Topic: Starting a build of an MTB

[Alan329]

Having recently completed my build of the Dimarcha, I looked around for a similar boat but military and I have settled on MTB 488.  I have had a look at the recomended list for motors but I am a bit confused.  The Dimarcha has 2 Kestrals running on 7.2v but is much slower than I expected, about half the speed of Rons Dimarcha in the Youtube video, but given a max speed of 19 knots for the original boat I can live with that.  With MTB 488 running at twice that speed at 39 knots, I want to make sure it is fast enough.  Looking at the youtube videos for the 488 and the 385, they both look pretty fast, but the 488 recomends 2 x Kestrals whereas the 385 recomnds 1 x Kestral.  Both boats are similar size, so why only 1 motor for 385?

[rondean]

Hi
 In you Dimarcha what props are you running ? and are your motors linked or separate with separate esc and batteries ?

the 385 is a single motor / batterie so 1/2  the weight, 1/2 the cost,  make it fast. that was the only way 25 + years ago, the larger boat (488 ) has les wetted area so can carry more weight, just as fast
 Ron

[Alan329]

Hi Ron,  I have uploaded a video to Youtube, I have obviously done something wrong as your Dimarcha is much faster in your video.  The two Kestrals are parallel wired to one ESC running a 7.2v Nimh battery on 30mm counter rotating props.  It runs and handles very well, it's just a bit slower than I was expecting. 

https://youtu.be/PImtD5UofUc