i-CONICA Posted July 5, 2012 Share Posted July 5, 2012 Why aren't there any tiny alternators to top up and keep our receiver/servo batteries topped up? Surely it'd just have to be a tiny dynamo which would draw almost no power from the engine but would prevent receiver batteries dying. Does anything like this exist, if not, why? Quote Link to comment Share on other sites More sharing options...
mugen mark Posted July 5, 2012 Share Posted July 5, 2012 do you have a feul tank that last a hour?no so you got to stop re feul ,so when you do that you can change packs,for the price,hassle,something else to go wrong,cost,extra weight of a alternator,a spare battery pack so much cheaper,so 2 battery pack would last nearly 3 hours,lipo/life 4 hours plus,it just another thing to go wrong,why spend 10 times as much as 2 batterys packs cost ? Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 (edited) do you have a feul tank that last a hour?no so you got to stop re feul ,so when you do that you can change packs,for the price,hassle,something else to go wrong,cost,extra weight of a alternator,a spare battery pack so much cheaper,so 2 battery pack would last nearly 3 hours,lipo/life 4 hours plus,it just another thing to go wrong,why spend 10 times as much as 2 batterys packs cost ? I don't have a fuel tank that runs for an hour, no. But I can just bring the car back, lift the flap, squirt some more in, and we're off again. To change the battery pack, I'd have to shut off the engine, get an Allen key out, unscrew two Allen screws, which go into plastic, so the more they're used the quicker it'll wear out turn forever, so I don't want to do that much, then because the battery pack's connector is stored in the receiver box to keep it protected from water, I'd have to open up the receiver box too. It's hardly practical, whenever my battery has died, I've just gone home... Plus, the engine will run 100% peak performance so long as it has fuel, whereas the battery fades and servo strength declines as the power runs even below half. The idea of a mini alternator isn't a stupid one. There are far more stupid things people want to bolt to their cars, the little superchargers, etc. This is a hobby don't forget. I get as much fun out of working on my car as I do driving it. I don't want a car that never breaks, nor do I want a "complete" car that I can't ever add to or tinker with. A mini alternator (actually any small dc motor would work) with a small gear touching the other side of the clutch bell, would generate some current to keep the battery from draining, even if it doesn't generate 100% of the current being used, it'd extend the battery's life into several hours, far more than is needed. Let's not dismiss the idea hey? If I could buy a tiny cute little shiny thing that bolts to my car and has some wires and a tiny gizmo to go in the receiver box, I'd buy one... Edited July 5, 2012 by i-CONICA Quote Link to comment Share on other sites More sharing options...
Joshyjol Posted July 5, 2012 Share Posted July 5, 2012 (edited) Kinda invented a solution to something that's not really a problem. Buy a receiver pack and just keep it charged and top it up when you go out with it. I never knew plugging it into the charger was so much hassle, but it's really not. Keeping check on the elecs is a big part of the tinkering side so you should keep your packs topped up. You want to extend battery life and run times? Cycle them properly or get a lipo battery and balance charge it Edited July 5, 2012 by Joshyjol Quote Link to comment Share on other sites More sharing options...
Joshyjol Posted July 5, 2012 Share Posted July 5, 2012 The idea on a petrol would be nice as it already produces elec to power the spark plug, but on a nitro it's kinda irrelervant imo Quote Link to comment Share on other sites More sharing options...
Nomsicle Posted July 5, 2012 Share Posted July 5, 2012 I agree with i-CONIA, would be a great idea. 2 Quote Link to comment Share on other sites More sharing options...
Andyw Posted July 5, 2012 Share Posted July 5, 2012 (edited) Doesn't the spark on the 2 stroke work off the flywheel and magneto? Which just sends a ignites the spark at the correct time, not really a DC motor. But also like the idea of it. In response to Joshyjol Edited July 5, 2012 by Andyw Quote Link to comment Share on other sites More sharing options...
Nomsicle Posted July 5, 2012 Share Posted July 5, 2012 *i-CONICA Quote Link to comment Share on other sites More sharing options...
mugen mark Posted July 5, 2012 Share Posted July 5, 2012 (edited) if you bash hard,it more to go wrong,when the guys are ramping there cars 40 foot plus in the air,they need the least bits on a car,not another belt driven piece, it will slow the engine,like a pullstart does,if your a engineering student it might be a good project but that about it,a well designed car it should take 1 min to change the battery, Edited July 5, 2012 by mugen mark 1 Quote Link to comment Share on other sites More sharing options...
