Motor Help

[TRWXXA]

Hi all!!

I have experience with RC sailboats only, and I'm starting my first electric boat project. Recently, I pulled my original, unassembled, Lindberg Sport Fisherman out of storage (in my parents' basement for the last 30 years), and am going to assemble it. The motor that came with it is loooooong gone, but I've acquired a Traxxas, "Stinger", 20-turn motor. Is this an OK motor for this boat? Any help with this project is greatly appreciated.

I do plan to use the stock gear set (about a 2.5:1 reduction) to drive the two props from the one motor, and I'm looking for realistic performance, not outrageous speed. I tried the "Stinger" motor with a Proboat ESC, and a 7.2V battery pack, and it seems to only control speed from FAST to REALLY FAST.

Also, I have another, new Sport Fisherman on order, and would like to build that one with two, independantly controlled motors. Any sugestions for motors, ESCs and/or radios for that?

Thanks in advance for the help.

Chris

[Shaun Hendricks]

The 'stinger' is the stock motor for a Traxxas Stampede and a few other of their cars/trucks. It's not an overly hot motor wind but is very efficient and rather torquey for it's 540 size. It should power a reasonably sized propeller with ease and with that gearbox on it, it will power a much larger propeller.

According to some the Proboat ESC isn't known for good control down at the lower ends. You can adjust the relative speed by changing the gear ratios in the gearbox. I'd get the hull in the water and weight it properly and see how it performs before making any adjustments to being 'too fast' or 'too slow'. You might find that the factory settings are dead on. Most gearboxes have alternate gears that go in them to change the ratio so I wouldn't worry overly much to start.

Good Luck! Keep us posted!

[Ghost 2501]

shaun you're right about the proboat esc, it tends to come in at 25% power but thats its only fault

[TRWXXA]

The gear set with the Sport Fisherman is just a set of plastic gears that take the motor's ouput shaft, and divide the power to two output shafts that drive twin screws. The gears are not interchangeable, and they just happen to have about a 2.5:1 reduction.

Is there another ESC that's better at low speed operation, and is not too expensive? Since I plan to eventually have a twin motor setup, I don't want to spend big bucks on each one.

[Shaun Hendricks]

There are plenty of ESC's out there. Some folks even use inexpensive car ones.

One of these days we should get around to making an FAQ sticky that has all that common info on it.

[TRWXXA]

There are plenty of ESC's out there. Some folks even use inexpensive car ones.

One of these days we should get around to making an FAQ sticky that has all that common info on it.
I know there are plenty of ESCs out there. The question was specifically which ones have good low-speed control. I don't think I've ever seen an RC car running slow. The drivers seem to run them at WOT all the time.

[RGinCanada]

Heres a candidate for a sticky:

ESC Thread (http://www.rcgroups.com/forums/showthread.php?t=877700)

Summary
Consensus on slow speed control seems to be the MTroniks viper line.
MCD also has a good name but are expensive, and hard to find.

[charlie eaton]

Yes it's true the proboat ESC is not good at the low end but with a boat as big as the Sportfisherman it presents no problem. I use it on all of my larger boats,it is very reliable. Even with my light weight Midwest Sportfisherman it does not pose a problem.

[Shaun Hendricks]

I know there are plenty of ESCs out there. The question was specifically which ones have good low-speed control. I don't think I've ever seen an RC car running slow. The drivers seem to run them at WOT all the time.

LOL! You've been watching a lot of bashers then...

On real tracks they have to slow down through curves and in heavy traffic or risk piling the car into the rails. Super slow is pretty rare but when doing fine maneuvers you may find yourself puttin on just enough throttle to 'coast' the car through it. Electric RC cars without power on the ESC tend to slow down rapidly as they generally don't have a clutch in them like the nitro ones do. That fine bit of throttle at the low end is crucial to competiton rashing. Braking is normally either a 3rd channel function or done at 'zero' or 'reverse' depending on the ESC.

Bashing, on the other hand, tends to be done with the throttle like an off/on switch... :D

Boats tend to be less sensitive as was just mentioned.

[CaptLee]

Have been trying out the replacement from HobbyPeople for my Mtroniks and it is a pretty nice unit. The call it a Ripmax Quantum and it has a 120amp continuos with a 440 amp burst. Low end is good, beats the Proboat by a mile, 6-12 volts, bec,etc. I think for the twin motor you need to look at the Vac-U-Boat 385 direct drive or his 545 in the same mode. I used the Graupner Speed 480's on 3.3 to 1 gearboxes and it is nice, but have to throttle back to make it scale speed. the reason for the 480's was due to the availiblity of revesed wound motor(came from the Ju-52 acft).