Is this possible?
12-31-2008 | 12:34 AM
#51
Thread Starter
RE: Is this possible?
If a coil could not be found with a flat surface, the surface must be made flat or rewind a all new coil. In the case that will not work, we will need a tiny alternator to power a CD unit. Here is a photo of a $13.95 outrunner motor that may work. Capt,n
12-31-2008 | 11:02 AM
#52
Senior Member
My Feedback: (19)
RE: Is this possible?
Reducing diameter of the magnet for the flywheel causes reduced speed as the magnet passes the magneto coil. The speed of the magnet passing the coil is directly proportional to the induced voltage. If it gets too low it won't fire the plug. Stronger magnets could improve this a bit, but it really depends on what is currently used by the engine manufacturers. The magnets aren't exactly small, so a rare earth magnet would have to be quite large. A magneto system has two poles in the system, a north and a south. This could be one or two magnets. The magneto coil can't get much smaller without increasing the magnet strength considerably. The problem with making a new coil is the lamination used for the back iron in the coil. The laminations would have to be designed and made. Design is possible with some study. Producing a handful of lamination is not easy or cheap. And by handful I mean a few hundred or thousand. The thin flat plate "flywheel" would probably fail quickly due to the stresses involved when the magnet passes the magneto. This type of arrangement would not be rigid and would flex. You'd have to be careful to make sure it didn't resonate throughout the expected RPM range.
The generator idea is useful if you are going to fly for hours at a time where carrying a large pack isn't practical. For models I see no point. I have a single 2200mAh LiIon running my RCEXL in my .40 size trainer. It should give several hours of run time. I could not in this case make a generator lighter than or equal to the weight of the battery.
Link to Minimag info:
http://www.modelenginenews.org/ed.2006.01.html#5
I can see where a smaller lighter magneto system is desirable, but at the same time I don't see why a battery operated system is so undesirable.
The generator idea is useful if you are going to fly for hours at a time where carrying a large pack isn't practical. For models I see no point. I have a single 2200mAh LiIon running my RCEXL in my .40 size trainer. It should give several hours of run time. I could not in this case make a generator lighter than or equal to the weight of the battery.
Link to Minimag info:
http://www.modelenginenews.org/ed.2006.01.html#5
I can see where a smaller lighter magneto system is desirable, but at the same time I don't see why a battery operated system is so undesirable.
12-31-2008 | 12:22 PM
#55
Thread Starter
RE: Is this possible?
ORIGINAL: gkamysz
Reducing diameter of the magnet for the flywheel causes reduced speed as the magnet passes the magneto coil. The speed of the magnet passing the coil is directly proportional to the induced voltage. If it gets too low it won't fire the plug. Stronger magnets could improve this a bit, but it really depends on what is currently used by the engine manufacturers. The magnets aren't exactly small, so a rare earth magnet would have to be quite large. A magneto system has two poles in the system, a north and a south. This could be one or two magnets. The magneto coil can't get much smaller without increasing the magnet strength considerably. The problem with making a new coil is the lamination used for the back iron in the coil. The laminations would have to be designed and made. Design is possible with some study. Producing a handful of lamination is not easy or cheap. And by handful I mean a few hundred or thousand. The thin flat plate "flywheel" would probably fail quickly due to the stresses involved when the magnet passes the magneto. This type of arrangement would not be rigid and would flex. You'd have to be careful to make sure it didn't resonate throughout the expected RPM range.
The generator idea is useful if you are going to fly for hours at a time where carrying a large pack isn't practical. For models I see no point. I have a single 2200mAh LiIon running my RCEXL in my .40 size trainer. It should give several hours of run time. I could not in this case make a generator lighter than or equal to the weight of the battery.
Link to Minimag info:
http://www.modelenginenews.org/ed.2006.01.html#5
I can see where a smaller lighter magneto system is desirable, but at the same time I don't see why a battery operated system is so undesirable.
Reducing diameter of the magnet for the flywheel causes reduced speed as the magnet passes the magneto coil. The speed of the magnet passing the coil is directly proportional to the induced voltage. If it gets too low it won't fire the plug. Stronger magnets could improve this a bit, but it really depends on what is currently used by the engine manufacturers. The magnets aren't exactly small, so a rare earth magnet would have to be quite large. A magneto system has two poles in the system, a north and a south. This could be one or two magnets. The magneto coil can't get much smaller without increasing the magnet strength considerably. The problem with making a new coil is the lamination used for the back iron in the coil. The laminations would have to be designed and made. Design is possible with some study. Producing a handful of lamination is not easy or cheap. And by handful I mean a few hundred or thousand. The thin flat plate "flywheel" would probably fail quickly due to the stresses involved when the magnet passes the magneto. This type of arrangement would not be rigid and would flex. You'd have to be careful to make sure it didn't resonate throughout the expected RPM range.
