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Old 07-11-2006, 08:29 PM   #136
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there is more to it than that...

when you run 6 cells there is more arcing so you need more spring tension, which in turn creates even more heat due to more friction, etc.
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Old 07-11-2006, 08:32 PM   #137
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Which would make brushless a perfect candidate for high voltage, no arcing. The world will go brushless eventually, HV brushless makes the most power its been proven in the Heli world a hundred times.
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Old 07-11-2006, 08:33 PM   #138
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I had predict this from the day JMRCA start 4cells rule:

4cells NiMH, 1350g -> 1cell LiPo, 1300g

By changing to 4cells NiMH first, the chassis layout will change into something else, and set the foundation of future 1cell LiPo era (same battery dimension, similar weight). This is logical approach to go LiPo or something else than NiMH, and the current 6cells chassis design is no where to go with new battery-tech era.

This change remind me 1/12 changed from 6cells to 4cells many years ago, although I didn't play RC at that time.
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Old 07-11-2006, 08:41 PM   #139
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Quote:
Originally Posted by WheelNut
Which would make brushless a perfect candidate for high voltage, no arcing. The world will go brushless eventually, HV brushless makes the most power its been proven in the Heli world a hundred times.
correct - however the current batch of brushless gear is inadequate.

brushless gear in helis & planes are far more advanced than the car stuff, car brushless systems need to play catchup very quickly if they want to take over completely.

the amount of brushless speedys i've seen catch fire is frightening, all we need is for one of these speedys to short out a pack and make it explode in some kid's face, and bam, there goes the hobby.
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Old 07-11-2006, 08:50 PM   #140
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I am going to throw in my opinion what should happen......

I have read this entire thread and most of the talk is about limiting the cells...I dont beleive that is the way to go....I believe the equipment that has been developed in the past years are very good...

I believe that the problem is the tecnology of the battery itself....
With the Miliamps increase that has become and the Voltage they can get from them now that is what is making the equipment overheat or fry...

With all the tecnology that has been aquired why dont we still have the voltage but limit the miliamps?

I feel if the miliamps were limited for racing say 2000mah or 2400 mah that would not only save the equipment but also bring the speeds down abit(which I do not feel is the problem)...

And for everyone that thinks there will be illegal cells at the races..you can monitor this by being able to take anyones cells at any time and conduct a test...set a maximum MAH(with a slight tolorence) and if found out of spec then that racers results are deleted from the event....

When people say "what if its one of their good packs" well with the technology the Battery companys have these days most all cells are so close now...if MAH is lowered the cells will be so close it will not make a difference....

With limiting the MAH not only will it be better on the equipment but also bring back the controlled driver standpoint(thinking drivers)as you will need to drive the cars much smoother to make time...these days you can pretty much go full throttle and still make time...bring back the chess matches that took place at many races by lowering the MAH..I think that will help..

Just my opinion,

Barry
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Old 07-11-2006, 08:51 PM   #141
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Car brushless controller is much much more complex than aero brushless controller. You can try to put the most expensive aero brushless controller on car, and see if you can brake/turn into perfect apex, and pullout in perfect throttle control. I see some people do this in local track, the system is only good as drag-racing, not track-racing.

I don't think aero need brake, drag brake, timing adjustment, freq adjustment, all those stuff that's must have for car nowday.
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Old 07-11-2006, 08:52 PM   #142
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It requires too much work to get these cars to run at the level we expect them to. When I was running my RDX I was constantly cleaning the car, swapping bearings, checking for tweak, checking the settings. I practically had to sleep with the damn car for it to work well. Racing quickly lost it's fun doing all of that. I work at my job and I use RC racing as a way to get away from the real world, working on my car is no fun.
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Old 07-11-2006, 09:36 PM   #143
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Quote:
Originally Posted by Barry Baker
I am going to throw in my opinion what should happen......

I have read this entire thread and most of the talk is about limiting the cells...I dont beleive that is the way to go....I believe the equipment that has been developed in the past years are very good...

I believe that the problem is the tecnology of the battery itself....
With the Miliamps increase that has become and the Voltage they can get from them now that is what is making the equipment overheat or fry...

With all the tecnology that has been aquired why dont we still have the voltage but limit the miliamps?

I feel if the miliamps were limited for racing say 2000mah or 2400 mah that would not only save the equipment but also bring the speeds down abit(which I do not feel is the problem)...

And for everyone that thinks there will be illegal cells at the races..you can monitor this by being able to take anyones cells at any time and conduct a test...set a maximum MAH(with a slight tolorence) and if found out of spec then that racers results are deleted from the event....

When people say "what if its one of their good packs" well with the technology the Battery companys have these days most all cells are so close now...if MAH is lowered the cells will be so close it will not make a difference....

