Thanks! Yes it seems everyone hates my music selection, especially for this vid. Noticed you just became a patron! It is extremely appreciated! I’m considering making music-free versions of the vids accessible to patrons. I do think you’ll find that with the later vids I get better at editing and that the music selection and usage improves. Editing video and audio has a steep learning curve and I’m self taught.
I know I am a little late to this game but better late then never.. I am a retired aircraft lofter and started this Busness in the early 80's with ink on mylar. Our tolerances were pretty tight especially on airfoil shapes; half a 00 ink line or +/- .005". I was looking fwd to the Loft Corrections at 20:51. But I felt you really glossed over that subject. I know that changing a station line (wing station in my case) can impact neighboring stations in front and behind the station you are working. So the impact can be far reaching. I have found myself chasing my tail many times trying to fair all the station, waterlines and butt lines. This is mostly due to the fact that any change to a wing can have big impacts on aero performance. As time moved fwd and we started doing this work on the computer, I found that looking at the second derivative (curvature) was most helpful. If the curvature was spiking, you were working with the wrong set of curves. These issues got even easier (that is relatively easier) when we started to loft in 3D with surfaces. It was still hard and took skill, but the time and iterations decreased a bunch. I started with stacked sets of lines on mylar with the Tomahawk Cruise Missile's wing and inlet and ended with the Learjet Model 45 using CATIA with surfaces; a multi million dollar CAD/CAM system on mainframes and mini computers. Now I have Fusion 360 for next to nothing and can do the same work on my home computer. We've come a long way.
yeah lofting corrections are a serious subject worthy of a video unto themself! I was worried that I had already overloaded the video with details and at may at one point return to the subject of corrections in a future neophyte byte. the hardest thing to assess in my experience is which corrections are worth pursuing vs which are negligible. I suspect tolerances are far tighter for airplane lofting than small boat lofting. but nevertheless, I think. I still said more about correction than most other content on lofting. and the animation at least gives a sense of the interconnectedness of buttock, water, and station lines. nevertheless, I really appreciate the feedback!
Absolutely fantastic series guys. I learnt a lot and the production quality was very impressive. I'm actually looking forward to lofting my boat now! (even though it looks very daunting!)
Very interesting! I work in aircraft and the ship drawings are the same or from the same methodology as ship design lofting. This helps me understand how this correlates. Thank you for sharing
Actually guys, you did't make a mistake by lofting the Waterlines first. They are the easiest to fair and therefor will often do the best job of making sure everything fairs together. That said, I was taught to kind of leap frog between the views, which has the effect of pulling fairness in from all of the views. That is a simplistic explanation as the process has a little more order to it but that is the basic idea. That said, there are many ways to approach the process and non are wrong but some have advantages over others. It is the process of correcting possible errors existing in any sets of lines that make one method preferred over another.
So the idea that we made a mistake came from conversations with Walter J Simmons. He argued that starting with the station lines was advisable for a number of reasons. His perspective was opposite to yours. The station lines are the "hardest" to fair bc the lines have more constraints (halfbreadths + heights above base) and tend to tighter more shapely curves. So station lines more readily reveal incompatibilities between waterline and buttock line offsets. Starting with waterlines was problematic precisely bc they are easier to fair. Waterlines are less sensitive (in terms of fairness) to changes and corrections. So you loft all the waterlines, ending up with perfectly fair lines, that alas wont agree well with buttock lines bc the fairing of them doesnt depend at all on heights above base. Best i can tell from my limited knowledge and experience is that really doesnt matter where you start. The corrections process will adjust for inconsistencies, but depending on where you start the corrections may be more or less extensive.
@@neophyteboatwrights Walter is quite correct but what I was trying to convey was not to lay down all the lines in on particular view at once but to use each view to its best advantage. The waterlines fair out the sheer area and below to the load waterline while the buttocks deal with the counter and aft portions below the waterline. Fair stations are of course the primary goal but these are the hardest to fair in at a small scale which is why we go through the full size lofting process rather than just copy the station shapes assuming they are flawless. I will have to do a video on my approach one of these days but as I am sure you guys have discovered, filming lofting is extremely challenging unless you are doing just for the camera.
