Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[madwelshman]

Hi folks, I have a few boat plans, such as Aerokits ones which as many will know are only 2 view and have no bulkheads etc shown on the plan.
Is there a relatively easy way of drawing these templates from a 2 view plan or can anyone point me towards an example/description of how to do this?


I have seen one where you draw a line at what appears to be 45 degrees at the end of the upper view and draw lines out from reference points on that view, plus from the lower view (if that makes sense)    but have no idea if that is a good way or if there is a better/more accurate way to achieve this.


Thanks in advance


Will

[tonyH]

If it's a hard chine boat then it's quite easy IF you've got the keel, chine and deck lines. You know the beam at any point so the only variation is likely to be whether the hull cuts in or out between the chine and the deck. So, chose a station along the deck that suits the hardware layout you want and it'll fall into place.

[madwelshman]

Thank you Tony.


So with that method, I would just take measurements off the plan and transfer them onto another piece of paper or card, is that correct?


The method that I had seen which involved drawing a line ahead of the upper view, took lines from set points on one view, to the 45 degree line, then at 90 degrees to the horizontal line drawn down vertical, below the second view. Then you did the same on the second view, out to meet the relevant vertical line. I have attempted doing it this way on a plan, but some of the dimensions are definitely different to some that someone drawn from bulkheads etc, before building.


Will

[tonyH]

Hi Will,
I just decided where I needed the bulkheads etc., drew the basic shapes on paper and stuck them onto the lite-ply with spray mount and then cut out the keel slot, stringer notches etc as required.

That's the method I used for Jackie S and Ultima Dea. UD was the easier because the deck was essentially flat in both directions whereas, with Jackie S the fore/aft line was straight but the lateral curve was very distinct.
Luckily I also had a decent pic of the transom in both cases so the 6 degrees of undercut in the hull of Jackie S was simple to incorporate.                                           
The method I used for JS deck, and passed on to Bob Zooma, was as the pic.You may have to adjust the length of the radius as the deck narrows fore and aft but you should find that you get a smooth curve IF the circle arc goes through x,y and z for each station but try it with some scrap to get the hang of it........

[madwelshman]

Thank you very much Tony, much appreciated
I will give this a go and see how I get on with it and how accurate I am.


Will

[warspite]

Do you mean this method

[madwelshman]

Do you mean this method

Warspite, yes, that's the same as the example that I had seen and had a go at.


Is this the way that you do it?


Will

[warspite]

This is the old draughting method - to confess, I have not as yet designed or built a boat that does not come out of a plastic fantastic box or is not a pre made hull, (not strictly speaking - I do have a hull thats nearly 30 years old in cardboard based on a castle class).


The method above takes the plan view and side elevation and creates an end elevation, the example above failed when I tried to check the hull form with a 3d solids view, though to be honest I didn't pursue it fully.

[madwelshman]

If I'm honest, I haven't actually built a boat from scratch, whether a kit, or from a plan, since I was young and that was a glassfibre hull.
One or two of the project boats that I have bought to restore have bulkheads that have delaminated and will need replacing. If I knew that I could get the bulkhead out intact, drawing around them would be simple enough, but there's a good chance that won't happen, so I will need to draw templates from the plans that I have for them.
Also, I would like to know any ways of doing this, simply so I know how people actually achieve these things.


Will

[madwelshman]

This is the example that I saw, albeit a very basic example.

[ChrisF]

Hi Will

Was going to post before but been down in Cornwall for a few days and Wi-Fi has been intermittent!
The 45deg method was what I used at school and whilst it works inaccuracies can be introduced if the line is not exactly 45deg and you are transferring lines quite a distance.

I find it easier and accurate to transfer the dimensions from the plan and side view using lines with cross lines marked on them for the relevant points which are used to produce the bulkheads. To do this you really need to use a drawing program or CAD. I know you are using PowerPoint and whilst I've used it in the past it wasn't for boat drawings and without giving it a try I don't know how effective it could be.

Once I'm back home tomorrow I'll post a picture off my PC of how I do it. I'm currently using Microsoft Visio which isn't ideal but I am producing good results. For accuracy it's best to draw the top and side view as well as the bulkheads and other templates so that when printed out they are a consistent size rather than mixing the bulkheads with templates taken directly from an existing kit plan etc.

Hope that makes sense?

Chris

[madwelshman]

Hi Chris, a weekend away eh, very nice.


I can understand how if the 45 degree line isn't actually at 45 degrees, then it could make a difference to the results.


What I do have on the laptop, is Sketchup, I could try using that in conjunction with your method and see how good the results are.


I haven't experimented very much with Sketchup yet, but now seems like an ideal time to do so.


