Log in or Sign up. Boat Design Net. Hi, My first post here, although I've been an avid reader for some time. I've been electric model boat kits effect with electric power for some time, have previously restored an old yacht and now want to build a minimalist inland waterway open launch, with an efficient electric propulsion. After much experimentation I've come to realise that, although a canoe hull is efficient and easily driven, it has some inherent disadvantages when it comes to stability and deck area for solar cells, particularly when scaled down to fit my transportability requirements.
The propulsion system is pretty much designed and built, using a cheap brushless RC model motor. This motor is rated at watts, but I've re-wired electric model boat kits effect to run at a lower rpm, fitted Hall sensors to allow it to be driven from a cheap electric bike controller and give very xod sailing boat 80 low speed torque and efficiency and fitted electric model boat kits effect to a home-made drive leg that has an internal helical bevel gearbox, stainless prop shaft and 8" two blade prop.
The battery is a 36V, 10Ah LiFePO4 unit that weighs just 4kg, taken from one of my other electric vehicle projects, but will probably be changed for a higher capacity one if the concept works. I believe that I should be able to reach xod sailing boat 80 cruise speed target with a power of around watts, perhaps electric model boat kits effect bit. From all the research I've done, including reading just about every post by Rick Willoughby many thanks!
Given that a canoe may not be the best way to go, I started looking at other efficient hull forms. I've always admired the shape and style of slipper launches, plus they are reputed to be easily driven.
The snag is that they don't fit with my "light weight" requirement and they tend to be broader in the beam than I'm aiming at. However, whilst playing with making some scale canoe models using the tortured ply technique I discovered that I could open out the stern and get a pleasing looking shape, with a fairly flat stern and narrow around 36" beam. This would be cheap to build and light, as it uses just two sheets of 4mm ply for the hull skin, plus some framing, deck bulkheads.
It would have tandem seating for two, set low in the hull for stability, with decks fitted fore and aft to take an array of solar cells I'm aiming for around 60 to watts worth. I'm hopeful that the broad stern and flat aft sections will xod sailing boat 80 stability without causing too much of a drag penalty from the greater wetted area, although I'm tempted to put just electric model boat kits effect bit more curvature into the aft sections.
The transom would be just clear of the water, for low drag. DL is around 56 and SL is about 1. I've estimated that resistance from the hull viscous drag at 4mph should be around 30N or so, and have assumed that wave making resistance will be negligible, as I'm below hull speed by a reasonable margin LWL is about 15ft 6ins. This is a photo of the electric propulsion unit, electric model boat kits effect I fitted a faired leg and skeg to the lower section.
I've looked at lots of designs before reaching the point of posting here, including the Bolger Sneakeasy, some sleek, fast row boat designs, all the iterations of Rick Willoughby's human powered boats and others as well as some of the work of proponents of the "long, narrow" school of thought, like Nigel Irens. Although I'm reasonably practical, and have a background xod sailing boat 80 aircraft design so understand the drag and power issues reasonably well, I am a complete novice when it comes to boat design so would really appreciate any thoughts people may.
Please feel free to call me crazy or offer any sort of critical comment Jeremy HarrisJun 22, This looks like a fun project. A few ideas. I'd suggest making it extremely easy to get them out of the boat for two reasons. That way, when the boat is straight up you'll have low drag. Hopefully, this is most of xod sailing boat 80 time. Yet, when the boat starts to tip it will pick up stability fast. Long overhanging counter with wide hips, like the model you're playing with, will do that, but they sometimes get their stability rather suddenly, when the boat puts the hip in the water.
It's a bit easier on the psyche of the crew to have it more progressive than that by having flare amidships. It actually has many of the characteristics you're looking for without you having to build. Once everything is debugged you could build your nice wood hull to put it all. BeauVrolykJun 22, If you have not seen the faux-tri concept I have been working on for a larger solar-wind boat then it is worth considering. The faux-tri will respond much better to increased power than the stable mono.
If you build in wood it will be a challenge to be car toppable with all things on board. GuestJun 22, WillallisonJun 22, The lowest drag hull for 4kts displacing kg will require 33W on the hull. You could double this power at the battery but still below your W. I have just ordered a Electric Model Boat Kits Free 5Ah 22V lithium battery.
It cost USD You would need two of these to get your three hours. They weigh about g. Electric model boat kits effect would only need 3 or 4 cells with that motor. The 40Ah would give your running time. Attached is the latest evolution of the faux-tri. I envisage a scaled down version of the hull but with forward facing arm chair aft of centre. Table in the middle with batteries under and aft facing arm chair forward of centre.
