Hmmm, lots of drag is what im thinking, from the slot in the foil for starters, that could get very messy, your effetively gonna have 3 foils under the boat. Rods arn’t the best shape moving through water, lots of drag there too, and you might have a bending problem both side to side and fore-aft.
Your idea for a winch powering the cant is similar to what im thinking of doing on my boat. The only problem is that it aint gonna be quick, but we shall see.
Luff 'em & leave 'em.
Dick, some considerations:
Breakthru’s are hard to come by and it is real important in an area like this to read all the information you can.
Under no circumstances give up; just try to learn more about drag reduction and keep on trying! Good Luck!
Doug Lord
–High Technology Sailing/Racing
Only two personal observation comments …
Split keels, like jib and main sail “can” work to your advantage, by allowing a flow thru from one side to another. To gain pointing ability, I recall (years back, I admit) that sailboard fins were often split with a slot in the middle. It “seemed” (at that time) that it resulted in reduction of vibration at high speeds (drag) and it also allowed the board to sail higher to the wind.
While I did admit to the rod being a source of straight line drag, I notice in none of Doug’s discussions of the sideways induced drag when one tries to move the flat side surface of the keel thru the water as it tilts. i.e. the Canoe Paddle Syndrome for lack of a more scientific term. If the rod were shaped at leading edge and perhaps flat on each side it could/would fill the void in the slot between the double (or split) keel when centered. If a leading edge rod, I had noted a possiblity of adding a foil shape to it’s leading edge. If a 1/4 inch diameter rod were able to support the weight, it has a projected frontal area of .25 x 14 inches = 3.5 sq. inches. What is the total surface area of the keel blade being pushed sideway throough the water each time the angle of tilt is changed? I would suspect it is considerably more. If we assume for discussion sake, a triangular keel with the chord of 3 inches at the hull (front to back) and the same 14 inches of depth, you are looking at 21 sq. inches of surface area pushing against the water (drag) each and every time you change the trim or tilt on the angle of tilt. So we have 3.5 vs 21 sq. inches of surface area. And Doug, you haven’t addressed the re-attachment of laminar flow back on to the keel blade after it has stopped moving sideways. Looking down from atop the hull, as the entire keel swings out, I would expect to see a huge vortex immediately behind the keel blade as it moves sideways thru the water. Again, try the canoe paddle experiment … Stand in knee deep water and place the paddle next to your leg with paddle blade facing away from you. Now - push the paddle away from you (to the side) and you will realize the physics connected with moving the paddle blade (your keel blade) sideways through the water. Now, same starting situation, but this time do the same thing forward and to the rear of you. It is a lot easier to move the paddle front to back thru the water when the only resistance is the thickness of the paddle going thru the water. If difficult to comprehend, then look at kayak paddles - they are opposed to each other by an angle to allow the blade to be flat and parallel to the surface of the water during recovery stroke to reduce windage and waves hitting the blade, yet when the blade enters the water, it is again rotated slightly by the paddler so that the flat, wide part of the blade catches the water and provide propulsion. In the case of the moving keel (or canoe blade) there is a reaction for every action taken.
I just point this out because it has never been discussed or identified in any previous posts. It does go to the heart of some suggestions by others, that a canting keel boat is not particularly well suited or the best idea for tacking duels or around buoy races.
Again, using the often offered comparison to big boats, most, if not all that cant their keels are off-shore boats who plan to be on the same tack for a few (a lot) of miles, so they aren’t planning on swinging the weighted canoe paddle back and forth (sideways) through the water many dozens of times during a short, shifting wind, pond race that most of us experience at our local venues. The smallest “canting keel big boat” that I am aware of is the Shock 40, and in scale perspective, I feel their race legs are considerably longer than ours in the r/c world. Remember - they are racing “miles” and a race lasts hours - not minutes!
If we are going to look at this as a concept “trainer”, lets at least be honest about the negatives to the theories being proposed - as well as positives - OK?
On any canting keel boat the sideways movement of the fin occurs when the boat is moving and the flow NEVER comes from the side while moving the keel with the boat also moving; there will be a slight (maybe 2 degree) change in the oncoming flow as the keel is moved. It is so small as to be negligible…
Now if the boat is stopped and you are playing- the rapid movement of the keel sideways (on a system fast enough) “sculls” the boat forward! Faster with the sails sheeted in.
But most model and full size systems are not that fast; there is zero problem ,in any case, whether fast or slow.
