60buick

I will describe my project before my question. So you know what I am trying to do.

I have a Dumas Thompson Fishing Trawler that I am heavely modifing into something that would be used for diving on shipwrecks and some recovery efforts. I have build from scratch a scale functional steel winch. All the rigging and crane will also be hollow steel. It sounds heavier than it is but it is very rugged and what beter way of duplicating rust than real rust. From the crane I am hanging a very powerful magnet to retrieve things from the bottom of lakes. Kind of like an electro magnet used in scrap yards. The goal is to find several small "shipwrecks" that are about to go into some remote lakes. I am building several small scale thinly constructed iron hull ships (fully detailed using the same materials as real boats, cloth seats ect.) and cabins to go out and sink in different ways then let them, sit for a year or so at the bottom. I am going to sink one with black powder charges, another with rifle fire and another will burn on the surface until it goes under. I want to try to find them with the magnet if possible and bring them back up to see the effects of time. I also think it would be a fun challenge to try to find them as I am sure they will move over time.
I have several requirments for the Trawler, I want a 4 stroke engine with reverse and it will need to run for hours at a time and run electric cranes and winches for extended periods. I plan to do this by hooking a 4 stroke .70 to a pair of overdriven can motors which will function as a generator. I will then have the prop, crane, outriggers, and winch run by electric motors but instead of batteries they will run off the generator.

My question is with the engine running and the prop turning I know where the voltage is going, to the prop motor. When the engine is idling and no other functions are being used where does this voltage go or does it just build heat? A fire in the middle of the lake would be fun to watch but then I would have to build another one to recover what is left and that would not be fun.

bubby83

Interesting idea, I would say everything will be fine as long as you don't use the generator to charge batteries. Asuming you will be using micro switches, you're left with an open circuit so there is nothing there to build heat and no circuit in which current to flow. I'm in no position to make this call, so I'd wait for someone who has a little more knowledge. Just figured I'd input what I did know.

ryan_t888

I'm also in no position to call the shots but this is how I look at it.

Im assuming the can motors are brushed. A very High torque motor (large diameter armature/strong magnets/many winds) would probably be best for a generator. I have seen them used before but running a high load off of them decreases brush life dramastically. If batteries are used they would want to turn the motor and not recharge, so avoiding them will be a must. Maybe consider using alternators that will also produce useable DC current(A 12v battery is then needed).

When there is no load(load being a function) on the generator (can motor) the voltage is STILL being induced in the generator but it is not being used so it's going nowhere. Also I do not believe any heat would build up in the generator with no load, as there would be no current flow.

Just remember every time a source of power is used to create another source of power there is a loss of efficiency.
I don't know why you need reverse on the gasser, although I would suggest running the prop by the 4 stroke engine and using this reverse in a tranny that disengages/engages an extra reverse gear to allow the boat to go backwards.

You are going to need a radio system with many channels as you probably already understand.
This is an interesting project! Good luck with the project/design and I will try to answer any electrical/mechanical problems you may encounter.

Please tell me what you think based on these 4 points.

Ryan

bubby83

Diodes will prevent the battery from trying to run the generators.

biteme

The setup could work. IMO, I would use a 12v system, I believe an 'avalanchc' diode would allow you to tap lower voltages for radio, servos, etc, but still allow 12v to push the winch and the prop (might need the extra oomf). this should be set up like a solar system (you could use solar rather than a generator/alternator), just make sure the generator puts out more voltage than the battery (for a 12v system, the generator/solar would have to produce say 15v). this way, the electronics will 'pull' electricity from the largest 'well' (15v) and any extra amps go into the battery. this way then the gas runs out( I like solar myself), you now use the 12v battery as reserve to finish up and get home.

As far as the alt/gen heating up, Ryan is right. this would happen under load only(put an electric fan to blow on it if your are worried), not when nothing is happening. when a gen/alt spins there is voltage(potential only) only when the system is closed do the amps flow. It is the flow of amps (rather the resistance of the wires to the flow - use heavier gauge wire) that produces heat.

My solar buggy was a tank tread type chasis. solar panel on top, directly connected to the batteries. the battery pack(with switch attached) was then tapped to power the motors. when the switch was off, the solar dumped directly into the batteries. turn the switch on and the vehicle would go. The vehile would operate with no batteries, but would 'die' when it hit a shadow. with batteries, the vehilce would slow to about 85% speed (transfer to battery power) and speed up again when the shadow was cleared. this vehicle ran as long as the sun shines (even a couple hours after, until the batteries died)

Probably late to ask (I am not familiar with the boat mentioned), but how big is this boat? would love to hear how this come out. Keep us posted on how you decide to do this; it sounds very interesting.
Sean

60buick

The boat is 36" in length. The mast will be 20" or close to it. I have not laid out dementions for the outriggers yet which will have pontoons on the end to lower into the water when hoisting something so I don't capsize and will add bouyancy the the boat. The crane will be 15" or so and cable operated.

