singlehanded fast cruiser design, build

[thefuture]

I know i'm going to get flamed for this but i also have been cruising this site for a long time and see that there may be a lot of advice to be had. I want to spend the summer designing, getting materials together, and basically planning out a build for the winter and beyond. I realize this may be a big project to take on but i have a good share of experience in the sailboat restoration and refit field although i have never built my own boat. I want to build the boat on a male mold with cedar strip planking for its cost effectiveness and lay up with fiberglass mat and epoxy resin. I started out the design with freeship and moved it into solidworks to get an idea of what it will look like. My next step in the design area will be to get full size templates made of the lofted sections. The boat will be 25' long. How many lofted sections should i need, and where would i find someone with a printer big enough to print the PDF files of the templates. I assume the printer does not need to be local because they could roll the drawings up and ship them anywhere right. Are there any good recommendations for a place? I am going to do this part by part and i have even considered building a 1/5 scale model for practice and to use later as a guide for construction. Any idea's?

[sharpii2]

Originally Posted by thefuture

I know i'm going to get flamed for this but i also have been cruising this site for a long time and see that there may be a lot of advice to be had. I want to spend the summer designing, getting materials together, and basically planning out a build for the winter and beyond. I realize this may be a big project to take on but i have a good share of experience in the sailboat restoration and refit field although i have never built my own boat. I want to build the boat on a male mold with cedar strip planking for its cost effectiveness and lay up with fiberglass mat and epoxy resin. I started out the design with freeship and moved it into solidworks to get an idea of what it will look like. My next step in the design area will be to get full size templates made of the lofted sections. The boat will be 25' long. How many lofted sections should i need, and where would i find someone with a printer big enough to print the PDF files of the templates. I assume the printer does not need to be local because they could roll the drawings up and ship them anywhere right. Are there any good recommendations for a place? I am going to do this part by part and i have even considered building a 1/5 scale model for practice and to use later as a guide for construction. Any idea's?

Why not just print up the offsets then loft it?

You will probably get greater accuracy than trying to put together strips of paper which can expand and shrink significantly due to heat and humidity.

How many mold stations you are going to need depends on two things:

1.) the thickness and stiffness of the planking, and
2.) the number and tightness of the curves the strips will be bent around.

A hull with thick strips and only one fair, but deep curve, for example, will need fewer mold stations than one with either a long gentle curve, where the strips could sag between molds, or a series of tight, reverse curves, which would require thinner strips to make the tighter bends.

I would suggest, when you build your model, that you use strips that have as close to the scale down of thickness as will be used on the full size boat. The model then could give you some guidance as to how many you will need.

My guess is at least a dozen.

Bob

[thefuture]

Thank you! I am all for getting full size print outs. Do you know how to save these from Freeship. From what i know i want to save as a PDF file to send to a printer? Are printers/plotters common to find in a given area?

[bistros]

Originally Posted by thefuture

Thank you! I am all for getting full size print outs. Do you know how to save these from Freeship. From what i know i want to save as a PDF file to send to a printer? Are printers/plotters common to find in a given area?

Working from offsets and lofting the stations yourself is how this is traditionally done. By working from offsets and using a batten you also can evaluate and adjust fairness of curves as they are lofted.

In my last project we imported the design files to Rhino and then sent the resulting output directly to a CNC 3-axis router - cutting stations and frames and panels directly from the design, as well as handling jigsaw-puzzle scarfing larger pieces at the design level.

Why bother with a paper stage where errors can get induced and amplified if you can go directly to station molds and frames? You could never cut paper templates by hand as well as a CNC or laser cutting shop can. Just wondering why.

[thefuture]

Again, great idea. The cnc machine here at our school is not big enough for the bulkhead cut outs i want. If i knew of one near buy i would go through them in a heart beat. I have transfered my file to solidworks and know how to use a cnc machine if i found one big enough i could send someone the mastercam file and it would be plug and play with a cnc machine. Now finding one large enough that is owned by someone who won't rape me comes into play. I'd like to do this on a budget, not neccesarily because the money isn't there (that's partly true) but to show with enough sweat equity and contacts it doesn't have to break the bank. Know of any CNC mills large enough or in michigan and what do you think they will charge?

Garrett

[bistros]

There has got to be dozens. Phil's Foils here in Ottawa, ON charged me $200 for cutting all the parts for a 14' boat. Contact West System Epoxy and ask Meade or Jan who in your area can do this. They are in western Michigan.

[AndrewK]

Thefuture

1. I chose a frame spacing of 600mm (~24") so that I could work between the stations. I think 10 - 12 stations would be a good number for your hull.

2. I strongly recommend having the stations router or laser cut. In my case here in Australia laser cutting was cheaper, I paid $1,000 for 21 stations that included the MDF board.
Get quotes for both and decide, for laser cutting look up metal cutters. Transportation is reasonably cheap so you dont have to stay in local area, email your dxf files to a few sites and find out.

3. If you want the stations plotted then get in touch with a few sail makers as they have the large plotters. If using this option I would also recommend you get it done on mylar film rather than paper. Mylar is a stiff clear plastic which will not destort so you will get very accurate transfer from this to the board. Nest the stations on top of each other to use minimum film. It can also be reused once you have transfered a set of plots clean off with alcohol and have more plots done.
Also dont forget you only need one half of the station plotted as your boat is symetrical.

Cheers
Andrew

[Chris Ostlind]

Originally Posted by thefuture

...The cnc machine here at our school is not big enough for the bulkhead cut outs i want. If i knew of one near buy i would go through them in a heart beat. I have transfered my file to solidworks and know how to use a cnc machine if i found one big enough i could send someone the mastercam file and it would be plug and play with a cnc machine.

Look to a large scale, high through-put cabinet shop in your area. They would typically have the big CNC machine necessary for cutting forms and/or templates of forms for you. Most of these big machines have the capacity to cut a 4x8 sheet of plywood or MDO and they are reasonable, especially considering the hit that the housing market has been taking recently.

Nowadays, lots of smaller cabinet shops have decent two axis cutting capability and would be able to handle the job at a lower shop rate for the machine.

Most of the time, a .dxf or .dwg file is the best thing to supply for 2D work. If you are cutting 3D, then a correctly formatted IGES file works best, from my experience.

Chris