Hi John, think somehow you've got the wrong end of the stick!🤔 All BECs are Battery Eliminator Circuits of one sort or another. The objective is to eliminate the separate receiver battery, sometimes necessary purely to save weight and/or space in small models. If you do that then the RX power must come from the main drive battery, which then has to supply all RX functions; servos, switched lights etc etc. Personally, if the boat / ship can carry it, I prefer to use drive batteries for just that and use separate battery for the RX and special functions. Some of which, like smokers for instance can be current gobblers. Cheers, Doug 😎 PS If you ever find a way of eliminating all batteries and still get the RX to work and the boat to move PATENT IT QUICK!! 😁 Cheers, Doug 😎 Hmmm! Maybe a raft towed behind with an array of hi-current solar panels!? 😁😁 Years ago in my work in NAVAL COMMS systems I once suggested to a shipbuilder, who was complaining about the number of antennas needed, to put some of them on a raft behind the ship 😉 Now they are doing just that with antenna buoys from submerged submarines! No credits 🤔 ... SIGH 😉
[Score: 8/10] 33"/3700g "Maureen Lee" Capable of 3mph and a runtime of 90mins Single Propellor (3 Blade 30mm) Direct Drive to a 550 type (3 Blade) Powered by NiMH (7.2v) 3Amp/h Batteries Controlled Through Unknown ESC - Comments: The “Maureen Lee” started out as a Bristol Bay ready-to-run semi-scale model of a typical European fishing cutter. Many modifications were made to her to make her look like an old, worn-out fishing boat. Factory-installed switchable work and navigation lighting means that she can even be operated at night. A 550-size electric motor and metal propeller allow for ample power. A Bristol Bay model is supplied practically fully assembled… you need only mount the two masts and install the batteries. Numerous robust details make this model look great at home or on the water! Technical specifications: Hull length: 850 mm Width: 220 mm Overall height: 737 mm Total weight: 3650 g
Adjusted the transom flaps and reprogrammed the ESCs to the softest start settings, retested. Until now, the test runs did not have the duration or stability to really examine what was happening. Using 3 S batteries acceleration is rapid and a is plane quickly achieved. However, as the acceleration continues and speed increases, the bow digs in. A cloud of spray then surrounds the model as the plane is lost. Brushless motors do not modulate as smoothly as brushed and adjusting power tends to be erratic or exaggerated. This is a scale model and the propeller shaft angles are per the plans. The thrust from the propeller has two components, horizontal and vertical. The horizontal propels the vessel forward. However, the vertical component forces the stern upwards and, correspondingly, the bow down. Have moved as much weight as possible towards the stern to counteract this, limited by maintaining the correct displacement and waterline. The easiest solution is to reduce motor power, decreasing both speed and the lifting component. Decided to retry the 2S batteries as they give reduced power. A plane is again achieved, but as the motor response is more docile, it can be controlled. If the speed gets too high the bow lowers, as before, but the motor output can be more easily adjusted. Spent a pleasant half hour or so with the vessel accelerating onto and off a nice, controllable plane. Much less spray and drama than with 3S and much more controllable. Have now decided to revise plans and use 2S rather than 3 batteries. A further advantage is the motor noise is muted and now sounds more like a gas turbine than a dental drill! Finally feeling comfortable with the model. Will thus shelve further building until the late fall when sailing in Canada concludes. Want to enjoy the rest of my fleet in the meantime! Will summarize my experiences with brushless motors in another blog shortly for the benefits of others contemplating their use. After restarting the model will resurrect periodic build blogs to advise progress.