Many thanks
Will

[warspite]

I assume the bulkhead is under a deck as well, creating a paper template is one option before removing it from the hull, taking the lumps and bumps along the profile as well, pieces of paper stuck in place, folded / creased along the profile and stuck in situe and then stuck together once cut to suit or markings applied to be matched up so when on the new piece of bulkhead it matches or at least approximates the bulkhead, made oversize and fettle to be closer as its offered up. Taken off the plan will not take into account the builders errors that invariably creep in - see the twisting and changes that martin experienced on the matchstick construction.

[ChrisF]

Will

This is how I drew one of the bulkheads for my Huntsman 31.

The required points are taken from the plan and side views and the intersections provide the points on the bulkheads required. I've used a drawing program but it could be done on a drawing board as they used to be. It could be done directly from the kit drawing using cardboard strips with the relevant points marked on and then drawn on paper or cardboard but you would have to be careful that inaccuracies don't creep in which will then have to be adjusted for when assembly takes place.

Chris

[madwelshman]

Thank you Chris, the example is easy to understand.
So when you are doing these, you take the measurements from the plan and transfer them onto whatever medium you are using, be it electronic or material (paper or card), is that correct?


Do you start with a centre line and add your measurements to that?


I have yet to attempt that method, as in taking physical measurements from a plan and transferring them onto something to give an outline. It's one that I also need to try though.


Will

[ChrisF]

Hi Will

I do all my drawing on the PC using drawing software. As I said previously, for the most accuracy it's best to work completely from the paper print and take dimensions from that to draw the bulkheads on paper or card or do as I do and print all the parts out - I have an A3 printer. You can take the templates directly from the kit plans and produce the bulkheads on the PC but you might have to fiddle with the print out to make sure they both match accurately.

To do this I import the kit or other drawing as  PDF and then "trace" the top and side views so that I can produce the keel and superstructure and obtain the points required for producing the bulkheads. To do this I position those Vertical and Plan "measuring" lines at each bulkhead on the plan and side view and mark each point required and then move the whole things to where I'm drawing the bulkheads. So there is no actual measuring done.The Plan one has to be rotated as well. It is then a simple matter to draw each bulkhead. I only draw half, copy and flip it and then join together to form the full bulkhead as this ensures greater accuracy. To do this, yes, I mark the centre-line.

Once all drawn up I print out, though the keel and superstructure usually goes over more than one sheet and I have to tape together.

Chris

[madwelshman]

Great, thanks very much for explaining that Chris.
I will have a go and see how I get on.


I'll apologise in advance though, as I expect I'll be asking more questions sometime soon 


Will

[ChrisF]

No problem. It's easier than it sounds and once you have produced one bulkhead it will all come together.

Chris

[madwelshman]

It's easier than it sounds and once you have produced one bulkhead it will all come together.

I'll tell you if I agree with this after I've had a go 

[RST]

This is the example that I saw, albeit a very basic example.

Try your diagonal line in opposite orientation (bottom left to top right, mirror of what you show here).  It should make a little more sense on the body between the profile and plan views. Port and stbd are a little bit messed up between the views the way you showed it.   (I don't lnow how to do a wink -but give this as a wink and a nudge of the elbow).

[derekwarner]

Remember this one from School all those years ago?............  


How many drew Side+First Angle projection correctly the first time around?..........

Come on, no fibs  ...I know one who had to stay in the Drawing Room at lunchtime until he got it accepted 

Derek

[madwelshman]

Try your diagonal line in opposite orientation (bottom left to top right, mirror of what you show here).  It should make a little more sense on the body between the profile and plan views. Port and stbd are a little bit messed up between the views the way you showed it.   (I don't lnow how to do a wink -but give this as a wink and a nudge of the elbow).

Cheers RST, I will try that too.


Will

[Bunkerbarge]

Remember this one from School all those years ago?............  


How many drew Side+First Angle projection correctly the first time around?..........

Come on, no fibs  ...I know one who had to stay in the Drawing Room at lunchtime until he got it accepted 

Derek

This one might interest you then,  The following has a front elevation and a side elevation shown, you simply have to draw the plan:

[mrzippy]

Tin Foil is useful for taking bulkhead patterns off the inside an existing model -
forms accurate shapes in awkward areas - I used this method to make my original Streaker patterns.
The difficulty is avoiding piercing holes through the foil, various burnishers with rounded edges are used to push it into corners,
gardening plastic seeds label with a tapered ends, adapted coffee stirrers etc,
it's delicate and fiddly to handle requiring lots of patience but does work,
foil patterns were transferred onto stiff card for final testing before scanning into a Mac and drawing up.
Paul.

[derekwarner]

BB...the example i used was according to the Standard as used in Australia in 1964. It was based upon an old British Standard


Having said this, it was just plain simply dumb  the side was called the front, the front was called the side........it was probably sketched up by Oliver Cromwells Draftsboy .......then so into British history


The example you show and name is in ISO format, which is logical    ...


The earlier sketches by a Bloke called Noah....depict his vessel in ISO format


Having said this, my mind is not capable and so will not allow me to complete the task........[not saying for a moment that it is a trick....but  ]