FE Class Suggestions for IMPBA Trial Period.
- Thread starter Paul Pachmayer
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Scott_T
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Paul's proposed classes are similar to what is proposed here in Australia -
EA - 12 NIMH cells
EB - 22.5V
EC - 39V
This is only a draft, and keeping one power level NIMH suits a lot of people. We're ditching the 6 cell / 7.5V class from the AMPBA rule book, but clubs may run them.
Our races are 5 laps on a nitro course (1500m total). Boats are launched at 30 seconds with a 1/2 lap mill (nitro guys have no problems with it), and you must complete the lap once you cross the finish line, so a mimimum of 6.5 laps are run.
Running electric only races at IC events seems to be going quite well, especially with the electric guys listening to the IC guys when it comes to racing, and our boat speeds increasing at every event.
EA - 12 NIMH cells
EB - 22.5V
EC - 39V
This is only a draft, and keeping one power level NIMH suits a lot of people. We're ditching the 6 cell / 7.5V class from the AMPBA rule book, but clubs may run them.
Our races are 5 laps on a nitro course (1500m total). Boats are launched at 30 seconds with a 1/2 lap mill (nitro guys have no problems with it), and you must complete the lap once you cross the finish line, so a mimimum of 6.5 laps are run.
Running electric only races at IC events seems to be going quite well, especially with the electric guys listening to the IC guys when it comes to racing, and our boat speeds increasing at every event.
Paul Pachmayer
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Hi Guys,
Paul.
There isn't really a "problem" with pulling into the infield but by not allowing it to happen a racer knows he has to plan ahead and know the boat will run at least ten laps wether it has to or not. Most heats would consist of 8 or 9 laps (on a nitro oval) start to finish. Plus there is no reason why you can't finish the entire race under power. All heats will be 1 mile regardless of course size.
Paul.
JfromJAGs
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A limitation in voltage is only half of the equation. Electric power equals voltage x current. So if you just limit the voltage, then this is NO power limit. A real power limit would consider voltage and current, or an energy limit voltage x capacity.
Joerg
Joerg
Andy Greene
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I never have and never will understand why you would "pull into the infield and stop" at the end of a heat?? instead of just bringing the boat back around and pitting.
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T.S.Davis
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Then neither organization currently has a power spec. With no changes at all today we have NO power spec. No limits at all. Just a voltage. That's both rule books today as I type this.
JfromJAGs
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Guys, I'm really tired of explaining this over and over again (here and in RR).
Terry and Jeff: there used to power limit, it was an indirect limit though: size of the cells (sub C) and Ni-chemistry. It was allowing some improvements, on mechanical construction of the cells and on filling the volume more efficient. As I have pointed out before: most of the gain in capacity of modern NiMH's cells came from additional weight.
The biggest step in capacity in the past 10 years came from changing from NiCd to NiMH, because NiMH has a higher energy density, thus more power from the same volume. After that 80% of the gain in capacity came from making the cells bigger (42mm -> almost 44mm today) and stuffing more material into them (56g -> 72g). But there will NEVER be 10,000mAh NiMH/NiCd cells in sub C size, especially when manufacturers get forced to step back to the original sub C size: 23mm x 43mm.
But as I said, I'm absolutely tired of explaining the technical background again and again. One of my the new year's resolution's is to stop arguing with people who don't want to listen and who don't want to understand - means writing on discussion boards. So consider this as my last post on the subject - and in general. I'm done.
Joerg
Terry and Jeff: there used to power limit, it was an indirect limit though: size of the cells (sub C) and Ni-chemistry. It was allowing some improvements, on mechanical construction of the cells and on filling the volume more efficient. As I have pointed out before: most of the gain in capacity of modern NiMH's cells came from additional weight.
The biggest step in capacity in the past 10 years came from changing from NiCd to NiMH, because NiMH has a higher energy density, thus more power from the same volume. After that 80% of the gain in capacity came from making the cells bigger (42mm -> almost 44mm today) and stuffing more material into them (56g -> 72g). But there will NEVER be 10,000mAh NiMH/NiCd cells in sub C size, especially when manufacturers get forced to step back to the original sub C size: 23mm x 43mm.
But as I said, I'm absolutely tired of explaining the technical background again and again. One of my the new year's resolution's is to stop arguing with people who don't want to listen and who don't want to understand - means writing on discussion boards. So consider this as my last post on the subject - and in general. I'm done.
Joerg
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Paul Pachmayer
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Hi Guys,
There's no point in second guessing what the proposal will be. We are working on this step by step so everything gets covered. So far voltage breaks have been accepted and now we move on to capacity. We will cover boat size, safety etc. later on. Now that Lipos have been voted in we are trying to taylor a solid FE program. We don't want the same old stuff on a different day do we?