Canting keels offer more speed in models and full size if they are carefully designed well engineered and built properly-but there is more…
A CK Trainer makes so much sense because it will give everybody the opportunity to experience the exhillerating and unparalled fun of sailing and racing a canting keel boat!
Doug Lord
–High Technology Sailing/Racing
Thank you Dick for acknowledging the points that i have been putting forward to this concept since the discussion began. The concept in theory works but in practise the obstacles that we are all coming up against makes the whole idea impractical.
Firstly there is the drag,turbulence or whatever else you wish to call it.
Secondly the power in a servo or winch setup required. I don’t think there is a product on the market to cater for it. As well as the problem of the extra battery power that is needed.
Thirdly this boat leads itself to only being able to be used in strict one design sailing or practise, it would be impossible to successfully race one of these boats in a mixed fleet and expect to do well.
I am of the belief if you are going to go to the effort required and spend the money to build a r/c boat whatever the class, you want to be able to at least race it. Maybe I am to single minded about being able to race whatever I build, but I sail to win if possible, and what helps that is to have a boat that is easy to sail,has as few controls as possible(two in the mini40 case) and if I don’t win at least I don’t go home stressing out.
In short, I think that a canting keel on a r/c boat is a complete waste of time.
Peter
Peter, you couldn’t be more wrong. What about the Ultimate Warrior by Wind Warrior?I’ve talked to two people that have sailed that boat-they say it is fast and loads of fun.
I’ve built and raced numerous prototypes and as of today in a 24 " trainer version a 3801 will work at very low current draw; another system is being put together using a Hi tec and two of my previous prototypes used specially made Guyatt 380 winches. The design is so refined now on the Guyatt winch in the F100CBTF system that current draw is less than a sail winch application!
You should not rule out something so completely until you sail it but I appreciate your candor and am glad your post is here to refer to …
Introducing new technology brings out the best and worst in people; your comments reflect an attitude not facts.
The only production canting keel boat sailing for the moment has gotten raves from all who have seen her and from at least two that I know who have sailed her. More boats are coming and the evidence of the extraordinary FUN and Performance of these boats will become more and more clear.Betting against a technology that has so much going for it and so many people working to make it available is probably not the smartest thing in the world-especially without ever having built or sailed such a boat!
Doug Lord
–High Technology Sailing/Racing
Dick
I really like your ideas;especially this one:
http://www.rcsailing.net/forum1/data/Dick%20Lemke/2004125133836_smCK1a.jpg
I will send you one of mine; of course its inspired by yours…was just thinking about drag…but then again I am NO specialist…will scan it and send it to you when I am back home…
I should work instead of reading the forums here LOL
Wis
if it isn’t broken, don’t fix it!
Doug
Doug
Fast compared to what? A laser is fast compared to an opti, but a vanguard 15 will kill a laser. Plese don’t make such an openended statement, give a frame of reference.
-Dan
Doug your talking double dutch. You say in previous post that you haven’t built a canting keel then you go on about having several prototypes, are these prototypes of canting keel boats or just foilers and whatever else. Maybe Wind Warrior has got a boat that has a canting keel that does work, Ben Lexcen designed Australia two’s winged keel and then came back to Australia built a 50 footer called Madame DEfarge that had a winged keel and was a huge flop, so much so that the winged keel came off the boat and it performed much better with a standard type keel. Wind Warrior has probably got lucky and it would be quite surprising to see two boats from different minds that both worked.
My view points are just that my points, if people read my posts have the same or different opinions to me I don’t really care, this is a forum for general discussions and personal viewpoints of the comments that are made. I am still waiting for you to comment on the ideas we have here in Australia for multihulls, because so far for you Doug anything that is different to what you think is right is wrong.
What I would like to see in the future is if possible a joining of the Mini40 rules and the F48 rules so that at some time in the future there could be a world championship in these craft, so I would like to add this to the topics of general discussions and see what we as the people who sail the things can come up with. Monohull sailing to me has nowhere to go except to new one design boats, whereas the multihull being so young is still the development class and I hope that it is the class that grows and becomes as dominant as some monohull classes have all over the world.
So Doug these ideas you have for multihulls please get them off the paper or out of your mind and make them into boats that can be sailed under a class rule and let’s get this highly exciting class moving.
Peter
Time out! In the very first post I mentioned that if you were not interested in the design of a canting keel trainer please don’t post. The question in some peoples minds as to whether canting keels work or not, are fast or not, belongs in another topic say “Canting Keels” on page four under “Technology”. Same for those that don’t understand canting keel technology-there is much reference work under “Technology” in easy to find topic headings that address those concerns or you can start a new topic.
