[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 Haig, seems to be a common mistake to get Schottel Drives (Z-Drives) and Voith - Schneider confused with one another! First two pics show a twin Voith propeller on a tug hull (as on the plan above) and the operating principle. 3rd pic is cross section of the Z-Drive as produced by the Schottel company. It is a 360° rotating 'pod'. Newer versions have electric motors built into the pod and don't need the mechanical Z transmission from inside the hull. With such pods under bow and stern even bow and stern side thrusters are redundant 😊 4th pic is the Graupner version, Mk II. https://www.graupner.com/Schottel-Drive-II-new-version-/2335... Cheers, Doug 😎
Could any of you kind folks please advise me on a brushed motor and propeller size and type please. I am doing a restoration of this boat I have taken the petrol engine out and hope to replace with electric, but would like decent speed. Many thanks.
Hi Navagsi, Don't know about the other bits, what scale is the hull?, but Raboesch do 4" Props. See page 3 of attached pdf catalogue. Or go here as you wish- http://raboeschmodels.com/index.php/en/component/virtuemart/... style='background-color:yellow;'>propellers/brass-propeller-metric-147-series-detail?Itemid=0 See part nos 147-33 and 147-34. The Raboesch props are stocked by Cornwall Model boats amongst others. They ain't cheap, but quality rarely is😉 Cheers, Doug 😎
Hi Please be careful with copper/brass alloy propellers as they often contain beryllium which is is highly toxic, read about the dangers and take the appropriate safety precautions. Before you work on these propellers, such as balancing, sanding, polishing or repairing.
Hope this works as I can't figure out how to post a video! Click on the media file and then on the download button. The file should then appear at the bottom of your screen. Spioenkop is officially a MEKO 200SAN class Frigate. I duplicated the unusual drive used in these boats in that they have CODAG-WARP; COmbined Diesel And Gas turbine - Waterjet And Refined Propellers. I have the main props motors and the jet drive on separate channels. The video clip shows the first test of this layout with the jet drive coming in after about 4sec of video and is switched off just before the end of the video. I was just so delighted that my system worked that I unashamedly ran it madly over-scale speed on this first outing....sorry!!
Blog 4 update – Adjustable transom flap using metallic tape did not work. Think the vibration caused flexing and fatigue, so it finally split. Fortunately had established the correct angle, so reproduced the flap arrangement with a fixed thin alloy plate. Much more robust. Have installed the new brushless motors and ESCs. The current layout is brushless motors on the outer propellers and brushed on the centre, all powered by a single 3S Li-Po battery and Rx. Am hoping to commence water trails this week, but have found an issue which was also present with the original brushless motors. When either brushless motor is powered up it operates nicely, however, as soon as the second motor is started either motor “stutters” and a pronounced “squeal” can be heard. The brushed motor is unaffected. Have now tried several ESCs but to no avail, the issue remains. It can be cured though by powering each brushless motor with it's own battery. When this is done everything powers up cleanly and quietly. The obvious solution is to use two Li-Po batteries and abandon the single battery approach. Am reluctant to do this as the model weight will increase yet again. Has anybody experienced this when using twin brushless motors and, if so, how was it resolved?
Added a 60A ESC of Chinese origin, improved waterproofing, and modified the rudder water pickup. Repainted trim tab extension as while it sat in the test tank (AKA the bath) the water got into the wood and split the paint work car spray paint not as water proof as I had hoped. On the test I found it was pulling over 40Amps which is not what I want as this is a race boat with limited battery capacity so cut down propeller by filling of the lagging edge of the prop via a drimmel and a file, so now pulls under 30A at full throttle. At the pond I will check current and prop-sizes.
Many years ago the council used barley straw bales on our model boat pond, no major improvement but a year or two later the bales started to break up and we had continual problems of straw being wrapped around our propellers. We prefer to put up with the green algae and let nature take its course. Alan