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Re: Full size drawings
By:NPenney
Date: 7/22/1998, 3:30 pm
In Response To: Re: Full size drawings (Mark Kanzler)

I threw it away before I finished. Got as far as the preliminary stitching before I gave up. Had a pretty good idea it wasn't going to be workable just trying to cut it out.

The program that CLC used to plot out the drawings used 5 stations as I recall, with three points between them. On a regular 8-1/2 by 11 piece of paper, that's fine looking. But when you stretch out a 13 foot drawing with that, you get straight sections that are about a foot long instead of curves. Even if one used the offset tables with one foot references you'd get straight lines 4" long. This just isn't a good way to make nice curves. Especially if you've got a gradual curve that only changes 1/8 an inch in several feet. You end up with anything but a nicely faired curve using straight line segments. Tighter turns are just plain hopeless, which is probably why CLC drew in the bow and stern curves by hand.

The problem of line width is not inconsequental. A thick photocopied line that is about 1/8 inch thick isn't the best way to detail a curve that has offset table definitions as fine as 1/32 of an inch. Stay within the line all you want, you're still making a horrible looking edge.

There is also the matter of keeping the paper perfectly aligned, without any shifting whatsoever along the full length of the plywood sheets. Something that is actually quite impossible to do with paper. The stuff stretches and shrinks quite nicely. Oh you can tape it all down, but you've no way of knowing if it's taped straight. Or if it was copied straight for that matter. Trying to run off a perfectly straight photocopy that is 13 feet long is an exercise in frustration at best. Sure those traction tires are of a perfectly matched diameter and have exactly the same slip.

My boat, the Millcreek, uses a flat bilge panel. Which is extremely sensitive to variations side to side. Trying to make it match perfectly with all the above problems proved insurmountable.

So I ended up with cut outs that instead of faired curves had lines like poorly laid concrete. Was the bilge panel straight? Dunno, didn't have a good way to measure it. Snapping a string along 12" just doesn't give precision to a 32nd of an inch.

After all the work of trying to use full scale templates (and it's a *lot* of work, taking days to do), I trashed it, and redid it all with the offset tables, one batten and some pins. It took me just one afternoon. That time I got very nice curves, a near perfect bilge panel, and a beautifull boat that stitched together very nicely.

I'll stand up and say full size drawings are a curse, while battens are a dream to use.

> You threw the boat away or the plans? I can't imagine a boat
> THAT bad.

Messages In This Thread

I need graph paper
Matt Weist -- 7/21/1998, 4:06 pm
Re: I need graph paper
Mark Kanzler -- 7/21/1998, 6:36 pm
CAD for lofting
Karl Kulp -- 7/22/1998, 2:45 am
Re: CAD for lofting
Mark Kanzler -- 7/22/1998, 10:27 am
Re: CAD for lofting
Steve Austin -- 7/23/1998, 8:21 am
Re: CAD for lofting
Karl Kulp -- 7/24/1998, 6:33 pm
Re: CAD for lofting
Nick Schade -- 7/22/1998, 4:59 pm
Re: Full size drawings
NPenney -- 7/22/1998, 11:25 am
Re: Full size drawings
Mark Kanzler -- 7/22/1998, 11:38 am
Re: Full size drawings
NPenney -- 7/22/1998, 3:30 pm
Re: Full size drawings
Mark Kanzler -- 7/22/1998, 5:38 pm
Re: Full size drawings
npenney@erols.com -- 7/22/1998, 7:35 pm
Re: Full size drawings
Bram van der Sluys -- 7/23/1998, 10:40 pm
Re: Full size drawings
Mark Kanzler -- 7/24/1998, 5:46 pm
Re: Full size drawings
NPenney -- 7/24/1998, 7:14 am
Re: Full size drawings
Mark Carroll -- 7/23/1998, 5:40 pm
Re: Full size drawings
NPenney -- 7/24/1998, 6:40 am
Re: Full size drawings
Paul Lund -- 7/24/1998, 10:44 am
Re: I need graph paper
Mark Kanzler -- 7/21/1998, 4:52 pm
Re: I need graph paper
Mark Kanzler -- 7/21/1998, 4:31 pm
Re: I need graph paper
Mark Kanzler -- 7/21/1998, 4:37 pm