Hi Onetenor Fuji 15 was a good glow engine which I don't think it is manufactured any more. Aero version max B.H.P was just below .40 when tested. If it was in a model aircraft it would have been around .20 to .25 depending on prop size which was good then for a small capacity glowplug . Marine versions when on the water put out a little less and the water cooled jacket was never as efficient as the finned cylinder jacket of the aero version. My two Aerokits boats, the Sea Commander and the Crash Tender are powered by single Speed 600 motors running on either 8.4 or 9.6 volt Ni Mh batteries. Performance is equal to that of marine diesel power such as the 2.46 Ed Racer and D.C 2.46 Rapier, the latter I used to watch in the fast steering events in the early 1960s at Fleetwood and Coronation Park in Crosby just outside Liverpool. Taycol powered versions would be obviously slower due to the additional weight were far more reliable and you did not have to put up with injuries from excessive use of a starting cord with kids watching and "extracting the urine" shouting "why wont it go mister". Boaty
My mate said it as Chrodite, with narey a hint of a pause, so I just assumed he knew what it was. I think it's effectively Admiralty brass, more or less. Not quite bronze, which is BLOODY hard! But ace bearing material. Goes brown but doesn't corrode further. He made hundreds of his own bolts from it, but had to sell the boat before he finished it. Bearings for a Supermarine? Mine has its original stuff, Just the end plates of Paxolin with felt oil pads held on with a pressed brass cap. It's worked all these years and there's not a thou. of slop. Amazing. I suppose though, mine never really got a lot of use in the few years I used it. Only odd weekends for as long as a pair of lantern batteries would last. Maybe 10 minutes each! Anyway, if it gets another working, great news. I'd like to see Colin's fleet of old codgers. I'd feel right at home Mind you, I sent off for a brushless ESC today and will have to get some batteries soon to test the motor. Its a tiddler, but it's 174 watts, so should work. Worth a try anyway as it cost me nowt. Martin
W1 by jbkiwi Chief Petty Officer Posted: 7 days ago
This is my scratch built 36" RNZAF British Power Boat 64' HSL (arrived in NZ 1940). I actually went on board this vessel in 1968 when it was still in original form (the RNZAF having disposed of it in the 50s) This vessel is still around and has been recently re modelled (2nd time since early 70s) and I was lucky last year to have met the present owner and go on board (2nd time in 49yrs!)and take a few photos. The vessel was modified a number of times by the RNZAF over the years (air intakes, removal of the fore deck machine guns, wheelhouse turret etc so I sort of went in the middle. I found a few drawings of the type in an old mag which had side and top views plus the bulkheads and their positions, so I took them along to a copying shop and kept enlarging them until I had the desired proportions. This worked out quite well and using a few methods from other models I had built, managed to frame (ply) the hull and then fully strip plank it in balsa. It was then fiber glassed. The deck is ply, lined and varnish stained. The wheelhouse is varnished balsa with the top removable for access. The wheelhouse interior has detail such as controls, instrument panels, skipper, steps to wardroom etc but is not too detailed as it is not seen. The boat has full lighting by remote switch, lights are all LED. The propulsion side has dual everything (motors, ESCs, sound units), would have had 3x but ran out of space! Motors are 28mm 2200Kv water jacketed in-runners (cooled by remotely switched pump) using 30A Chinese ESCs (have 5A BEC, Fwd and Rev). Twin sound units are 'GT Power' car units which have around 40 different sound selections, from Cosworths to diesels and are computer programmable (as well as manually on the unit ) for various functions. I am using one of the v8 sounds (8 cyls short in my application) which I think is as near as you are going to get to 3 Napier Sea Lions (for which there is obviously no sound available) They 'start' 'Idle' and are fully proportional in fwd and rev and can sound quite realistic (will attempt to put up a vid later). Batteries are 2x 2200mah 2s 20c LiPos which will last around 2hrs at least of sailing (they also run the sound units) Still have a few small things left to do (have just made wheelhouse air intakes) but don't want to get too fiddly. Just want to keep it a practical model.
