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Old 10-16-2008, 04:04 PM
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Default The future of 1/12 scale

The future of 1/12 scale is to be explored, experiment, and discussed here.

As you all know that lipo is here to stay. Other scale of electric racing now can enjoy the benefit of lipo except 1/12 scale. Over here, I want to show people what I did with 1/12 scale car with a 2-cell lipo battery pack.

What’s going to be for 1/12 scale with lipo, will it be using single cell or 2-cell for racing? Well, there is a thread discussing using single cell for 1/12 scale on RC Tech, you can read it here:
http://www.rctech.net/forum/electric...cell-lipo.html

However, let me be upfront about it, I’m in favor of the 1/12 with a 2-cell lipo. I’ll explain to you why I think a 2-cell racing package is better than a single cell racing package. I’ll show you what you need and how to do about it. You can post you opinion here even you’re for single cells, but just be more on 2 cells. I wish all the 1/12 scale racer have an open mind about all the discussion here, whether you’re for single cell or 2 cells, and that we don’t rush ROAR into making any decision until more options are tried by more people. I suggest that a track that race 1/12 allow both type to be run together, only then we can see which type is a better way to run the 1/12 scale.

Now, let me reveal what do I have in mind, something that I have played around with, given a lot of though, and invested some time, money and effort to come to this conclusion that this will be the ultimate class for on road racing. Here is what I use: one 1/12 scale car, small capacity lipo, about 1550mah in the very beginning, but now I’ve found a perfect sized 2400 mah pack, and esc and brush less motor for 1/18, like the one made by MOMBA. Go ahead, laugh about it, make fun of it, but I’ll change you mind if you stick around,

The whole thing is about 20 oz ready to run, this may make some of you think:“ It’s outrageous”. This thing has 7.2 volt of power, and that’s double outrageous. Well this thing uses tiny motor that generate a lot less power than a 540size motor. Some of you may start to doubt that will this ever be accepted by ROAR and IFMA, it’s too much different than the current rules that we use now. But, you see, the rules will have to be changed a couple of years down the road, and whether it’s a change to a minimum of, say 25 oz, or to a minimum of 21 oz., It’s a change, one way or the other. While we are at it, we might as well, Once for all, make the necessary change to make the 1/12 the best it can, if that means we also need to change the motor, so be it. Who puts a gun at our head and demand that we have to run this class with a certain size of motor, certain capacity of battery, or even at a certain weight that a 1/12 has to be? The answers are no, no and no! If you prepare a car, especially those who have a spare car sitting on shelf, and do what I did, you’ll agree with me that this is the way to go for 1/12. If enough of you do that, and have ROAR looked at it. The rules may be changed to such, who knows, right? But before that, we need to put this out there so more people can see it, try it and get excited about it.


Let us try it, let people race with different package even that maybe one package seems (much) faster than the other, let’s allow them to run together along with conventional legal racing package and see which one is the best all around. Technology is here already, let’s make the right choice and benefit the most out of it. Of course it takes fellow racers who still use conventional racing gear to tolerate, to accept, and not to be upset and complaining the lose to someone who uses the “illegal” stuff. I can see them, the “illegal” stuff, not being allowed in a trophy race, but let’s encourage them on a regular club race.

Why do we have to let this happen? You might ask. Well, if we don’t, we are going to see the death, or near death, of 1/12 scale, based on what I see in my local area, Long Island, NY. It was just three years ago, we had more than thirty people race 1/12 scale every week, and the number were growing, but now, we usually have only 5~7 people racing it. And I know the reason. A lot of people don’t race 1/12 now because they, and I’m one of them, don’t want to buy Ni-MH ever again after using and knowing the benefit the lipo brings. So, if your are a die hard 1/12 scale racer, like I am, that’s why I’ve spent more than a week to prepare this article, and care about the future of 1/12scale racing. Do you want to see the class dwindled further? And it’s not going to get back up anytime soon, because it is not worth the money, $50.00 a pack of 4 cells x 4 = $200.00 battery alone, for 3 month of racing, to get into a class where there is no good competition. And three month is what NiMH usually good for in high level of racing. Almost all of the A-main driver in 1/12 scale in my local track is no longer racing 1/12 scale for now. So, IMO, 1/12 scale racing won’t be meaningful much for the next few years, even for the regional event.

