Cheers from Perth Scotland . I found your presentation very inspiring and instructive. I’ve been mulling over a boat build for a few years but never found a design that fitted. Your take on this has motivated me to chase my own ideas and design to build my own boat. Thanks again . Salut!
Glad to have found your channel from your visit to Doug and SV Seeker, I'm busy building may first boat a small pacific proa and am especially interested in the design theory of the rigging and mast position etc. Much appreciated .
Thank you so much. Putting ideas to lines on paper and making adjustment thereafter is an interesting process. I like to add that in the old days, sailors did not start with pencil and paper. They carved wooden half-model of boats and take direct measurement of lines off it. For both ways, I think, the starting point is forming a boat whose lines and curves simply look and feel good - a raw beauty to be made.
Thanks for the interesting videos. I've always loved boats and boating, but I never had the courage to start building my own. After seeing your videos on building Grace, I've started planning my own boat. Bought a couple of books on boat building, too... :) Greetings from Finland!
Re you comment on building with stitch and glue, i.e. you need to know the shape of each panel, actually you can shape either your bilge panels, or side panels, temporarily sttich them together (with a stick(s) to hold them apart at the correct distance) and then use cardboard and duck tape to shape you other panels as a template to be cut out on plywood. I've seen it done both ways (side, or bilge panels first) and it works equally well. Your drawing needs L.O.A., beam and shear height to cut the first panels. Take some poster board, cut two identical strips to simulate your side panels, tape the bow, attach an approximate transom, expand them to the correct beam and look at it. You have a good idea of how the boat will look. You now can decide on how you may want to alter them. So much easier. And quicker.
Sam Devlin also details in his book how to convert any "Hard Chine" plans to a half model, that you can then take panel measurements from. Currently working on converting an old set of motor launch plans to Stitch & Glue.
Great video, and very helpful. One of the most important, if not THE most important, things to determine is the point around which the hull pivots, the centre of lateral resistance (CLR). On a simple planing hull that would be where the centreboard/daggerboard is, but the hull shape and even the placement of thwarts and lockers inside the hull can affect the CLR.
Thanks! I'll admit the term is new to me but it gets at the idea I was pursuing...it would vary with the position and even set of the sail as well right?
@@rudywoodcraft9553 Yes, but the position and set of the sail affects the COE (centre of effort) more than the CLR, but not by much, actually. The COE is easy to calculate: using basic geometry: find the centre of each sail on your sail plan and join them with a line. The halfway point of that line is the sail plan's COE. (Obviously, with a cat rig all you need is the centre of the single sail; that will also be that sail's COE.) I vaguely recall from my days designing dinghies back in the 70s, that you can get a fairly workable idea of the CLR by finding the centre of your boat's side view. Simply draw a rectangle on the side view so as to get as much of the side view as possible in. The centre of that rectangle should give you a fair idea of where the CLR will be. If the dagger- or centreboard is slightly aft or for'ard of that point you can tweak the CLR slightly. Oh, and the idea is to have the COE slightly aft of the CLR, hence creating weather helm.
Wow I am so glad I found this video , thank you for sharing how to go about designing your own boat drawings, and all the tips that go with it, really love boat building so now I can get going on my own designe for a sail boat , liked and subscribed thank you again so much appreciated . 👍
Great video. Thank you. I would be very interested in hearing your learnings on placement of sail and dagger/center board - especially whether there are any rules-of-thumb or ratios that can help guide that aspect of the design.
Thanks Lee--I wish I could say I had a more scientific approach but I don't. I know there are ways to calculate the center of effort for the net sails (for the various points of sailing), and then working with the goal of minimum safe weather helm, I bet there are experts who could advise. Bottom line: I'm feeling happy and fortunate that my rough estimation approach has worked out well so far!
I wish I had a precise answer for you; I raised the bow a bit more than normal in part to get the front thwart as high up as possible, knowing I wanted a stayless mast. So the most distance between the mast step at the keelson and the thwart, the better mechanical advantage for taking the stresses on the mast. I knew I wanted the freeboard to be enough, but not too much (too high looks clunky, and makes it hard to climb back into the boat if you go overboard). So the height at the transom flowed from those decisions...