@@Nomadboatbuilding wow ive never thought of the lines in those terms - waterlines for above lwl and buttocks below. I think there remains something to be said about the strategy behind corrections which i imagine the above idea (that i'll call the Reuten principle) is applicable. Madison and I definitely observed that there were corrections that mattered more than others. Some errors, even when ironed out, didnt precipitate any refinement to the station lines, while others did. Best I can tell this depended on the proximity of a given waterline-buttockline intersection to the station line. Those intersections floating out in the space between stationlines were less important than those that occurred closer to a given stationline.
@@neophyteboatwrights wild anomalies are not uncommon and are probably just a mis-measurement at the small scale. The importance of the various lines is well addressed in Chapelle’s Yacht Designing and Planning. In some cases you can not bother drawing in portions of lines that are likely to be inaccurate because of their relativity to the body lines. Waterlines in a shallow counter for instance or buttock lines at the bow. Perhaps a better way to think of this is that these lines are so sensitive to change due to these relationships that they may mislead you to make adjustments beyond the level of accuracy that we require. Ultimately in the case of lapstrake construction, the process is self fairing and you need to be sensitive to that during the planking process.
In our case, the plans provided inboard and outboard offsets for the keel along with the thickness of the bevel and shoulder. So each crosssection was drawn according to those offsets.
@@neophyteboatwrightsI had the same question. So, how would you figure it out without the dimensions given for the keel cross section? I take it that you would derive the breadth of the bottom of the keel, and bevel angle for the rabbet from the station lines, where they meet the rabbet line on the lofting board? In the video you were trying to fair the station line with the bevel angle on your cross section, that is taken to be correct? However, how would the designer derive the cross section if not from lofted lines themselves (before the age of CAD!)?
@@richardparsons7012 that’s more or less it. Although you wouldn’t have to determine it at full scale. Designers work in a smaller scale first. So you’d have to determine the profile of the keel first. Is it flat? Rockered? Determine the thickness of the material, whether the keel will be rabbeted or beveled, etc. transfer the relevant info to the body plan, which would basically prescribe at what height each station line should terminate. Then lift the appropriate bevels from the lofted station lines
@@neophyteboatwrights It is fascinating to guess at where the balance of experience lies with a designer. You must have a close idea of the bevels as you run along the keel rabbet, as you design, from experience. But, I can't see how a final cross section plot would be made without the full scale lofting? So, when you loft from a table of offsets, are you not likely following a table derived from the designer's own lofting? Therefore only starting off with a design that is as fair as the designer's own working? Ah well, thanks again. Hope you manage to get some more content onto the channel. But then again, hopefully you are also busy in the workshop too!
Well, if the designer never lofts at full scale, then there is more scope for errors the the offset table. Scaling up from from a rule, or however it's done, by hand is notorious for introducing estimation into drawings. Building wise, nobody lets out scale plans without a clause stating 'do not scale', so you have to work from stated dimensions.
If you have a table of off sets to layout your stations that's all you have to do to begin build. the rest of the lines well is ......how to get a table of offsets. Just trust them and make adjustments
While I think there are some simpler hull designs for which this may be true, in general this is not correct. Buttock and waterlines do not generate offsets. The table of offsets are coordinates not only for the station lines but also for the waterlines and buttock lines. If they were unnecessary then designers wouldn’t include them in the table. The buttock lines and waterlines help to refine the station lines, they help to ensure consistency and fairness in the hull shape, they are essential for determining bevels at the stem and transom, essential for developing the transom expansion. Heck some hulls require diagonals to be lofted in addition to the standard lines in order to ensure consistency and fairness. The point of a lofting is to develop a full scale drafting of the hull that is completely self-consistent from all three elevations. By only lofting the station lines you are taking a gamble with time and resources. The good news is some boat designers offer templates for all the components and stations. So no need to loft if you don’t want to go to the trouble!
I am not actually using any software to perform the lofting. All of the lofting was done by hand on the lofting board. The animations in the episode were done with adobe illustrator and after effects
If by “las cuadernas” I understand you to mean the ribs or frames, then for our build these will be steam bent into the hull after planking. They are not lofted. If instead of you mean “molds” then check out ep 10. We go over the whole process of how to make the molds
Stem halfsiding should begin where the keel ends and end at the forward perpendicular. It depends on the designers specifications ultimately, so be careful there.
@@neophyteboatwrights And, it is then parallel with the bottom of the keel--assuming a flat/straight keel? I should mention I am working with a boat that is sort of half way between a canoe and a rowboat, and that I have very small lines drawings in an article figure but not proper plans with a table of offsets--so I am fishing for reference points in a couple of places.