With limiting the MAH not only will it be better on the equipment but also bring back the controlled driver standpoint(thinking drivers)as you will need to drive the cars much smoother to make time...these days you can pretty much go full throttle and still make time...bring back the chess matches that took place at many races by lowering the MAH..I think that will help..

Just my opinion,

Barry
Hey Barry,

the problem with this is it's really a backwards step ( imho)
I've been there before, the guys that did best were the guys who had not only the best packs, but a brand new pack for every run. I'm sure you remember the days of having your pit guy topping up the charge on the line with seconds to go before the start of a run.
Why is restricting the number of turns on the motor not a better way to go?
This way even average packs get plenty of run time, and straightline speeds are all pretty close, makes it easier for Joe Not Sponsered to try to compete, and keeps costs realistic.
Every single form or class of motorsport out there has restrictions, why not RC?

Oh and with regard to the old WRC some guys were talking about, it was Group B, which had development continued unabated, was going to go to even crazier group S !
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Old 07-11-2006, 09:55 PM   #144
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Quote:
Originally Posted by stulec52
Hey Barry,

the problem with this is it's really a backwards step ( imho)
I've been there before, the guys that did best were the guys who had not only the best packs, but a brand new pack for every run. I'm sure you remember the days of having your pit guy topping up the charge on the line with seconds to go before the start of a run.
Why is restricting the number of turns on the motor not a better way to go?
This way even average packs get plenty of run time, and straightline speeds are all pretty close, makes it easier for Joe Not Sponsered to try to compete, and keeps costs realistic.
Every single form or class of motorsport out there has restrictions, why not RC?

Oh and with regard to the old WRC some guys were talking about, it was Group B, which had development continued unabated, was going to go to even crazier group S !
Stu, you have a point ...but back then the technology of the batteries were not the same as they are today....the batteries today are much better...in fact at most races I just leave the same pack in my car and it gets better and better each and every run and stays very good for a long time...no change in runtime or voltage......
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Old 07-11-2006, 09:56 PM   #145
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Running capacity limitation is very much like change Sub-C cell to AAA cell, you facing the same problem with 4cells Sub-C NiMH or 1cell LiPo: the weight and dimension are very differnt to 6cells Sub-C. This means new chassis layout. So if you facing the same chassis layout change, why not just go for 4cells Sub-C, which is good foundation for future 1cell LiPo?
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Old 07-11-2006, 09:58 PM   #146
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Quote:
Originally Posted by stulec52
Why is restricting the number of turns on the motor not a better way to go?
Because then racers try to push these motors to go faster and blow them up
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Old 07-11-2006, 10:13 PM   #147
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How about an inline current limiter that is installed on the car for big races? Its been brought up in ROAR I can tell you that for sure. Have 3 limiters. Stock, 19 turn or intermediate and Mod. Hand them out at the big races and take them up the end of the day then hand them out again the next day....everyone gets a different one just for arguments sake. This would take MOST of the battery AND motor stuff out of it.

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Old 07-11-2006, 10:27 PM   #148
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Quote:
Originally Posted by ttso
Running capacity limitation is very much like change Sub-C cell to AAA cell, you facing the same problem with 4cells Sub-C NiMH or 1cell LiPo: the weight and dimension are very differnt to 6cells Sub-C. This means new chassis layout. So if you facing the same chassis layout change, why not just go for 4cells Sub-C, which is good foundation for future 1cell LiPo?
Im sorry to say but if we go to 4cell the batts are still going to change with each new generation of cell brought out....with limiting the MAH you will have the same cell size for as long as they keep to this limitation.....
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Old 07-11-2006, 10:42 PM   #149
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Quote:
Originally Posted by Barry Baker
Im sorry to say but if we go to 4cell the batts are still going to change with each new generation of cell brought out....with limiting the MAH you will have the same cell size for as long as they keep to this limitation.....
how much further can the capcity of sub-c cells be pushed though?

and more to the point, will battery companies willingly produce 2000mah batteries? knowing that they can produce cells with close to 5000mah and insane voltage, whats to stop them from producing cells which are 2000mah, but ~1.4v instead of the ~1.2 instead, hell they're already doing it with the current batches of 4200s.

while it would be a good idea to have the power input limited like you suggest, i think the 'limit' as such needs to be more natural at 4 cells, or a voltage regulator style one. (lipo with a 6v regulator would be nice)

i know there's a way of limitting the output voltage... is there a way of limiting the MAH released by a battery pack?
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Old 07-11-2006, 10:43 PM   #150
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If we went to five cells, wouldn't this effectively do what moving from 7 to 6 did? Possibly make the cars easier to drive, motors last longer, and we would still have the runtime that a basher/ newbie finds to be the 2nd most important piece of rc behind speed...
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