OK, usual story so far. Dad started a build in about '62 and by about '66 had a complete running ED diesel powered boat that did some trips across ponds in S London. He did a nice job too, odd because while he is a great mechanic and a passable metal worker you wouldn't ask him to put shelves up or do anything with wood as a rule. All steamed in the kitchen with an overworked kettle apparently. it never got a top coat of paint or radio, the latter as it was too expensive at the time for him. There it rested until the early 80's when a 14 year old me painted it the wrong colours (but not far out), put the fittings on and replaced the coolant pipes etc. Radio still too pricey on a paper round salary so it did some more trips over Gorleston pond. Finally it made it's way out of Dads loft in October this year to be finished off.
So here we are in 2012. The 2.46 ED diesel was being run on the bench, spraying a gentle rain of castor oil and kerosine over everything within 3 feet when disaster struck. All went quiet except for the still spinning flywheel. The crank output end has loosened from the rest of it. it could no doubt be repaired and I would love to run the boat as intended but an electric conversion makes sense of course. The sight and sound of a diesel Mk2 screaming across the pond, trailing a rainbow of unburnt fuel on the wake behind is set to be denied to Norwich. Better news, the boat is sound structurally, all well protected with primer and interior paint at build although there are two small delaminated bits on the upper structure to fix. Many of the fittings are damaged and need replacing and the upper deck paint needs freshening after 25 years in a loft, the rest is OK though. Colours on the hull are wrong, it is all dark blue but I did that all those years ago and it is still shiny and waterproof so I'll leave it for now. Plan then is for a Graupner 700BB turbo 12v running either 7.2 or 8.4V (depends what will fit), fit radio a basic 2.4Ghz 2 channel and ESC and see what happens. I will leave the 40mm 3 blade prop at the moment and the original shaft which means a custom coupling. I should say I know next to nothing about RC or model boats in general and am on a limited budget so it may all go horribly wrong! Having said that I am an engineer by trade so should manage to muddle through...time will tell. I am off shopping for bits this week so hopefully will start work on it soon.

OK, went out and spent MONEY, not nice but as Dad is financing the final build of his boat it wasn't as bad as usual! Played with the new toys for a while than decided the motor mount was first up for attention. Problem one, motor is a bit longer than expected as I hadn't allowed for the connector lugs sticking out the back and the UJ, a Graupner 5-6mm, is much longer than it needs to be so I had a bit of a clearance issue, I.e. I didn't have any between the motor and the bulkhead, in fact it is all about 10mm too long. So I have edited a bit out of said bulkhead and will be bonding on a stiffer to what remains (only a 2" diameter cut out so not too weakened). That done the next job is to make the motor mount itself, could have bought one but around £13 for a bit of ally bent wrongly (with the grain) and a couple of holes in it sounds too much to an aircraft sheet metal herbert like me. While I am borrowing company time making that I will turn the old prop shaft down from 1/4" to 6mm at the motor end then we shouldn't be far off installation of these bits. Photo's soon.

OK finally got going for real at start of Feb. in Jan all I did was reinforce some of the old joints on the hull that looked a bit dry and dubious, used Araldite resin AW106, not the lightest way of doing it but it will work OK and I could run it up under the deck/hull joints as well as the bits I could reach. I didn't fancy taking the deck off, what with my woodworking skills...The motor mount is more my area and this was quickly folded up and drilled from .071" aluminium alloy, slotted holes allow a good alignment to the shaft. The rudder was always a problem, a very short tube (I'm sure there is a tech name for it) allowed water to get in with the boat at speed so I changed that for a longer one and new rudder, which is far too big at the moment I suspect but I will wait and see before I cut it down. The servo is mounted in the aft bay on a galvanised steel bracket, there should be enough room for a link and again I slotted the holes to help set up the correct ratio. I am currently doing a bit of framing to sit the new aft hatch and electronics tray on, the latter is going just aft of the motor in what might be called the 2nd to last bay (are the divided areas in a boat called bays???). The learning point is the speed controller, I bought two 7.2v batteries thinking to run at either 7.2 or 14.4 depending on how I found the performance/my RC skill (none) ratio. Then I bought a 12v ESC... 😯 I don't know, can I push my luck and see if it will take 2.4v extra without setting things alight or do I buy a new ESC or 2 6v batteries?

