I just purchased four 2.3AH 6.6v A123 LifePo4 packs. This should give me some flexibility in mounting and voltage. Steve
I plan to run a pair of smallish motors in my Le Terrible. Probably with Dumus dog-bones. That way if I lose a motor, I will still have some mobility. The Frenchies are big enough, and heavy enough to carry the weight. Mikey
Anybody have any thoughts on wiring dual (brushed) motors in series or parallel? Team Novak states that series configuration will give you more torque but a lower rpm, which sounds good for our application. http://www.teamnovak.com/tech_info/How_to/dual_motors/index.html Steve
I run mine in parellel, preferring to keep full voltage to both motors versus splitting it between to series motor. Also, if one motor dies for some reason, at least I still have another motor that works.
Although if you get mossed up and stall one motor, it is still drawing full voltage but with zero CEMF to resist current flow. Could burn out (or at least damage) a motor. In series, the still-running motor prevents the stalled motor from seeing max current. On the other hand, with brushless motors like Steve's using, the ESCs will either trip on overcurrent as they try to turn the stalled motor, or they'll fry themselves, sparing the motor haha. Thus far, my brushless ESCs seem to be quite adept at protecting themselves, so I'd say go parallel at the inputs to the ESCs from the battery, as that'll give each ESC more voltage to work with, which is a good thing. But it will have no direct effect on the motors' performance.
Tug, I've decided to try some brushed motors that look good and tested well instead of brushless. The brushless motors may still be used just to see how they work. May still use one of them for the pump. The configuration will be two motors direct drive with one ESC. I'll test series and parallel setups to see which gets the best acceleration once it's on the water. Steve
My experience is that the Mogodor is a challenging build. You need to think small and keep weight low in the hull. I've got two 385 doing direct drive on the props. The hull is quite tight and I'm not happy with this set up. I'd rather go with a gear box and a single motor, I think a single 385 would work. I stayed scale and have a pair of 4 blade 3/4 inch props. These are not terribly efficient as you don't get much blade on a 3/4 inch prop and there is no advantage over a three blade prop. My biggest problem is space, she has a very small amount of space and I wanted to seal the back deck so just getting to everything is a pain. I have a palmer rock-the-boat regulator so she runs off a 16g co2 cylinder. She is a fun ship to play with.
Never, run drive motors in series!!!! The difference in internal resistance makes one run faster than the other and eventually only one will get almost all of the voltage drop.
