Hey, I'm looking at my options for pumps for the Baltimore, and I'm not liking what I see. The rules say the Baltimore has a 1-1/4 GPM pump. But the only low current StrikeModels option for pumps in that range is the small pump with a 12V motor. I would prefer to use 6V batteries instead of 12V batteries. So I'm considering using an ESC on a 6V pump with a 1/4" restrictor instead of using no ESC on a 12V pump with an 1/8" restrictor. If the motor current is linear with respect to pump capacity, then I can make a 10Amp pump only draw a little over 3amps doing this. Has anyone here tried using an ESC on a pump? Was the pump capacity in GPM linear to current draw? If not, does anyone have any data on the relationship between current draw and pump capacity? Thanks, Carl
I do use an ESC on the pump. With the transmitter end point adjustment, it is pretty easy to dial down the pump motor until the pump is doing 1.25 gallons a minute. I suggest not trying to measure pump output via current draw. All motors are not created equal even if they are the same type. Instead, measure how long it takes for the pump to pump out 1 gallon of water. The target is 48 seconds. Measure with the pump in the ship to get a true gpm reading.
The reason I wanted to know the current draw was to get a feel for how big a battery I need, not to measure the pump capacity. I'm planning separate batteries, 1 for the pump and 1 for everything else. Glad to know others are using ESC's, too. Thanks, Carl
I've been using an ESC in my Treaty ship. Its a standard BC pump with a 1/4" outlet run off 6 volts. It draws about 0.9 Amps when using the ESC and pumping 3/4 gal / min. When using a straight resistor, it uses about 1.5 Amps to pump the same amount. Be forewarned, if the ESC is not really, really, water proof you will find out. I sure did. I have a brand new small Strike Models pump with the 12 volt motor. I'll try to test it out by this weekend and post what the amp draw is.
I finished putting the Strike Models small pump with the 12 volt motor together and added an ESC for testing. I tested with a 6.0 volt 4.5 AH SLA and a Castle Creations Pixie 20. The no-load current was 0.1 Amps. The full load current was 1.5 Amps. It pumped 1.6 - 1.7 gal/min at this current draw through 12" of tubing with a 1/4" outlet on the end, raised 3"-4". So I would guess a 1.3 - 1.4 Amp draw would get you 1.25 gal/min.
I generally have my pumps on speed controllers, but that is mainly so it is easy to turn them on and off remotely. For lower output 6V pumps, it is also easy to replace the motorl with a lower powered one. I have them available. Stephen Morgret Strike Models
Stephen, I don't see the lower power motors on your pumps page. How much are they, and do you have any currrent draw specs on them? Thanks, Carl
