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the pancake skiff - episode 1
I have made a Freeship model of the hull I am interested in.
page with file link- http://www.norcom2000.com/users/dcim...oat_makin.html -or Tiny- http://tinyurl.com/2g8h8f8 This is not the 100% final version, just a close approximation. The idea is basically a extra-wide rowboat hull with a very flat bottom. There will be a flat sealed floor set 6" above the hull bottom on frames spaced every foot. This is a inland/fla****er boat only. I would get it rated for a small motor, 5 HP I think. Not very fast, but as light & broad as the hull is, it's just not going to be safe going fast anyway. Other 14" boats seem to be running 20-30 HP regularly. 10 MPH is okay for this, I just need a motor that's "faster than rowing" while being and "less effort than rowing". :) One 14" commercially-made boat I found used 2mm (~.078") for the hull, I dunno what alloy. I have no idea how thick to go for the floor. I think the usual sheet the local metals supplier has on hand is 5052. ------- ,,,,Coincidentally [if you are a USA poster] I cannot find out how to rate a home-built boat for horsepower on the USCG website. I found the home-builder's handbook stuff, they go into all the math to find hull displacement and determine gear and passenger capacity and they have a table giving weights for engines of increasing sizes,,,,, but they say nothing about how to decide how much power to hang on a boat. Is there a formula for this, or is it just--you ask for as much as you want, and they make the final call? ~ |
the pancake skiff - episode 1
On Fri, 30 Jul 2010 11:50:17 -0500, DougC
wrote: I have made a Freeship model of the hull I am interested in. page with file link- http://www.norcom2000.com/users/dcim...oat_makin.html -or Tiny- http://tinyurl.com/2g8h8f8 This is not the 100% final version, just a close approximation. The idea is basically a extra-wide rowboat hull with a very flat bottom. There will be a flat sealed floor set 6" above the hull bottom on frames spaced every foot. This is a inland/fla****er boat only. Your URL links to a site that provides a ZIP file which expands to be a FBM file. My system doesn't read fbm files. I would get it rated for a small motor, 5 HP I think. Not very fast, but as light & broad as the hull is, it's just not going to be safe going fast anyway. Other 14" boats seem to be running 20-30 HP regularly. 10 MPH is okay for this, I just need a motor that's "faster than rowing" while being and "less effort than rowing". :) Why do you want to "get it rated" for a motor? Are you going to manufacture it commercially? One 14" commercially-made boat I found used 2mm (~.078") for the hull, I dunno what alloy. I have no idea how thick to go for the floor. I think the usual sheet the local metals supplier has on hand is 5052. You can't equate length and skin thickness. You need to first develop the actual structure of the boat and then decide the force which must be opposed by the skin. To exaggerate - a boat with no formers or stringers depending solely on the skin for strength, i.e., monocoque construction, would require a totally different material then one that used a "egg crate" type of structure.. ------- ,,,,Coincidentally [if you are a USA poster] I cannot find out how to rate a home-built boat for horsepower on the USCG website. I found the home-builder's handbook stuff, they go into all the math to find hull displacement and determine gear and passenger capacity and they have a table giving weights for engines of increasing sizes,,,,, but they say nothing about how to decide how much power to hang on a boat. Is there a formula for this, or is it just--you ask for as much as you want, and they make the final call? ~ I believe that the question is "why" Cheers, Bruce (bruceinbangkokatgmaildotcom) |
the pancake skiff - episode 1
On 7/30/2010 7:33 PM, Bruce in Bangkok wrote:
On Fri, 30 Jul 2010 11:50:17 -0500, wrote: I have made a Freeship model of the hull I am interested in. page with file link- http://www.norcom2000.com/users/dcim...oat_makin.html -or Tiny- http://tinyurl.com/2g8h8f8 This is not the 100% final version, just a close approximation. The idea is basically a extra-wide rowboat hull with a very flat bottom. There will be a flat sealed floor set 6" above the hull bottom on frames spaced every foot. This is a inland/fla****er boat only. Your URL links to a site that provides a ZIP file which expands to be a FBM file. My system doesn't read fbm files. Sure it does. Just go download and install Freeship, and you'll be all set. (at times it is spelled FREE!ship) http://sourceforge.net/projects/freeship/ Freeship is rather dated but downloading it does not require registration, as the Delft program seems to. I would get it rated for a small motor, 5 HP I think. Not very fast, but as light & broad as the hull is, it's just not going to be safe going fast anyway. Other 14" boats seem to be running 20-30 HP regularly. 10 MPH is okay for this, I just need a motor that's "faster than rowing" while being and "less effort than rowing". :) Why do you want to "get it rated" for a motor? Are you going to manufacture it commercially? I thought that (assuming US laws of course) any given powerboat had a rated horsepower limit. Stated on the HIN plate. As I said, this part of the USCG "homebuilder's handbook" is not real clear. They have an "outboard example" that says how to figure out the displaement, persons and gear capacity, then they just say the boat's HIN plate would say it was rated for X people, X lbs of gear and "100 horsepower"..... they never say how they arrived at the 100 HP figure as safe or allowable. One 14" commercially-made boat I found used 2mm (~.078") for the hull, I dunno what alloy. I have no idea how thick to go for the floor. I think the usual sheet the local metals supplier has on hand is 5052. You can't equate length and skin thickness. You need to first develop the actual structure of the boat and then decide the force which must be opposed by the skin. To exaggerate - a boat with no formers or stringers depending solely on the skin for strength, i.e., monocoque construction, would require a totally different material then one that used a "egg crate" type of structure.. Yea but if I was using metal half as thick (-or twice as thick-) as comparably-sized commercial boats usually use, that would seem to indicate something rather odd. I have found a couple companies that use 1/8" plate for the decking. On boats about 15'. I know (in rough terms) what finite element modeling /is/ , but I have no access to software that can do it. Nor (I would bet) do most of the people on Earth who build small low-speed boats they've designed themselves. ~ |
the pancake skiff - episode 1
ON the page link above is also another link showing a small test model
I'm working on. ~ |
the pancake skiff - episode 1
On Fri, 30 Jul 2010 20:59:13 -0500, DougC
wrote: On 7/30/2010 7:33 PM, Bruce in Bangkok wrote: On Fri, 30 Jul 2010 11:50:17 -0500, wrote: I have made a Freeship model of the hull I am interested in. page with file link- http://www.norcom2000.com/users/dcim...oat_makin.html -or Tiny- http://tinyurl.com/2g8h8f8 This is not the 100% final version, just a close approximation. The idea is basically a extra-wide rowboat hull with a very flat bottom. There will be a flat sealed floor set 6" above the hull bottom on frames spaced every foot. This is a inland/fla****er boat only. Your URL links to a site that provides a ZIP file which expands to be a FBM file. My system doesn't read fbm files. Sure it does. Just go download and install Freeship, and you'll be all set. (at times it is spelled FREE!ship) http://sourceforge.net/projects/freeship/ Freeship is rather dated but downloading it does not require registration, as the Delft program seems to. Why do you believe that I would want to download and install yet another program only to advise you on your projected design. I would get it rated for a small motor, 5 HP I think. Not very fast, but as light & broad as the hull is, it's just not going to be safe going fast anyway. Other 14" boats seem to be running 20-30 HP regularly. 10 MPH is okay for this, I just need a motor that's "faster than rowing" while being and "less effort than rowing". :) Why do you want to "get it rated" for a motor? Are you going to manufacture it commercially? I thought that (assuming US laws of course) any given powerboat had a rated horsepower limit. Stated on the HIN plate. Do home built boats have a HIN plate? Cheers, Bruce (bruceinbangkokatgmaildotcom) |
the pancake skiff - episode 1
On 7/31/2010 6:58 AM, Bruce in Bangkok wrote:
... Why do you believe that I would want to download and install yet another program only to advise you on your projected design. Because it is the most awesome example of maritime design ever, and you will weep tears of joy the moment you lay eyes upon it. -------- I am kinda wavering on it tho'. The engine will about double the cost of the thing, but rowing a very-wide hull would be a tremendous chore. I like the idea of a flat deck, but there's more than one way to do that. Do home built boats have a HIN plate? If they are used on navigable waterways inside the USA and have a motor, then yes--they do. ~ |
the pancake skiff - episode 1
On Sat, 31 Jul 2010 10:36:09 -0400, I am Tosk
wrote: In article , says... On Fri, 30 Jul 2010 20:59:13 -0500, DougC wrote: On 7/30/2010 7:33 PM, Bruce in Bangkok wrote: On Fri, 30 Jul 2010 11:50:17 -0500, wrote: I have made a Freeship model of the hull I am interested in. page with file link- http://www.norcom2000.com/users/dcim...oat_makin.html -or Tiny- http://tinyurl.com/2g8h8f8 This is not the 100% final version, just a close approximation. The idea is basically a extra-wide rowboat hull with a very flat bottom. There will be a flat sealed floor set 6" above the hull bottom on frames spaced every foot. This is a inland/fla****er boat only. Your URL links to a site that provides a ZIP file which expands to be a FBM file. My system doesn't read fbm files. Sure it does. Just go download and install Freeship, and you'll be all set. (at times it is spelled FREE!ship) http://sourceforge.net/projects/freeship/ Freeship is rather dated but downloading it does not require registration, as the Delft program seems to. Why do you believe that I would want to download and install yet another program only to advise you on your projected design. I would get it rated for a small motor, 5 HP I think. Not very fast, but as light & broad as the hull is, it's just not going to be safe going fast anyway. Other 14" boats seem to be running 20-30 HP regularly. 