Without a doubt, lipo and brushless bring many ex-rc racer back to racing (touring) again. It will do the same magic for 1/12 scale too. But which way should we go about it? I personally think a 2cells is the way to go? Here are why:

1) It’s fast.
2) It’s simpler.
3) It’s cheaper!


IT’S FAST! And it can go much faster, believe me!
Well, both set up are capable of running slow, or slower than, like stock pace. And both set up are capable of fast pace also, it’s all depend on motor and gear selection. But a 2cell set up like mine can easily going faster than fast. For now, I don’t want to scare you how fast can this thing go. I just want you to know, from my testing, this set up can go fast with ease when driving, another word, the car is easily under control even when driving fast. It can also go much faster if you want it to. That we can talk about much later on.


IT’S SIMPLER.
It’s like plug and play. You hook up your electronic like you would with any other electric chassis. Plug you steering servo and esc into your receiver, and that’s it. But not so with single cell set up. With single cell you have to have a receiver pack to begin with, and during the day you may need to charge them more then once or twice.
From what I heard, there is no punch whatsoever with 13.5T, It’s almost full throttle all the way. Why so? May it be that the battery does not provide enough voltage? With a hotter motor, the voltage will drop even more under heavy acceleration. Another electronic device may be needed to boost up the voltage. That’s been said/mentioned in the “SMC 5700mAh 25C Single Cell Lipo” thread. If they ever make such a, “voltage booster” or ”step –up circuit”, then we may have to deal with another problem this new product brings. Imagine Novak makes one that convert 3.7V to 4.8V. Two month later, other company comes out with one that claim convert the voltage to claimed 4.8V but hide their actual convert to 5.2V, and lead or mislead, however you want to define, consumer to think they have a better product and make its user go faster. Or three month later, Teken comes out with one that indeed convert 3.7V to 4.8V but claims lower internal resistant. Do you or do you not put the Novak made on the e-Bay and buy the Tekin made? And what will stop Lrp to make another one that claims an even lower internal resistant than Tekin’s 5 month later? Do we really need to go down this road?


IT’S CHEAPER!
A single cell made by SMC is around $65.00, the battery that I use is around $25.00, Of course, once if it’s determined and become race legal it then may be 15~20 dollars more to have them made hard case. But in the end, it’s still going to be more likely cheaper than the SMC single cell. The motor is cheaper. The 540size motor is around $75 and up. The motors that I have tried most are all around $15.00~$18.00. The Momba motor for 1/18 car is around $50.00. The esc is cheaper. Better esc that majority racers use is more than likely to be $150.00 and up. The esc that I use for this project is $50.00. It’s cheaper to begin with.

With everything else being the same, chassis, tire, servo, receiver and body, my 2-cell set up costs me a another total of less than $100.00 to get it going, $25 for the battery, $50.00 for the esc, and $20.00 for the motor. And it will costs $310.00 for a single cell set up to get it running, and that price tag does not include the maybe needed voltage booster. That is $65.00 for the battery, $75.00 for the motor, $150.00 for the esc, $20.00 for the receiver pack, and may be another $50.00~$80.00, for the voltage booster if they ever make one. The $50.00~$80.00 is just a number I throw out, anything less than that will give manufacture no incentive to make one, anything more expensive will prove we are stupid to go about this route.

It’s also cheaper to keep it running. Being only 20oz.in weight, the tires will last at least twice as long. And when you hit something, being much lighter, that’s less damage done to your chassis and your body. If you race once a week, in less than three month, my estimation, racing with this set up, just the savings from the tires usage and body probably be more than enough to cover you the total cost to put this set up together. And it will continue to save more money down the road.
As if I still haven’t convinced you yet, let me repeat: “Just the savings from the tires usage and body probably be more than enough to cover you the total cost to put this set up together.” Or am I talking to a piece of wood?


