Results 1 to 29 of 29

Thread: New two-sheeter: Square stern motor canoe

  1. #1
    Join Date
    May 2009
    Location
    Vienna, Austria
    Posts
    266

    Default New two-sheeter: Square stern motor canoe

    The family is still growing. Although the new member is not completly developed, I would like to present it to the forum:

    A two sheet square stern motor canoe (LOA 14' 10", beam 40")













    Thoughts?
    Last edited by flo-mo; 02-04-2011 at 05:31 PM.

  2. #2
    Join Date
    Jan 2011
    Location
    St. Augustine, FL
    Posts
    708

    Default Re: New two-sheeter: Square sterned motor canoe

    Beautiful design, beautiful model. That's a lot of boat out of two sheets. What is the freeboard? Where do you propose seating- the sole? How would you power her?

  3. #3
    Join Date
    May 2005
    Location
    upstate ny- thats north of the catskills
    Posts
    456

    Default Re: New two-sheeter: Square sterned motor canoe

    very pleasant lines, I like it.

  4. #4
    Join Date
    Oct 2008
    Location
    Walney, near Cumbria UK
    Posts
    18,003

    Default Re: New two-sheeter: Square sterned motor canoe

    Ditto, that one is a keeper.
    It really is quite difficult to build an ugly wooden boat.

    The power of the web: Anyone can post anything on the web
    The weakness of the web: Anyone can post anything on the web.

  5. #5
    Join Date
    Sep 2003
    Location
    Vienna Austria
    Posts
    45

    Default Re: New two-sheeter: Square sterned motor canoe

    That is a very nice design! A small minn-kota and you can go boating on the Neusiedlersee.

    My only thought is where do you get 2 good sheets of marine-ply in Vienna??? Hrad???

  6. #6
    Join Date
    Dec 1999
    Location
    Eagan, Minnesota, USA
    Posts
    11,292

    Default Re: New two-sheeter: Square stern motor canoe

    Look out, fish! Maybe not to stand up in and fly cast, but from the house or shore or dock out to the nearby hole where they are, perfect!

  7. #7
    Join Date
    Feb 2002
    Location
    Duncan, Vancouver Island
    Posts
    25,017

    Default Re: New two-sheeter: Square stern motor canoe

    I'll be picky. Something not quite right at the stern. Sheer's off a bit, and maybe a little tumblehome on the transom instead of that chiney thing? But beautiful forward. Add a 2hp outboard and a long tiller.

  8. #8
    Join Date
    Nov 2004
    Location
    St. Charles, IL
    Posts
    1,126

    Default Re: New two-sheeter: Square stern motor canoe

    Maybe the aft chine is messing with the visual look of the sheer, cause I like the sheer...but not the aft chine. A 2 horse would be perfect. And standing to cast wouldn't be too bad--lots of folks doing that on Stand up paddleboatds of 32ish".

    Dan

  9. #9
    Join Date
    May 2009
    Location
    Vienna, Austria
    Posts
    266

    Default Re: New two-sheeter: Square stern motor canoe

    The purpose of my one sheet- and two sheet designs is merely a mind game. I try to get the maximum out of the plywood to form a decent boat-like shape with a certain design aim and keep it as simple as I can.

    Maybe there is still room for improvement for this design but I think I have almost reached the limit.








    Hull depth amidship is 13" and freeboard at 500lbs displacement is 9".
    If made of 6mm oukume plywood estimated weight is 70lbs.
    In "Boats with an open mind" Phil Bolger recommended for his motor canoe, which is a more stable design than mine, to sit on the bottom to compensate for the high power head of the motor - so this is what I would recommend too.

    I have no idea of outboard motors and motor boats in general so I am not able to give any information about powering the boat. Maybe a 2hp outboard as suggested twice is the right choice? Anyway it should be as light as possible.
    Last edited by flo-mo; 02-07-2011 at 02:48 PM.