Thank you! Walking through that was VERY helpful, especially drawing the different views. Now I have a lot more confidence in my ability to draw out plans. You mentioned that you used a pre-made sail kit, dagger board and rudder on at least one of the boats. Did you make your own on the other two? If so, did you come up with the size and shape from experience and intuition or calculate out the sail area to displacement ratio and all that? Also, how did you size the dagger boards and rudders on the other boats? Thanks again, this was fantastic!
Very good questions for sure! Yes on the other three boats I designed my own sails, dagger boards, and rudders. I looked at similar popular boats like the sunfish (also 14' like Grace), with 75sq ft of sail; I targeted 85 for Grace and eventually added a jib. Then ratios of wetted area in square inches for the dagger board and rudder to square footage of sail were helpful, again based on some common successful boats. Those numbers are easy to come by--like for a Laser. Nomad was harder; not alot of boats were similar, but I arrived at 45 sq ft of sail--enough to sail well but manageable in terms of heeling moment. For Grace I chose the gaff rig because it allows a shorter mast that lays down into the boat, and seemed more doable to be done stayless. For all three, the rig kept the sail area lower (and so less tippy, more forgiving, maybe a bit less stress on the mast) than a traditional triangular mast/boom rig. Hope that helps maybe another video about rank amateur sail designing--I definitely had challenges. All three were made for me by Duckworks.
@@rudywoodcraft9553 Good advice again. I will take a look at comparable boats. I'd like to do a stayless mast as well but I want to try making a soft wing sail. Something between David Tyler's design and Oceanwings. Thank you for all the information!
No the center board is on the drive area. maybe a dagger slanted back to line up the following edge of the mast. Mast keeled dinghy is much safer and faster sailboat.
Cheers from Perth Scotland . I found your presentation very inspiring and instructive. I’ve been mulling over a boat build for a few years but never found a design that fitted. Your take on this has motivated me to chase my own ideas and design to build my own boat. Thanks again . Salut!
Wonderful to hear you found the video helpful! All the best on your build and happy sailing!
Glad to have found your channel from your visit to Doug and SV Seeker, I'm busy building may first boat a small pacific proa and am especially interested in the design theory of the rigging and mast position etc. Much appreciated .
Hi Tusk congrats on your build love to see some pictures if you have a chance. Nothing like building your own boat (and then sailing it!)
Thank you so much. Putting ideas to lines on paper and making adjustment thereafter is an interesting process. I like to add that in the old days, sailors did not start with pencil and paper. They carved wooden half-model of boats and take direct measurement of lines off it. For both ways, I think, the starting point is forming a boat whose lines and curves simply look and feel good - a raw beauty to be made.
Yes--maybe some day I will try that kind of traditional soft-chine boat based on a scale model to start with. Thanks for watching.
Thanks for the interesting videos. I've always loved boats and boating, but I never had the courage to start building my own. After seeing your videos on building Grace, I've started planning my own boat. Bought a couple of books on boat building, too... :) Greetings from Finland!
wonderful Joel-Evert please let me know how your projects go! Hope all is well for you in Finland...
Re you comment on building with stitch and glue, i.e. you need to know the shape of each panel, actually you can shape either your bilge panels, or side panels, temporarily sttich them together (with a stick(s) to hold them apart at the correct distance) and then use cardboard and duck tape to shape you other panels as a template to be cut out on plywood. I've seen it done both ways (side, or bilge panels first) and it works equally well. Your drawing needs L.O.A., beam and shear height to cut the first panels. Take some poster board, cut two identical strips to simulate your side panels, tape the bow, attach an approximate transom, expand them to the correct beam and look at it. You have a good idea of how the boat will look. You now can decide on how you may want to alter them. So much easier. And quicker.
Sam Devlin also details in his book how to convert any "Hard Chine" plans to a half model, that you can then take panel measurements from.
Currently working on converting an old set of motor launch plans to Stitch & Glue.
Great video, and very helpful. One of the most important, if not THE most important, things to determine is the point around which the hull pivots, the centre of lateral resistance (CLR). On a simple planing hull that would be where the centreboard/daggerboard is, but the hull shape and even the placement of thwarts and lockers inside the hull can affect the CLR.
Thanks! I'll admit the term is new to me but it gets at the idea I was pursuing...it would vary with the position and even set of the sail as well right?
