Ross M
04-11-2006, 08:52 PM
(Recovered from internet cache)
Posted by Blue (Member # 3292) on 05-10-2001, 01:20 PM:
I and in the process of building the 18' Handy billy launch similar to the one in woodenboat. I have finished the frames and am now trying to calculate the bearding and midlines. I've never done any of this before and am getting bogged down. If you know the skills your help would be greatly appreciated.
Thanks Blue
Posted by ishmael (Member # 1866) on 05-10-2001, 02:42 PM:
Read some of the standard texts. Macintosh's book might be good place to start. Basically, they are established by measurements from a baseline, faired with a batten. Then you cut some references the width of a chisel and finish by connecting those. What materials are you working with? Don't forget to sharpen your tools.
Posted by CKG (Member # 1955) on 05-10-2001, 03:48 PM:
Make a plank fid.(a chunk of material the same thickness as your planking,if the plank is 3/4", make the fid out of 1/4" plywood - 3/4" wide - 4 or 5" long.this stick is square on it's ends.)
Go to the full size body plan you lofted.Look at the centerline -the width of the keel should be drawn and set off to either side of this line. Where the various station lines come into the sides of the keel indicates the Height of the rabbet at that point. Since Handy Billy is drawn to the outside of the planking, slide your Fid down the inside of any given station line until it's lower corner just touches the side of the keel - that point is , of course, the rabbet. The height of the middle line is the corner of the fid thats buried inside the keel- and the bearding line is where the upper edge of the fid passes out through the drawn side of the keel. With a marking staff, take these heights to the corresponding stations in the profile drawing of the keel.
Seeing as you got the rabbet, all the way up to station 1, given to you in the offsets- it,s just a matter of plotting the heights of the mid and bearding lines above that rabbet, then fairing them in. Presto!
Well, fine and good, you may say- but what about the Rabbet and friends at the forefoot and on the stem?
Two options - scale the rabbet at the stem off of the plans and transfer it to the loft-
or,-
Draw some waterlines above the chine line in the body plan.-Draw them in the forward part of the profile view - Develop them in the half-breadth plan.- where these waterlines intersect the stem siding in the half-breadth plan, take those points to the corresponding waterlines in the profile.(Do this by indexing your marking staff to a station line in the half-breadth, the W.L.-stem intersections are fore and aft locations. At the waterlines in the profile, plot those fore and aft locations.)
this will give you enough points in the profile to fair in the rabbet.You can get your mid and bearding lines using the plank fid in this operation,too. (sounds easier to just scale the darn thing off the plans.plus it only works good on the upper,more plumb part of the stem.)
For the rabbet at the fore foot and rest of stem, you need to draw a "raking station" at right angles to any given point on the curve of the stem. You basically develop these views the same way you draw and station in the body plan. You need some developed waterlines below that hard chine, though, in order to develop those raking stations.
The explaination is long and requires sketches and waving of hands in the air.
Read Greg Rossel"Building Small Boats" or Robert Stewards "Boat Building Manual" they both explain with drawings.
Posted by Blue (Member # 3292) on 05-11-2001, 11:27 AM:
CKG...Thank you a ton for the help. It sound as though you have done this a bunch before. I have been looking in a number of books. I have a good grasp on what goes on from the curve of the forfoot back along the keel, and from the chine up to the sheer. It is the area that requires the waving hands that is a tough one to grasp. I am able to develope more waterlines but creating lines perpendicular to the forfoot is where the problem lies.
Thank you for the help
Blue
quote: Originally posted by CKG:
Make a plank fid.(a chunk of material the same thickness as your planking,if the plank is 3/4", make the fid out of 1/4" plywood - 3/4" wide - 4 or 5" long.this stick is square on it's ends.)
Go to the full size body plan you lofted.Look at the centerline -the width of the keel should be drawn and set off to either side of this line. Where the various station lines come into the sides of the keel indicates the Height of the rabbet at that point. Since Handy Billy is drawn to the outside of the planking, slide your Fid down the inside of any given station line until it's lower corner just touches the side of the keel - that point is , of course, the rabbet. The height of the middle line is the corner of the fid thats buried inside the keel- and the bearding line is where the upper edge of the fid passes out through the drawn side of the keel. With a marking staff, take these heights to the corresponding stations in the profile drawing of the keel.
Seeing as you got the rabbet, all the way up to station 1, given to you in the offsets- it,s just a matter of plotting the heights of the mid and bearding lines above that rabbet, then fairing them in. Presto!
Well, fine and good, you may say- but what about the Rabbet and friends at the forefoot and on the stem?