  10. #10
    Join Date
    May 2010
    Location
    Sioux City, Iowa (Idiot Out Walking Around)
    Posts
    1,827

    Default Re: New two-sheeter: Square stern motor canoe

    Only two things come to mind...you should add 15 degrees of rake to the transom. This will allow the motor to tuck under and help push the bows back down. Remember...you have the weight of the skipper, fuel and motor in the back...all concentrated within the last 3 feet of the hull. Add the propulsive power trying to lift the nose and you need something to counter act this tendency. The second thing is strictly aesthetic...but most motorboats don't have a upward curving sheer at the stern...they tend to be flat or very near flat from the lowest point aft. You don't really need that little piece sticking up back there. You may have to raise the height of the transom...the shortest legged motors need a vertical height of within 1/2" of 15" at the transom. otherwise either too much is in the water causing drag or too little and you run the risk of burning out the motor through lack of coolant or the prop will aerate and throw water all over and not move the boat properly.
    Steve Lewis
    Formerly Lewisboats (don't try to change your email address!)

    http://angelfire.com/ego/lewisboatworks

  11. #11
    Join Date
    Aug 2005
    Location
    SF Bay Area- Richmond
    Posts
    13,370

    Default Re: New two-sheeter: Square stern motor canoe

    Lewis - My gut reaction on the sheer at the stern is just the opposite, strangely enough. I think he needs more of it, along with the rake you recommend. This is because I strongly suspect the boat needs a bit more freeboard, but materials limitations keep that from happening.

    I understand the limitations of working with only 2 sheets of ply make the materials a driving factor in these designs, most of which are brilliant (and have certainly changed my previous bias against plans based on materials limitations rather than use and ease of building). But other than flat water boating in locations with no powerboats, I'm afraid the above design might have a real risk of swamping over the sides.

    I operate a boat with low freeboard, and not only struggle with powerboat wakes and swell, but have realized just how much the average powerboater relies on all nearby boats having significant freeboard. I've had skiboats come back and apologize for nearly swamping my boat -- they just don't expect anyone to be threatened by a 3' wake!
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  12. #12
    Join Date
    May 2010
    Location
    western canada, ex safa
    Posts
    120

    Default Re: New two-sheeter: Square stern motor canoe

    so... what about a three sheet power canoe- more freeboard- a tad longer, more beamy- with say a 5hp or 7 hp- but same overall concept.- she would then be a really capable and safe boat, with a small family carrying capacity.
    i love stefans designs, inspiring, simple , easy to construct, and beautiful to boot!!!
    keep it up stefan
    dont quit.
    wayne

  13. #13
    Join Date
    Dec 2003
    Location
    on-the-cuyahoga
    Posts
    13,407

    Default Re: New two-sheeter: Square stern motor canoe

    Quote Originally Posted by wayne nicol View Post
    so... what about a three sheet power canoe- more freeboard- a tad longer, more beamy- with say a 5hp or 7 hp- but same overall concept.- she would then be a really capable and safe boat, with a small family carrying capacity.
    i love stefans designs, inspiring, simple , easy to construct, and beautiful to boot!!!
    keep it up stefan
    dont quit.
    wayne
    He's in Vienna and his plywood has come from neighboring Hungary. Unfortunately Hungary is looking at an economic meltdown and further supplys of marine plywood may be doubtful.
    I am not a naval architect nor do I ply one on TV but a three sheet boat capable of handling a 7 HP motor looks like an impossibilty.
    Here's a flat-bottomed 14 ft. rowboat that will take a 7 HP.
    http://www.bateau.com/studyplans/FL1....htm?prod=FL14
    It was done by a naval architect. The bill of materials say 2 sheets of " and 4 sheets of 3/8". To make it seaworthy required losing 15% or more to scrap.
    Last edited by Cuyahoga Chuck; 02-10-2011 at 11:33 PM.

  14. #14
    Join Date
    May 2010
    Location
    western canada, ex safa
    Posts
    120

    Default Re: New two-sheeter: Square stern motor canoe

    hey chuck, thanks for the link-- cool!!
    those were just random thoughts within very rough parameters i threw out there- it would not be imperitive that a 7hp used- merely implying that to go with a bigger motor would be ok.
    i kinda imagine just keeping within the same design approach, and using 3 sheets , maybe one could produce a sligfhtly larger boat with more freeboard- but hey- i am no architect, just a consumer- just some thoughts- i love stefans designs
    thanks mate
    wayne

  15. #15
    Join Date
    Oct 2009
    Location
    South Puget Sound/summer Eastern carib./winter
    Posts
    9,742

    Default Re: New two-sheeter: Square stern motor canoe

    I just bought a wee OB. The 3.3hp weighs one pound more than the 2hp!!

