gonzo
09-08-2003, 11:10 AM
I couldn't find if there was anyone supposed to draw a final blueprint. Will there be a complete set of lines and specifications?
View Full Version : Final blueprints
Willallison
10-23-2003, 06:16 PM
Gonzo, I'd be happy to the drawing. Once I'm up to speed on me CAD work, I'll almost certainly give it a shot - you can all sharpen your bricks and get ready for the hurling.... The lack of interest shown (until now;) ) has just slowed it all up....
Willallison
10-23-2003, 07:08 PM
These are the lines posted so far. There's still a great deal of refining to do, but it's a start....
gonzo
10-24-2003, 11:59 AM
Could we get more flare forward?
Willallison
10-26-2003, 06:46 PM
We can get whatever you want:D
This more to your liking? (Original lines are on the right)
This more to your liking? (Original lines are on the right)
8knots
10-27-2003, 08:13 PM
I HAVE NOT PARTICIPATED IN SO LONG I REALLY HAVE NO GROUNDS TO SPEAK ON THIS BUT HERE IS MY UN-EDUCATED OBSERVATION. i THINK i WOULD LOWER THE CHINE FLAT DOWN A LITTLE CLOSER TO THE WATERLINE IN THE FORWARD SECTION THIS WILL ADD A LITTLE MORE LIFT SOONER BUT STILL ACT AS A SPRAY RAIL. THIS WILL COMPROMISE THE FINE ENTRY BUT THE EXTRA BOYANCY AND ROOM FORWARD WOULD HELP TOO!.
WILL: YOU CAN TELL ME TO STUFF IT! I WON;T BE HURT!!;)
YOU DO GREAT WORK, JUST MY OPINION.
8KNOTS
WILL: YOU CAN TELL ME TO STUFF IT! I WON;T BE HURT!!;)
YOU DO GREAT WORK, JUST MY OPINION.
8KNOTS
Willallison
10-28-2003, 05:29 PM
8 - nobody's participated in the thread for ages (me included) so you have as much right as anybody else to contribute. Besides - it's not a job here - we should be free to come and go as we please...:D
Now as to your suggestion - it's really up to the group, but for my 3 cents (the Aussie $ isn't as strong as the greenback:D ) I think that even though the finer entry will reduce the space available for accomodation, there is only likely to be a v-berth up here, so for a smoother ride it is an acceptable trade-off....
Thoughts?
Now as to your suggestion - it's really up to the group, but for my 3 cents (the Aussie $ isn't as strong as the greenback:D ) I think that even though the finer entry will reduce the space available for accomodation, there is only likely to be a v-berth up here, so for a smoother ride it is an acceptable trade-off....
Thoughts?
gonzo
10-28-2003, 06:26 PM
I meant flare on the sides. Concave sectiond forward direct the spray away. Sometimes though, it seems to make the spray go up and then down with force into the back of your neck. I think the chine you drew will throw spray down too. It has a nice sweep.
Willallison
10-28-2003, 06:48 PM
The hull sides in my model - & lets remember its only my suggestion, it's for the group to decide how everything should be done - anyway, I made the model so that the hull sides are made from two panels (upper and lower) to keep construction more simple (all of the boat is developable). As you suggested, I tried to align them so that the sides were convex (flared) but wound up with a very peculiar looking boat (I think as a result of the way I modelled it). Then I tried the convex shape - it will increase interior space and hopefully should be reasonably dry too. It give a bit more shape than a single panel would, but is much easier to produce than strip planking would be....I think....
Do you like the 'new' shape better? (sections on the left) - and what about 8's suggestion about dropping the chine a bit...?
Do you like the 'new' shape better? (sections on the left) - and what about 8's suggestion about dropping the chine a bit...?
gonzo
10-29-2003, 09:49 AM
I think a lower chine would help at lower speeds. What was the target speed? Flat panels limit the choice of shapes. It looks pretty good though. Lines make the discussion easier.
8knots
10-29-2003, 11:24 AM
Will:
What software are you running? I like the looks of it. You are in module 3 of westlawn aren't you now. Just wondering if you are learning the software for your own fun or if you need it for your studys at W.
8Knots
What software are you running? I like the looks of it. You are in module 3 of westlawn aren't you now. Just wondering if you are learning the software for your own fun or if you need it for your studys at W.
