If I work at it long enough I can make the simplest thing complicated. Just rambling, and this is of no practical interest, but...
Imagine that the laser pivots around an axis (say, a photo tripod) that's tilted back (away from the boat). At the center of the boat, it'll be pointed higher that it will when it's pointed to either side. So the line on the boat will be curved downwards at each end (or up in the middle). If the tripod is pointed straight up then the line will be straight. That's only looking at it from the side, of course -- if we look down then it curves along the side of the hull - but it should at least follow the level of the water (assuming we got it in the right place. So the waterline curve is never straight in 3 dimensions, and only in two when we transfer it in a particular way. I wonder, too, whether we actually want it straight. If the boot stripe is a constant width then (I'm no artist but) I'm not sure it looks right on hull that's curved and has a sheer curve (rather a graceful one, I think). Oh, boy! Talk about needing to simplicate things. I never did paint a boot stripe on Umiaq, and on Dolphin I just followed the line molded into the hull -- which turns out to be several inches underwater, so my boostripe is underwater and (because Rustoleum doesn't work as anti-fouling) looks like a strip of green shag carpet running around the hull just under the water. Giles Morris Arlington VA Montgomery 15 "Umiaq" Vancouver 25 "Dolphin" Miscellaneous small craft -----Original Message----- From: wayne yeargain [mailto:[EMAIL PROTECTED] Sent: Saturday, February 22, 2003 10:45 AM To: [EMAIL PROTECTED] Subject: Re: M_Boats: Vibration Hi Giles Intresting observation.. if the boat or laser were tilted would the straight line transferred from the laser onto the curved hull surface (and painted on) produce a curved line when the boat was righted?? Lasers produce only straight lines because they rotate about a axis (of evil?) which is prependicular to the direction of the beam.of light. If the laser were set up so the axis (that word again) were not parallel to the axis of the boat it would still produce a straight line, just not parallel to the waterline, or perhaps parallel but above or below it. The question is, would that straight line be curved when the boat was righted, I say yes Keep sailin' Wayne ----- Original Message ----- From: "Morris, Giles" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, February 21, 2003 1:52 PM Subject: RE: M_Boats: Vibration > Just thinking about this, and I'm sure you got there before me... > > The axis that the laser rotates in will have to be perpendicular to the > plane of the laser and the waterline, otherwise the pointer will follow a > curved path. Did I make that obscure enough? > > Giles Morris > Arlington VA > > Montgomery 15 "Umiaq" > Vancouver 25 "Dolphin" > Miscellaneous small craft > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Friday, February 21, 2003 2:45 PM > To: [EMAIL PROTECTED] > Subject: Re: M_Boats: Vibration > > > Sybil, > > Great idea for marking the "real" water line of the boat. > > But now I've got my new toy and will have to play with it before I can > try your idea. > > Thanks for the idea. > > Connie > > _______________________________________________ > http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats > > _______________________________________________ > http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats > _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