@@rudywoodcraft9553 Yes, but the position and set of the sail affects the COE (centre of effort) more than the CLR, but not by much, actually. The COE is easy to calculate: using basic geometry: find the centre of each sail on your sail plan and join them with a line. The halfway point of that line is the sail plan's COE. (Obviously, with a cat rig all you need is the centre of the single sail; that will also be that sail's COE.) I vaguely recall from my days designing dinghies back in the 70s, that you can get a fairly workable idea of the CLR by finding the centre of your boat's side view. Simply draw a rectangle on the side view so as to get as much of the side view as possible in. The centre of that rectangle should give you a fair idea of where the CLR will be. If the dagger- or centreboard is slightly aft or for'ard of that point you can tweak the CLR slightly. Oh, and the idea is to have the COE slightly aft of the CLR, hence creating weather helm.
@@raytheron Thanks for the info! The distinction between CLR and COE is new to me.
Wow I am so glad I found this video , thank you for sharing how to go about designing your own boat drawings, and all the tips that go with it, really love boat building so now I can get going on my own designe for a sail boat , liked and subscribed thank you again so much appreciated . 👍
Excellent all the best in your build and if you find time, let me know how it goes!
Enjoyed your video, thanks for taking the time to make it. It explained it in an easy to understand way. Cheers
Glad you found it helpful
Great video. Thank you. I would be very interested in hearing your learnings on placement of sail and dagger/center board - especially whether there are any rules-of-thumb or ratios that can help guide that aspect of the design.
Thanks Lee--I wish I could say I had a more scientific approach but I don't. I know there are ways to calculate the center of effort for the net sails (for the various points of sailing), and then working with the goal of minimum safe weather helm, I bet there are experts who could advise. Bottom line: I'm feeling happy and fortunate that my rough estimation approach has worked out well so far!
Thank you, that was really well explained and interesting.
Glad you found it helpful Alex.
Thanks for that great lesson. I´m spending my free time in modelism. And i´d like to know how you considered the overall height at bow and transom.
I wish I had a precise answer for you; I raised the bow a bit more than normal in part to get the front thwart as high up as possible, knowing I wanted a stayless mast. So the most distance between the mast step at the keelson and the thwart, the better mechanical advantage for taking the stresses on the mast. I knew I wanted the freeboard to be enough, but not too much (too high looks clunky, and makes it hard to climb back into the boat if you go overboard). So the height at the transom flowed from those decisions...
Thank you! Walking through that was VERY helpful, especially drawing the different views. Now I have a lot more confidence in my ability to draw out plans. You mentioned that you used a pre-made sail kit, dagger board and rudder on at least one of the boats. Did you make your own on the other two? If so, did you come up with the size and shape from experience and intuition or calculate out the sail area to displacement ratio and all that? Also, how did you size the dagger boards and rudders on the other boats? Thanks again, this was fantastic!
Very good questions for sure! Yes on the other three boats I designed my own sails, dagger boards, and rudders. I looked at similar popular boats like the sunfish (also 14' like Grace), with 75sq ft of sail; I targeted 85 for Grace and eventually added a jib. Then ratios of wetted area in square inches for the dagger board and rudder to square footage of sail were helpful, again based on some common successful boats. Those numbers are easy to come by--like for a Laser. Nomad was harder; not alot of boats were similar, but I arrived at 45 sq ft of sail--enough to sail well but manageable in terms of heeling moment. For Grace I chose the gaff rig because it allows a shorter mast that lays down into the boat, and seemed more doable to be done stayless. For all three, the rig kept the sail area lower (and so less tippy, more forgiving, maybe a bit less stress on the mast) than a traditional triangular mast/boom rig. Hope that helps maybe another video about rank amateur sail designing--I definitely had challenges. All three were made for me by Duckworks.
@@rudywoodcraft9553 Good advice again. I will take a look at comparable boats. I'd like to do a stayless mast as well but I want to try making a soft wing sail. Something between David Tyler's design and Oceanwings. Thank you for all the information!
@@timmbot6082 look forward to hearing more on your project!
Concept to working plans to building to selling or sail. A concept for a more seaworthy and faster sailboat.
A concept to shake Ellison and Bertolli Spain 2010 America's Cup.
Thanks--the "concept to boat" is exactly what I've enjoyed so much. That they've worked out has been a bit of luck I think, but very enjoyable!
No the center board is on the drive area. maybe a dagger slanted back to line up the following edge of the mast. Mast keeled dinghy is much safer and faster sailboat.
Thanks for watching Mark
I've heard good feedback about the Stodoys plans.