Bear Lake 8/3-8/7: Homemade Downriggers

[Quicky]

I built those downriggers that y'all are referencing. I can give you the specs on what I used. I used the wiper motors from a nissan pathfinder first gen. They had a shaft long enough and the shaft also had flats that could drive a spool. The diameter of the spool is critical since there is a limited amount of torque available for those motors. too large of a spool diameter and your weight will stall the motor. Too small and you will break cables and raise/lower the weight too slow. Empirical testing will have to be done to determine the stall torque of the motor you choose to use. Use a rod and a heavy duty spring scale so that the center of rotation and center of pull is 12" apart. That's your stall torque in ft-lbs. Use that torque value to drive the pulley size that you can get away with, but provide a safety factor. Example: Stall torque of 15 ft-lb use about 10 ft-lb. You can use a 6" diameter spool and lift a 20# weight with some safety factor in there. This should get you started if you already have motors. Check out SurplusCenter dot com for gear motors and they might have something you can use if you want to go new.

http://www.surpluscenter.com/Brands/Stat...5-1649.axd

There are a few things I would do differently now that I have used them for some time. I wont hijack this thread to go into more detail though..
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