"Reynaud" wrote in message
...
I would like to build an replica of an old Chestnut canoe. I have the
full size boat to refer to but am not sure how to take off proper
measurements . Could someone suggest where to find information or clue me
in. Help would be much appreciated.

Rey

@#@
Thanks for all the information gentlemen, I'm going to put it to good use.

Rey

Do a search of the magazine archives at WoodenBoat Magazine's web site. I
got about 4 articles on the topic of the taking of lines off a boat there.
There's more than one approach though, and having the boat level and square
is a convenience ...it can be done with the boat out of level too. The
article that I liked the best described both the method where you use
centerlines, baselines, and a level boat AND the method of taking of lines
via triangulation ...very accurate, especially for rounded hulls. This
article was written by D.W. Dillion in WoodenBoat issue Number 107 ...not
sure of the date as I only have a Xerox copy of the article. Not sure where
my issue #107 went. There's also an article in WoodenBoat #19 from Nov/Dec
1977 by David Littleton-Taylor that's reasonable ...although not as
informative as the one by Dillion in #107. Note that regardless of which
method you use, you will still need to use appropriate 3-view drawing and
fairing methods to produce new, exact, lines. Or you could use one of the
newer CAD packages like Rhino or ProSurf to fair the lines once they've been
recorded.

On the boat that I'm currently building, there were no lines available for
the boat ...just loftings and a building/construction manual in book form.
I took the lines off my boat for my own purposes and I used the baseline
method since in my shop, there was no room to physically use the
triangulation method. See http://www.reelboats.com/tongass/step15.html for
photos and text describing what I did.

Have fun!

Brian D



"Reynaud" wrote in message
...

"Reynaud" wrote in message
...
I would like to build an replica of an old Chestnut canoe. I have the
full size boat to refer to but am not sure how to take off proper
measurements . Could someone suggest where to find information or clue me
in. Help would be much appreciated.

Rey

@#@
Thanks for all the information gentlemen, I'm going to put it to good
use.

Rey

I'm also keen to take enough measurements of my current boat to allow some
modelling, I suspect the engine should be a bit further aft - and moving it
on a whim is not trivial.

This is a 24 ft carvel launch, 1950's vintage. I use my club's fairly
agricultural slipway, so when it's out of the water, it's never going to be
parallel to the slip's rails, it's difficult to get it exactly level from
side to side, and it will be bow up by about 10 degrees. The surface under
the slipway is very amateur concrete, with rails and the trolley obstructing
things even further. About the only good news is that the waterline is easy
to establish, and that on one side there is an open space. I could pay to
use a commercial slipway, but the boat would still be bow up, and the
underlying surface curved.

I'm wondering if the best option is to mark the waterline, pay a surveyor
with a "total station" to do lots of measurements from one side, and take it
from there. I have no idea of the accuracy one might achieve. Or of how
difficult it would be to import the results into an appropriate boat
related package .....

I suspect that a decent survey package could manipulate the results to level
it in both axes, and give an output in co-ordinates and dxf format.

anyone tried something like this?

David Flew
"Reynaud" wrote in message
...
I would like to build an replica of an old Chestnut canoe. I have the
full size boat to refer to but am not sure how to take off proper
measurements . Could someone suggest where to find information or clue me
in. Help would be much appreciated.

Rey

Hi Rey,

here's what I did with my 22 footer.

I taped a laser pointer to a spirit level and placed it pointing down
(alongside) the hull about 3 feet away. You need to get this as square to
the hull as possible. I used that as my datum. Then I built a simple
crucifix-like jig and taped rulers to both the verticle and horizontal arms.
The horizontal arm needs to be able to slide up against the hull and down
the vertical leg. The jig needs to be about the height of and half-width of
the hull. I also taped spirit levels to both arms. Basically, you move
your crucifix down the hull reading the height of the horizontal arm from
the red dot and the distance of the hull from the vertical leg (via the
horizontal arm). Sounds simple but you really need to take your time to set
everything up just so or you may find that your offsets are totally
undrawable! A level floor really helps to simplify the math later on.

Cheers,
arnold

As you see there are many way's to do what you want, ------ the laser
pen thing isn't that bad a choice but maby you need a bit experience
with other methods before you use that , but it make me wonder about a
method I would think --- havn't tried it though but often thought about
trying it --- emagine you draw chalk lines outside the hull
coresponding the ribs and take a foto from the end of the boat, do
likevise from the side . Now if the foto with chalk lines will bring
what you want, the laser pen is just the tool to make the chalk lines.
You can buy these water level laser pens everywhere at low price place
something in the picture you know the exact size of and I am sure the
foult will be minimal.