German S-100 Class Schnellboot (Fast Boat)



The SBoot Electrics

I recently (2015) bought three 120Amp waterproof brushless speed controls:

These seem to work OK and have reverse which starts from about mid stick position, however they don't seem all that smooth at the low end of the revs but we'll wait and see if that is an issue or not. Having the same amount of reverse as forward is not a good idea in a boat as it will "dig in" going backwards and swamp the boat, even in a car you only have 1 reverse gear, I'd prefer to have more forward stick and a smoother start with only about 10% reverse speed but getting a speed controller with reverse at all seems to be a bit of a trick so lets not be too choosy.

 I also tried one of these speed controllers on the 1/35th Schnellboot model with three much smaller brushless motors all wired in parallel to see how that works, could have been a disastrously short trip as I wasn't sure what the speed controller would make of the signal back from all three motors but as long as the motors can run freely they seem to sink up ok and all run at the same speed and quite controllable so this is the path I will take for the 35th scale models, i.e. one battery, one speed controller. The 35th scale props for the Schnellboot that I bought from G-Force have counter rotating wing propellers so one motor needs to be running in a reverse direction to the other two, to achieve this, two wires of the reversed motor need  to be swapped over.

This is the 35th scale Schnellboot hullframe with three small AXI brushless motors installed all wired in parallel running on one 120Amp HobbyKing brushless speed controller.


I have purchased a 2.4Ghz Futaba 7 Channel radio system:

This is awesome, I can use all 7 channels to control various functions! One paddle (and one hand) could control steering and speed so the other paddle can be used for gun altitude / azimuth or similar and there is another rotary knob to proportionally control a servo which I may use to experiment with the "Llursen" effect, this then leaves two toggle switches to turn things on/off or launch torpedo's or similar. So five proportional controls and two switches.


I also bought a number of 5000mAH Turnigy Lipo batteries a while ago and recently a Venom balance charger:

I've had these batteries for well over a year and had no effective way to balance charge them until I bought the Venom charger in early 2016 and I was surprised how well the batteries have kept their charge.

Balance charging is so important for Lithium batteries as all of the cells are in series and if they are not balanced (in voltage and therefore charge level) one cell can become discharged before the others, especially at high loads (and I am planning very high load currents) and then that cell will reverse polarity with disatrous results.


(C) Copyright 2016  - John Drain