Trolling motor thrust test?

Discussion in 'Boats and Motors' started by BigChessie, May 29, 2008.

  1. BigChessie

    BigChessie BIG PIMPIN' "GIGELO"

    Is there anyway to "test" how many pounds of thrust a trolling motor is putting out. I was thinking maybe using a volt meter and checking to see how much juice was running through it, but I am far from an electrician and am just guessing:( . I picked up a 24 volt 67 lb, while testing to see if it worked, the prop does not seem to spin fast enough. My 52 lb seems to spin alot faster. So before I do all the work of mounting it I was wanting to see if I needed to replace or repair anything. Thanks, BC
  2. just remember speed is not thrust, you can have the fastest motor out there but no thrust(torque) there is no way that i know of to test thrust the only thing you would get with a meter is how many amps the motor is pulling.

  3. BigChessie

    BigChessie BIG PIMPIN' "GIGELO"

    Seems like there would be some way of figuring out if your getting all of the pounds of thrust your supposed to. I guess I will just have to mount it and see how it does in the water. Thanks, BC
  4. Bassnpro1

    Bassnpro1 OSU outdoorsman

    I thought the same thing when I got a new motor, but once I got it on the water it almost threw me out of the boat! I'm sure it will work fine on the water.
  5. BigChessie

    BigChessie BIG PIMPIN' "GIGELO"

    I got it from a fellow member so I am sure it will work out. Just wondering if there was a way to check it or someway to "rebuild" them if needed.
  6. Is the prop size comparable between the two? And the pitch? Perhaps the higher thrust TM has a prop with a larger pitch thus displacing more water per revolution. I would think perhaps the amperage and resistance testing could determine if the motor is working at the desired range but that still would not tell you anything about the thrust itself. You could have one prop that spins more freely than the other allowing the motor to work less to spin it and I don't know that you would see that reflected in any electrical readouts. Perhaps you can find a way to temporarily mount it alongside the current motor and compare the two on the water? That seems to me the only way to really know.
  7. You can measure the thrust by nosing your boat into something solid and place a scale between the boat and the solid object. Once you get it positioned, kick your motor on full nuts. It will read pounds (thrust in this case). Kind of like measuring your weight (in pounds) on a scale, gravity is accelerating your mass with a given force (force=mass x acceleration) toward the center of the Earth thus giving you your weight...a force measurement. I'd be interested to see how this little test works if any of you adventurous souls try it.
  8. Or if you have a fish scale or similar that goes beyond your thrust rating, you can tie it off and have the boat pull away from it.
  9. That would probably be the easiest Nixmkt. Tie the boat off from the dock, the only thing to remeber is neither will show their actual thrust because of drag etc. The electrical measurements won't work because if it is in fact broken it may have a short etc. inside that will cause it to draw more power but still not turn that drawn power into thrust.