Solar would work but then I could not take advantage of the smoke and sound of the 4 stroke. That would also not let me take advantage or running around at night as I will have full lights.

I originaly planned to run the prop off the 70 but that makes reverse far more complicated than just have a motor and ESC. I would then also have to worry about an engine dying and being stuck in the middle of the lake. By having and electric motor, I can switch to a backup battery for the prop and still get home. I would also run the radio off of a separate battery. I would need separate channels for the crane hoist, winch, rudder, prop, backup battery switch, lights, pontoons, and engine throttle so I am just going to use one of my heli radios which gives me 8 channels.

I have more to add but lunch is over.

ryan_t888

sounds good. Although it may be too much of a load for the 2 can motors acting as a generator but I am unaware of the current demanded from all of the accessories you will run at one time.

Would one alternator and small 12v lead acid battery work for you? Or do you wish to avoid heavy batteries/use of alternator.

Ryan

PAINLESS

My Feedback: (19)

You will also have to provide cooling for the .70 4 stroke engine. Be it an electric fan or water cooled with an electric pump. It will not run for very long periods of time with out some type of additional cooling. This could be a very interesting project, and very complicated.

60buick

I am running a mechanical water pump off of the belt drive spinning the can motors. It is basically a serpentine belt drive like what is on a new car engine. The pulleys and belts are out of a 1/10 4wd nitro car. I don't think there will be to much current draw. At the most it would have lights and the crane and winch running. It would not be much trouble to add a third can motor if 2 do not have the power needed. I am trying to avoid batteries because they take up room that could be used for fuel. I would like it to hold a gallon which would last a while if the engine has the torque at 1/2 throttle to keep the voltage where I need it. I won't know how big of a tank I can make untill I get everything in the hull. I will then build the tank in as central of a location as I can to avoid the ship listing once the tank empties.

biteme

Dude!
As far as running at night, 12v could still work. A wheelchair battery 12v, 12a, will last(pushing a wheelchair mind you)continuously running for 4-6hrs, and can be charged with other than solar (like a car charger). smoke and sound could be reproduced. Might make the whole thing simpler (unless the aim of the project is to prove hybrids)
Question! for the magnet to be used, is it an electromagnet? if not, consider: If this is a 'lifting magnet' how many pounds can it lift? How much weight will the boat support? I've seen 'lifting' or 'retrieval' magnets sold that can lift as much as 150lbs. If, while searching for one of your sunken mock-ups, you find instead, say, a 250hp Black Max Mercury outboard. yea, its a great find, but your 36" salvage boat is now stuck to it if you cannot let go; or worse - winch yourself under. things you might wish to consider. Sean

bubby83

LOL funny you should say that. My uncle found a 150 Black Max under water once. Absolutely nothing wrong with it. We let the electronics dry, flushed the cylinders, and it ran fine.

60buick

I,ve though off finding something to heavy to lift or even finding one of my sunken ships to heavy to lift. After a years time or so a lot of sediment can be deposited in the boat making it to heavy. In that case all I have to do is apply forward throttle and let the winch out until the cable runs out and it will release. The cable is steel so it will sink to the bottom and not entangle the prop. I will have quite a few magnets lying around so I plan to loose some. The magnet I am using is not an electro magnet but is used to mount computers to the steel frame of heavy equipment. It is strong enough to lift 50 pounds or better and is already in a frame with a hole to run a bolt through and weld an eyelet to attatch the cable to. That makes them perfect for use and I can bolt several together to add lifting power. If I can find my sunken boat and it is to heavy to pull up I can always add larger pontoons that would not be scale or build a barge with a crane that will pick up what I need and tow it with the trawler. I am not worried about rolling the trawler because it will be completely sealed from water. I have a steel plate mounted in the bottom of the hull which acts as a keel and the winch mast and everything will be run through the upper deck and welded to the "keel". That plate which ties everything together should be enough to self right the boat using an outrigger if I can keep everthing up top low and lightweight. I am also going to run a clunk in the fuel tank to try and keep the engine running but I think the exsaust stack going under will chock the engine. The goal is to something that has never been attempted and to have a reason to deliberatly sink some ships which should be fun. Speaking of recovering objects what would I do if I found a knife of handgun??? There has to be a couple within throwing distance of shore.

biteme

If you find a knife or handgun, try not to cut or shoot yourself, beyond that....LOL

60buick

Well I just had an idea and I want to know if this would work. I don't see why it won't. I have just bought a mini cordless video camera off ebay to go in the boat so I can moniter all activites on deck of the boat. I was wondering if I bought 3 or 4 would they all transmit of different frequencys or run together. I may have to wait until it arrivers to know. But my idea was to hook a RCV (remote camera vehicle) to the crane and lower it to the wreck and see it under water just as they do with real recovery efforts. I can use a second radio and use switches in the trawler to send power to props on a remote control RCV with lights, remeber a radio will not go through water. The only thing is I would need the antenna of the camera to extend ubove water to transmit a signal. I know all this seems like talk of a dreamer that does not know about RC reality but I make stuff like this all the time.

ryan_t888

Cool, I believe it will work as I make stuff all the time too. What parts have you collected?

