I bought this yacht as a kit in Auckland New Zealand 1973 as a project i was in the merchant navy working for the New Zealand Shipping co. on the M.V. Ruahine after we had dropped our passengers in wellington we would move around the coast picking up cargo it has taken me a long time to get the yacht like this a lot of alterations including the R/C

Sun was out, wind was down, so took the boat for swimming lessons. Went very well, no problems other than the silicone couplings trying to screw themselves off as usual, (too much bite and torque) and bunching up to the motor causing friction), (have a possible fix I'm working on for that today) Heaps of power from the 2 - 540 HV brushed motors only running on 3s. Never went much more than a tad past 1/2 throttle which was spot on scale wise.

Very quiet as well, - mind you, couldn't hear much anyhow with a road milling machine working at the end of the pond about 150m away, at around 80db where I was!!😠😠😠😭 Of course it would have to be there today,! something like this always stuffs my plans up, cars, trucks, screeching seagulls, people talking to you while you are trying to make a nice quiet video etc etc. Can't seem to get away from noise. Added to that, the video's crap,- as soon as it uploads to YT it turns to rubbish,- was quite acceptable till then.

Must be the wide format they use, as it's fine in a small screen (ie YT preview) and my computer. Worst thing is, it took an hour to load this rubbish on a fibre connection!! Not loading any more till I get a better camera, "Santa, did you hear that ?"😁

I might de-power it a bit, as it has too much power really,- might put 2 540 45T motors in which will run on 2s nicely with 30mm props (has 35s at the moment) and not be as touchy on the throttle. You can steer this just using the throttles it's so bitey. Spins on the spot like a jet boat as well. Stereo worked well, but the IR remote doesn't like working too far away in bright sunlight, (have a separate vid, but YT would give a copyright warning, so I won't put that up) The vid is garbage, but you'll get the idea😁

Short vid taken by a friend recently, of the model, towed by the RC scratch built Jeep -(taken with his tablet, - a bit shaky but he is over 80) I probably shouldn't have been doing circles around him, but we were doing this in a carpark behind his apartment, (magic location by the way, right on a marina.) Had trouble finding reverse due to the EL Cheepo ESC,- have a new one coming. Jeep uses a geared 550 motor on 3s LiPo.

Boat is featured on waitematawoodys.com today as well, with all the big boats,- quite a privilege, as they don't often feature models! Lucky to have had my ST and HSL on there in the past also, as they were models of ex NZ RNZAF boats which were being featured.

https://waitematawoodys.com/ (site for all NZ built classic Launches)

Video by Ken R.

Fitted the new 550 45T brushed motor as a replacement for the ancient and slow 70s Graupner monoperm. Goes a lot better now and has a decent speed range. Handles and rides quite well for a skinny boat. Prop is a Graupner 40mm 2 blade (don't know the pitch, -fairly fine) Using a 2200mAh 2S LiPo battery which probably gives around an hours running slowly, or 30 mins of hooning around.

Battery was only charged to 8.25v and ended up at 7.7v. (45%) after about 3/4 hr. I'll probably fit a Hobbywing ESC as well, for a bit better reverse action, as the El cheapo car one is a bit slow finding reverse at times.

Part 1. ideal conditions; nearly 30°C, cool Bier at hand😜
Sea Scout built by Dad in the early sixties with a Taycol Target and 6V lead acid wet cells (very wet😡). Renovated and dragged into the 21st century over the last several months 😉
See Build Blog 'Sea Scout 'Jessica'' for details!
Motor: Propdrive 2830, 1000kV, 30mm 3 blade Raboesch prop. Quicrun 16BL30 (30A) ESC with BEC.
Tested with 3 battery types, all started with 99% measured capacity-
1. NiMh 4.2Ah 7.2V, nom. 408gm.
Result: Speed sedate (OK 😉scale river cruising!) No planing.
Max current: 3.6A
End status V / capacity left: At end of short run ca 3 mins. 7.78V 99%.
2. 2S LiPo 4.0Ah 7.4V nom. 257gm.
Result: Speed still sedate but due to lower batt weight at least the forefoot came out of the wet stuff! Max current: 4.1A
End status V / capacity left: At end of short run ca 3 mins. 8.25V 93%.
3. 3S LiPo 4.0Ah 11.1V nom. 315gm.
Result: Now we're getting somewhere!!😁
Good speed, manoeuvrability and planing 😊 Max current: 7.5A
End status: 11.95V 74% after several long runs, ca 20 mins total.
Estimated (extrapolated) endurance on a 4Ah LiPo around one hour - mostly 'full bore' - 'Pedal to the metal man' 😊

