Hello, Looking at getting into the Little Rock soon and was just wondering about motors. It will be built to Treaty specs, which would give it a speed of 32.5 knots or 27.5 secs/100 ft I have a pair of BC Johnson 550's with a pair of GB500 gearboxes. Just wondering about how many amps that set-up draws? and would it be smarter to use something like a Speed 300 on direct drive/geared or possibly a Speed 400? Thanks
The two Johnson 500s will give overkill speed under treaty rules I run a heavier tubbier I-boat on two 400-size motors, and it does 26 seconds, driving a pair of 1.5" props, with another pair of 1.5" props unpowered as drag props. If I geared them down, I could get it to your speed. But 550's are overkill. Not that there's anything wrong with overkill
What are you planning to use for batteries? Voltage I mean? I think it will depend on how many volts you have in the boat. Are you thinking a 6 volt gel-cell, or Nicads (Nihms), with 7.2-8.4 volts? Mikey
Well I'm open to suggestions. I haven't really thought it out as I don't have a lot of experience/knowledge when it comes to this stuff. My idea was to try and have the most efficient set-up possible, rather then a lot of wasted power.
HMCS I am running the PE using 300 motors in direct drive 6v, to 25 pitch 4 blade 1/2 in props and it pushes the PE at 28 seconds fast gun MWC/IRCWCC, which is great considering the model is much heavier at 18lbs,sits deeper than the ship you want to run and is much fatter. It takes about 3 seconds to reach top speed and about the same to stop from full speed. No ESC, no drag props , no gears are installed. You may be able to get away with a direct drive using these props with drag props, and your ship is thinner and lighter with less drag coeffecient on the hull. Funny that the PE will be slightly faster than your destroyer...hope you don't encounter it in battle. Check with bb26 he can tell you where he got the props. CURT COMBAT-X IJN YAMATO DKM BISMARCK DKM TIRPITZ USS CALIFORNIA HMS PRINCE OF WALES WATCHFUL CARETAKER ROMA DKM GRAF SPEE
Treaty rules are different. A Treaty VU class would go minimum warship speed of 38sec/100ft. USS Little Rock is a Cleveland class CL. I've ordered a pair of 300's as well as a pair of 400's so will see where that gets me. The BC props included with the hardware kit are 3 blade 25 pitch.
