Hi Pete, Go easy with the prying!! You're right. The spring loaded button is the way in. But it can be very stiff and underneath the hatch is a dense foam rubber gasket which makes the hatch catch (😆) difficult to release. Press the button firmly down while trying to ease the hatch forward with your blade. In my basic version there ain't much underneath except the rudder servo. But that's where I intend to put a decent battery. Re electronic speed controller (AKA ESC); it MAY be on the cct board but I doubt it cos I don't see the FET power transistors for the outputs to the motors! Unless that's them in the bottom left corner in the second pic? In mine it's a separate square block with the heat-sink tabs of the transistors clearly visible. Trace the wires back from the motors to find yours😉 Everything else, RX and switched outputs, is on the cct board. Check out the blog with the link above and you will find all the secrets about removing the deck without busting anything👍 More later, ciao, Doug 😎
Evenin' Rowen, So far so good, nice job👍 Let me go through your comments one by one😉 1) "Moved the battery towards the stern and, at speed, the forefoot lifts slightly clear of the water. The plane is now almost flat. The battery is not well positioned when near the bow." Battery in the bow is almost always bad news🤔 too much weight forward of the CoG or natural balance point when planing. 2) "The 2S battery used was a 4000mAh 30C; suspect this battery does not have the capacity to operate the model. Every motor will run up smoothly until a second one is operated. The first motor then “stutters” and a fuse might blow, this could be indicative of a power surge. Any comments from the electronic experts among the group would be appreciated." First the battery: you may be right. Especially with 3 x4500 kV motors Since you are using 3 ESCs how about feeding each one from a slightly smaller (lower weight) battery? Precondition of course is that all three are equally charged to the same voltage and capacity AND have the same (or very very similar) internal resistance! Complicates the issue of course and motors with a lower kV rating and one power source may well be the better solution😉 Second the 'stutter': How and when did you switch in the second motor? If the first was still at 'Full Ahead', i.e. 'Pedal to the metal!, I might expect the battery voltage to dip and then recover with the sudden additional load and a sharp rise in total current drawn. But no particular excuse for a sudden current rise in the first motor ! Where was the fuse that blew? I suspect in the primary supply lead from the single battery🤓 since with brushless motors you can't fit individual fuse in their supply leads like you can with a brushed motor. BUT you can to the ESCs feeding them!!! You can't get a power surge from a battery, not like a surge on the mains network due to lightning etc! But you can get a voltage dip and recovery if you suddenly present it with an additional load😲 3) "The 3S battery was 10,500mAh and 40C; with this battery all three motors can be run at full speed together and fuses do not blow. It was also very heavy at 1700g, holding the model down." All run up together to full speed or 'switched in' as described above? There's a big difference between a gradual increasing of load on a power source and a sudden step increase! 4) "The motors are 4500 kV. On refection, think a slower motor around, perhaps 2000 kV would have been a better choice." I did think at the outset that 3 x 4500kV was perhaps a little ambitious😲 2000 - 2500 sounds much better, and more controllable👍 Then you could also get good performance results with a single battery of capacity lower and weight 👍 The function of the third (centre) motor for 'action speed' would also be more pronounced👍 5) "Would concur with comments by others that a simple single or two bladed propeller layout for this model is probably best - that is unless you want to capture the true scale layout. The centre propeller seems to have little effect on overall performance, (see above re 4500kV motors- Doug😉) although it will power the model quite nicely when operating by itself. Have had several suggestions about how best to use the centre propeller. Will think about them and decide later how to do this when I start to finish the model." As a 'Scale Purist' (as far as my skills and tools allow!) personally I would frown on the use of 2 blade props, much less only a single prop. Do that in a fictitious power boat if you will, but for 'Brave Borderer' ? 😡 Do her justice please😉 Many three screw (😲) boats (including the full size originals of this era) only used the third motor for additional manoeuvring speed in action situations. My personal experience of FACs (Fast Attack Craft) and FPBs (Fast Patrol Boats) over the last three decades shows me that the three screw configuration has been largely dropped, especially since the introduction of much more powerful engines such as improved diesels and gas turbines. Many use a combination of diesel, for cruising, and gas turbine for 'action speed', so called CODAG, COmbined Diesel And Gas turbine. 6) "The 2 blade Hi – speed propellers both increased performance and current draw. The model is more than fast enough with the original scale layout." As I believe the 2 blade props were of larger diameter (and perhaps also of larger pitch) than the 3 bladers the higher current draw is a logical conclusion! Stick with the scale config! 👍👍👍 7) "Will purchase a lighter, 3 S battery as that seems the best choice for performance and weight." 👍 but don't overdo it to the other extreme by reducing weight and therefore capacity too much😲 You want a decent sailing time don't you? 8) "Testing using the bare hull with a minimum of detail worked well. For a models with a complex power train, this is a good approach as access to the internals can be gained easily. Nothing worse that finishing a boat carefully just to find the performance disappointing. Then having to to rip it apart to make major modifications or adjustments!" Heartily agree 👍👍👍 Bon chance mon ami😊
