Daz........
I understand you have chosen your electric motor .....and from memory it was from a mobility scooter??........if this is correct, the design of the machine [gearing??] would be for the motor to rotate in one or a 'preferred direction'
Would I be correct in thinking that model Tugboats would spend 80% of their time on the water going FWD?........and not actually manoeuvring astern?......
So if you plan a direct drive system, why not test the motor and current draw on the bench [preferably with an external power supply.....not a battery]........ let the motor run for 30 minutes....... thumb & forefinger will get hot
, try a wooden clothes peg pressed over the shaft as the load .....then 30 minutes in the opposite direction......
You may actually find
that the motor has a preferred direction of rotation.....[remembering the 80/20% estimate]
There may be 5000 pages of technical yes's or no's on propeller LH or RH........I haven't found any clear definitive proof of the advantage of a RH to LH single direct drive .....or LH to RH
for Tugboats...& lets not further
confuse any other Class of vessel
Derek