  16. #16
    Join Date
    Dec 2003
    Location
    on-the-cuyahoga
    Posts
    13,407

    Default Re: New two-sheeter: Square stern motor canoe

    Quote Originally Posted by wayne nicol View Post
    hey chuck, thanks for the link-- cool!!
    those were just random thoughts within very rough parameters i threw out there- it would not be imperitive that a 7hp used- merely implying that to go with a bigger motor would be ok.
    i kinda imagine just keeping within the same design approach, and using 3 sheets , maybe one could produce a sligfhtly larger boat with more freeboard- but hey- i am no architect, just a consumer- just some thoughts- i love stefans designs
    thanks mate
    wayne
    The object of this exercise is to get a boat out of 2 sheets of plywood not to produce an optimal design. For instance a tiller-steered outboard needs a pilot sitting near it. If the pilot weighs 250 lb. the aft section of the boat may be overloaded before any motor goes on. When you are limited to 2 sheets of ply you get what you can and alter your boating habits to conform to the boat's demands. I know this because I paddle a two-sheet plywood pirogue.

  17. #17
    Join Date
    May 2010
    Location
    western canada, ex safa
    Posts
    120

    Default Re: New two-sheeter: Square stern motor canoe

    that s why we like to use extensions on our working skiffs- for booming, and pulling sticks etc
    although this would not be a work boat- certianally recreational.
    thanks

  18. #18
    Join Date
    Feb 2006
    Location
    Pennsylvania
    Posts
    6,081

    Default Re: New two-sheeter: Square stern motor canoe

    I'm seeing a boat that wants enough power to go up on plane, which would need a bit more than 2 hp. (I'll bet 4 would do it with one person if not too heavy a dude.) Or, if for a small light motor or a trolling motor, then I'd want to put more rocker in the bottom to keep it very efficient. That would make it paddle or row better, too. My personal preference would be to add rocker so the transom doesn't drag, and think in terms of electric power. That would make a nice, fairly portable fishing machine.

  19. #19
    Join Date
    May 2009
    Location
    Vienna, Austria
    Posts
    266

    Default Re: New two-sheeter: Square stern motor canoe

    Thank you all for your comments -- they are very helpfull.

    I understand this design does not have the capability I wished it would have.

    The main flaws are:
    -A profile of a planing hull but too little buoyancy at the stern to take a motor that is powerfull enough to get her planing
    -Too little freeboard, stability and capacity in general
    -A transom not high enough to take a standard outboard motor and the need of 12-15 rake of the transom

    For a two sheet design I see no way to make these changes exept for the transom. With three sheets it might be possible but this would take a totally different approach.

    So I think Woxbox's proposal will be the way to go:

    ...Or, if for a small light motor or a trolling motor, then I'd want to put more rocker in the bottom to keep it very efficient. That would make it paddle or row better, too. My personal preference would be to add rocker so the transom doesn't drag, and think in terms of electric power. That would make a nice, fairly portable fishing machine.
    The design at it's present state with a 15 rake of the transom would make sense if you find two 5' x 10' plywood sheets. The boat will be larger by 25% in all dimensions and all problems listed above would be solved.

    The specifications for the two 5'x10' sheet motor canoe are:

    LOA 18' 7"
    Beam 4' 0"
    L@WL 18' 3"
    B@WL 3' 4"
    Displacement 800lbs
    Draft 4"
    Depth amidship 16"






  20. #20
    Join Date
    May 2010
    Location
    western canada, ex safa
    Posts
    120

    Default Re: New two-sheeter: Square stern motor canoe

    thats looks pretty good!!!
    would you have some lines and offsets for that.
    that looks like a nice little craft that could do some work!!!
    thanks
    wayne

  21. #21

    Default Re: New two-sheeter: Square stern motor canoe

    I second the offsets! This is a great design!

  22. #22
    Join Date
    Jan 2007
    Location
    North Shore, Massachusetts
    Posts
    1,932

    Default Re: New two-sheeter: Square stern motor canoe

    4'x10' sheets are much easier to come by than 5'... how about if you increased the deadrise of the garboards, this will give a tiny bit narrower hull but increase freeboard significantly. I think long and narrow could be good for this hull, like an old torpedo boat.

