full size plotting

[b_rodwell]

Just for fun, I now have designed my perfect tender for my cruising catamaran (to be). It is a 5m sharpie. It is light, stable, good for rowing, sailing and a 2-4hp motor. It starts with plywood set up in (obviously temporary) female frames. The first step is conventional 'tack and tape'.

I want to build it and offer the design to others. I want to include full size plans for the sides, bottom and building frames (you almost won't need a tape measure). Idealy the plans would be plotted in different colours. What are the options for full size plans about 5.5m long and 1.2 m wide? Is it mandatory to use Mylar? Does the plotting have to be done on a flat bed plotter? I have checked around and the costs are a bit frightening and there are very few places that can do it at all. What do other designers do?

[SailDesign]

The plotting can be done on any plotter that has the capablility to do "long" plots (i.e. paper is on a roll). You are pretty much limited to a max paper width of 40" on most machines, but I have seen plots up to 50ft long...
I know Encad does one (inkjet) and HP does a few, pen or IJ, and CalComp has a couple. Just check with local architects, designers, etc.
Steve

[gonzo]

Another method is to plot what you cut out. For example, the bottom pattern will have about half the width. For the frames, all you need are the angles. Bruce Roberts has been very succesful with that system.

[BrettM]

I had one builder recently request for paper patterns not film for a 6.5m alloy boat. (Lets not mention cnc) The biggest thing I've found is to double check the output measures what it should.

if your patterns are larger than the plotter then splitting the shapes up is fine as long as suitable datums etc are included.

For me colour is not necessary. Just label things properly.
Brett

[duluthboats]

b,

I just want to say lots of things can go wrong. But yes, it works. If you’re going to the corner print shop, you’ll have to find out what driver you need to post a file that their plotter will read. Then I suggest a small trial run, because most will charge by the area of material used. You’ll want to be sure that the CAD program your using will export true 1:1 plot files. Put several reference lines of a known length in the plot to have a check for accuracy. Mylar is the most stable material; some paper will change dramatically with changes in humidity. This is just a few things I have learned when having full size plots done. My preference would be to supply cut files for CNC or to offer the parts in a kit.

Gary

[Dim]

b,

On how much I know, very much important point - quality of a material on which you will print. Temperature and air humidity result in significant deformations of a paper. Because of this measurement can be not exact.

Dim.

[Chris Krumm]

Mylar will be more stable for plots regarding temperature and humidity, but lots more money. But many designers offer full scale plots or even bluelines of plots on paper and it works fine. Unless you can carge enough for the plans to recoup cost of generating new mylar plots each time, I'd make yourself a set of master mylar plots and run paper bluelines for the mould stations to send with blueline plans sets.

If you cut out a batch of bulkheads from full size paper plots under similar climatic conditions (i.e. do 'em on the same day or have a climate controlled shop) I can't imagine it's that big a deal. For your small cat, If paper patterns shrank a fraction of a percent and you out mould stations a fraction of a percent small, the change in displacement might amount to a six pack of beer.

[gonzo]

It would depend on whether it amounts to being able to take or not that six pack. I agree that the difference is minimal. They are not patterns for machinery where tolerances are in the thousandths. Wood shrinks and warps; so does metal. Boatbuilding, like all engineering, is about being within tolerances. Regular blueprint paper works fine. There are thousands of boats and homes built out of measurements taken from paper.