8Knots
Guest
10-29-2003, 03:12 PM
Will,
Been a while since we played with this. I will hazard a comment on the drawing. The sections show an increasing waterline beam all the way to the transom. That and the sharp entry will guarantee some exciting runs downwind in waves.
The chine angle of attack in the aft sections is interesting since I have been using a similar design for some time and it works well at inducing early planing and preventing squating of the stern. However, this will also make the situation mentioned above worse, especially if you still plan on running fast where the chine will act like a fixed tab and drive the bow down.
Gotta see if I can get myself unguested on the forum.
Tom Lathrop
Been a while since we played with this. I will hazard a comment on the drawing. The sections show an increasing waterline beam all the way to the transom. That and the sharp entry will guarantee some exciting runs downwind in waves.
The chine angle of attack in the aft sections is interesting since I have been using a similar design for some time and it works well at inducing early planing and preventing squating of the stern. However, this will also make the situation mentioned above worse, especially if you still plan on running fast where the chine will act like a fixed tab and drive the bow down.
Gotta see if I can get myself unguested on the forum.
Tom Lathrop
Willallison
10-29-2003, 05:24 PM
8 - the software is a very old version of Multisurf LT (the 'light' version). I was lucky enough to be able to borrow an (equally old) laptop with the program installed. I like the way the program operates - unfortunatley I could never afford to update to the current, full blown version.
As far as it relates to Westlawn (I'm posting off the final lesson in module 2 today) there's no doubt that you can complete the entire course using manual drafting. Many of the calculations and design alterations will take longer, and if you're planning in going into the design industry, then getting into CAD at an early stage in the course would be to your advantage. However, if all you ever want is to be able to complete that (rather lovely) LRC of yours, then I can't see why you'd need CAD at all.
Tom - I too hope you can get "un-guested" as I always look for your posts....
I think it's probably a function of the image size that makes the beam appear to increase all the way aft. In fact it remains constant for about the aft 1/3. I did it that way only to maximise the volume available for accomodation - but you are quite correct in suggesting that it might be better if it was slightly narrower at the transom - I'll add it to the list of fixes. I'll drop the chine a little too, post the updated images and see what you all think....
As far as it relates to Westlawn (I'm posting off the final lesson in module 2 today) there's no doubt that you can complete the entire course using manual drafting. Many of the calculations and design alterations will take longer, and if you're planning in going into the design industry, then getting into CAD at an early stage in the course would be to your advantage. However, if all you ever want is to be able to complete that (rather lovely) LRC of yours, then I can't see why you'd need CAD at all.
Tom - I too hope you can get "un-guested" as I always look for your posts....
I think it's probably a function of the image size that makes the beam appear to increase all the way aft. In fact it remains constant for about the aft 1/3. I did it that way only to maximise the volume available for accomodation - but you are quite correct in suggesting that it might be better if it was slightly narrower at the transom - I'll add it to the list of fixes. I'll drop the chine a little too, post the updated images and see what you all think....
Willallison
10-29-2003, 07:22 PM
Ok, slightly lowered chine up fwd, narrower towards transom (also sheer narrowed a little towards trnsm).....
Willallison
10-29-2003, 07:25 PM
also an enlarged view of the stations.
One concern I do have is that the at-rest waterline (in cyan above) is very narrow fwd. I reckon it'd be a bit tippy at rest...?
One concern I do have is that the at-rest waterline (in cyan above) is very narrow fwd. I reckon it'd be a bit tippy at rest...?
gonzo
10-30-2003, 04:11 PM
The aft sections can provide sufficient initial stability.
BrettM
10-31-2003, 05:08 PM
Will,
Have you done any detailed weight estimate ie Weight & LCG ?(VCG not so important)
I suspect your wl may be in the wrong place. Doesn't appear to be much boat in the water?
Have you done any detailed weight estimate ie Weight & LCG ?(VCG not so important)
I suspect your wl may be in the wrong place. Doesn't appear to be much boat in the water?
Willallison
11-02-2003, 05:22 PM
Brett,
The displacement as shown is 1450kg (our target for O-1 was around 1500)
LCB (and hence LCG if boat is to float 'level') is 63.4% of LWL.
No detailed weight estimates have been done as yet as we are still to make final decisions about build materials. As I have almost no experience in designing appropriate cinstruction details, I was rather hoping someone might chip in with some suggestions....
The displacement as shown is 1450kg (our target for O-1 was around 1500)
LCB (and hence LCG if boat is to float 'level') is 63.4% of LWL.
