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.
This Is a 40" long model of a gas powered Berkley Company kit of a US Air Force crash boat from 1955. The plank on frame kit was In production for about 10 years and was meant to be powered by a model airplane gas motor with a single shaft. It depicts an experimental 50 knot rescue boat (painted In a peace time color scheme) during service with the USAF. If successfull It would have been put Into production designed to be a replacement rescue craft for all Air Force 65' crash boats. Unfortunately for the crash boat program the Air Force lost Interest as helicopters were become a reliable way of rescueing downed pilots along the coast. The prototype and a sister boat were scrapped, as was the entire program. The model was given to me to be restored(top picture) for the son of a retired USAF veteran that was a crash boat crewman. The model was built In 1957 and had been run a few times on a tether line, R/C was pretty expensive back In the day. I stripped the hull, filled In all the cracks and rebuilt the mast. I added a small boat, davit, liferaft, coxswain station, spray shield and deck hardware among other things. Actually all the owner wanted was a paint job, he was very happy with It's new appearencep! Although I fiberglassed the wooden hull and made It watertight, the owner doesn't plan to run It, just a memorial to his dad's service. I really enjoyed working on this "rare bird".
Has anyone tried to build a model ship with a gasoline or butane powered generator/alternator providing the electricity to keep the batteries charged for longer run times? Hi When I was In the model engineering club. One or two of the lads had locos that were powered by a Briggs and Straton lawnmower engine which turn an alternator. It was a good setup but the work Involved (to me) I would have just stuck to a gas(petrol) engine drive. One lad had a dynamo from a car driving (altered to a motor) his loco on a 12 volt battery. Good Idea and lots of Info on the net.Lets know how you get on Seaspray
So, first task was to remove all outer fittings, rails and any brass support bars for the walkways either side of the uper deck, as well as doing same "bit" removal on the daughter boat. After taking some advise on both this site and another build forum, I chose to use " SAFE STRIPPER" made by a company called "Langlow". It Is readily available via mail order from a boat store called www.marinemegastore.com. Its a gel like consistancy and can be difficult to get to stay In place on vertical surfaces, so I found It easier to do flat surfaces at a time, turning the hull on Its side to get those done. It takes time for this stripper to work, so dont expect miracles on Initial application as It hardly looks like Its doing anything! [dont be fooled]. Same goes for using skin protection, please make sure you wear protective gloves and be careful you dont splash any of this stuff where you dont want It!. The stripper washes off easily with warm soapy water, the only down side I found was It does actually "stain" the white plastic slightly a "green" colour. This however will easily paint over and does not show through [see later]. I say all this now, as Ive already passed this stage, but wanted to be sure myself, before saying anything to others who may now decide to use the product. After Initial paint stripping I did find certain areas of paint hadn't been removed, this was where another suggestion from the blog site came In. "Fairy power spray"! comes In a handy spray bottle, so easily applied and to be honest, works extremely well and quite quickly too! be careful, It smells quite strong, so work outdoors at all times and dont leave this stuff to dry off, or Its even worse to try and remove the paint again. Once the paint appears to blister, use a broad blade screwdriver or paint scraper to remove the outer layers, allowing the stripper to work on those underneath as you go. obviously what you use, depends on how accessibile the area to be stripped Is on your boat, I had a few niggly tight areas on mine, so used a various amount of screwdrivers with different width blades to help lift the paint off as It was loosened by the stripper. Removal of the paint revealed what I had bought finally! I dont mind this type of project as you can see results fairly quickly and changes soon become apparent as you go along, rather than start a project from brand new and you simply build as you go and follow the correct build plans and Instructions, this way you have to become part of the original builer and see how they "thought" when It was originally built, see where they went , er "astray/wrong" and then be prepared to carry out some rebuilding/reconstruction to get It back on correct track. The upper deck on the daughter boat had the original windows badly cut out of Its blank form, so Ive decided to replace the upper deck with a replacement structure and of a more modern looking construction, so It looks more like a lifeboat than the little harbour boat It originally did. Ok, so yes, I'm now modifying It away from Its originality, but like everyone else, we all make our mark on a build project. "trust me" [as they say - ] wait till later In the project to see the resultant shape of this, as, yes, Its still In project mode and going through a few balsa wood block build samples at the moment , till Im happy with Its shaping and styling, so It still fits In with the main boat and Its country of origin.