@@adambrown30 Assuming the stem is not diminishing or increasing in thickness between the base and the head of the stem, then it should run parallel with the keel. Are there any construction details included in the lines drawing?
@@neophyteboatwrights Sadly, none. They are more about describing a boat type than how to build it--so I am reverse engineering more than following plans. I do have other reference material on strip-and-canvas canoe building, which should work well since the boat type is basically half way between a canoe and a rowboat (it is called a finger lakes trout boat).
For those of us with ADHD the background music is hella distracting. This is really about boatbuilding, right? It doesn't serve to clarify your teaching of an already complex subject; it only obscures your efforts to communicate.
Hey Sean, point taken. I appreciate the feedback. It certainly doesn't make much sense for me to alter the vid audio and re-post it, but I'd be willing to make music-free versions of my videos for access through patreon.
I kind of liked the music. Everyone is different I guess. Thanks for sharing. I’ve been trying to work lofting out on my own for awhile. This is helpful.
Hey Mike, have you checked out ep 2, 4, and 5? All were devoted to lofting and go over many of the basics. That being said, lofting is a discipline unto itself. Lengthy books have been written about the subject. However, I think you will find when compared to other video content out there that our episodes include lots of details that are otherwise glossed over.
This video is the 2nd part in a two part series. ua-cam.com/video/RyGDZhp5vNg/v-deo.html Shows the beginning quite clearly. We also have two other introductory episodes on lofting. Ep 2 gives a general introduction and Ep 4 explains the origination of the lines drawing.
Your multicolor & isolated lines video graphics were exceptional,
Wonderful series. So great to have the mysteries of lofting made so clear and great filmmaking. Thanks.
The animations are brilliant.
Thank you!
The videos are absolutely great. I wish I could say that same of your background music, it is painful. Lol
Thanks!
Yes it seems everyone hates my music selection, especially for this vid. Noticed you just became a patron! It is extremely appreciated! I’m considering making music-free versions of the vids accessible to patrons. I do think you’ll find that with the later vids I get better at editing and that the music selection and usage improves. Editing video and audio has a steep learning curve and I’m self taught.
I know I am a little late to this game but better late then never.. I am a retired aircraft lofter and started this Busness in the early 80's with ink on mylar. Our tolerances were pretty tight especially on airfoil shapes; half a 00 ink line or +/- .005". I was looking fwd to the Loft Corrections at 20:51. But I felt you really glossed over that subject. I know that changing a station line (wing station in my case) can impact neighboring stations in front and behind the station you are working. So the impact can be far reaching. I have found myself chasing my tail many times trying to fair all the station, waterlines and butt lines. This is mostly due to the fact that any change to a wing can have big impacts on aero performance.
As time moved fwd and we started doing this work on the computer, I found that looking at the second derivative (curvature) was most helpful. If the curvature was spiking, you were working with the wrong set of curves. These issues got even easier (that is relatively easier) when we started to loft in 3D with surfaces. It was still hard and took skill, but the time and iterations decreased a bunch.
I started with stacked sets of lines on mylar with the Tomahawk Cruise Missile's wing and inlet and ended with the Learjet Model 45 using CATIA with surfaces; a multi million dollar CAD/CAM system on mainframes and mini computers. Now I have Fusion 360 for next to nothing and can do the same work on my home computer. We've come a long way.
yeah lofting corrections are a serious subject worthy of a video unto themself! I was worried that I had already overloaded the video with details and at may at one point return to the subject of corrections in a future neophyte byte. the hardest thing to assess in my experience is which corrections are worth pursuing vs which are negligible. I suspect tolerances are far tighter for airplane lofting than small boat lofting. but nevertheless, I think. I still said more about correction than most other content on lofting. and the animation at least gives a sense of the interconnectedness of buttock, water, and station lines. nevertheless, I really appreciate the feedback!
Absolutely fantastic series guys. I learnt a lot and the production quality was very impressive. I'm actually looking forward to lofting my boat now! (even though it looks very daunting!)
Thank you!
Very interesting!
I work in aircraft and the ship drawings are the same or from the same methodology as ship design lofting. This helps me understand how this correlates.
