All donations are securely managed through PayPal. Amounts donated are not published online.
Many thanks for your kind support.
Model Boats Website Team
March 2018: 9 people February 2018: 8 people January 2018: 25 people December 2017: 7 people November 2017: 13 people October 2017: 9 people September 2017: 15 people August 2017: 10 people July 2017: 4 people
Slow progress recently, partly due to snow(!) but also because I have had some engineering to catch up on. Anyway, I have cut and fitted but not completed shaping the bow and stern blocks, fitted the prop shaft and fabricated the rudder assembly. This was silver soldered using a little piece of 3mm silver steel and sheet and channel brass. Yes, the keel looks a bit of a mess in this area but I am going to cover the ply with mahogany veneer to match the planking when I have completed that, and of course it will all be painted below the water-line. I also made a rough cradle to keep the boat steady while working on it - to be replaced with a posh one when everything is done!
Hi CB, Re 'Faraday Cage: I see what you're getting at, of course you are correct that a sealed and grounded metal box would shield the surroundings from spark generated RFI. The 'box' would need to be 'hermetically and electrically sealed', not easy with prop shaft an' all. One hole is enough and Whoops, all those nasty waves have escaped😡. But actually a Faraday Cage works the other way round! It's purpose is to protect people and 'things' inside the cage from outside influences such as high voltage discharge (e.g. lightning) or unwanted radio or other high energy waves by conducting them around the outer skin of the cage to ground. I sat in one during my years of development of mobile radio systems to try to make sure that my test measurements weren't being falsified by external influences. I also didn't want to ruin the tests and alignments my 'bods' were doing on the current production equipment just outside😉 I also had the pleasure 🤔 about 30 years ago of standing inside one at the Deutsches Museum while about a million volts was fired at it! Hair raising😲 but I'm still here to tell the tale😊 and bore the pants off you all😁 Happy suppressing all, cheers Doug 😎
Hi All. all good advice for the normal brushed motors in cans with carbon brushes. But the Taycol is a totally different animal! It has no carbon brushes. They are simply stamped thin copper or phosphor bronze sheet. Contrary to carbon brushes they need OILING to reduce the wear and sparking! Attached are some pics from my Taycol Target renovation and modification to graphically illustrate the point. Pic one 'Before', pic 2 the new phosphor bronze brushes I made. BTW: don't EVER put oil on your carbon brushes! Try it if you're curious, but then buy a new motor or try to find some replacement brushes 😉 If you run the Taycols dry they wear the brushes through until they have a hole in the middle and spark like crazy Pic 1. You can put what capacitors you like on, you'll still get interference especially at 27MHz. Pic 3 shows the effect this has on the commutator. Pic 4 shows the renovated commutator, there was more 'meat' left on it than I expected😊 Pic 2 shows the new brushes I made from phosphor bronze sheet. The spark energy density spectrum peaks in the HF band (e.g. 27MHz!) and falls off rapidly in the VHF band (30MHz upwards) to virtually nothing in the UHF and Gigahertz bands. That (and the frequency hopping process the 2.4Gig sets use) is why they don't suffer such interference. BTW: as a matter of probably no interest 😉 most sets only use 16 or 32 of the 85 frequencies available in the band! 😲 The capacitor values given above are unusual and will only work with a 'canned' motor, which the Taycol ain't! The norm for a standard canned motor with carbon brushes would be 0.1µF across the terminals and 0.047µF from each terminal to the can, which with a Taycol you ain't got! Earthing to the prop shaft is also a problem. Where do you connect the wire? There's no 'can'. Frame? That's paxolin! try soldering to laminated iron core if you want. Good luck. Won't achieve much even if you manage it🤔 Once again I ask which Taycol you have, as the construction varies and hence the suppression methods / connections. Imperative is the condition of the brushes and commutator to minimise the intensity of the spark generation in the first place! Also important is how you are controlling the speed: also 'Period' with a Bob's Board or resistor coil and servo driven wiper?? These can also be spark sources😡 Never mind wasting precious battery power as heat😲 If you want to convert to using an ESC with proportional forwards and reverse, which Taycol field motors can not do without reversing the polarity of EITHER the field coil or the rotor coil but not both, I can show you how. I did it with Dad's old