10 MPH is okay for this, I just need a motor that's "faster than rowing" while being and "less effort than rowing". :) Why do you want to "get it rated" for a motor? Are you going to manufacture it commercially? I thought that (assuming US laws of course) any given powerboat had a rated horsepower limit. Stated on the HIN plate. Do home built boats have a HIN plate? Cheers, Bruce (bruceinbangkokatgmaildotcom) Yes... I am not sure about the other 50 states but trust that each one marks that boat somehow so they can collect taxes on it;) You mean that you cannot build yourself a boat anymore, without the Gomment sticking their fingers in the pie? Cheers, Bruce (bruceinbangkokatgmaildotcom) |
the pancake skiff - episode 1
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the pancake skiff - episode 1
On 7/31/2010 8:46 PM, mmc wrote:
http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ |
the pancake skiff - episode 1
"DougC" wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. |
the pancake skiff - episode 1
On 8/2/2010 3:29 PM, mmc wrote:
wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Well okay, let me elaborate: I wand an "open" floor. Boats like that always have seats extending across that (I'd bet) are structural pieces. I think in three days I've had three different ideas about what would be perfect.... :/ ~ |
the pancake skiff - episode 1
"DougC" wrote in message ... On 8/2/2010 3:29 PM, mmc wrote: wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Well okay, let me elaborate: I wand an "open" floor. Boats like that always have seats extending across that (I'd bet) are structural pieces. I think in three days I've had three different ideas about what would be perfect.... :/ ~ How will you brace your hull if not ribs or seats? |
the pancake skiff - episode 1
"DougC" wrote in message ... On 8/2/2010 3:29 PM, mmc wrote: wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Well okay, let me elaborate: I wand an "open" floor. Boats like that always have seats extending across that (I'd bet) are structural pieces. I think in three days I've had three different ideas about what would be perfect.... :/ ~ Thanks for the Freeship link. Very cool. |
the pancake skiff - episode 1
On 8/2/2010 7:17 PM, mmc wrote:
wrote in message ... On 8/2/2010 3:29 PM, mmc wrote: wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Well okay, let me elaborate: I wand an "open" floor. Boats like that always have seats extending across that (I'd bet) are structural pieces. I think in three days I've had three different ideas about what would be perfect.... :/ ~ How will you brace your hull if not ribs or seats? What I like the idea of is covering the hull inside-bottom mostly with a floor that is raised a couple inches above the water level of a typical load. Then you can install drains/plugs in the sides of the boat right at the floor level, and in a bad weather situation (with the plugs removed) the boat becomes self-bailing. ~ |
the pancake skiff - episode 1
In article m,
says... "DougC" wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Or a couple of nice skegs... -- Rowdy Mouse Racing - We race for cheese! |
the pancake skiff - episode 1
On 8/3/2010 8:58 AM, I am Tosk wrote:
In ting.com, says... wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Or a couple of nice skegs... Where I live the lakes tend to have large shallow areas. This boat would need to be able to float in 3 inches of water with a typical load in it (~300 lbs, not including the boat). What I was thinking was to make a bottom that was nearly flat, and then have a removable skeg that hangs off the transom, like a rudder. That would be a lot easier to make than the retractable skegs that sea kayaks have. I wouldn't need the skeg all the time, since you don't need it in three inches of water anyway. -------- I bought a kayak a while back. The kayak is great in some ways, but not-so-much in others. I have no plans to get rid of it, but I am desiring an alternate for certain situations. The reason I considered building a boat at all is because I can't find anything already made that would do what I wanted. ~ |
the pancake skiff - episode 1
"I am Tosk" wrote in message ... In article m, says... "DougC" wrote in message ... On 7/31/2010 8:46 PM, mmc wrote: http://spacecoast.craigslist.org/boa/1874022332.html Some great deals out there.......... The price is right, but the floor isn't flat... -and how well does it row? The engine is an "extra" for me. It'd be nice to have if I needed it, but don't think I'd use it much of the time. I don't want to listen to the noise of an engine all the time I'm moving. ~ Not my boat. Looks like the hull is flat bottomed which would lead to a flat floor. A flat bottom boat isn't going to track well when rowing, better off with a shallow v. Or a couple of nice skegs... -- Rowdy Mouse Racing - We race for cheese! Doug, you talked to Scotty (Tosk)? He's a pro at this stuff! |
the pancake skiff - episode 1