The generator idea is useful if you are going to fly for hours at a time where carrying a large pack isn't practical. For models I see no point. I have a single 2200mAh LiIon running my RCEXL in my .40 size trainer. It should give several hours of run time. I could not in this case make a generator lighter than or equal to the weight of the battery.
Link to Minimag info:
http://www.modelenginenews.org/ed.2006.01.html#5
I can see where a smaller lighter magneto system is desirable, but at the same time I don't see why a battery operated system is so undesirable.
12-31-2008 | 12:32 PM
#56
RE: Is this possible?
ORIGINAL: gkamysz
I can see where a smaller lighter magneto system is desirable, but at the same time I don't see why a battery operated system is so undesirable.
I can see where a smaller lighter magneto system is desirable, but at the same time I don't see why a battery operated system is so undesirable.
I am sure I can make the aluminum plate work with the forces involved. Whether it will be too heavy or not is a different problem.
For magnets, here is an example of what is available (ignore the price, something is goofy there): http://www.houseoftools.com/product.htm?pid=15555
They are available from 1/4" diameter up to 1" at least. The 1" ones are so powerful you can't pry them off a steel surface.
Mark
12-31-2008 | 12:33 PM
#57
Senior Member
My Feedback: (19)
RE: Is this possible?
No, I'm not sure, but those are the issues. It's possible but like many things, I think development and production cost will kill it before it has a chance to get anywhere. This market is small and that makes the cost of things extremely important, unless it is to be a niche item that only those willing to pay for will end up using. Consider what it cost to buy a mass produced flywheel and magneto. Now, cut production quantity to 1/100,000th and factor in a completely new design. Put a price tag on it and see what happens.
12-31-2008 | 12:40 PM
#58
Senior Member
My Feedback: (19)
RE: Is this possible?
The more powerful you make the magnet the stronger the attraction when it passes the magneto. This means the flywheel needs to be stronger. An axial arrangement only makes this worse. To strengthen it you make the flywheel deeper, this of course increases weight so now you are machining it to make it light again. Machining is not cheap no matter where you do it. Somebody really needs to look at the cost of actually making one.
It looks like some of the Zenoah engines have relatively small diameter magnetos. Are these not made specifically for the RC market? Why aren't they smaller?
It looks like some of the Zenoah engines have relatively small diameter magnetos. Are these not made specifically for the RC market? Why aren't they smaller?
12-31-2008 | 12:47 PM
#59
Thread Starter
RE: Is this possible?
The way I look at it ...the people that sell light-weight engines would be selling more engines yet. A engine that does not NEED a battery, CD ignition and all the electrical wires ect, would be a very good reason for a lot of customers to buy one. Many RC people out there just do not trust all the things that go with CD ignitions in the first place. Hey engine producers...take note and be the first! Capt,n
12-31-2008 | 12:52 PM
#60
Thread Starter
RE: Is this possible?
ORIGINAL: gkamysz
The more powerful you make the magnet the stronger the attraction when it passes the magneto. This means the flywheel needs to be stronger. An axial arrangement only makes this worse. To strengthen it you make the flywheel deeper, this of course increases weight so now you are machining it to make it light again. Machining is not cheap no matter where you do it. Somebody really needs to look at the cost of actually making one.
It looks like some of the Zenoah engines have relatively small diameter magnetos. Are these not made specifically for the RC market? Why aren't they smaller?
The more powerful you make the magnet the stronger the attraction when it passes the magneto. This means the flywheel needs to be stronger. An axial arrangement only makes this worse. To strengthen it you make the flywheel deeper, this of course increases weight so now you are machining it to make it light again. Machining is not cheap no matter where you do it. Somebody really needs to look at the cost of actually making one.
It looks like some of the Zenoah engines have relatively small diameter magnetos. Are these not made specifically for the RC market? Why aren't they smaller?
12-31-2008 | 12:55 PM
#61
Senior Member
My Feedback: (19)
RE: Is this possible?
They must realize this. Does anyone use a magneto in TOC competition? Is it used in Giant scale racing, other than the classes that are required to? That is where innovation comes from. That is where the needs for weight and reliability come from.
12-31-2008 | 12:58 PM
#62
Thread Starter
RE: Is this possible?
Here is mag appears to be very lite. Capt,n EDIT to add this...cut the fins off= better yet. This can be found on the Toni Clark web-site. His products are know to be lite.