Joshyjol Posted July 5, 2012 Share Posted July 5, 2012 (edited) Doesn't the spark on the 2 stroke work off the flywheel and magneto? Which just sends a ignites the spark at the correct time, not really a DC motor. But also like the idea of it. In response to Joshyjol Might be able to rewire it so when it sparks its chucks some power in the battery, not too sure on this as I don't own a petrol but the hardware is there to adapt and make possible I suppose. Agree with Mugen Mark on this, it would just be another gimmick on a nitro, I hardly ever have to charge my packs, I just cycle them and they are decent batteries so they hold charge amazingly! It's never been a big problem. Also agree it would be a good project and not a retail idea Edited July 5, 2012 by Joshyjol Quote Link to comment Share on other sites More sharing options...
heavyleftthumb Posted July 5, 2012 Share Posted July 5, 2012 wouldnt having an alternator driven by the engine put small amounts o resistance on the engine and thus lower power output? Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 wouldnt having an alternator driven by the engine put small amounts o resistance on the engine and thus lower power output? Yes, it would. But only by a tiny amount. My full size 1:1 car's alternator uses less than 1 HP to power it, that's a 5-6KG alternator. A tiny one for a nitro car wouldn't use a hundredth of that. You wouldn't notice. I was thinking, rather than an addon that'd be self contained and add weight, the flywheel could be replaced with one that has magnets around the edge, and a coil could be fitted to a mount, supporting it close to the magnets. As the magnets flow around the coil, it'd produce a charge, even at idle speed, the flywheel is turning really fast. It'd generate quite a bit of power and drain almost nothing from the engine's power. The problem would be getting the power generated regulated properly and managing the battery so that it doesn't get over charged. if you bash hard,it more to go wrong,when the guys are ramping there cars 40 foot plus in the air,they need the least bits on a car,not another belt driven piece, it will slow the engine,like a pullstart does,if your a engineering student it might be a good project but that about it,a well designed car it should take 1 min to change the battery, "Like a pullstart does" How does a pull start slow the engine? "well designed car it should take 1 min to change the battery" That means buying another battery. If I could buy an alternator and never buy another battery (within reason) it'd be better. Also, my battery is cable tied into the battery mount, so I'd either have to re-cable tie the new battery, snip off the old ones, or buy another battery clip, even then I've still got to unbolt the battery mount, and bolt the new one on. It's not a 1 minute job. Kinda invented a solution to something that's not really a problem. Buy a receiver pack and just keep it charged and top it up when you go out with it. I never knew plugging it into the charger was so much hassle, but it's really not. Keeping check on the elecs is a big part of the tinkering side so you should keep your packs topped up. You want to extend battery life and run times? Cycle them properly or get a lipo battery and balance charge it I have a balance charger, That iMax B6. The problem is, how on earth do you "top up" a NiMH battery? You can't top them up like you can a Li-ion. You're supposed to run it flat, then fully charge it. I don't understand why everyone is being so negative about it. I've seen similar threads in the past. Is this hobby closed off to innovation and improvements? Isn't a car that's only consumable is fuel a good idea? I'd love to never have to worry about the electricity on the car. It obviously wouldn't work for dc brushless cars, but for nitro and petrol, it seems obvious. It doesn't have to be a huge heavy thing, it can be a new fly wheel, and a "ferris wheel" shaped surround that sits up next to the flywheel and has two small wires running into your receiver box... Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 To expand on the scale of it, and sucking power. Don't forget that nitro engines generate an incredible amount of power for their scale. Scaled up, a full size car would be around 2500 to 4000 HP! My alternator generates about 70 Amps at 12v (about 14.4v actually, so the battery will take on power), but we need 6 volts (about 7.2v actually), that equates to 140 Amps, but we don't need 140 amps, we need about 140Ma. A thousandth of the current. The scale is tiny. If my full size car's alternator that generates 140A relative to the voltage we need, and only pulls 1HP from my engine, if it were scaled down and used a thousandth of a HP from my nitro engine, I wouldn't notice the drain, its nothing. There's more resistance from ball bearings than a contact-less induction loop would cause... Quote Link to comment Share on other sites More sharing options...
Gaz! Posted July 5, 2012 Share Posted July 5, 2012 how do you meter/govern the amount that gets pumped into the battery?? surely a days bashing would cause damaged cells in the battery or worse still a fire! so you would then need a voltage regulator of sorts to cut off when full then of course that needs power direct from the battery too. heres a simple solution for you, change the way your battery is fitted in the car and get another will be a lot cheaper in the long run and keep the (heaps of money spent in r&d too) balance of these designed chassis to run to their best abilities..... Quote Link to comment Share on other sites More sharing options...
adolf hamster Posted July 5, 2012 Share Posted July 5, 2012 tried it for a baja, its perfectly possible. but for something as small as a nitro its more hassle than its worth especially considering how well modern rx packs last. its more than just bolting a motor to it and running cables to the rx. for mine i had to gut a motor [traxxas ez start motor of all things] and make a new squirrel cage can for it. plus on top of that you'll need a good circuit to keep everything in shape. i tried it 3 years ago and you'd be amazed how hard that circuit is to design when you've never heard of a zener diode you'll also need to bear in mind that the bearings will get a lot of abuse, even with just a 1:1 drive it'll spend a lot of time at 15krpm plus. Quote Link to comment Share on other sites More sharing options...