Just imagine how easy and how much money this could save for the future generation to come? How attractive this class will be for the new comer? Just being that much cheaper is good enough to make such a change, won’t you agree?

Historically, ROAR made a lot of decisions based on the fact a decision is made so because it will save racer money. And historically there is not a change ROAR made can save racer money as much as this change can. What says you, ROAR?

I hope that I’ve illustrated how much sense I’ve made. I hope you all see the big picture. But I won’t be so arrogantly say I’m such a genius and absolutely right about it, and demand such a change right away. I only wish ROAR will take a leadership position and announce some type “Temporary class” or “Transitional class” for 1/12 scale for the next year or two, and let all type of combination of lipo and brush-less motor to race each other and see what will stand out. Such an announcement will encourage people to go ahead and experiment new ideas and new things so we have more choice to choose from, and then can make the right decision for us and for the next generation to come.


For you to take more than a few minutes to read up to this point means you somewhat care about 1/12 scale racing. So I urge you to try it, be it a single cell set up or my set up or both, just remember, my set up is very inexpensive and readily available. Think about the whole scenario that I’ve just presented to you and talk about it with your racing pals. Or better yet, you try one set up while your racing pal try the other and do the comparison. Don’t just stand there on the sideline and do nothing. If you choose to do nothing that means you’re waiting for somebody to make decision for you. But who knows if this somebody is really smarter than you are. So, do you really want some body, who may not be smarter than you are, decide what’s good for you? And if the decision turned out to be no good for you and you did not have a say in it. That would be sad, don’t you agree?

---------------------------------------------------------------
The following is from post #78, because I didn't have time to put verything together in the beginning. I decide to add them here because when people first read a thread that's new to them,and if the thread gets kind of long, they tend to read the first page and then skip to current page, then, they will miss these informations. Also, in this editing section, I can not add any pictures. Please go to post#78 for some pictures. So, here we go:

These are things I used to set up my car, where to get what, and how to put them together.

Motor and motor mount:
In the attached pictures, you will see the parts you need to mount the Momba motor on the motor mount of a 1/12 scale.
You will need:
2 3mm x 12mm screw
2 2.5mm x 4mm screw
4 split washers
2 washers
2 3mm nuts
1 aluminum plate
1 1/8” plastic tube, some antena tube will work fine. And if it's too tight, cut a slit on the tube.

You can use momba 5400kv motor, with 1.725" tires, I use 16/88 ratio.
You can also get this motor here:
http://www.hobbycity.com/hobbycity/s...idProduct=4215
I have this coming my way, it's a slower motor:
http://www.hobbycity.com/hobbycity/s...idProduct=4216
I've also try Momba 6800kv, it's like mod speed, but very hard to gear though.
You have to use very small pinion and tires.


Battery:
Just a few days ago, a 1800 mah became available on the ebay, click the link :http://stores.ebay.com/seemmy999
In the battery category, you will be looking for:
7.4V 1800mAh 25C Lipo Battery for 1:18 RC Car Truck
It comes as 2-cell 7.4 v.
I used a 2400mah pack like this:

http://www.rk2trade.com/rk2trade/pro...roducts_id=161
It came as a 3-cell 11.V, I had to use my Dremel. Both are perfect in size. The 1800mah is lower in capacity, but higher C rate. It should provide more than 10 minutes run time. After 8-minutes qualifier with the 2400mah pack, I plug it into my charger, it showed that I still had 45 % capacity left in the battery. l did not feel any drop in speed for 12 minutes with this battery.
This set up is the best thing happen to 1/12.

ESC.
It’s also available on www.hobbycity.com, here:
http://www.hobbycity.com/hobbycity/s...verse_programm.
Or better yet, it's cheaper here, the same place you can order the 2400mah battery:
http://www.rk2trade.com/rk2trade/pro...roducts_id=190

I use this esc without the fan, I don't think it's needed for the tiny motor. This ESC will allow you to use it in 1/10 scale down to 9T motor, but in sensor less mode.
Attached Thumbnails

Last edited by Roland S; 10-18-2008 at 10:45 PM.
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Old 10-16-2008, 04:37 PM
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First, I think it's an interesting vision. Whether it's something that people are willing to accept, well, time will tell.

What I'm interested in is seeing pics of how you mounted a 380 in a 12th. It's an idea I've been kicking around for a while (for many of the same reasons) and I think it'd be neat to see it.

Cheers
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Old 10-16-2008, 04:48 PM
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Good ideas. It's been done out here in Seattle. Brian Bodine of Slapmaster has prototyped and run one. Exactly as you've described. A small 2S lipo, 380 motor, and it goes like a bullet. To really optimize it would require some additional engineering, but the concept is sound.
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Old 10-16-2008, 04:49 PM
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Damn Roland... that is intense. I don't write that much for an English class essay. I will comment back when I am done reading.
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Old 10-16-2008, 04:49 PM
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I read the whole thing. It'll be an interesting topic to follow.

I've heard people speak of using 380-sized motors for 12th scale to offset the jump to 7.4V lipo (EDIT: just read PutAwayWet above) and that or a 1/18 motor may be a great idea. The rear pod could be so much smaller and the motor could be way down low.

I'm sure brushless/lipo will be the standard in 12th scale within a couple of years, and good for you for experimenting with it.

You'll get some , some , and some but that's what makes for a good debate.
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Old 10-16-2008, 05:00 PM
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I like the idea of trying it. People like to waste a lot of time bitching about hypotheticals. The only way things move forward is putting them to the track. Lipo was Satan himself 2 years ago, it turned out most of us sold our souls and he turned out not too bad of guy after all. This is the same thing. Forge through the crying and preaching, and show us all how great it is. We'll follow.
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Old 10-16-2008, 05:02 PM
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Also, how about some pics?

That and details on exactly what cells and motor/ESC you're running would be very helpful.
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Old 10-16-2008, 05:05 PM
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This has been discussed at length in a previous thread on this topic. This has long been my thinking on where the future of 1/12th could and maybe should go. Slapmaster has done some pretty extensive testing with just such a setup. Many people and manufacturers feel this setup is too light for the cars work. With the tires we run today I can see that point...it may grip fine on high grip carpet but on asphault may not be able to get enough grip. Softer tires may be needed all around then what is currently produced...but that won't be hard to test...can always mount rear whites on front rims and true them down. It will also mean some eventual chassis redesigns, making the pods smaller and the chassis longer which will shift the weight bias all around as well.

That said we have a long time before that becomes a reality. NiMh isn't going away anytime soon and by the time it does there may be a better alternative out there.
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Old 10-16-2008, 05:10 PM
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As for allowing them to run together...I could see that in a mod class where things are more open...but not in stock. It would be very difficult to arrive at any equivalency to keep the playing field anything close to resembling even. Heck look at all the debate of 10.5 vs 13.5 for a 19T equivalent.
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Old 10-16-2008, 06:33 PM
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I will totally disagree with going the 2S lipo route. WHY WHY WHY?

Why change the car design, then the motor, then the batteries then the weight limits when all that is needed to be changed is the battery from 4.8V NiMH to 3.7V Lipo?

Going to 7.4V lipo will create more changes and that will just lead splits in who runs what. Some clubs will hold to the 4.8V while other will adapt to 7.4V.
Here the changes

First 380 motors and 2S lipo are still more power that what is needed to create a STOCK, SUPER STOCK AND MODIFIED class structure.

Secondly, going to lipo reduces the weight so does decreasing the motor size. Now you have a bigger power to weight ratio than 4.8V NiMH ever had. I want to race, not be a rocket tester.

Thrid, going to a different motor size will require pod parts.


Put this into perspective. My solar car weighs only 1000g, or 200g more than a 1/12 racer. At only 20watts of solar power my car is already going faster than what most stock classes would like go. I built my car using common pan car parts including the motor pod. The motor I am using is rated for 50watts of continous power so putting in some batteries that are rated for a gazillion amps will just make my car faster. Can you guess how small my motor is?

33g , about 1/3 the size of the purposed 380 motors like Novaks Three80 series


The lowest rated Three80 motor willl produce over 125watts with a 2S LiPO combo. That is 25watts more than a 13.5 with a 4.8V NiMH battery so speeds are going to be faster.

If you take a off the shelf 13.5 motor and use it with a 3.7V lipo, the wattage will be around 65watts. 65watts is close to the power needed to keep the speeds in check for stock racing. If that is too fast, 17.5 would be around 50watts.

Since the motor is not changing, retailers can keep stocking motors that are compatible for just about any race class instead of another FAD product raising the cost to the hobbyshop and then you.
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Old 10-16-2008, 06:34 PM
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The biggest problem is the pods all being redesigned, along with a separate motor from all the other classes.

Both this and the 1s lipo are not perfect solutions, imo. I know a lot of people don't like nimh, but at this time, it's really the best thing. I think trying this sort of stuff is good for mod, or on the local level. Unforunately, for every guy who doesn't like nimh batteries there is another guy who doesn't want a different size motor or likes t bars and can't mount a 1 cell pack.

That doesn't mean don't try it. I think lipo has been great for racing, but 1/12 has been coming back lately on a national level. I wouldn't want to see those gains lost because we HAD to have lipos in the cars. I really hope a chemistry will become available that will have a proper voltage for 1/12. I have heard something that would work is out there in the automotive world, but it's just not widely or at all available right now.
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Old 10-16-2008, 06:45 PM
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With 3.7V Lipo, 3 Cell NiMH could be ran together as allowed with 6-Cell / 7.4V lipo.
This would allow the T-plate guys a chance to still run their cars and would also allow NIMH fans an option for racing. What to do with the extra battery slot? ESC? Balance Lead? RX pack?

Only Change the rules when needed, not because the technology allows.

Ask your parents to change where they sit in church and that will be very though to get done. Most people avoid changes when they can be avoided. Now ask everyone to change their 1:12 car, batteries, and motors and you are really pulling teeth to get that accomplished.

At least with 3.7V LiPO a compromise can be struck with NiMH users and T-Plate users without raising the cost or giving means to adapt. Everyone's cars will still be raceable, everyone motors will still be legal, and hopefully everyone will still be racing.

Last edited by trailranger; 10-16-2008 at 06:57 PM.
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Old 10-16-2008, 07:46 PM
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In my area, pan car /direct drive racing has risen back massively by way of Tamiya's F103 re-release. It gave us the picture that 7.2 or 7.4v packs running Mabuchis are fast enough. As a result, I intend to use a small 2s lipo pack on a mabuchi powered RC12L3 I have lying around. I think mounting the pack on the chassis shouldn't pose much of a problem even if I have a T-bar chassis to work with. If it creates enough interest, maybe my club can start a class based on that. Nothing can be cheaper than using existing equipment, mabuchis and small 2s lipos to start with I believe.
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Old 10-16-2008, 07:54 PM
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Trail ranger has to be one of the most wise guys I know.I read his posts both here and hobby talk and he is a rational voice in this sport. He is right, not saying that your idea isnt a good one,But you are asking for too much change at one time. I personally would like to see the 3.7V li-po and still keep our current motor format.(17.5 =stock, 13.5 = super stock etc) I know that people are going to say well I dont want to go slower!!. well stop and think about the money that alone would save a stock class racer just in tires in the course of a race season.Not to mention slower speeds in stock would make 1/12 more beginner(or convert from touring, or dirt buggy, etc.) freindly for those who have never driven a 1/12 car to get set-up and driving style nailed before going ballistic. I think we would see a huge increase in the # of guys willing to make the change.I think we would see a lot more close racing if the speeds of stock class were lowered with the 17.5 single cell combo.Much like the brl has done with their li-po 21.5 class, I can see the future of 1/12 racing being very bright if we take our time and really figure this out right the first time for the li-po brushless combo in a 1/12 car.For the guys that want to run faster, you can always run 13.5/19t or mod and go as fast as you want.For those of us on a budget the 17.5 single cell would truly be a giant leap in the right direction.
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Old 10-16-2008, 08:05 PM
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I'm not too worried about going slower...I could go for that. But I don't want to get to a point where I have to run a reciever pack.
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