Taycol Target, see my Build Blog 'Sea Scout Jessica'. Pic 5 shows my Taycol target dismantled, before the renovation. Pics 6 & 7 the reassembled motor after renovation. Pic 8 shows the motor voltage across the terminals before the conversion, complete with gigantic sparks of amplitude 100% of supply voltage. Pics 9 & 10 show the waveform on the terminals of the modified motor at slow and fast speeds, hence different pulse width; broad pulse more speed, narrow less speed. BUT: virtually NO SPARKS😊 and no capacitors😊 Trick is in the bridge rectifier used to connect the motor to a standard brushed ESC. The diodes in the rectifier suppress the sparks😊 Pic 11 shows the wiring 'lash-up' I made to test the motor before mods. Pic 12 the PSU used for the tests. ESC is a 30A Graupner Navy. Instead of TX and RX I used a simple servo tester to drive the ESC. Scope used speaks for itself! As expected speed control was possible but no reverse. Media File 1 Vid shows the renovated motor running but unmodified, complete with sparks😡 Sorry Dave_M, I can't upload the ozone smell🤔 Media File 2 shows the scope display of the unmodified motor test, complete with the sparks that cause the kind of interference you are suffering from. Wanted to add the final vid showing the clean waveform after the mods but it's too big for the site: 30MB max and the vid is 47MB 😭 Penultimate pic shows the circuit used to connect to a standard ESC (Brushed!) for full remote control proportional forward and reverse. Final pic shows the test set up for the fully modified motor. Note 4 connections: 2 to field coil, 2 to brushes (i.e. rotor coil) as per circuit diagram of the interface board. Have fun, cheers Doug 😎
Could try general suppression capacitors arrangement, I have also seen the can or frame of a motor connected to earth via a wire soldered to the brass propshaft. You could shield the motor by enclosing it in a metal box, be careful not to short circuit anything, similar to Faraday cage .
Scratch built at 12th scale from pictures and profiles of the internet. The boat was originally built in Sweden a class of fast military assault craft originally developed for the Swedish Navy by Dockstavarvet Speed: 40 knots (74 km/h) Draught: 0.8 m (2 ft 7 in) Length: 15.9 m (52 ft) Overall; 14.9 (48') Complement: 3 (two officers and one engineer); Up to 21 amphibious troops with full equipment Armament: 3 × Browning M2HB machine guns; 1 × Mk 19 grenade launcher; 4 naval mines or 6 depth charges . The Model I was attracted to this boat due to its great performance and maneuverability, this was mainly due to the use of twin water jets as the main propulsion, this is a trade off with efficiency. So my start point was to collect as much information as possible about the boat this involved collecting pictures and profiles of the craft from various sources. http://www.dockstavarvet.se/products/combat-and-patrol-boats... Eventually I found some plans of sort :- http://laurell.today/boats/combat/plans.html My Dad was a boat builder in the days of wooden yachts, and had showed me how to make plans and frames from a line drawing. I went about this first by creating a prototype about 24 in long out of light ply. I then created full size plans of the model to be made. Pictures of small prototype finally painted plain green. The Main model Used my computer to print out the frames onto paper, cut them out and used them as templates for the ply ribs. The construction was simple chine style, with 1.5 mm ply. I tried to build jet drives but failed to produce a effective unit. So reverted to propshafts which worked out well with better control and the bot can spin on it own axis by putting one engine in reverse the other in forward and adjusting the twin rudders. That it for now, hope it was of some interest
Hi Doug, Looking at my rudders comparing them to some pics I’ve found online, my rudders are too big and therefore I will reduce them in size, no biggie, 10 minutes work should see that done. Back to the struts. I would have made them from brass, however as my propshafts are in brass tubes for the whole length, I feel that the plastic versions I’ve made should be ok for aesthetics as the brass tubes seem rigid enough, hopefully no chance of any whip? I’m planning on running this on 2S lipo to give a scale speed, all depends what the watt meters says when I test the motors with props in water. Having the option to go to 3S if needed. I don’t plan on having a great deal of rudder throw and will programme in some expo to soften the rudders throw. Of course, if needed, I am more than happy to make adjustments and incorporate recommendations as given by the lovely people on this forum. It’s still a learning curve for me as I bring 45 years of aircraft experience over to the boat world! If anyone requires any aircraft advice, I’m your man!