Two options - scale the rabbet at the stem off of the plans and transfer it to the loft-
or,-
Draw some waterlines above the chine line in the body plan.-Draw them in the forward part of the profile view - Develop them in the half-breadth plan.- where these waterlines intersect the stem siding in the half-breadth plan, take those points to the corresponding waterlines in the profile.(Do this by indexing your marking staff to a station line in the half-breadth, the W.L.-stem intersections are fore and aft locations. At the waterlines in the profile, plot those fore and aft locations.)
this will give you enough points in the profile to fair in the rabbet.You can get your mid and bearding lines using the plank fid in this operation,too. (sounds easier to just scale the darn thing off the plans.plus it only works good on the upper,more plumb part of the stem.)
For the rabbet at the fore foot and rest of stem, you need to draw a "raking station" at right angles to any given point on the curve of the stem. You basically develop these views the same way you draw and station in the body plan. You need some developed waterlines below that hard chine, though, in order to develop those raking stations.
The explaination is long and requires sketches and waving of hands in the air.
Read Greg Rossel"Building Small Boats" or Robert Stewards "Boat Building Manual" they both explain with drawings.
Posted by TomRobb (Member # 1216) on 05-11-2001, 02:18 PM:
I never could make sense of it as written words. Someone showed me and I had one of those Ooooooh moments. Find someone in driving distance and beg them to show you. (I can't imagine actual begging would be needed) Once seen it turns out to be more or less simple. I don't think calculating has anything to do with it. You pick them off the lofting. I suppose it depends on whether you are verbal or visual of mental bent.
Posted by Bob Cleek (Member # 1211) on 05-11-2001, 05:12 PM:
Make yourself a model of the keel, heel and stem to 1"=1' scale (or the scale of your paper plans, if different) out of soft wood. Mark your rabet line on the model off the plans. Take a small piece of scale "planking" stock to use as a "try piece." Estimate the angle of the frames along the way with your try piece (this is a throw away model, so it doesn't have to be right... it just gives you the idea). Carve your rabet with an x-acto knife or whatever, following the instructions above. Do this a time or two, until you get the "ah-ha!" lightbulb lit above your noggin, and then tackle the full size expensive timber. Cut a bunch of little notches along the rabet line, with the try piece as your guide for deptch and angle of the back rabet and bearding line, then connect them up in a smooth arc. It's easier to do than describe, but the little short hunk of planking stock as your thickness gauge is the key to it.
Posted by TomRobb (Member # 1216) on 05-14-2001, 08:42 AM:
Yah, exactly. What Bob said http://media5.hypernet.com/~dick/ubb/biggrin.gif
Posted by Blue (Member # 3292) on 05-10-2001, 01:20 PM:
I and in the process of building the 18' Handy billy launch similar to the one in woodenboat. I have finished the frames and am now trying to calculate the bearding and midlines. I've never done any of this before and am getting bogged down. If you know the skills your help would be greatly appreciated.
Thanks Blue
Posted by ishmael (Member # 1866) on 05-10-2001, 02:42 PM:
Read some of the standard texts. Macintosh's book might be good place to start. Basically, they are established by measurements from a baseline, faired with a batten. Then you cut some references the width of a chisel and finish by connecting those. What materials are you working with? Don't forget to sharpen your tools.
Posted by CKG (Member # 1955) on 05-10-2001, 03:48 PM:
Make a plank fid.(a chunk of material the same thickness as your planking,if the plank is 3/4", make the fid out of 1/4" plywood - 3/4" wide - 4 or 5" long.this stick is square on it's ends.)
Go to the full size body plan you lofted.Look at the centerline -the width of the keel should be drawn and set off to either side of this line. Where the various station lines come into the sides of the keel indicates the Height of the rabbet at that point. Since Handy Billy is drawn to the outside of the planking, slide your Fid down the inside of any given station line until it's lower corner just touches the side of the keel - that point is , of course, the rabbet. The height of the middle line is the corner of the fid thats buried inside the keel- and the bearding line is where the upper edge of the fid passes out through the drawn side of the keel. With a marking staff, take these heights to the corresponding stations in the profile drawing of the keel.
Seeing as you got the rabbet, all the way up to station 1, given to you in the offsets- it,s just a matter of plotting the heights of the mid and bearding lines above that rabbet, then fairing them in. Presto!
Well, fine and good, you may say- but what about the Rabbet and friends at the forefoot and on the stem?
Two options - scale the rabbet at the stem off of the plans and transfer it to the loft-
or,-
Draw some waterlines above the chine line in the body plan.-Draw them in the forward part of the profile view - Develop them in the half-breadth plan.- where these waterlines intersect the stem siding in the half-breadth plan, take those points to the corresponding waterlines in the profile.(Do this by indexing your marking staff to a station line in the half-breadth, the W.L.-stem intersections are fore and aft locations. At the waterlines in the profile, plot those fore and aft locations.)
this will give you enough points in the profile to fair in the rabbet.You can get your mid and bearding lines using the plank fid in this operation,too. (sounds easier to just scale the darn thing off the plans.plus it only works good on the upper,more plumb part of the stem.)