  23. #23
    Join Date
    Sep 2011
    Posts
    214

    Default Re: New two-sheeter: Square stern motor canoe

    I have a plastic old town 17' square stern. Much smaller transom. Data tag says max rated for 5 HP I use a 2.5 HP. Goes about 6-7 MPH carries a lot more then you'd expect and being pointy on both ends is quite seaworthy with a bit of care.

  24. #24
    Join Date
    Dec 2003
    Location
    on-the-cuyahoga
    Posts
    13,407

    Default Re: New two-sheeter: Square stern motor canoe

    Quote Originally Posted by Daniel Noyes View Post
    4'x10' sheets are much easier to come by than 5'... how about if you increased the deadrise of the garboards, this will give a tiny bit narrower hull but increase freeboard significantly. I think long and narrow could be good for this hull, like an old torpedo boat.
    That's not a torpedo boat. That's TURBINIA. It was the first turbine powered boat intended by the builder to interest the Royal Navy in steam turbine power. It could boogie along at about 45 MPH. They displayed it's speed at a gathering of the Royal Navy at which the monarch was in attendence. It cut thru' the whole fleet at full power. It was there and gone. I don't recall if the Royal Navy bought any.

  25. #25
    Join Date
    Jan 2007
    Location
    North Shore, Massachusetts
    Posts
    1,932

    Default Re: New two-sheeter: Square stern motor canoe

    Quote Originally Posted by Cuyahoga Chuck View Post
    That's not a torpedo boat. That's TURBINIA...I don't recall if the Royal Navy bought any.

    hmmmm, Ive been taught If u cant say something nice dont say anything... but I have sooooo many things to say.

    OK, yeah I know that Turbinia never carried any torpedos but she was designed using the torpedo boats of the day as a model and this is one of the best photos around of a boat of that type at speed.
    Here's a real torpedo boat for Chuck... not so very different... Ok back to the beautifull power canoe Flo-Mo is working on.


  26. #26
    Join Date
    Dec 2003
    Location
    on-the-cuyahoga
    Posts
    13,407

    Default Re: New two-sheeter: Square stern motor canoe

    This thread was started 2 years ago and hasn't gone anywhere since. Time marches on.

  27. #27
    Join Date
    May 2009
    Location
    Vienna, Austria
    Posts
    266

    Default Re: New two-sheeter: Square stern motor canoe

    Quote Originally Posted by flo-mo View Post
    I understand this design does not have the capability I wished it would have.

    The main flaws are:
    -A profile of a planing hull but too little buoyancy at the stern to take a motor that is powerfull enough to get her planing
    -Too little freeboard, stability and capacity in general
    -A transom not high enough to take a standard outboard motor and the need of 12-15 rake of the transom

    For a two sheet design I see no way to make these changes exept for the transom. With three sheets it might be possible but this would take a totally different approach.
    I am quoting myself to underline what's the problem with this design.

    If however you have access to the infamous 10'x5' plywood sheets (9mm) then this design may make sense. That's why I revised the panel-layout so there is a raked transom and made some minor corrections.





    If someone is still interested in the offsets - here they are (two sheets 10' x 5' marine grade plywood 9mm):




  28. #28
    Join Date
    May 2009
    Location
    Vienna, Austria
    Posts
    266

    Default Re: New two-sheeter: Square stern motor canoe

    Even though I pointed out the flaws of the design made of two regular sheets of plywood (8' x 4', 6mm) a forumite still requested the offsets.

    So here they are as well:




  29. #29
    Join Date
    Jan 2008
    Location
    Lake Champlain, Vermont
    Posts
    1,207

    Default Re: New two-sheeter: Square stern motor canoe

    Instead of the slight angle turn you put on the top sides of the transom I would like to suggest that you join the two side pieces of the side panels (the big panels and two little wedge shape pieces) with a Payson type joint http://www.duckworksmagazine.com/04/...gen/17/ron.cfm and then change the side of the transom into a geltle arc to give the boat some tumblehome. I am convinced that it could be done, having tortured some plywood myself with great success. Just seem it would give that tranny some sex appeal and get rid of that awkward (sorry) transition. Love your work and would like to see plans some day but where in the world could I get 5x10 ply?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •