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-   -   12th Scale (and oval) and Lipo - Making it work soon. (https://www.rctech.net/forum/electric-road/201257-12th-scale-oval-lipo-making-work-soon.html)

Mason 01-17-2008 05:37 PM

This entire thread is about the discussion of the future. Whether or not you like it, change is a constant. I'm not saying that we're running it tomorrow. or next month.. but soon. As time goes on with the power tool industry, nimhs wil be phased out of the majority like nicds were. Did they go away completely? no, you can still find el-cheapo power tools with nicds (and you get what you pay for), the 2nd tier stuff is nimhs and then you get up to the high end of things.

Let's not piddle around and wait a few more years until somebody already has some c.ckamami product out there that people start using and it becomes nearly too late to make a decision on this. Let's work it out for the better. You guys want "growth", don't shut the door on the opportunity to make it happen.

If you are not going to be realistic, that's fine. I'll thank you for your 2 cents and let you be on your way.

:tire:

Unregistered 01-18-2008 06:51 AM

I agree that there is a lot that needs to happen with the cells before they'll be good enough for 12th. They need to be able to source more current and we need a cell that will fit both types of cars (saddle and stick).

The weight thing isn't really an issue. You just add lead. It's really quite easy and not that expensive.

Drew_Cat 01-21-2008 07:53 AM

KO PROPO 302F
 
most of the people who knows me, if they see me without a 1/12 scale at the track they would think something is wrong (TRIPS):lol: with that being said, in the short time i have been running 1/12 scale the reciver of choice for me has been KO-PROPO 302f -- it has a nice little boster circut in the reciver to allow it to operate below 3.7v the only thing you'll need thier speedo (VFS-series). The new speedo from KO (C3) sould have lipo cut out but don't quote me on that.

InspGadgt 01-21-2008 10:40 AM

That's a cool sounding reciever...But that is just 1 case where it is going to work. We need something that will work across the board.

trailranger 01-21-2008 11:18 AM

Why not just leave the 1:12 scale alone and make a new scale?

It is understood that any change in weight, motor, battery will greatly affect the car forever. With indoor tracks getting more expensive, maybe a slightly smaller scale would be better so less space would have be to leased or bought for the actual track.

1:14/15/16 scale pan car...Change the motors to 380. Make a 6-cell 2/3A battery tray. This would allow LiPO or NiMH during the transistion. Make the parts metric since the golbal enconomy is bigger than the USA.

The 1:18 pan cars are just a little too small for my taste, the 1:12 are perfect and the 1:10 too big for most indoor small tracks. The problem is that you can not outright change anything on the 1:12 class and expect the results to be the same. So I opt for a newer slightly smaller class and a slightly smaller part bag when I go to the track.

Josh Cyrul 01-21-2008 12:12 PM

We already race 1/14 scale SportWerks Recoils here every week....

rcgen 01-21-2008 12:53 PM

For oval we started a 21.5/lipo class. Simple rules: Novak 21.5 brushless motor, Team Orion/Peake 3200 hardcase lipo. Minimum weight still undecided.

InspGadgt 01-21-2008 01:12 PM


Originally Posted by trailranger (Post 4101203)
Why not just leave the 1:12 scale alone and make a new scale?

Because sooner or later 1/12th will have to change due to a lack of battery support.

James35 01-21-2008 02:40 PM

Hehe, I think sub-c's will be around for quite some time.

On a different note, A123 Lithium Ion Nanophosphate batteries could possibly be an option. They are superior to LiPos.
http://www.evworld.com/images/a123_csize.jpg
Each cell is about the size of a full C battery, but a little longer. 3.3V per cell, 2300 mAh.
Designed to take a 10 amp charge! Wack 'em over and over in the same day.
Chemically designed so they cannot explode.
Hard case.
After 1000 cycles, they only drop 5% of their initial capacity!
They only drop 3% of a charge per month!
Something silly like a 70-90amp continuous discharge rate.
$8 per cell.

Dewalt and Black and Decker are using them in their cordless Lithium packs. Full size car companies use them in their electric cars. RC air plane guys love them.
I practice oval with a 13.5 and two A123 cells. I'm pretty sure I've lasted 8 minutes before. I bet the 6.6V with a 21.5 will be just about right. I doesn't require a chassis change for oval, but probably would for road course. The weight would be centered more to the centerline of the chassis, so that would be nice.