mugen mark Posted July 5, 2012 Share Posted July 5, 2012 if you hang anything on the end of a crank it slow it down,you lose about a 1000 rpm with a pull start,hence why raceing engines dont have pull starts,this idea in the same bag as superchargers,trubo,ect for nitro,and a batterys Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 (edited) how do you meter/govern the amount that gets pumped into the battery?? surely a days bashing would cause damaged cells in the battery or worse still a fire! so you would then need a voltage regulator of sorts to cut off when full then of course that needs power direct from the battery too. heres a simple solution for you, change the way your battery is fitted in the car and get another will be a lot cheaper in the long run and keep the (heaps of money spent in r&d too) balance of these designed chassis to run to their best abilities..... For christ sake! I'm not trying to solve a problem here, just have some fun with a bloody soldering iron. What's your problem? Will people stop telling me to charge my damn batteries before I leave the house! That's not the point of what I'm considering! And if you read the previous posts properly you'll see that I mentioned voltage regulation and battery management already. Edited July 5, 2012 by i-CONICA Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 if you hang anything on the end of a crank it slow it down,you lose about a 1000 rpm with a pull start,hence why raceing engines dont have pull starts,this idea in the same bag as superchargers,trubo,ect for nitro,and a batterys 1 Quote Link to comment Share on other sites More sharing options...
Ziggy122 Posted July 5, 2012 Share Posted July 5, 2012 the issue is the battery packs wouldnt take to much to running off a constant draw and charge The way forward is to have a capacitor to store energy from the ""alternator"" and use the reciever pack as a back up when its flat as its not been charged etc etc Cars generate serious amps and store some serious amps, and millions of Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 tried it for a baja, its perfectly possible. but for something as small as a nitro its more hassle than its worth especially considering how well modern rx packs last. its more than just bolting a motor to it and running cables to the rx. for mine i had to gut a motor [traxxas ez start motor of all things] and make a new squirrel cage can for it. plus on top of that you'll need a good circuit to keep everything in shape. i tried it 3 years ago and you'd be amazed how hard that circuit is to design when you've never heard of a zener diode you'll also need to bear in mind that the bearings will get a lot of abuse, even with just a 1:1 drive it'll spend a lot of time at 15krpm plus. Well luckily for me, I know all about zener diodes, and as I'm a professional computer programmer, designing a simple circuit board that I actually get to build at the end of it doesn't phase me, that is not a problem. As said already, it would be completely contact-less. There'd be no bearings, and no contact with the flywheel or any part of the drive train. Quote Link to comment Share on other sites More sharing options...
landmaxdriver Posted July 5, 2012 Share Posted July 5, 2012 I really like the idea of this, please make it, I'd love to see if, in practice, this will actually work I doubt it would catch on but its a pretty cool idea 1 Quote Link to comment Share on other sites More sharing options...
i-CONICA Posted July 5, 2012 Author Share Posted July 5, 2012 the issue is the battery packs wouldnt take to much to running off a constant draw and charge The way forward is to have a capacitor to store energy from the ""alternator"" and use the reciever pack as a back up when its flat as its not been charged etc etc Cars generate serious amps and store some serious amps, and millions of Quote Link to comment Share on other sites More sharing options...
Ziggy122 Posted July 5, 2012 Share Posted July 5, 2012 your right - your applying the sense of what a 1:1 car does however im with everybody else here The extra work on the engine - the extra maintaince - increase buying costs - Another thing to go wrong How many people will buy it? tbh, very few its costs something silly like 5p to charge up a Hump pack - Free if you get a Decent 12v car bat + solar charger setup Tbh - its not worth it Ziggy Quote Link to comment Share on other sites More sharing options...
camstreet Posted July 5, 2012 Share Posted July 5, 2012 it's an alright idea, i mean I do see the application and all that (trust me i'm trying to work on something stupid for a 1:1 leccy car) but A the flywheel thing wont work on a racer as they are started via the flywheel, B you'd need to mod your chassis and widen the whole the flywheel pokes through, as well as raise the motor itself and finding the room for the induction loops would be pretty hard to find since you'll have the gearbox / brake in the way by all means do it, I'd love to see it work, it'd be kinda like that hydrogen car, a good idea but for the time being people would probably prefer to stick to what they know for now also, those added magnets if you dont raise the motor will stick out of the chassis at the bottom and be prone to hitting things, and your coil's wont be able to go the whole way around the actual flywheel...... but here's a video that might help you if you could stick magnets to the flywheel either side and put 1 coil in between.... Quote Link to comment Share on other sites More sharing options...
HATZY Posted July 5, 2012 Share Posted July 5, 2012 its a great idea if you wanna build it as a project just to say ive done that. go for it mate Quote Link to comment Share on other sites More sharing options...
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