open day 2021 had 2 sessions - IC fast electric in the morning, scale sail in the afternoon...

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 built this model during four long years. my Lulonga is nearly whole scratchbuilt model (about 75 cm long) except the steering wheel and position lamps.
The model has a plywood and balsa hull construction ,plywood decks,from hard polystyrene sheets made superstructure,laminated with veneer. Sidewheels with skew paddles, two DC 12V independent electric motors with gearboxes controlled by ESC. Electric LED lights, steam sound module, sirene and horn.Tx/Rx 6 channel HK 2,4GHz.
completion expected in spring 2014
More infos about building you find at > www.paddleducks.co.uk <

some videos are here at Model Boats too >
http://mdlbt.com/19852

wiring diagram you can see here in my albums
http://tomarack.rajce.idnes.cz/RC_model_Lulonga#lulongaelschema1.jpg

This is the four foot Sterling model of the Chris Craft Corvette with sound module installed. I was able to reupload the video after using "Handbrake" software. Appears youtube doesnt like lower resolution videos.

Finally got a good day to try the new brushless motor. Boat goes 100% better now (if a bit noisier) 3s 25c 2200mAh liPo got a bit too hot, so probably need to up the C rate to 40 to keep it cooler (maybe install a fan as it's closed under the seat) It's pushing a 6lb boat with a 26mm jet with a 3000kV brushless so it has an excuse to get hot, (only got down to 3.7V/cell after that run, so not too bad). Runs with a more scale look now which is what I wanted. Took a bit of experimenting, but got there in the end. Thermostatic cooling fans for the motor worked well, and within 10 mins the motor was cool. Only used around 2/3 throttle so as not to stress the coupling too much (you can hear it protest a few times, - silicone tube slips slightly making it squeal)- automatic rev limiter😁

Sorry, vid is blurry again ☹️ (original's fine -HD) but something happens when it goes through my movie editor then to YT. Keep procrastinating about getting a better camera (or maybe it's just the editor. - More experimenting, this is getting tedious😐

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😁

Finally got a good day, so raced down to the pond and threw the boat in. 2 problems, 1: battery had run down a bit with all the testing, and the new 18kg digital servo winch needed every bit of 4.8v, so functioned intermittently, meaning not much sail control, 2: jib boom needs a kicking strap to stop it 'skying' and tangling (knew it would happen but wasn't a worry). Apart from that, everything worked perfectly ( cheapo China Futaba knock -off rudder servo still worked fine on the low battery which is a bonus)

Sailed brilliantly like it did over 40 yrs ago, and as it's set will sail hands off on a reach, being nicely balanced, (even with the crappy jib,- which I had to make,- well actually my mother made for me,- back in 1980 after the original was stolen by a kid at the beach, while my back was turned😠) Funnily enough it was made on the same Bernina I used to sew (horrendously) the jib foot after trimming it for the boom a few days ago.

A few more things to improve and add, but pleased to have it back on the water. Another crap video, -seems to get blurry once it's been through the movie editor and You tube ) One day santa might bring me a Gopro, ("yeah right"!)

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.😐

Policing at the Pavilion Gardens Lake enlist a new "Rookie" from the Buxton Model Boat Club.
Under the watchfull eye of owner and builder Graham Royle, Decoy Duck Donald, turns a few heads while he Ducks and Dives to maintain decorum - !.
REMEMBER - change "quality settings to HD 1080p " when viewing on youtube.
More photos on "Boats Clubs & Lakes" / "Buxton Model Boat Club".

Surprise! 😀😂
A good laugh from 92 years ago😊
See also

😎

As a follow-on to Grahams' comment on our latest collaboration on a smoke pulsing 'capacitor driven' device, we thought it was time to 'chuck it out there' and see what you think. I saw the vid on the guys warship with the very fancy gun smoke system a while ago and thought there must be a simpler way than the sophisticated and technical way he did it.

Having done press setting in my early days, I remembered that a big press we used to set had a hydraulic capacitor which helped get the ram moving (pretty much what electrical capacitors do for motors etc) I started with a common party balloon with no container and knew Graham would be interested, and it progressed from there. As usual, Graham has done a fancy bit of electronic control on his, with solenoid and timing and has it working nicely.
(just received my new solenoid which I will be adding in due course)

Balloon is stopped from filling by a micro switch to the air pump and air is released by solenoid at whatever timing you need (depending on how well your smoker can keep up). If the system has no leaks, the 'capacitor' can hold air indefinitely, ready for use, and will re-fill automatically, (pump only runs to re-fill) This idea can be modified to suit anything (guns, exhaust startup and run, steam to simulate steam whistle etc) Balloons of all shapes can be used eg -(long thin sausage balloons could be fitted inside a tube if space is an issue).

With a good air pump, the 'capacitor' will fill quite quickly and some good pressure can be achieved.
JB