Looking at your drawing my guess is tha the flat bottom will create a
lot of bow steer and the transom will create a lot of drag. Curve the bottom so that the stem is above the WL and the transom is right at the DWL and I think you have a winner. |
the pancake skiff - episode 1
What I like the idea of is covering the hull inside-bottom mostly with
a floor that is raised a couple inches above the water level of a typical load. Then you can install drains/plugs in the sides of the boat right at the floor level, and in a bad weather situation (with the plugs removed) the boat becomes self-bailing. Sort of like a Water-Letter-Outer? If it was self bailing why would you have the plugs in the first place? |
the pancake skiff - episode 1
"Steve P." wrote in message ... What I like the idea of is covering the hull inside-bottom mostly with a floor that is raised a couple inches above the water level of a typical load. Then you can install drains/plugs in the sides of the boat right at the floor level, and in a bad weather situation (with the plugs removed) the boat becomes self-bailing. Sort of like a Water-Letter-Outer? If it was self bailing why would you have the plugs in the first place? For it to be self bailing, won't it require a pretty good flow of water going past the drain? Probably more flow than can be realized rowing? |
the pancake skiff - episode 1
On 8/9/2010 9:00 AM, Steve P. wrote:
What I like the idea of is covering the hull inside-bottom mostly with a floor that is raised a couple inches above the water level of a typical load. Then you can install drains/plugs in the sides of the boat right at the floor level, and in a bad weather situation (with the plugs removed) the boat becomes self-bailing. Sort of like a Water-Letter-Outer? If it was self bailing why would you have the plugs in the first place? Because it may not be self-bailing with a heavy load. Suppose you have a design for a flat-bottom rowboat, with a raised floor. With one person on board, it sinks three inches into the water. With a full load (three people) it sinks seven inches. And suppose you put the floor five inches above the bottom of the hull, and put two drain holes (with plugs) in the sides, right above where the floor meets the sides. Now this would mean that when lightly loaded, the floor height is higher than the water level.... so if you took out the drain plugs, any water that got into the boat would just run out the drain holes, since the floor was two inches above the water level. With the full load, you'd want the drain plugs in, since the water level would be higher than the floor level. If you set the floor level high enough that it was always above water level, that would be (I'd think) a very tippy small boat. I know that BIG boats do it that way, but aside from sit-on-top kayaks I'm not sure many small ones do. ---------- I don't know if this is ever done with small boats or not, it was just an idea. I will likely be boating alone most of the time, and I wanted a shallow-draft boat, with a flat (raised) deck.... When I was sketching carious designs out I noticed that with a light load, the raised floor usually ended up above the waterline anyway. ~ |
the pancake skiff - episode 1
On 8/9/2010 8:54 AM, Steve P. wrote:
Looking at your drawing my guess is tha the flat bottom will create a lot of bow steer and the transom will create a lot of drag. Curve the bottom so that the stem is above the WL and the transom is right at the DWL and I think you have a winner. Two points: 1--that Freeship model still posted is not what I am considering now, I haven't done a freeship model of the "latest design" pram yet. 2--that model also doesn't show the floor, or seating arrangement. I need to put up a new diagram, it is easier to show than explain. The seating and floor arrangement I want has not changed from the first design... ~ |
the pancake skiff - episode 1
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the pancake skiff - episode 1
On 8/9/2010 10:28 PM, I am Tosk wrote:
In ting.com, says... "Steve wrote in message ... What I like the idea of is covering the hull inside-bottom mostly with a floor that is raised a couple inches above the water level of a typical load. Then you can install drains/plugs in the sides of the boat right at the floor level, and in a bad weather situation (with the plugs removed) the boat becomes self-bailing. Sort of like a Water-Letter-Outer? If it was self bailing why would you have the plugs in the first place? For it to be self bailing, won't it require a pretty good flow of water going past the drain? Probably more flow than can be realized rowing? The idea is to put a false floor at the waterline and put the holes slightly above that. The last couple of inches would not "self bail" but you would get the boat up to the water line anyway. Yea but but but,,,, same difference, really. This boat will probably be rated for 700-900 lbs, and the draft will vary a lot with the load. Most of the time I'll probably be using it alone, though. So if the waterline is == floor when there is a full load, then the floor will be higher than the waterline with a light load. ~ |
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