Thank you for sharing
Actually guys, you did't make a mistake by lofting the Waterlines first. They are the easiest to fair and therefor will often do the best job of making sure everything fairs together. That said, I was taught to kind of leap frog between the views, which has the effect of pulling fairness in from all of the views. That is a simplistic explanation as the process has a little more order to it but that is the basic idea. That said, there are many ways to approach the process and non are wrong but some have advantages over others. It is the process of correcting possible errors existing in any sets of lines that make one method preferred over another.
So the idea that we made a mistake came from conversations with Walter J Simmons. He argued that starting with the station lines was advisable for a number of reasons. His perspective was opposite to yours. The station lines are the "hardest" to fair bc the lines have more constraints (halfbreadths + heights above base) and tend to tighter more shapely curves. So station lines more readily reveal incompatibilities between waterline and buttock line offsets. Starting with waterlines was problematic precisely bc they are easier to fair. Waterlines are less sensitive (in terms of fairness) to changes and corrections. So you loft all the waterlines, ending up with perfectly fair lines, that alas wont agree well with buttock lines bc the fairing of them doesnt depend at all on heights above base. Best i can tell from my limited knowledge and experience is that really doesnt matter where you start. The corrections process will adjust for inconsistencies, but depending on where you start the corrections may be more or less extensive.
@@neophyteboatwrights Walter is quite correct but what I was trying to convey was not to lay down all the lines in on particular view at once but to use each view to its best advantage. The waterlines fair out the sheer area and below to the load waterline while the buttocks deal with the counter and aft portions below the waterline. Fair stations are of course the primary goal but these are the hardest to fair in at a small scale which is why we go through the full size lofting process rather than just copy the station shapes assuming they are flawless. I will have to do a video on my approach one of these days but as I am sure you guys have discovered, filming lofting is extremely challenging unless you are doing just for the camera.
@@Nomadboatbuilding wow ive never thought of the lines in those terms - waterlines for above lwl and buttocks below. I think there remains something to be said about the strategy behind corrections which i imagine the above idea (that i'll call the Reuten principle) is applicable. Madison and I definitely observed that there were corrections that mattered more than others. Some errors, even when ironed out, didnt precipitate any refinement to the station lines, while others did. Best I can tell this depended on the proximity of a given waterline-buttockline intersection to the station line. Those intersections floating out in the space between stationlines were less important than those that occurred closer to a given stationline.
@@Nomadboatbuilding also yes filming and discussing lofting in vids is very challenging, but you should make the vid anyways!
@@neophyteboatwrights wild anomalies are not uncommon and are probably just a mis-measurement at the small scale. The importance of the various lines is well addressed in Chapelle’s Yacht Designing and Planning. In some cases you can not bother drawing in portions of lines that are likely to be inaccurate because of their relativity to the body lines. Waterlines in a shallow counter for instance or buttock lines at the bow. Perhaps a better way to think of this is that these lines are so sensitive to change due to these relationships that they may mislead you to make adjustments beyond the level of accuracy that we require. Ultimately in the case of lapstrake construction, the process is self fairing and you need to be sensitive to that during the planking process.
Somehow I missed how you got the cross sections for the keel at each station that you then used to establish your termination point. Help?
In our case, the plans provided inboard and outboard offsets for the keel along with the thickness of the bevel and shoulder. So each crosssection was drawn according to those offsets.
@@neophyteboatwrightsI had the same question. So, how would you figure it out without the dimensions given for the keel cross section? I take it that you would derive the breadth of the bottom of the keel, and bevel angle for the rabbet from the station lines, where they meet the rabbet line on the lofting board? In the video you were trying to fair the station line with the bevel angle on your cross section, that is taken to be correct? However, how would the designer derive the cross section if not from lofted lines themselves (before the age of CAD!)?
@@richardparsons7012 that’s more or less it. Although you wouldn’t have to determine it at full scale. Designers work in a smaller scale first. So you’d have to determine the profile of the keel first. Is it flat? Rockered? Determine the thickness of the material, whether the keel will be rabbeted or beveled, etc. transfer the relevant info to the body plan, which would basically prescribe at what height each station line should terminate. Then lift the appropriate bevels from the lofted station lines
@@neophyteboatwrights It is fascinating to guess at where the balance of experience lies with a designer. You must have a close idea of the bevels as you run along the keel rabbet, as you design, from experience. But, I can't see how a final cross section plot would be made without the full scale lofting? So, when you loft from a table of offsets, are you not likely following a table derived from the designer's own lofting? Therefore only starting off with a design that is as fair as the designer's own working? Ah well, thanks again. Hope you manage to get some more content onto the channel. But then again, hopefully you are also busy in the workshop too!