Thought I might be doing some gentle turns around the pond by start of March but didn't get further than the bath! The job was going well, a new frame for the aft end and a cover/deck to sit on it, a frame and tray for the electronics to sit on. The water pick-up for the jacket on the diesel engine now runs water around in a loop and out the back of the boat without actually doing anything but I thought it might look a bit more interesting to retain it. All electronics mounted and working, batteries in situ alongside the motor. Bit of a bother with the receiver/ESC/servo connections in so far as the instructions that came with the (cheap) 2CH 2.4Ghz set gave no real clue as to what went where. There were 4 sockets, marked /- then Ch1,2 and 3(?). The instructions showed the ESC on Ch1 and the servo on 2. The leads from the ESC and servo have no key/spline to ensure they only fit one way around so I crossed fingers and plugged in. Various combinations later, mostly resulting in the throttle lever on the Tx operating the rudder and nothing else, I ended up with the ESC in /- and the servo on Ch1 which seems to work fine. I think I am lucky not to have let the smoke out of the circuits really but being an RC virgin I had no idea of what the set up should have been. I also noticed that the motor runs a higher rpm in reverse, is this an internal ESC resistance thing, the higher rated amps for fwd causing the resistance increase? Haven't checked it with a meter so can't comment on the voltage actually being delivered as yet.
Anyway, I put everything in and gave it a spin on the stocks- god, what a row. The motor is quiet enough on its own but with the shaft and UJ in it is awful. I did know the original brass shaft was a bit loose to be honest but hoped to get away with it just for a test run or two but no, it has to go. Most of the noise seemed to be from the UJ though which I thought a bit odd as it has almost no angle to run at. Solutions, replace known problem of shaft and try a different UJ. I didn't fancy getting a 50 year old hull too upset removing the old tube so have gone for a 4mm stainless shaft/tube which will fit inside the old 1/4" ID tube and save disturbances. I don't think the motor will produce enough torque to twist the shaft. This is the next job along with making another motor mount as the thing needs to be in a different place now.But I couldn't resist a quick if noisy test so into the bath just to see what we had- at 7.2V it is moving a fair bit of water with its 35mm 3 blade prop and revs don't drop much under the load so nothing seems to be stressed there but I am sure we could go a bit bigger on the prop and of course when I resolve my battery issues (see below) we will have about 12v anyway. No idea what this all might translate to in terms of forward speed but that doesn't really matter that much anyway. Tune in for the next exiting episode soon...

OK, end of March 13 finaly saw the beast on the water at Gorleston pond, where it last ran about 30 years ago!
It was a 50/50 first test, and on the plus side she didn't leak or capsize, didn't crash into the submerged hazard the local council call a fountain and it trimmed OK. in the neutral camp we had fairly sedate performance with only 7.2V available on the 40mm/3 prop. I swapped that for the only spare I had, a 35mm/2, and she went a little better. At which point the negatives need a mention, like the rudder not having enough travel, turning circle of a real supertanker, and worse, the propshaft seized. End of test.
Once home I found the stuck shaft was down to my choice of lubrication. I went for a dry lubricant which seems to turn into glue with a little water and rpm so a poor choice. I replaced it with a very thin ultra low temp grease designed for aircraft which is another odd choice I suppose but it has good load bearing and will not drag the shaft too much. The rudder links got adjusted for more sweep at the business end and finally I looked at the volts issue.
I had two 7.2v Nimh 6 cell batteries. Had I realised the limitation of my speed cotroller I would have bought two 5 cell but there you go. Not having the funds for replacement I pulled one apart and removed two cells, soldered a new link and re-insulated it. Then I made up a series link with a couple of new Tamiya type connectors and had 12v at last. I also changed to a 45mm/2 prop.
Test run 2 was at Sheringham pond. Very nice venue. A much livelier boat, she was getting her bow out of the water a bit and accelerated well. Gentle turns at low speed OK, tried a bit more speed in the turn and oops, bit unstable. I moved the batteries back to about 6" aft of the middle of the boat and that sorted it, much better, nose up more at speed and stable at a sensible speed in the turns, which were now as tight as I would want. I was quite chuffed, she looked good despite the scruffy paint and no deck fittings, with the bow up and stern below the water line. I can't claim a rooster tail (it's not a speed boat) but the water had a sort of coming to the boil look! The next test run is just for experimenting with prop sizes when I have a couple more to try then it will be time for a proper battery mount and paint.

OK, last post for a bit, did another run today at Sheringham with a 45mm X prop- blimey, how fast (to me at least). Bows and all the mid section out of the water and spray everywhere- too fast really as very windy and into the wind I really thought we would be right out of the water 😱 . I think the 45mm S is best for most times but if I want the speed I know she has it in there!

X45 prop which is too much really, and rudder that looks too big to me but works fine.

Might need a little fettling on the rather rough servo bracket. And I need to make a permanent link rod now I know the length although I might try a longer arm on the servo yet.

Need to re-do the mounting plate to neaten things up and tidy the wiring but everything works.

700BB turbo and UJ, yes the motor is in the middle of that cut-out!