See also:

The competition!

Final run. (Beer was getting warm😁)

Cap'ns log entry:
Boat dead-weight w/o battery: 1.8kg.
Spray rails to be added!😲
Slight list to port to be trimmed.
Rudder servo to be reversed!!😲
Keel protection to be added: some scratches and flaking from stony sloping shore 🤔
Summary: much as expected👍 Forget anything less than 3S.
Anyone want to buy a batch (4) of new 2S 4Ah 45C Lipos? 'One careful owner'!
Happy boating people, Cheers Doug 😎
PS Many thanks to Camera girl Gisela 👍
Recorded in 1080p HD.

I wanted to try the driveshaft brake I'd recently fitted and thought I might as well do it on an actual ramp. This ramp has around a 30deg slope so it was a good spot for a test. Tried it with just the trailer first, (don't want my boat model disappearing down the ramp at high speed) and it worked well. I've done another vid where I but a 3kg water bottle on the trailer to simulate the weight of the boat, and that also worked well (although it's a bit scary when 13lbs starts rolling down the ramp backwards.

Lost the trailer a few times going over a big join in the ramp ( forgot the tow ball lock nut) so had a few goes to get it right. I was surprised how well a piece of string round the driveshaft could hold that weight so easily. Only negative is that it's not as good in forward, (would need another wound the opposite hand on the shaft) but that's not as important as reverse control. Still waiting for the weather and tides so I can try another launch. This ramp's not bad, but a little rough !

Set the new Surpass 3000KV 36 diam finned in-runner up in the boat, and did a tank test. Lots more power than the HV brushed 1200kv 550, but with higher idle. Re-did the reinforced silicone coupling and fitted a small collar to the inner end of the motor shaft to hold the tube from moving forward against the motor, as with the extra torque of the in-runner, it was trying to twist the tube off the shafts. Seems to be hanging in there static which is a promising sign. Once running, the load will come off which should help.

Runs full at around 4A and the battery holds at around 3.8v/ cell )alarm is set at 3.6 for safety, (as a sort of rev limiter) performance should improve a bit now. Have to wait till tomorrow as the restrictions end at 6am Sunday, (then have to hope for good weather for the test) The prop in the jet is a 28mm 3 blade racing prop which I modified to fit. Don't think I'm going to get much more out of the jet unit without it exploding😁, (it's only plastic I think, not GRP), - might have to buy a back-up and fit it with better quality bearings etc. If the jet was in the usual 'plastic' 24" toys it would be a rocket, but it's pushing 6lbs which is a challenge😀

Note the police chase outside in the background😁- always action around here, lots of hoons in cars😁

I purchased a small BT player which has a number of features including recording. It can output using BT to a BT speaker, so I recorded an engine sound (Detroit 4-53 for the seaplane tender) I found, and copied it a number of times using the player and the vid on the computer (paused the recording, ran the video back, started recording again, etc etc) worked reasonably well. Very hard to find a sound which is continuous for a decent length of time, especially sounds of older engines which may not exist or are in museums. Used the BT feature to send the sound to a small BT speaker sitting in the boat.

