Copied over from Colin's 'ESC motor pairing' thread, re motorising LST 368 (as she will become😉)
Nerys,
Most of your questions are already answered in Colin's thread, esp. re two motors on one ESC😉
Yes, but ONLY with brushed motors. You won't need brushless for a slow, hefty displacement hull. I don't suppose you want to get into LiPo batteries either.
Actually earlier LSTs had a top speed of around 18knots.
But you're right, the Mk2s, such as 388 or your Dad's 368, top speed was around 12/13 knt and cruising speed 10knt.
Model-wise-
Your model is (will be) a tad over 1m.
For comparison
My 1.35m, but much slimmer, destroyer goes like the proverbial off the shovel with two 540 type brushed motors on 12V (2 x 6V in series).
I reckon for your LST 2 x RS385 type will be more than adequate, with some reserve.
I say 385 and not 380 as the 385 has 5 poles and thus starts and runs much smoother than the 3 pole 380s. They'll draw about 1A or so on load and stall current is about 4 to 5A.
They have short circuit (jammed screw) protection anyway👍
Suitable 385s you can get here at Cornwall Model Boats. Nice trip out to pick 'em up, if you're allowed🤔
https://www.cornwallmodelboats.co.uk/acatalog/mfa-re385.html#SID=2304
ESCs
If one per motor then perhaps Mtroniks Viper Marine 10.
https://www.cornwallmodelboats.co.uk/acatalog/mtroniks-viper10.html#SID=2177
If one ESC for two motors then Mtroniks Viper Marine 20. Cheaper than two Marine 10s as well😉
https://www.cornwallmodelboats.co.uk/acatalog/VIP20PNP.html#SID=2177
Battery;
The motors are most efficient at close to 12V, and your model will need a fair bit of ballast, a pair of 6V 10Amp hour SLAs in series (as in my destroyer) will do nicely. And run your ship all afternoon, ca 5 hours at least. e.g.
https://www.cornwallmodelboats.co.uk/acatalog/vrla6_10.html#SID=426
If 4kg (2 x 2kg) is too heavy then-
https://www.cornwallmodelboats.co.uk/acatalog/info_P5510035.html#SID=426
These are 4Ah and weigh less than 1kg each. Should be good for at least 2 -3 hours running.
If you can fit this 12V 7Ah SLA in it should give you a run time of 3.5 to 4 hours or so and weighs only 🙄 2.2kg.
https://www.cornwallmodelboats.co.uk/acatalog/info_P5510050.html#SID=426
Contra rotation?
Yes. I've read in the LST development history that the engines were designed so that the shafts could be coupled at either end. So to reverse one shaft they simply installed that engine bassackwards😁 For best manoeuvrability I'd recommend inward turning shafts, as the ship only had one rudder. I.e. to move ahead and seen from behind; port prop turns clockwise and the stbd prop anticlockwise.
Deans don't mention them but I assume the props are included in the kit as the shafts and toobs are.
Hope this helps. Now stop your 'argy bargy' and clear the decks for Dad's LST!😁
Cheers, Doug 😎