Another boat, but not quite as small this time. The hull for this came from the same attic clearout that Eric the tug came from, but I built this one up first; I can’t remember exactly when I started it off-hand, but I think it was the early years of secondary school. Anyhow, the hull’s a thick fiberglass job, probably dates from the 60’s. Tidied it up, made a new superstructure for it, roughly styled on the NWNWSFC Aegis patrol vessel, but kind of re-worked round the back end, and labeled up as general coastal rescue. It’s been through a variety of different powertrains; It’ll have had a petrol engine originally, but this had been taken out by the time I got it. I initially put in a direct-drive drill motor, a couple of lead acid lantern batteries, and a kind of crude homebrew PWM ESC, controlled using a servo linkage, a pot, and a couple of microswitches from a duff microwave to trigger full speed and reverse. That setup lasted a fair few years, until one of the power transistors lunched itself and went short-circuit, leaving me with three speeds; almost full speed, actual full speed, and full power reverse. On a pond full of boats rather more detailed, rather more expensive, and, I suspect, rather more breakable than mine. Thankfully, I got it into the side, and my dad caught it; took the lid of to an amazing quantity of theatrical smoke. So, that was kind of that. Swapped it out for the ESC from an old traxxas buggy that I’d just put a new ESC in, (it was fusing the relay contacts in the old one), which stayed there until this year. For some reason, it had a really nice grumbling and growling motor sound with this setup; Never really figured out why, but I suspect that it probably wasn’t doing anything good to the motor. Sounded the part, though. Unfortunately, however, the battery life wasn’t exactly spectacular in this setup; I think it tended to last 20-30min or so. I decided that I probably ought to gear the prop down, as it runs a pretty steep racing prop, so I rigged up a ~2 or 3:1 step down. Gave it a bit more performance, and a bit more battery life, although it wasn’t the best sounding of geartrains, and, since it was still running with two lead-acid batteries, it was a bit on the heavy side to lift up and plane. So, time for the modern world. Earlier this year, I made the jump to LiPo & brushless on it; It’d worked out OK on the tug, and the parts were relatively cheap (I think the whole cost including battery was maybe £20?) so in went a 5000 mAh 3C LiPo, a ~200W outrunner, and a BLHeli ESC, mounted in on a laser-cut plywood frame, which fitted over the original motor mounts. Or, at least, should have; Unfortunately, since I was in uni, and the boat was with my parents, I was asking my dad to take measurements, and I accidentally managed to flip the one of the dimensions, so my nice precise motor mount had to be stood up on a few blocks of balsa wood for the gears to line up. The power boost & diet helped; it comes pretty close to planing now, but the balance still isn’t perfect, and neither is the gearbox; still, that’s where it is at the moment.
So, plans for the future…
- Re-do the motor mount. I’ll either re-cut it so it actually sits on the motor mount and lines the gearing up correctly, or I’ll drop back to direct drive, and assume the relatively low KV motor has enough grunt to spin the prop better than the old brushed drill motor.
- Fresh coat of paint; it’s still all rocking the original coat of household paint I put on it originally, and it’s picked up a few dinks over the years. Also, I didn’t do the greatest job of sanding it, so there’s a few ridges between planks of balsa in it.
- Wire up some lights, and maybe an interior.
- Up the details a bit, and add a rotating radar mast.
- Swap it over to 2.4ghz
So, that’s that. Bit of a text-heavy and photo-lite one, this; I’ll try to add more pics, but I’m feeling lazy at present, so I’m just going to pick out a cover pic and leave it there.