Not me, never heard of 'em til now, but here are the specs and a pic😉 https://en.wikipedia.org/wiki/Huckins_Yacht_Corporation Happy Huckin', Doug 😎 Technical Specifications Lindsay Lord, a commander in the United States Navy who was stationed in Hawaii during the war, examines wartime PT boat design in his "Naval Architecture of Planing Hulls" and records the Navy's planing hull research and findings. This is the most complete source of information on PT boat hull design and construction, and provides hull test data as well as detailed analysis and comparisons of the various PT boat designs. U.S. Navy Technical Specifications of the Huckins PT Boat (Patrol Torpedo) Motorized Torpedo Fast Boat: Crew: 11 Length: 78 ft (23.77 m) Beam: 19.6 ft (5.97 m) Draught: 5 ft (1.52 m) Displacement: 42 tons Machinery: 3 x Packard 12-cylinder gasoline engines delivering 1,350 horsepower each to 3 x shafts. Surface Speed: 40 kts (46 mph) Range: 0 miles (0 km) Armament: 4 x 21-inch (533mm) torpedo tubes for 4 x Mark 8/13 torpedoes, launchers arranged as inline pairs along port and starboard sides. 1 x 37mm OR BOFORS 40mm Dual-Purpose cannon fitted on forecastle. 1 x 20mm Oerlikon anti-aircraft cannon at stern 4 x 0.50 caliber (12.7mm) anti-aircraft, air-cooled heavy machine guns in dual mounts (2x2), one emplacement amidships and one forward, offset to starboard. Optional 0.30 caliber machine guns, mortar launchers, rocket projectors and additional 20mm cannons (and captured 23mm anti-tank guns) as required/available. Ship Class: PT 95 Number-in-Class: 18 Ships-in-Class: PT 95-102; PT 255-264 Initial Year of Service: 1942
PT 109 by CB90 Fleet Admiral! Posted: 7 months ago
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.
[Score: 8/10] 36"/3600g Perkasa Class Capable of 10mph and a runtime of 25mins Triple Propellors (3 Blade 35mm) Direct Drive to a 2x 600 + 1x 700 type (3 Blade) Powered by NiCad (7.2v) 3Amp/h Batteries Controlled Through China (25Amps) ESC - Comments: A Malaysian Fast Patrol Boat Perkasa produced by Vosper in1966,she has 3 gas turbines engines and a speed of 54 knots, and diesels for cruising. The model was built in the 1980s but has only recently been fully powered up for planning speed, handle choppy water very well, port and starboard motors are 2x Graupner 600 7.2v and centre motor is a 700 type motor, 3 shafts run 3x 35mm propellers and it has two rudders, the guns are remote controlled (Please note the stern/rear gun is not accurate and is just a copy of the forward gun Bofors 40mm and not the 20mm Oerlikon. Search lights, radar, running lights all work the 3xESCs are a cheap China ones that do the job but need to go to neutral before going in reverse, just use self centring joy sticks on the transmitter.
Only way to see if it works is to make a test rig and hold the exciter in place to see what it sounds like. Don't use the glue pads for now just hold in place with light pressure. Radar should be ok weight wise. All batteries should not be charged in a model, ever! They all contain chemicals and if a fault develops or they leak explosive gases the last place they should be is in an enclosed environment. There are high power NiMhs that may be suitable as they can be had in different formations. Component Shop will make up a pack to your specs. If you rush the only thing being spoiled will be the boat!
[Score: 10/10] 32"/4500g Sprinkles Capable of 3mph Twin Propellors (3 Blade 45mm) Geared to a Electrofly (3 Blade) Powered by NiMH (9.6v) 5Amp/h Batteries Controlled Through Viper ESC - Comments: Sprinkles is a scratch built U.S. Coast Guard PWB, patrol waterways boat. Operating features include; searchlight and running lights, revolving blue emergency light, rotating radar, and a water monitor that fires 10-15 feet and can I studied various styles of water monitors and finally decided on one that is a composite of several types. Bending the tubing was difficult, nozzle was made on Unimat. Power is from Sig "gas passer" pump. I purchased the rotating beacon on ebay and power is from 5V voltage regulator.
Batteries!, always a problem in the 50s on "paper round" money, used to cadge,"borrow" or steal batteries for our boats.Used to be able to buy a cheap kit and even a cheap Japanese motor (coupled to the prop shaft with bicycle valve tubing) but it would be unused for weeks until I could afford a battery, and then they did not last long.Used to borrow batts from my dads bike lamps,my grannies gas stove lighter and the door bell!.Also use to be able to remove cells from the "winner 120" batteries from my dads sky queen radio as the HV cells used to discharge first.This was the downfall of glowplug motors,we could start them at home but on getting to the pool the tall 1.5v battery would be flat.My dad showed me how to locate good cells on duff car batteries by putting a load on them and measuring the voltage across each cell,we then emptied the acid out into mums washing up bowl and sawed the good cells out,refilling them with acid filtered through a handkerchief!,this worked a treat for starting glow motors but my hankie and the pocket I kept it in suffered!I eventually sorted the power problem by using a clockwork motor removed from the family gramamphone to fit an autochanger.