Here there are still such questions left as what rig would be better for a trainer-main and jib or una? Should it be reefable?
Size is still a consideration as it becomes clearer what is possible with various off the shelf winches.
Another point: which stick do people that haven’t sailed a CK boat think the keel should go on on the transmitter and why.
Doug Lord
–High Technology Sailing/Racing
I think the keel control may be best on the same stick as the sheet, on the horizontal axis. So if you move the stick to the right the keel moves to the starbord side of the boat. I think that makes most sense…
Luff 'em & leave 'em.
Doug and Dick,
With regards to the B32. I would suggest that the first boat be built as is by Dick (if he is willing to do so for his family) and then loaned to Doug for evaluation. If the boat looks viable, then a SECOND boat kit should be purchased that can be modified prior to assembly with a canting keel system.
When the SECOND boat is complete, it can be sailed alongside the FIRST boat (unmodified) for comparison.
Now, I am not sure if Doug is willing to buy the first boat or not. But I think it wise to not try and modify a finished boat. More than likely it will be much easier to modify it before you build it all the way to completion. Plus it would be nice to have a unmodified boat as a trial horse when the CK trainer is completed.
So Dick, you mentioned that you would be willing to build a B32 as a family boat? If you are still willing to do so, I suggest that you do that and then loan it to Doug for his evaluations. Maybe the two of you want to split the cost of that first kit (it is not very expensive, but…).
Will Gorgen
Doug,
I would prefer to have the canting ballast on a “side to side” channel. Since the rudder is on one stick (side to side), the ballast should be on the other stick (side to side). Also, since the up-down on this stick is usually the sail trim, it makes sense that the ballast also be on this stick. That way the ballast and sail can be trimmed together (by moving the stick at an angle) to control the heel of the boat.
At least that is the logic I am using with my canting mast boat. I think it makes sense…
Will Gorgen
Since I made my offer the other day regarding the B32 I have made a decision to evaluate a 24 " hull almost immediately testng a new canting installation system in the process.I will consider building a 30" version depending on the results from Matthews experiments and from the 24" hull.
I have SERIOUS reservations about the B32 as a suitable canting keel trainer. I think those that think it would be a good boat for the purpose should take the lead in experimenting with it.
In the interest of helping someone do that my offer still stands with the exception that I don’t want to spend the time on a canting conversion of that boat -at least within the next two to three months…Will, you like the boat for this purpose and think it will work-sounds like you get my vote to work on it…
Doug Lord
–High Technology Sailing/Racing
OK Doug,
I’ll buy the B32 kit and take a look at it. If it looks promising frm the standpoint of adding a canting keel mechanism, I’ll purchase a second one with a suitably upsized rig.
Unfortunately, the US1M project is going to take priority. But if I get the US1M done this winter, I’ll take a crack at the B32. I won’t be able to sail any of these boats until about April given the hardness of the water around here, so don’t expect any sailing updates before then…
Will Gorgen
Will, if you have the time to complete it I’ll pay the freight down here and back so I can sail it if that would help. I won’t modify it-just sail to get my impressions…If it looks to me like a canting keel might work I’ll help in any way I can. If you need a sail servo or rudder servo just say the word.
So as it stands now Skiffy is going to do his own design, Matthew is going to do an existing hull conversion at 30", I’m going to test a 24" hull and new cantng mechanism using a 3801 mechanism and a 30" design later and Will will build an evaluate a B32 as well as a new mechanism using a Hi tec 805(?) .And perhaps Dick will try an experiment or two…Once any of us come up with a boat that we think is good enough to be the CK Trainer we have to find a way to get it to the other guys to evaluate or all get together for a “CK Trainer Meeting” someplace…Meantime see my previous post -there are still issues to discuss as the work goes forward…
Sounds like a good way to proceed and come up with hard and fast answers rather than speculation. As DC would say-way to go guys!
Doug Lord
–High Technology Sailing/Racing
Doug,
I think one of the biggest issues for all these designs is coming up with a servo that can do the job of canting the keel.