For the rabbet at the fore foot and rest of stem, you need to draw a "raking station" at right angles to any given point on the curve of the stem. You basically develop these views the same way you draw and station in the body plan. You need some developed waterlines below that hard chine, though, in order to develop those raking stations.
The explaination is long and requires sketches and waving of hands in the air.
Read Greg Rossel"Building Small Boats" or Robert Stewards "Boat Building Manual" they both explain with drawings.
Posted by Blue (Member # 3292) on 05-11-2001, 11:27 AM:
CKG...Thank you a ton for the help. It sound as though you have done this a bunch before. I have been looking in a number of books. I have a good grasp on what goes on from the curve of the forfoot back along the keel, and from the chine up to the sheer. It is the area that requires the waving hands that is a tough one to grasp. I am able to develope more waterlines but creating lines perpendicular to the forfoot is where the problem lies.
Thank you for the help
Blue
quote: Originally posted by CKG:
Make a plank fid.(a chunk of material the same thickness as your planking,if the plank is 3/4", make the fid out of 1/4" plywood - 3/4" wide - 4 or 5" long.this stick is square on it's ends.)
Go to the full size body plan you lofted.Look at the centerline -the width of the keel should be drawn and set off to either side of this line. Where the various station lines come into the sides of the keel indicates the Height of the rabbet at that point. Since Handy Billy is drawn to the outside of the planking, slide your Fid down the inside of any given station line until it's lower corner just touches the side of the keel - that point is , of course, the rabbet. The height of the middle line is the corner of the fid thats buried inside the keel- and the bearding line is where the upper edge of the fid passes out through the drawn side of the keel. With a marking staff, take these heights to the corresponding stations in the profile drawing of the keel.
Seeing as you got the rabbet, all the way up to station 1, given to you in the offsets- it,s just a matter of plotting the heights of the mid and bearding lines above that rabbet, then fairing them in. Presto!
Well, fine and good, you may say- but what about the Rabbet and friends at the forefoot and on the stem?
Two options - scale the rabbet at the stem off of the plans and transfer it to the loft-
or,-
Draw some waterlines above the chine line in the body plan.-Draw them in the forward part of the profile view - Develop them in the half-breadth plan.- where these waterlines intersect the stem siding in the half-breadth plan, take those points to the corresponding waterlines in the profile.(Do this by indexing your marking staff to a station line in the half-breadth, the W.L.-stem intersections are fore and aft locations. At the waterlines in the profile, plot those fore and aft locations.)
this will give you enough points in the profile to fair in the rabbet.You can get your mid and bearding lines using the plank fid in this operation,too. (sounds easier to just scale the darn thing off the plans.plus it only works good on the upper,more plumb part of the stem.)
For the rabbet at the fore foot and rest of stem, you need to draw a "raking station" at right angles to any given point on the curve of the stem. You basically develop these views the same way you draw and station in the body plan. You need some developed waterlines below that hard chine, though, in order to develop those raking stations.
The explaination is long and requires sketches and waving of hands in the air.
Read Greg Rossel"Building Small Boats" or Robert Stewards "Boat Building Manual" they both explain with drawings.
Posted by TomRobb (Member # 1216) on 05-11-2001, 02:18 PM:
I never could make sense of it as written words. Someone showed me and I had one of those Ooooooh moments. Find someone in driving distance and beg them to show you. (I can't imagine actual begging would be needed) Once seen it turns out to be more or less simple. I don't think calculating has anything to do with it. You pick them off the lofting. I suppose it depends on whether you are verbal or visual of mental bent.
Posted by Bob Cleek (Member # 1211) on 05-11-2001, 05:12 PM:
Make yourself a model of the keel, heel and stem to 1"=1' scale (or the scale of your paper plans, if different) out of soft wood. Mark your rabet line on the model off the plans. Take a small piece of scale "planking" stock to use as a "try piece." Estimate the angle of the frames along the way with your try piece (this is a throw away model, so it doesn't have to be right... it just gives you the idea). Carve your rabet with an x-acto knife or whatever, following the instructions above. Do this a time or two, until you get the "ah-ha!" lightbulb lit above your noggin, and then tackle the full size expensive timber. Cut a bunch of little notches along the rabet line, with the try piece as your guide for deptch and angle of the back rabet and bearding line, then connect them up in a smooth arc. It's easier to do than describe, but the little short hunk of planking stock as your thickness gauge is the key to it.
Posted by TomRobb (Member # 1216) on 05-14-2001, 08:42 AM:
Yah, exactly. What Bob said http://media5.hypernet.com/~dick/ubb/biggrin.gif