No detailed weight estimates have been done as yet as we are still to make final decisions about build materials. As I have almost no experience in designing appropriate cinstruction details, I was rather hoping someone might chip in with some suggestions....
BrettM
11-02-2003, 09:14 PM
Will,
Take a stab at it anyway. You will probably need to take a lot of guesses but you you can update it anyway on a spreadsheet. Construction wise - Take your best guess at the shell material apply it to all your surface areas and add at least 50% for stiffening etc.
Add 10% to everything at the end as these things always get heavier. Don't really know how this happens it just does...
Best to know earlier than later.
Take a stab at it anyway. You will probably need to take a lot of guesses but you you can update it anyway on a spreadsheet. Construction wise - Take your best guess at the shell material apply it to all your surface areas and add at least 50% for stiffening etc.
Add 10% to everything at the end as these things always get heavier. Don't really know how this happens it just does...
Best to know earlier than later.
DTVM
11-05-2003, 11:29 AM
What size wake will this hull design produce?
gonzo
11-05-2003, 05:21 PM
What is the length of the boat. An 8 cylinder gas engine with drive is about 550 kg. It doesn't leave much for the rest of the boat.
Willallison
11-05-2003, 06:04 PM
DTMV - I don't know any way other than using past experioence with vessels of similar form, or tank testing to estimate wake height. Someone else may have access to the very complex computer programmes that predict these things - but not me!
Gonzo - LOA is (currently) a shade under 30ft. Power is to be o/b - approx 100hp will give max speed of about 25knots - so figure weight <200 kg
Gonzo - LOA is (currently) a shade under 30ft. Power is to be o/b - approx 100hp will give max speed of about 25knots - so figure weight <200 kg
Dutch Rub
11-14-2003, 01:26 AM
......Im still lookin for this thing to be at least 50 foot long......... if I had a semi with a 671 in er, I know I could tow it down to the river..........
gonzo
11-14-2003, 10:32 AM
It is possible to keep the weight of the boat to 1450 with durakore and lightweight plywood. The interior needs to be very basic too. Maybe nidacore or other honeycomb core for all the bulkhead and interior construction. If the boat floats so high, the beam is too wide for the displacement. Either flatten the bottom section or narrow the beam. Also, the max beam may have to be a bit further aft if we put an outboard.
Willallison
11-18-2003, 07:32 PM
I ran a weight schedule on a model I did for O1 early in the piece (an open 'express' style with the head located down with the berths). Based on using corecell or similar for all the construction, weight for the basic structure (excluding furniture) came in a just over 1000kg. Add an engine, tanks and a few other bits and 1500 will soon come and go - but with a little careful thought, we might just keep the (dry) weight to the target 1500kg.
Waterline beam is only 2.02m (6' 7 1/2 ") and transom deadrise is 12 degrees. Other than it might be rather tender at rest, why do you see the boat floating so high as a problem?
To make things a little clearer, this is a lift of the waterlines (DWL in blue) - do you still think we should move max BWL further aft?
Waterline beam is only 2.02m (6' 7 1/2 ") and transom deadrise is 12 degrees. Other than it might be rather tender at rest, why do you see the boat floating so high as a problem?
To make things a little clearer, this is a lift of the waterlines (DWL in blue) - do you still think we should move max BWL further aft?
gonzo
12-16-2003, 02:06 PM
I think with and I/O it would be more stable because the engine is low in the bilge. An outboard is top heavy and will raise the CG. The beam is narrow by modern floating box standards but will give a nice ride. I think it looks fine.
rlewis
10-04-2004, 03:26 PM
Hmm, it has been a while since anyone showed interest in this. HAs anyone tried working in GRP? I am inclined to try to build this thing using C-Flex, I'm not sure why foam core is better, it seems to me lkike C-flex would be sitffer, stronger, and lighter.
Anyway, I'm assuiming GRP would need a plywould frame with ribs and/or bulkheads. Did anyone work this out? What about the transom?
Actually, if anyone knows of free plans somewhere for a planing hull in GRP at abouut 30' in length that is really what I am looking for. I know there are lots of resources, I just can't find plans for a GRP planing hull of that size. The hull and the transom are the critical parts I think, the transom needs to be engineered for an outboard of about 100 hp.
Thanks in advance.
Anyway, I'm assuiming GRP would need a plywould frame with ribs and/or bulkheads. Did anyone work this out? What about the transom?
