Boat Lift Math........

I knew this was the mental gymnastics we all would love........

Yes. GFCI breakers - GFCI on the motor, GFCI on the dock outlets. Kids wear belts at the dock.... Mr. and Mrs. Safety here .........along with ridiculous Shoreline Management inspection requirements.

As far as visiting parents, only one survives and I wish our kids could have been around them more when the kids were young and they were alive.......

Thanks, Joe - I was thinking a proportional approach would help with perspective (as it did for motor speed increase).

As far as changing belts, there is easily enough wiggle room to go to a 3-inch pulley with the same mounting plate and belt.

The G25 is the next purchase. I rode a trick ski behind PN Jeff's at WL and got an incredible adrenaline rush just getting up single! Val is shooting for a pontoon, but we can sit more on a G25...... and I always wanted a third mortgage.   

So yeah Pete is generally correct here in that the lift capacity has not changed from the 10k, however you are using the motor that was sized for the 10k in a different way. Now checking amps and yadda yadda would be what would be needed if you were actually lifting 10k - which you aren't unless your new G25 showed up since we talked last.

If you want to answer the question that your wife is really asking -

So as stated above - nothing is going to break in terms of cables, gear drive, etc. up to the original rating.

For the motor it is running basically the same speed it was always running - and was presumably adequately sized for the load that the gear box would put on it with a 10k boat. we don't know what that load is but lets assume it is x. If we don't want to tax the motor any more than the manufacturer intended ( which again is what Val wanted to know) then we would not want to apply more torque on the motor than we would at x.   You changed the pulley radius from 1" to 1.5" effectively increasing the torque at x by a factor of new radius (1.5) divided by old radius (1) give you 1.5 times the torque at x. Neglecting things that are reasonably neglected here you can simply divide the original rating of the hoist by the 1.5 (10000/1.5) and as long as you are only lifting 6666.7 lbs that motor doesn't know the difference between that and lifting 10000lbs with a 2 inch pulley.

If you lifted 10000 lbs with the 2 inch pulley and measured the FLA and then measured 6666.7 lbs with the 3 inch pulley they would be the same... but just measuring the same 3400 lb ish boat twice at both pulley sizes won't tell ya a whole lot cause neither scenario would really be fully loading the motor as god and the original specifying engineer intended.

Orlando76 wrote: 8122pbrainard wrote: Orlando76 wrote: Both, motor side and breaker side and compare the difference. . Todd, You won't see a difference in amps from the breaker end to the motor end. I feel you are thinking voltage drop. For the given drop in voltage due to load wire size and length of wire, the amps stay the same. Back up Pete and rethink that.... the amps will go up.

Todd,
Yes, the amps go up with the voltage drop but what I'm saying you will get the same amp reading at the breaker or the motor end. Maybe I misunderstood what you were saying?

Steve,
I assume you purchased a longer V belt after putting the larger sheave on the motor. Hopefully you got an AX belt (cogged) and didn't just get a 4L fractional HP belt at the hardware store.

Orlando76 wrote: Both, motor side and breaker side and compare the difference. .

Todd,
You won't see a difference in amps from the breaker end to the motor end. I feel you are thinking voltage drop. For the given drop in voltage due to load wire size and length of wire, the amps stay the same.

Both, motor side and breaker side and compare the difference. When I say breaker side, I mean where it originates at the house, I suspect a noticeable difference there. But I don’t expect much difference in motors fla. never really thought about that before.... And for the sake of everyone make sure the ENTIRE circuitry going to the dock is GFIC protected, not just at the receptacle/device itself.

Steve,
The lift capacity remains the same. For the given weight of the load, the torque through the worm and spur gears stays the same.


Now the potential problem is the FLA (full load amps) of the motor. I highly recommend you check it against what's listed on the motor nameplate before you burn it up! Is the motor thermally protected? If so, that may save you from damaging the motor.

Clamp on: