALWAYS get that wrong on the first try and "hunt" for proper placement, and quite suddenly, I can see exactly why).
Bottom line, I didn't find Glenn's post "unnecessary" at all. It was quite the opposite. To me, it was the most helpful post so far, in terms of boosting my own understanding, and I hoped that my own elaboration/re-phrasing of what he said reflected that, and perhaps even helped someone else who has the type of mind that thinks clearly about individual and combined forces. A very similar thing goes on with ferries. One can do perfect ferries while totally misunderstanding the forces and the concept of relative motion that's involved (and most people do), but for me, everything is more clear when understanding it properly.
Well, come to the Wisconsin event
and weâll be sure to go over it for sure. Most persons that have had the pleasure(?) of having me as an instructor rarely manage to escape without going through the fulcrum ray discussion. If one grasps the concept, the âsweet spotâ sure seems to kick in for most a whole lot quicker.
pagayeur
GBG, since Glennâs remarks were in response to my post I meant only that it was it was unnecessary for me, not the rest of the world. I always welcome good debate, however long and complex.
sometimes its not debate
but merely a different way of explaining something.
Oftentimes we are all on the same side of the canoeâŚand not in the water.
I welcome even repetitive posts. Sometimes what does not click the first time will later from someone else.
Glenns post clicked with me.
The answer about heeling during an axle
I think the answer, regardless of the boat, is that heeling immediately after initiation will provide the greatest turning assist, and the other two options will provide lesser assists, #2 being more of an assist than #3.
All the explanations are consistent
You learn to do sideslips by experimentation and feel. The posts by Marc, Pag and Canoeist11 tell you all you need to know about the practical way to learn the strokes.
I and GBG were simply explaining what is going on in the world of canoe physics once you ARE doing the strokes properly.
No one knows where the heck the pivot point (or CLR) actually is in any given canoe. But once youâve learned to do a perfect sideslipâonce youâve learned the proper blade angle and found the proper fore-aft âsweet spotâ by experimentationâthe physics lesson is simply that your paddle will then be pointing directly at the pivot point.
The different type of posts on this subject simply reflect âhow to do itâ vs. âwhatâs going on when you do do it.â
different learning styles
This discussion sounds like an illustration of different learning styles, âkinestheticâ vs âvisualâ in terms of one learning style classification scheme. For some people the âwhat is going onâ explanation comes after the acquisition of the physical skill. For others there is a much better chance of success learning a physical skill by first having a mental picture of âwhat is going onâ. Iâve found that if I donât have a mental image of the âhowâ before attempting a maneuver I donât have a mental frame of reference for connecting my actions and the results and feel at a loss for how to modify my actions for a better outcome.
My learning style
These theoretical deep discussions with obscure descriptive words are fun, but for me, to learn how to sideslip each of my canoes I just attempt it again and again and again. Till my mind absorbs the feeling of what it takes to achieve what I want. Repetition repeated, practice. I bet Marc has practiced all his effortless moves hundreds of times. Each of my solos require different paddle songs. I would do it better if I only paddled one canoe, but how much fun would that be?
Turtle
You guys have kind of lost me
If the question is where do you place the paddle to initiate a sideslip, Iâd say in a neutral position about at the hip â at least for drawing sideslips. It will feel slightly rear of center when you are in the boat and require pretty good torso rotation. From there you can set the blade angle, and it is easy to move the paddle forward or back depending on what the boat does. Depending how fast or far you need to travel sideways, you lean the boat away from the direction of travel. If the boat is not moving fast enough, you can quickly move to a draw or sculling draw.
I do need to work on my prying sideslips, and I suppose you could do a sculling pry as well â good skills to have. For good or bad, I have gotten into the habit of cross strokes for offside turns or maneuvers.
Someone smarter than I once said
"The only thing completely predictable is unpredictability." or something to that effect.
This weekâs postings was a prime example of that. I posted something that was incorrect and it led to a flurry of well reasoned comments. All of them enhanced the discussion.
Iâll try not post erroneous information again (no promises)but would encourage all who are following this thread to contribute as they have, including those who have been sitting on the sidelines. A simple huh? or howâs that work? or can you explain? etc. may be all thatâs needed to spur on the conversation.
Some of us learn in different ways. Some of us use different teaching methods or explanations. One thing that became clear this week was that any one explanation does not work for all.
Go Pro videos of Prying Side Slips
Iâm a week behind in posting this but I didnât want to interrupt the physics lesson.
Prying Side Slip from a stern mounted GoPro camera at normal speed
http://www.youtube.com/watch?v=xISHfK8oIsw
Prying Side Slip from a stern mounted GoPro camera at 1/4 speed.
http://www.youtube.com/watch?v=uI0NKwaA5kU
Iâm not sure where we lost you.
It seems youâve summed it up nicely. As Glenn explained, some find an explanation of the physics behind it all, very helpful. Others, not so much. I think most of us can agree that the discussion got pretty deep at times but for some that was helpful or at least interesting.
youre spot on
about the placement for a drawing sideslip. Some like the discussion about why it works in a certain place and others really only want to do it and feel it!( and donât want the cerebral clutter. All is fine)
A reminder that if we all wrote well we would be famous authors. We arenât and write imperfectly⌠So a "come again? " can well be expected.
Sorry - donât mean to discourage
the discussion. I hadnât looked at this thread in a while, and I guess my mind overloaded half way through the last section - maybe it was just too early in the morning. Iâll try it again when I have more time Keep it up - it is all good.
Blade angle
It looks to me like the angle of attack of the blade is steadily made steeper as you move the paddle position farther forward. Earlier that didnât make sense to me, as it seems that with a constant amount of straight-sideways push, the ideal blade location would not move forward as the speed gets slower. But this is not a straight-sideways push, and now that this has been explained in the context of what the true direction of force applied by the blade is, and how the direction of force must point toward the effective center of the boat to cause neutral sideways motion, I can see how increasing the angle of attack would make it necessary to move the blade forward (or visa versa, moving the blade steadily forward would make it necessary to increase the angle of attack). Iâm pretty sure that when I move the blade forward in that manner, I end up correcting for yaw at some point, or I set up the maneuver in a way such that the induced yaw accomplishes what I want. It will be really interesting to try this again while paying close attention to blade angle, and eliminating yaw.