I'm with you there Skydive 👍What Boatshed means is the part of the rudder in front of the stock. Thinks: are you building an Offshore Power Boat or a scale Lifeboat? If the former then follow Boatshed's recommendation. If the latter and the rudder is 'scale' then leave it alone. Any braking effect, which usually is only significant in a fast racing boat model or other fast planing types, can be diminished by reducing the rudder servo throw at the TX. One should also consider how the original behaved, maybe they did 'dig in' maybe not. There has to be a reason why such rudders were developed, and surely not just to annoy modellers 😁 One more minor point that struck me - Ouch 😭 Your prop struts! "not that it provides a huge amount of support but adds to the scale appearance." Even in a model they can be important. To help reduce potential whipping of the propshaft, especially if the model is overpowered. Actually in the originals they were vital, especially in larger vessels. The purpose of these struts, in larger vessels 'A' frames, is to provide support to the end of the shaft which carries the prop weighing several tons and, more important, to carry the bearing for the outer end of the shaft! Actually in the originals the shaft tube, or 'Stuffing Box' would not extend significantly beyond the hull. Thus the strut or A frame was vital for the shaft end bearing, fitted immediately in front of the prop for maximum stability. Attached pics of my HMS Belfast (sorry don't 'ave nutt'n smaller with this feature🤔) show the arrangement. Have witnessed such construction in various shipyards around the world. Last one in UK was the first T45, quite an experience! 😲 In the end she's your boat, if it feels good do it! 😉 I would leave the rudder alone if it is 'as fitted'. 👍 I make my struts and A frames from brass sheet and tube. Cheers Doug 😎 PS Stick with the brass Donnie! 👍
Today has seen the prop shafts and motors installed, all nice and straight and bind free. Once all That was epoxied in and set, I made a pair of prop shaft struts from plasticard and tubing, not that it provides a huge amount of support but adds to the scale appearance. I also fashioned some approx scale sized rudders using standard off the shelf rudders, removing the blades and making new blades with 0.8mm brass sheet, pinned and soldered and painted in oxide red primer. Last job of the day was to start building the cockpit floor and to give the hull another coat of resin.
Most of this actually took place last August / July! Regular readers may have seen that when Dad built this boat in the 60s he put a Taycol Target field motor in it. About 25 years ago I put a Decaperm and 'modern' transistor ESC in her to provide forward and reverse. Performance was sedate to say the least. I have since modified the Taycol (see below) so it can be run forward and reverse and decided to put it in an ancient Billings Boats Danish fish cutter (Gina) that I inherited from an Aunt. The cutter is badly in need of renovation (see pic 1) and the Taycol will be more suited to her performance requirement! On advice from Canabus in Hobart I obtained a Propdrive 2830 1000kV brushless motor, appropriate ESC and a 35mm 3 blade prop from Raboesch. Pic 2 shows the old and new motors. Next step was to trial fit new motor mount, coupling and prop. Pics 3 &4. While doing this it became obvious that a new shaft was in order, as mentioned in last update. Soooo, - appropriate stainless steel rod, thrust washers and set ring were acquired and back to the workshop. After cutting to length to accommodate the new coupling type a 3mm thread was cut a the prop end. At the inboard end I milled recesses for the grub screws in the set ring and the coupling, pics 5 - 7. I don't like to just file(or even mill) flats for the screws cos they have a tendency to slip and work loose😡 Trial fitted the new shaft and found I'd boobed a bit with the measurements and need extra thrust washers to make up the difference. 😲 Pic 8. No sweat, they came in a pack of 50 anyway😊 You can also see in this pic that I decided to fit an oiler pipe while everything was in bits anyway.😉 To solder it on in a cramped space without setting the boat on fire 😡 I packed a wet rag underneath and used a gas Kitchen Torch! Known as a 'Gas Gourmet Burner'. Yep, those handy little gas torches like your Missus uses to melt the brown sugar on her Crème Brûlée!! So do I, delicious 😜😉 The torches are not expensive, small, very handy, refillable with lighter gas and can be adjusted to a very small hot flame. Ideal for this job. See pics 9 & 10. Pic 11 shows the new motor & mount, shaft and coupling all trial fitted after using a brass alignment tool I quickly made up on the lathe. Pic also shows the trial electrical installation after cleaning up the 'machinery compartment' a little and painting with silver Hammerite. A Quickrun BL ESC is sitting in the bottom in one of the trays my Dad originally fitted for the 2 wet cell (very wet!) 6V lead acid batteries. The home made board on the left carries the battery and ESC connectors, main ON/OFF switch with LED, blade fuse holder with a 20A fuse and a green LED which tells me if the fuse is blown! Stuck on the walls (OK Bulkheads!) with so called Servo Tape are a 6 ch Turnigy iA6 2.4Gig RX and the arming switch for the ESC. Battery compartment is sized to fit 2S and 3S hard case LiPos. For trials I can fit my Wattmeter forward of the switchboard and splice it into the battery supply using Tamiya connectors. Might change these to XT60s later if current drain is more than 12 to 15A. All for now, all this was pulled out again preparatory to cosmetics on the hull, decks, cabin roof and walls inside and out. But that's another chapter so, 'Tune in next week, same time same channel when once again it's time for 'WHAT DO YOU MEAN BUCK RODGERS IS APPROACHING!? 😁 Or 'The Saga of the Cabin Roof' 😉 Cheers Doug 😎 BTW: After drilling the shaft tube for the oiler pipe I flushed it out with light machine oil (pumped in from a big syringe) and shoved a few pipe cleaners through (rotating them on the way) to remove any remaining drill swarf!!