The boat having a beam of 1. Solar panel on fore and aft electric model boat kits effect. The chairs could be used sideways as well but you would need a person on either side of the hull to reduce roll.
A trailer would be more gentlemanly than rooftopping. Rick W. Attached is a 20ft version I did electric model boat kits effect time ago. I would do it a little differently. A boat designed for 4kts would be around 4. Very many thanks for all the tips and advice, much appreciated.
The electrical stuff and propulsion I'm reasonably happy with, as I've a fair bit of experience with electric vehicles. I had about three goes at making the electric drive system, trying to minimise losses as far as possible. The first thing I found as that the HTD belt drive reduction that I first built soaked up about 20 watts with no load. I then opted to modify the motor, by re-wiring it from delta to star to reduce it's kV rpm per volt to a level where direct drive might be possible.
This worked very well, but using the standard RC motor speed controller, which relies on back EMF feedback from xod sailing boat 80 motor to stay in sync, meant that the low speed torque and efficiency were poor. The solution to this was electric model boat kits effect fit Hall position electric model boat kits effect inside the electric model boat kits effect and change to a controller designed to operate well at low speeds.
The gearbox losses are very small, between 1 and 3 watts as far as I have been able to tell. It has a small reduction ratio of 1. The biggest losses come from the seal on the prop shaft. I've reduced these as far as possible by polishing the shaft, but I'm still losing about 5 watts at the moment this may get better as the seal beds in.
I looked at direct drive via a conventional shaft, and at the flexible shaft systems that you've used, Rick thanks for posting all that useful stuff, BTW, it's a goldmine for people like me! I really need to be able to lift the prop out of the water to clear weed and allow beaching, something that's not impossible to engineer with a long conventional shaft, but not too easy.
The drive leg system will fit into a hinged box set into a case like a centre board, so that it can be pivoted up. I've thought long and hard about the weight and concluded that I need to be able to keep the hull light and make things electric model boat kits effect seats, the motor and battery removable.
I'd fix these with some form of quick release. The battery is very light. My current electric bike battery pack a 36V, 10Ah one, that will easily deliver a true watt hours plus weighs just 4kg, including the home made composite box I made for it. That box contains the LiFePO4 cells, plus a battery management system circuit that ensure that the cells cannot be damaged from over-discharge.
The BMS also controls the charge process and balances each cell to ensure maximum life. At 4kg and just a little larger than a standard house brick it'd be easy enough to lift in and out of the boat, and if I can get an average of 30 to 40 watts from solar cells it might be enough to give me the 8 hours endurance I'm looking.
Thanks very much for the tips on hull form, this was just what I was looking. I'd already thought about changing the cross section from a flat bottomed "U" into more of a shallow curve, but had wondered what this might do to stability. In particular, I'd like to get the transition at the aft waterline a bit smoother, by putting more curvature into the run up to the transom.
If I can get the empty hull weight less seats, motor and battery down to around 25 to 30kg then I think I should be OK. That gives me around 10kg to play with for the decking and solar cells, which I think should be OK.
The solar cells I'm looking at are the resin encapsulated crystalline ones, that come bonded to a fibreglass substrate. I think I can probably get away with using very thin ply electric model boat kits effect the fore and aft decks and gain some stiffness by bonding the solar panels down with epoxy might be a problem if one needs replacing!
I like your trimaran xod sailing boat 80, Rick, but would prefer something more traditional looking, purely from the aesthetic standpoint and to be in keeping with it's intended use rivers and inland waterways where traditional craft abound.
I would like to be able to show that it's possible to have a sustainable i. Thanks again for the useful advice, I'll post an update on progress xod sailing boat 80. Jeremy HarrisXod sailing boat 80 23, Jeremy Seems you are a wunderkind with the electrics.
I have a Mars xod sailing boat 80 with the Hall sensors and consider it overkill for the boat application. You do not need fine speed control because the prop slip at low rpm is quite high. Anyhow you have a nice set up. I have found the curved spring steel shaft to be very good. I electric model boat kits effect used gearboxes under water and they work fine but have more drag than the curved shaft.
You could use a curved shaft with a electric model boat kits effect and rudder mounted just behind the xod sailing boat 80 with the ability to lift up but what you have should be fine.
A single alternative care can be a instruments. it simply went earlier as well as faster. It will action as the stabilizer. Last step is to repair electric model boat kits effect propeller to physique of boaat vessel regulating rubber rope .
|
Model Steam Boat Kits Uk 8a Making A Paddle Board Rack Ipad Wooden Watch Repair List Yacht Builders Fort Lauderdale 12 |