Now I need to find out how to get the sound to accelerate and somehow get it into my 'GT Power' engine sound unit files, (the sounds on that are in lots of small WAV files linked to the TX throttle movement (I think they are on an SD card and they just loop where you stop the throttle, and advance or retard to the next file as you move it) A bit of investigation is in order.😀

Just for fun ! (I did this for the local school kids where I was caretaker about 6 years ago).
Best wishes to all !!⛄

Second test was slightly better, using the aluminium spiral cut universal which came with the jet unit. As you can probably hear, it was horribly out of balance (even with cable ties to reduce it). It was not even drilled centrally and the spiral is right hand when it should be left hand, (like a spring twisted against the wind, it wants to deform). Slight improvement in speed on the first test (no slip this time) but the noise was horrendous.

Have pulled the jet apart and found that the 3 blade prop is around 1 mm too small for the hole, causing cavitation (see loads of bubbles in the jet stream) which is causing loss of thrust. The prop is the wrong type as well, with rounded blades, so I have modified a larger prop with more pitch to fit snugly in the unit to hopefully increase thrust. The shaft is also wrong, with a flat cut almost half the diam and carrying on through the bearing, allowing the grease to fly out.

I actually saw a Chinese site on Al Expr stating that "some dimensions on the product may be different due to the number of machines and operators involved in its' manufacture," SERIOUSLY!!??? their quality control must be utter crap and the operators not skilled enough to eat their lunch😐 Why bother having a dimension at all?? Little wonder nothing fits properly.

Unfortunately, most model shops sell the very same stuff, unless you want to shell out muchos dolleros for European stuff. I have just ordered some 4mm silver steel to make a new shaft, so a coupling or silicone tube will fit better. Also ordered some solid connectors to try. Vibration is wasted energy so it needs to be eliminated. Hopefully the mods will improve things and allow the motor to run on 4s rater than 3s. Worked out that the motor is only 1200KV, so it's only doing around 13,000 rpm under load. Probably will need around
18,000 rpm for proper performance. Onwards and upwards (or forwards as the case may be.😁)

Sorry about the blurry vid again, but my camera lens is knackered.

Weather was perfect tonight for a test, so I did the 15km trip out to the Gulf harbour pond (most weed free pond) to throw the boat in. After a thorough under water hull inspection from the marine department, she was off. Everything worked ok except the silicone drive tube which had become enlarged due to soaking in the grease coming out the front of the jet shaft. It was slipping badly and probably losing about 60% of its' thrust. Manoeuvrability is excellent but reverse leaves a bit to be be desired. Steering in reverse is perfect but the thrust is not going forwards enough from the bucket. Might have to build in some nozzles to direct it better.

Smoke air and water are working as well as can be expected, (smoke is a bit wafty, but with too much air introduced it will disappear as it gets thinned out too much to see) I was not expecting miracles as this was a bit of an experiment (modified cheap jet unit with unknown abilities) but at least it shows promise😁. If I can find a coupling which is concentric it will solve the drive problem.

Trouble is, the Chinese insist on making a 4mm shaft, 4.95 (or whatever) which is useless for balance in a 4mm ID bearing for example. Fine for cars, but no good for boats or planes due to balance requirements (it's a mission trying to balance plane props due to this thinking,- they do it with everything) shafts for electric motors are a nightmare at times as the play they build in, can ruin an otherwise good motor. I might have to buy a flexible rubber/nylon universal or a collet style( preferable as these take up any undersize on shafts) to fix it. They included a spiral alloy one with the jet unit which is as loose as a rooster in a sock, and only good for slower things like 3D printers etc. One of these days they will learn how to machine things to fit.😐

Some details of Thor. - by Dean Ratcliffe.

Thor is a freelance design of a multicat vessel. These rather unusual ships are real workhorses, designed as a work platform, often with a hiab crane. The square hull gives a large flat deck, with plenty of open space for a work area or for deck cargo. The design also enables the vessel to be used as a tugboat, either pushing or towing and are often equipped with large deck winches and strong points for this purpose. A true Swiss army knife of the sea, able to adapt to most roles, some even have additional internal fuel tanks for refuelling other vessels.
More info found on -
Model Boats Website - BoatClubs & Lakes - Buxton Model Boat Club

https://model-boats.com/places/60518