[Score: 7/10] 40"/3000g PT 109 Capable of 9mph and a runtime of 30mins Twin Propellors (3 Blade 35mm) Direct Drive to a Graupner 600s (3 Blade) Powered by NiCad (7.2v) 4Amp/h Batteries Controlled Through 2x Aquapower (30Amps) ESC - Comments: PT 109 The famous ww2 PT boat skippered by JF Kennedy (later to be President of the USA) This has be one of my have to have model boats and it was by luck that I found one for sale on a model boat club's web site in 2013, £100.00 later and a journey from Cumbria to Yorkshire and back, I had myself a ProBoat PT 109 This was a ready made RTR model when new and is 40in (1m) long, the boat needed some small repairs but after a test run I found that the running gear was noisy and on investigation discovered that both propshaft were bent and had no bearings from new, the couplings were just direct connections. So with great care I replaced both prop-shafts, propellers, coupling for two double Huco's (universal) and the single ESC by two new Aqua speed controllers and both motors with Graupner speed 600's Note I also foamed the front compartments to make it unsinkable in theroy.
PT 109 was one of the hundreds of motor torpedo boats (PT) of the PT 103 class completed between 1942 and 1945 by Elco Naval Division of Electric Boat Company at Bayonne, New Jersey. The Elco boats were the largest in size of the three types of PT boats built for U.S. use during World War II. Wooden-hulled, 80 feet long with a 20-foot, 8-inch beam, the Elco PT boats had three 12-cylinder Packard gasoline engines generating a total of 4,500 horsepower for a designed speed of 41 knots. With accommodations for 3 officers and 14 men, the crew varied from 12 to 14. Its full-load displacement was 56 tons. Early Elco boats had two 20mm guns, four .50-caliber machine guns, and two or four 21-inch torpedo tubes. Some of them carried depth charges or mine racks. Later boats mounted one 40mm gun and four torpedo launching racks. Many boats received ad-hoc refits at advanced bases, mounting such light guns as Army Air Forces 37mm aircraft guns and even Japanese 23mm guns. Some PTs later received rocket launchers. This Proboat PT 109 model was brought in 2013 for £100 these boats are rare now, This one had a few faults with the propshafts they were bent and noisy both were replaced, with quality 4mm shafts, motors twin 600s were also replaced by Graupner versions along with mounts and couplings, basically all the running gear, also two ESCs by Aquapower were added and a 2.4G RC system.
So, managed to get all the glass clothing done at work at the weekend! So far, 1 coat of resin followed by 2 thinned coats to come. Today has seen all the fenders/rubbing strakes added. It took some careful measuring to get positioned correctly but well pleased with the outcome. It paid to pre-shape them prior to fitting. I’ve added filler where needed and a couple of coats of sealer, all seems to be faired in nicely. May need some touch up after priming. Also fitted the rudder mounts as today’s final job. Tomorrow should see the prop shafts fitted, motors mounted and will make the shaft struts. Postie arrived with some RNLI resin crew figures that will add a great touch when painted.
This is not a build but a modification of a cheap Chinese boat just for fun, I got a bit bored of scratch building projects as they take so long especially as I am not retired yet. The NDQ 757 Coastal Brother 1:25 Radio Controlled Racing Power Boat cost about £25 from Amazon. These boats have a basic 27mhz radio and two 380 type motors which have forward and reverse and you steer by powering one motor or both for straight ahead. I bought two of these boats as they are light and about 24 in long, one to convert/upgrade radio, esc and brushed motors the second was to upgrade radio, esc for brushless motors. The brushed motor version I put in two higher rated motors (390) with cooling fans built in, but same motor diameter but longer body I had to modify the mounts, kept same couplings and shaft/propellers. I did remove trim tabs (fixed) and replaced the straight running adjuster for a racing rudder. The brushless version is the same but has brushless motors 2x 2845 2600KV sensor less Specifications: KV(RPM/Volt): 2600KV RPM: 50000 Max Current: 42A