My dad built this over a long period of time, starting in the '80s. The hull is fibreglass and the rest is scratch built from plastic card, balsa, ply, wire and anything else he could adapt. Although he installed the motors, props and rudders he never completed the RC installation or tested it. I inherited his boat models a few years ago and wanted to "finish the job", getting the model on the water. After installing the RC gear and batteries over the last few months, this weekend was the first sailing outside the bath at the Valley Gardens boating lake. Happy to report that it sailed really nicely, seems to be reasonably stable although I did restrict it to calmer times when the MTBs and faster boats weren't running ! HMS Cadiz was a battle class destroyer, laid down and launched during WW2 although she didn't receive her commission until 1946 so didn't see combat with the Royal Navy, serving with the home fleet. Due to the changeover in pennant numbering she was originally allocated R09 and later, when the admiralty decided to revert to the D for Destroyer pennant numbering she was assigned D79. To reflect this my model has D79 on the starboard side and R09 on the port side. She was sold to Pakistan in the late '50s, and renamed PNS Khaibar. She was sunk with the loss of nearly all hands in 1971 in the Indo-Pakistan war.
Thank you both. Do not have plans or a laser, but I take the point about allowing for the load re batteries ect. Only just starting with filler primer so have a little time yet to get the bits. Cheers all. NPJ
If you have access to the drawings, then measure in several places, level on the bench according to your marks and then run a pencil mark around the hull. Then you have a continuous line to align the tape with. Depending on the hull build, you might have to measure down from the deck (My dad added .75" to the depth of hull to gain displacement for batteries etc.) This led me to measure from the deck line. Once model is in the water, shift ballast around until it is level with the line.
Been researching the squeal and stutter on other websites and conclude RFI is probably not the major contributor. Others attribute it to a mismatch in the ESC / motor timing, which seems more likely. Whatever caused it, resulted in the affected motor failing. Which came first, the failure causing squeal or squeal causing failure is open to conjecture. Much to my surprise the manufacturer has decided to replace the motor under warranty. In the meantime, the motors I had planned to use originally (2800kV Outrunners) came into stock, so purchased a couple. Until now have had to use the ESC default settings as did not have a programming card. This also arrived with the motors. Following advice from another contributor reprogrammed the motors with “softer” start and acceleration settings. Fitted and tried the new motors and settings. On the bench, the squeal and stutter have almost gone. The motors are also more tractable. As the brushless motors are now going to be used for high speed operation only, with slow on the centre brushed, thought could simplify the controls by putting the brushless ESCs on one control system using a “Y” lead. However, this introduced inconsistent and erratic motor responses. Reverted to the two previous separate controls, port and starboard. On the water the performance is fine, as is the reliability. The 2S battery gave almost half an hours operation. The bow lifts nicely with both 2 & 3 S Batteries; plenty of spray. Hopefully resembling a 50 knot vessel! Another adjustment is needed to the transom flaps to try to hold the bow down later as she accelerates. Feeling now to finally be making progress with this model. The squeal has not gone, nor has erratic motor operation. The squeal is high pitched screech, rather like treading on a budgie! When it happens, bringing the control back to neutral and advancing it again almost always overcomes it. The erratic operation happens also when starting and is rather like the motors are not getting a signal to react to the control. Again, returning through neutral briefly seems to correct it. The revised motors and ESCs have increased the weight to 6lbs for the hull including all running gear, excluding batteries and superstructure. Whilst still trying to control weight have concluded this figure is satisfactory as the performance certainly is.
If you go to page 11 video blog and half way down there are 2 better videos of the Schumschimmer taken last year on its first voyage [ for Gordon that is ] I think he bought it on ebay . Its very light made of thin plastic carries a brush-less motor and modern batteries both of which i dont know the details but could find out if you wish.The smallest leaf or twig causes it to come off the foils which is why in the video you see it reversing to clear them. Les
As I was saying.etc If original head is inside it might clean up. If on the bare cylinder you may have to rebuild the jacket.The engine looks like a Sparey Maybe from a kit.👍 Re being pre 1948 I am and remember my uncle having this little radio you could carry round . There were valved porties before that but care had to be taken not to bump it in case you collapsed a valve and they were quite heavy . I think the early trannies had two 6v lantern batteries so were fairly heavy but nothing like the valve jobs. Making the old type Tx means finding the old valves which might be hard.👍
Hi Ed, I have MTroniks ESC's including a couple of PNP types. What I do is to start by moving the stick to reverse then back to the middle, (You can observe the direction of rotation). Then to the top and back to the middle. This works. The SLA batteries have nothing to do with the issue.