InspGadgt 01-21-2008 02:49 PM

Probably...but with LiPo now allowed in 6 cell we will see a switch in emphasis by the manufacturers and matchers. Though they may still be around in the future it will be more and more difficult to get good race packs. Look at NiCad...it is still around but it's near impossible to find good race quality packs. And that only took a few years to happen once NiMh was legalized.

InspGadgt 01-21-2008 03:26 PM

Interesting battery...once again though they may work in existing chassis to fully realize their potential will still need a chassis redesign. Whichever technology gets adopted in the fugure manufacturers are not going to just keep using an old chassis design just because it will fit. Everyone tries to get a competitive advantage...especially manufacturers.

Crashby 01-21-2008 04:29 PM


Originally Posted by James35 (Post 4101906)
Hehe, I think sub-c's will be around for quite some time.

On a different note, A123 Lithium Ion Nanophosphate batteries could possibly be an option. They are superior to LiPos.
http://www.evworld.com/images/a123_csize.jpg
Each cell is about the size of a full C battery, but a little longer. 3.3V per cell, 2300 mAh.
Designed to take a 10 amp charge! Wack 'em over and over in the same day.
Chemically designed so they cannot explode.
Hard case.
After 1000 cycles, they only drop 5% of their initial capacity!
They only drop 3% of a charge per month!
Something silly like a 70-90amp continuous discharge rate.
$8 per cell.

Dewalt and Black and Decker are using them in their cordless Lithium packs. Full size car companies use them in their electric cars. RC air plane guys love them.
I practice oval with a 13.5 and two A123 cells. I'm pretty sure I've lasted 8 minutes before. I bet the 6.6V with a 21.5 will be just about right. I doesn't require a chassis change for oval, but probably would for road course. The weight would be centered more to the centerline of the chassis, so that would be nice.

What kind of charger would be required?

James35 01-21-2008 06:14 PM

I use my Team Checkpoint (or ICE) charger, even though it wasn't designed for it. I charge it at 10 amps, and manually reduce the amps as it reaches 7.2V. As soon as it reaches 7.2V at 3 amps, it's ready. Basically, it shouldn't go over 7.2V. I use the Li-Ion setting, but it really doesn't actually get to the CC-CV feature during the charge. Most chargers with Lipo or Li-Ion settings don't charge A123's properly since the batteries are 3.3V per cell instead of 3.6V or 3.7V per cell. It's just a software programming thing that I wish we could update.

You don't have to manually reduce the amps as I do. You could set it at 3 amps and then stop the charge when the battery hits 7.2V. There was one time where I missed it completely and simply forgot. It went up to 7.8V, peaked and the charger detected the delta peak. But this was higher voltage than the manufacturer recommends. A123 has their own charger, but I don't know much about it. Hyperion EOS0606i, EOS1210i , and EOS0610i 6S have the proper programming for the A123 cells. There are other brands too, but I just don't know them. The biggest air plane forum (RCGroups.com) has a huge forum dedicated to batteries and chargers.

Since the air plane guys are not racing, they don't have any rules and therefore they end up using the newest RC technologies first. For example, they were running brushless, lipo, A123 cells long before we were. If my memory servers correctly, I think the Spektrum 2.4ghz was first used with air planes as well.

trailranger 01-21-2008 06:21 PM

About the A123 M1 cells, Many of the higher quality LiPO chargers with balancers built in have LiFePO4 chargers. I use the Hyperion 610i, which is capable of a 10amp charger rate while balancing.

The car most capable of a conversion would be the old style 4-cell saddle pack cars. They had slots long enough for the A123 m1 cells but not wide enough. Using a drill press and a bandsaw someone could whip out a prototype chassis in an hour that would fit the M1 cells. The slots were long due to the T-Bar being long. The t-bar was long because 1:12 used to have 6-cell saddle packs. Back at square one!

The second most capable cars of conversion would be Darkside MX2 and the Diggity Designs 3d series. The cars would still need a new lower chassis but little other work.

This is just me talking, but if 26650 or 18650 sized cells were allowed, I would say cut the race time from 8-min to 5-min. The reason for the reduction in time would be that fitting four 26650 cells in the car will be hard so capacity will be limited to 2300 for A123 cells and 2700mah for brands like Falcon. Over time, these cells will be in the 4000 range and the race time can be taken back to 8min.

Mason 01-21-2008 07:49 PM

LiFePO4 requires a different charging technique from lipo according to everything i've read by the manufacturer and distributors/oems making stuff for it. If you aren't going to use the proper charger for it, i hope you are atleast using the same techniques they describe their charging method to be for your safety sake.


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