Hi Donaldbear and all,<br>You asked in an earlier
post if you could have a copy of some Motor/prop data
for your spreadsheet. I'm going to be doing some
motor, prop and gear testing in a month or so. If your
interested I'll send you a copy of the data I collect. The
data will have e-meter output, shaft rpm, and boat
speed. Along with the data I can give you the specs. for
the equipment used so you have a baseline. (I have a
friend with tons of props I can swap out until I find
the right one) BTW, a very accurate and cheap Tach
can be had at "Wal-Mart ($19.97). It's sold as a
"BELL" Bike Speed computer but it works great as a RPM
sensor. It uses a Hall effect sensor and magnet for
sensing and with two magnets is good to +/- 4 RPM (0~1660
rpm). After mounting(on prop shaft), to use, read the
speed of the display and convert it to RPM using (RPM =
speed read from Bell bike spedo*5280*12/62.9/60/2). The
"62.9" is for the 27" wheel setting of the Speedo and
the "two" is for two magnets. You can record your
boat speed and tach readings and convert it later.
Using a tach of some kind to get shaft revs will give
better data to work out the gearing with..<br>Enjoy the
Holidays<br>Joe Peek<br>ECB<br>P.S. in you speadsheet how high an
eff. are you seeing with the data collected so
far...like hp in, hp out or % eff?
