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Sunday, February 18, 2007

More Advanced Tick-Stick Techniques

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10/2008 Update:
The tick stick method described below has worked pretty well so far. After plotting the angle/distances from the grid paper into CAD, then printing out the curve on a plotter using 1:1 scale, the bulkheads cut from the template have needed only minor modifications to get a good fit. A couple even required no modifications.

Came up with an idea to improve the tickstick measurement process. This builds on the previous process using CAD described earlier.

Electronic Cutout Templates
Advanced Tick-Stick Techniques

The previous method used a long stick, with a yard stick attached, touching the hull, then finding an intersection on the grid, scribing an angle line, and reading a measurement off the yard stick. Then you had to go back to CAD and, from the intersection point (which would be different for each measurement), plot the vector using polar coordinates (distance, angle) to produce the "ticks".

The new method replaces the stick with a laser distance measurer hot glued to a thin strait piece of plywood with the laser beam aligned with the scribing edge. A hole is drilled in the end of the plywood which is used a common hinge point or vertex. On the sketch board, long thin bolts are mounted in all corners and midpoints near the edge. Now the process is attach the laser assembly to the bolt, swing the laser assembly aimed at the hull , every few inches, and take a reading. This method goes much faster, can be done by one person, and does not involve holding a long stick in place.

The laser distance measure is a device I already had. Note this is not the "cheap" "Straight-Line" measurers which tend to imply they are "laser measures". They have a laser for targeting, but the measuring is done acoustically. This means you pretty much need a flat surface as a target, it doesnt work against a curvy inside of a hull where things will just echo. This measurer is a Stanley true laser distance measurer that measures the speed/distance of the laser light. Supposedly accurate to a tenth of an inch.

Within an hour, I got three bulkhead measurements. Most of the time was setting up the sketch board vertical and level. Otherwise, taking the measurements went very quickly.