Actually, if anyone knows of free plans somewhere for a planing hull in GRP at abouut 30' in length that is really what I am looking for. I know there are lots of resources, I just can't find plans for a GRP planing hull of that size. The hull and the transom are the critical parts I think, the transom needs to be engineered for an outboard of about 100 hp.
Thanks in advance.
rlewis
10-04-2004, 03:28 PM
Thinkgs I really nead are, if I use C-flex, how many layers do I need on the inside and outside of the hull? How may bulkheads, and what thickness? Are we talking about 1" marine plywood for the bulkeads? I could go nots and put in lots of ribs but that would probably drive the weight too high. I need enough strength and stiffness so it doesn't pull apart in the water, but need to make it light enough so that it will plane.
Willallison
10-04-2004, 06:15 PM
Free boat plans are very few and far between - quite apart from the fact that that's how designers earn their living, I would think that possible liability issues would make many nervous about supplying plans with no control over them.
Having said that, I sincerely hope that over time O-1 can be brought to completion. The concept allows for construction using a variety of sheet materials - whether ply, cored FRP, or even aluminium - some of the construction details will need to be altered, but otherwise it's simply a matter of doing the scantling calcs.
As far as your question regarding scantlings, get a copy of Elements of Boat Strength by Dave Gerr - you can work them all out yourself and gain a better understanding of how things should be done in the process
Having said that, I sincerely hope that over time O-1 can be brought to completion. The concept allows for construction using a variety of sheet materials - whether ply, cored FRP, or even aluminium - some of the construction details will need to be altered, but otherwise it's simply a matter of doing the scantling calcs.
As far as your question regarding scantlings, get a copy of Elements of Boat Strength by Dave Gerr - you can work them all out yourself and gain a better understanding of how things should be done in the process
rlewis
10-05-2004, 01:36 PM
Hmm, thanks. I just saw that book. I think that is what I need.
However, the basic elements should be a standard, like how much glass to use and how many bulkheads. If someone worked this problem out fo O-1 it would be a great place to start. And, since the idea is to produce the plans for O-1, it would be a great resource for everyone.
Maybe if I get the book I can work it out. If I do I'll post the plans here.
However, the basic elements should be a standard, like how much glass to use and how many bulkheads. If someone worked this problem out fo O-1 it would be a great place to start. And, since the idea is to produce the plans for O-1, it would be a great resource for everyone.
Maybe if I get the book I can work it out. If I do I'll post the plans here.
Willallison
10-06-2004, 06:13 PM
no there's no standard that covers all boats - each is different and requires complete scantling calculations.
At the time that we reached the point where preliminary scantling calcs could be done on O-1 (and I'm not really too sure that we're quite there yet...) I didn't have sufficient knowledge to do it myself - and since nobody else has leaped in to do them, the project stalled somewhat. Alas my Westlawn studies are taking precedence over O-1, so unless someone else wishes to do the calcs, it will be a while before scantlings can be done...
At the time that we reached the point where preliminary scantling calcs could be done on O-1 (and I'm not really too sure that we're quite there yet...) I didn't have sufficient knowledge to do it myself - and since nobody else has leaped in to do them, the project stalled somewhat. Alas my Westlawn studies are taking precedence over O-1, so unless someone else wishes to do the calcs, it will be a while before scantlings can be done...
rlewis
10-11-2004, 03:00 PM
Yes, please help. Some dedicated volunteer step forward please and bring this wonderful project to completion!
I am sure given enough time I'll have to learn this stuff and try to do it myself, but I'm not sure I would want to go in the water in a boat I designed ;-)
I am sure given enough time I'll have to learn this stuff and try to do it myself, but I'm not sure I would want to go in the water in a boat I designed ;-)
yacht371
08-09-2005, 02:02 PM
The deep fine entry of your design will likely cause "bow steering" in a large following sea. Lowering the chine would help some.
Attached are the lines of a very successful aluminum (developable) hull done in Autoship. This boat has a remarkable combination of smooth ride and stability. She is 25 x 8'6". The stations shown are 24" apart.
The upturned chines forward prevent "chine slap" at anchor and also deflect water aft rather than sideways when running fast.
Attached are the lines of a very successful aluminum (developable) hull done in Autoship. This boat has a remarkable combination of smooth ride and stability. She is 25 x 8'6". The stations shown are 24" apart.
The upturned chines forward prevent "chine slap" at anchor and also deflect water aft rather than sideways when running fast.
View Full Version : Final blueprints
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