If we use the mechanicm I sketched up, we need a servo that can cant through about 290 degrees. This is a major stumbling block for me on my US1M project as well. If we cannot find a way to modify the servos, we can modify the geometry of the mechanism, but we will loose the ability to lock off the cam (so the servo will be eating a lot of power the entire time). We could also use a winch with lines and blocks but again, we would not be able to lock that off…
I don’t thnk I will need anything as big as the HiTec 805 for the B32. I think I can work with a smaller servo, especially if the spring loading idea pans out. I will get the 805 for my US1M and work out the mods to get the rotation we need. If that works, I may fab up a structural bench test to see how much canting torque this thing can put out and what (if any) effect the spring has. I can also work out the bugs in the geometry that way before I finalize the bulkhead design for the US1M.
I will certainly share all my results…
Will Gorgen
Doug - given the way this topic has moved, I am still a bit confused about what we are trying to accomplish. Originally, this was to be a “TRAINER” - to allow new sailors to “try” the idea of canting keel technology, and what it takes to sail a boat with a canting keel.
It had been proposed to be a one-design with the exception of “personal” ideas and development about the keel. This would keep all boats identical except for the keel, which would allow easy comparisons.
When ideas were provided, all of a sudden we got lost in issues of drag and turbulence - nothing at all about “TRAINER” ideas and canting keel “training”. Suddenly you are trying to optimize the ideas and technology - which many (probably most) could care less about to start. It was to be a “TRAINER” (to use your exact words.) As such, it only needs to sail and have the basic controls to handle canting of the keel. If one is trying to optimize “performance” the F-100 Class is the place to do that!
Who really cares about turbulence in a “TRAINER”? Who cares “how” the controls are set up on a transmitter? The thing is a “TRAINER” and to put it into terms most can understand - it’s like an Opti Dinghy - it certainly doesn’t have canting keels, moveable foils, spinnakers, or hell - even a jib! It is used to teach boat handling skills to new sailors. Isn’t this what we are trying to do with this “concept”?
Now, we suddenly have 4-5 different hull designs/configurations, all of them with canting keels of various ideas. How are you going to benchmark any one hull to another if everything is different? If one hull is longer, shorter, wider, thinner, lighter, heavier, more or less sail area please explain exactly how you are going to determine if it is the keel - or OTHER VARIABLES that is making a difference in performance - since you seem focused on performance? You have boats in length from 24 inches to 32 inches. What is your benchmark?
Hard to build and expect realistic testing and comparison when there is no “baseline” boat to compare it to. Now - seeing as you are always the idea man, far be it for me to even “suggest” there should be a baseline boat specifications so that there can be an equitable comparison, but What are you going to COMPARE to what?
What happened to the idea everything is equal except the canting keel ideas? What happened to the idea of having a boat that others measure up against? Or- doesn’t it matter, since it is a trainer - not a performance class boat?
I’m lost on this - please explain how you intended to come up with a meaningful comparison.
Will,I agree with you. For what it’s worth when I size a winch for a canting keel application I start with the worst case scennario: the keel vertical relative to the boat(parallel to the mast) and the boat lying with the mast parallel to the water: a knockdown scenario—
canting takes less power than that does.
So on the 24" boat using a 3801 modified for 180 degrees the 1.75" arm will be set up to be nearly parallel with the servo and the line from the inside lever running across the center of the servo horn when at max cant. So at max cant it will use the least power. But since the servo arm and lever are sized for the worst case scenario the boat would take a knockdown without overpowering the servo.The whole arrangement is inserted into the boat in a very light simple molded unit to which the servo is attached-no rigging will have to be done down in the boat.
On a thirty inch boat it looks to me that with a 14" fin and 2 pounds(up to 3 easily) ballast a Guyatt 280 could be used. If a balanced rig requiring a 3003 modified to 180 is used the cost won’t be too bad especially utilizing the new canting keel installation system if it works on the 24. A Guyatt 280 at 4.8-6v using a block arrangement,springs and pre creeped Spectra line would handle the load easily and quickly with very low current draw. For reference a Guyatt 380HD at 7.2 volts will be used on the F100CBTF.
A balanced main only rig offers tremendous potential to downsize a sail servo. The pivot should be put at about 15-19 % aft of the mast which reduces the sail sheeting load a whole lot. A small carbon boom is used to hold the mast and boom. For experimental purposes the mast can be stepped in a .625" carbon tube with the pivot just aft and a smaller carbon tube going aft for the boom.
A main +jib offers more power lower down so that needs to be looked at from cost and performance and the required cost of a sail servo. A modified 3003(suitable fo a mast stepped in the boom unarig) is around $25…
Doug Lord
–High Technology Sailing/Racing