A quick check on the specs of your motor /esc combo states its good up to 5s LiPo. So step 1 get a watt meter ( cheaper than burned out motors ) Step 2 check with your bank manager ( or wife) for available funds Step 3 buy the biggest 4s or 5s LiPo you can fit in the available space. you will also need a LiPo charger do not attempt to skimp on that step LiPo batteries need special handling and can be spectacular if you do it wrong. You have not mentioned the prop your using if you use the watt meter you can play around with different props so the current used by your setup heads towards the point you pick twixt performance / running time. If you do go LiPo you will also need a battery monitor part of the careful handing includes not discharging them below around 3.3 Volts per cell. 3s =3cells 4s=4cells etc. So if you go 4s then you should not discharge below 13.2V. http://www.rchelicopterfun.com/rc-lipo-batteries.htmlhttp://www.4-max.co.uk/pdf/prolong-life-lipo.pdf some text on the care and feeding of LiPo batteries. The reason for your problem is a simple case of battery chemistry a lead acid accumulator cannot deliver a high current for extended periods gasses on the plates prevent the electrolyte coming in contact so the battery loses power. After a while the gasses are re dissolved and the battery can then go on providing power. Nothing wrong with the battery its just a case of wrong tool for the job.
Hi Edward, Its a fine balancing act of electrolysis to hydroide gas, compression then ignition but utillising vacuum formation as an assisting force to the power stroke so effectively making it a one stroke which sounds odd.still in development ive tried turbine,oscillator pistons and hydraulic recoil as end movers but the best seems to be the straight reciprocator. Its scary,how the hell can they tax water??? cheers Neil.
Hi Wellard I think we need a bit more info to give helpful advice. Electric or Gas depends on the noise level nuisance. May not be a problem for off shore use. Probably greater endurance than with electric but not as good for the speed you envisage. As speed is not important (3-4Km/h) then a brushed motor may be preferable to brushless. Generally the prop should be about the same diameter as the motor case. Larger props will require some form of reduction unit to reduce the load on the motor. Sounds like there will be plenty of room in the hulls to carry a good power source and as you are operating at some distance SLA is possibly better than say LiPo where discharge voltage is important. I think you may have a problem with the range (20-30Kms) as this is somewhat greater than the normal range of domestic RC sets. As you are off shore there may be additional problems with wave height as the signal may be obscured when the model is in a deep trough between waves. At the end of the day you need a motor prop battery combination that will move the craft thro the water at the required speed and last for the full duration of each sail. It's quite a large model and I suspect will need say two 800 size brushed motors to allow for wind/waves and current. I suggest you come back with your thoughts as you may have specific requirements to fit in with other equipment you are instaling. dave
Hello I bought an old swordsman from a friend recently and have started to refurbish it This will be my first foray into refurbishing wood models so I think I will learn a lot! It was a gas-powered boat but this will change to electric. So far, I have sanded the paint back to the wood and have filled the bow section damage. I have found an area around the hole for the prop shaft that has delaminated and come away from the keel. My plan is I am going to use Zap ultra-thin penetrating CA to re laminate the ply sheet. then use cascamite glue to reseal all the joints around the hull. Would this be a good way to repair this damage or is there a better way? I will keep this thread up dated with new photos and progress reports over the coming weeks. Richard i am going to use Zap penit
Not generally a good idea to charge batteries in a boat, especially if you can't see them to check for any abnormalities or monitor the temp. If they should gas you may have the risk of an explosion. Assuming your battery is connected directly to the ESC and you intend to run a lead from this connection for the ve and -ve then the ESC will be subject to the charging voltage from your charger which will be higher than the battery voltage and could be above the ESC max voltage. Also the ESC may be live and if it has a BEC so will any connected devices (Rx/Servo). Some ESCs have an on off switch so you can switch off the BEC but the power will still be fed to the ESC. If you really wish to proceed I suggest you use an accessible plug to connect the battery to the ESC and swop this to your charger to isolate the ESC when charging.
: Boaty Great idea that, using a pulse jet. I understood that in the past this has been tried on tethered hydroplanes and certainly it would be cheaper than gas turbine units. Nearest large area of water to myself, apart from the River Mersey is Bala Lake in North Wales but I dont know how the locals would react. Only person I knew who sailed a model boat on Bala was in the late 1980s and the boat was a scale model tug. Fastest model I ever had was a J.B Marine Hypercat in 1994/95. This was powered by a water cooled Graupner 700 brushed motor running on 2 X 8.4 volt nicads with top speed being 35 to 40 m.p.h. However, the boat met its end on Walton Hall Park lake in Liverpool when some debris fouled the rudder and it crashed into the concrete bank , took off and nosedived onto the footpath. It did have a nice rooster tail and thrilled many spectators. I have been contemplating getting another fast electric and wonder if a waterjet unit is available to give equal performance. Boaty
HI hawkgripen Long time since looking at site what with Christmas, the weather and computer problems. Thanks for suggestions and I think I will have to silicone the two cabin assemblies, as with any luck these may not need to be removed. The main equipment will be Installed In under the main hatch and I think I will seal this with a rubber gasket, the cover being held In place by magnets and steel strips, these rare earth magnets are very powerful and provide quite a high holding force.