Well, if the designer never lofts at full scale, then there is more scope for errors the the offset table. Scaling up from from a rule, or however it's done, by hand is notorious for introducing estimation into drawings. Building wise, nobody lets out scale plans without a clause stating 'do not scale', so you have to work from stated dimensions.
If you have a table of off sets to layout your stations that's all you have to do to begin build. the rest of the lines well is ......how to get a table of offsets. Just trust them and make adjustments
While I think there are some simpler hull designs for which this may be true, in general this is not correct. Buttock and waterlines do not generate offsets.
The table of offsets are coordinates not only for the station lines but also for the waterlines and buttock lines. If they were unnecessary then designers wouldn’t include them in the table. The buttock lines and waterlines help to refine the station lines, they help to ensure consistency and fairness in the hull shape, they are essential for determining bevels at the stem and transom, essential for developing the transom expansion. Heck some hulls require diagonals to be lofted in addition to the standard lines in order to ensure consistency and fairness.
The point of a lofting is to develop a full scale drafting of the hull that is completely self-consistent from all three elevations. By only lofting the station lines you are taking a gamble with time and resources. The good news is some boat designers offer templates for all the components and stations. So no need to loft if you don’t want to go to the trouble!
Great series so far, lots of detail!
Shout out to the music selection, too - been an MMW fan forever!
Much appreciated!
What program are you using for lofting?
I am not actually using any software to perform the lofting. All of the lofting was done by hand on the lofting board. The animations in the episode were done with adobe illustrator and after effects
Hola me gusta su trabajo pero deberias explicar bien como crear las cuadernas bien gracias
If by “las cuadernas” I understand you to mean the ribs or frames, then for our build these will be steam bent into the hull after planking. They are not lofted. If instead of you mean “molds” then check out ep 10. We go over the whole process of how to make the molds
Why u dont use cad?
No need
How do you establish the location and length of the stem halfsiding line?
Stem halfsiding should begin where the keel ends and end at the forward perpendicular. It depends on the designers specifications ultimately, so be careful there.
@@neophyteboatwrights And, it is then parallel with the bottom of the keel--assuming a flat/straight keel? I should mention I am working with a boat that is sort of half way between a canoe and a rowboat, and that I have very small lines drawings in an article figure but not proper plans with a table of offsets--so I am fishing for reference points in a couple of places.
@@adambrown30 Assuming the stem is not diminishing or increasing in thickness between the base and the head of the stem, then it should run parallel with the keel. Are there any construction details included in the lines drawing?
@@neophyteboatwrights Sadly, none. They are more about describing a boat type than how to build it--so I am reverse engineering more than following plans. I do have other reference material on strip-and-canvas canoe building, which should work well since the boat type is basically half way between a canoe and a rowboat (it is called a finger lakes trout boat).
For those of us with ADHD the background music is hella distracting. This is really about boatbuilding, right? It doesn't serve to clarify your teaching of an already complex subject; it only obscures your efforts to communicate.
Hey Sean,
point taken. I appreciate the feedback. It certainly doesn't make much sense for me to alter the vid audio and re-post it, but I'd be willing to make music-free versions of my videos for access through patreon.
@@neophyteboatwrights Thanks! That makes perfect sense and sounds great.
I kind of liked the music. Everyone is different I guess. Thanks for sharing. I’ve been trying to work lofting out on my own for awhile. This is helpful.
To bad all these series are not for beginners.
So much material left out in the instructions.
Hey Mike, have you checked out ep 2, 4, and 5? All were devoted to lofting and go over many of the basics. That being said, lofting is a discipline unto itself. Lengthy books have been written about the subject. However, I think you will find when compared to other video content out there that our episodes include lots of details that are otherwise glossed over.
Heres a like to ep 2 where we start with a much gentler conceptual intro to lofting: ua-cam.com/video/aQXeYDF2M8Y/v-deo.html
You started out without showing the start, and got worse. Not even worth a thumbs down
This video is the 2nd part in a two part series. ua-cam.com/video/RyGDZhp5vNg/v-deo.html Shows the beginning quite clearly. We also have two other introductory episodes on lofting. Ep 2 gives a general introduction and Ep 4 explains the origination of the lines drawing.