Ryan

60buick

So far I have the Trawler and the hull is complete and painted. I have not weathered it yet. I have installed the scratch built rudder and the prop. I have the steel keel bend to the contour of the hull and ready to weld the winch and mast/crane mounts to it. I have to weld them on before I can attatch it to the fiberglass hull so I don't melt anything. I have the upper deck fully contructed and the topside is glassed. I do need to fuel proof the lower side. I have all the material to construct the crane and mast and all the rigging and hardware kits from dumas. The cabins interior is fully detailed with bunks tables equipment and hardwood floors. I even bought a womans watch to make a working clock for the wall. But now that I have a camera I will remove the captains seat and mount the camera and a servo under the floor to rotate side to side. I may just put the camera in the seat. With that I would not even have to see the boat to operate it! I have my crew members but only 2 are detailed so far. The winch is constructed but I have not installed the drive motors yet or the legs to mount it to the keel. There are 2 motors for the winch, one for the recovery cable spool and one spool to raise and lower the crane by cable. I will need to wait and mount the motors after the engine and generator are mounted since they are heavier and the heavier stuff needs to be the lowest in the hull. I have the O.S. 70 and its mount made. I will scratch build the exsaust system with 3 chambers to collect the oil. I will also scratch build the fuel tank out of brass. I have the pulleys and belts to drive for the generator but I do not have the can motors yet. I have a radio but I may just buy one with more channels if I do an RCV. I would need 10 channels. I have started construction of the water pump. It is just a scaled down car water pump. Very simple design and sealed with o-rings. I have all the magnets to pick stuff up but I think using a RCV would be more fun and quicker to do since outriggers would not be needed. I could make an RCV in an hour. It would just be a water tight tube with 2 small independenty controlled motors on the outside. The wires would run up the cable to the ship for control and power. The camera would be behind glass in the tube and there would be a light mounted on the tube drwing power from the boat. I would run ?? feet of wire from the camera's antenna to the ship with the other wires to transmit a signal. I still have a long way to go but I have most of my ducks in a row.

As for the 1st boat I am going to sink it is just a set of plans right now but I can slap it together cheaply in a week or so. A very simple design made of sheet metal. By having a plasma cutter things go together quicker than a wood hull would.

green-boat

I hope to god you don't find that sewer lid that I threw out there.

Busch1981

do you have any pics of your set up?

mfr02

Any unloaded generator, when unable to dump current, will build up a considerable voltage. When an electronic load is applied, the electronics might well suffer in the time it takes for the voltage to be brought down. To save brushes, it would be better to use a brushless motor as a generator, and rectify the output with a collection of VERY knobbly diodes (have a look in the engine bay of your car - there is an alternator in there). In practice, the voltage regulators that you would use to feed the battery and the other stuff would PROBABLY keep the excess voltage under control.
In standby power supplies as used in telecommunications, there is a requirement to supply at the same frequency as the normal mains at a closely regulated voltage. The frequency is achieved by running the motor at a fixed speed. As the load varies, and thus the voltage offered to the system, a sensing circuit opens or closes the throttle as required.

NobodyFamous

This is a great project, but you will have some major problems wit your power generator setup.  As MFR02 said, voltage will fluctuate.

NobodyFamous

here is the type of battery I was thinking, thin, small, long, 12v, lead acid so it can take the abuse.

NobodyFamous

here is an interesting alternator designed for RC airplanes.  They talk about custom voltage regulators, so you could get them to design it for 12V output.

NobodyFamous

another way to go would be simply to use an automotive voltage regulator, like this one, that happens to be marine.

cyclops2

The post ended in 2006.......................[:@]

Busch1981

how about this I will restart the project as i am build a hybrid boat using a .90 marine engine and a large motor i will try and use a bridge rectifier and an ESC(s) to control the drive motor speed
my set up is planed out as so:
Engine->genorator->bridge rectifier->large capasitor->ESC->drive motor(s)
I'm thinking of mixing the Engine throttle and ESC(s) together so thet full Fwd/Reverse on the ESC(s) is full throttle on the engine to produce max power under drive load.

What do you all think of my layout?