Paul.
There's no point in second guessing what the proposal will be. We are working on this step by step so everything gets covered. So far voltage breaks have been accepted and now we move on to capacity. We will cover boat size, safety etc. later on. Now that Lipos have been voted in we are trying to taylor a solid FE program. We don't want the same old stuff on a different day do we?
Paul.
T.S.Davis
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Joerg,
The limit that you feel we currently have in our books is based on the "sub C" size requirement. The maximum capacity that can be stored in that particular size is "X". At the moment X = 4600mah? Maybe. If we accept the notion that NiMh accounts for a percentage of the increase in capacity. What of the next chemistry change? The manufacturers are sleeping while they sell NiMh? They're surely searching for an even more energy dense material to stuff into the cells. If a 7000 mah cell becomes available that is Sub C would I use it? Of course I would. Then there is NO limit today. We are limited only by the technology available to us.
So for arguement sake we should assume that "sub C" imposes a limit on us based on it's size alone. Then we assume further that the technology of a Sub C will not advance to a 10000mah capacity. Where will it advance to then? 5000? 6000? At the same time you want us to assume that speed controllers will advance overnite to 400 or more amps to use the LiPo power available.
Keep up the good work Paul. No matter what happens you have us all thinking of the possibilities.
The limit that you feel we currently have in our books is based on the "sub C" size requirement. The maximum capacity that can be stored in that particular size is "X". At the moment X = 4600mah? Maybe. If we accept the notion that NiMh accounts for a percentage of the increase in capacity. What of the next chemistry change? The manufacturers are sleeping while they sell NiMh? They're surely searching for an even more energy dense material to stuff into the cells. If a 7000 mah cell becomes available that is Sub C would I use it? Of course I would. Then there is NO limit today. We are limited only by the technology available to us.
So for arguement sake we should assume that "sub C" imposes a limit on us based on it's size alone. Then we assume further that the technology of a Sub C will not advance to a 10000mah capacity. Where will it advance to then? 5000? 6000? At the same time you want us to assume that speed controllers will advance overnite to 400 or more amps to use the LiPo power available.
Keep up the good work Paul. No matter what happens you have us all thinking of the possibilities.
L
lohring
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The proposals I have heard that can be inspected for limiting power are weight limits on the battery pack and an electronic circuit breaker that would directly limit the total watts that could be taken from the battery. The first encourages early adaption of new technology, but guarantees high costs for those who really want to win. The second is "restrictor plate" or fuel flow limited racing and would make the competition closer. Are there any other suggestions?
Lohring Miller
Lohring Miller
Lohring
Nobody on this thread is talking about these type of limits.
Nor do we want them.
Larry
Paul the simple class structure is good
I am with Joerge on the need for further specification to preserve the benefits of lipo. If cells are not properly specified the weight and cost advanatages of Lipo will be lost. Right now a lipo boat of 5AH 25C pack costs less to own than a nitro boat of the same performance. These benefits need to be preserved so more people can learn to walk, and then run.
I am with Joerge on the need for further specification to preserve the benefits of lipo. If cells are not properly specified the weight and cost advanatages of Lipo will be lost. Right now a lipo boat of 5AH 25C pack costs less to own than a nitro boat of the same performance. These benefits need to be preserved so more people can learn to walk, and then run.
K.R.Joye
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PAUL those classifications sound so simplistic, must be nice starting from a clean slate in IMPBA.
Change Open to 40V, multi-motors permitted.
Good luck with it!
KRJoye
Change Open to 40V, multi-motors permitted.
Good luck with it!
KRJoye
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L
lohring
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As Jorg pointed out power is volts X current. If you only regulate volts it would be like setting nitro classes by bore size. The question is how do you regulate power in a way that will allow new technology and create fair classes? Internal combustion engines have done this successfully with displacement for a very long time.
Lohring Miller
Lohring Miller
Darin Jordan
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Paul... I've been thinking...
Is it really necessary for IMPBA/NAMBA to still allow multiple motors in these classes? Wouldn't it quell the fears of "unlimited power" somewhat by limiting the amount of power one could feasibly use if this allowance was removed?
I'd remove the allowance to run multiple motors in all but the open classes...
Is it really necessary for IMPBA/NAMBA to still allow multiple motors in these classes? Wouldn't it quell the fears of "unlimited power" somewhat by limiting the amount of power one could feasibly use if this allowance was removed?
I'd remove the allowance to run multiple motors in all but the open classes...
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drobie
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Brilliantly stated.
Only comment is that I wouldn't be suprised if we saw some pretty spectacular stuff in a shorter time period than 5-10 years.
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