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Old 01-16-2008, 10:43 AM   #3781
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As I recall my conversations with Brian when I was out at SIR last year...He allready built and tried a car using 2 cell lipo and a 380 motor and it worked out fine.

One thing with a 380 motor the pod will be much smaller, making the chassis longer and giving more room for the placement of the batteries and electronics. With this extra room we could move the electronics and battery around to where it will balance best.

I don't see where the manufacturers would have an issue with this. They allready produce large amounts of 380 sized BL motors and ESCs for the 1/18th cars so they really won't be missing out on anything.
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Old 01-16-2008, 12:39 PM   #3782
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With all this talk of LiPo/Brushless, I thought I'd throw this in as well. One of our local racers has been experimenting lately trying to find combinations that work for 1/12th scale. This past weekend he ran a 1 cell LiPo with a 8.5 brushless motor. The lap times were the same as a 4 cell powered stocker. The only problem seems to be some speedos have an issue with the BEC and the low voltage. But I'm thinking a receiver pack is well worth racing all day with one battery.

Just my $0.02.
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Old 01-16-2008, 01:17 PM   #3783
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With the smaller motors and the current cars,it will not work. The designs will have to change drasticlly to accomodate the lack of weight in the pod. You lose almost all forward and lateral grip. I have tried a car with lipo and a 360 motor that a guy was running at the local track. The traction was decent for asphalt and the car could not put the power to the ground. I have not tried to make it work but from what i have seen and from my experiences in 1/12th
, It will take a redesign to make it work. You may be able to get away with it on high bite carpet but the cars need to work on all surfaces or 1/12th will lose alot of peoples interest.
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Old 01-16-2008, 01:45 PM   #3784
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Yes I agree it will take a redesign to fully realize the potential. However as LiPo gets more popular and Ni based batteries start going away the class will have to evolve somehow. Even staying with 540 can motors will need some redesign to deal with the weight difference with LiPo.
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Old 01-16-2008, 02:04 PM   #3785
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These are great ideas, and I hope they remain just that - ideas. The upheaval we have recently had over LiPo and BL in TC has its foundations in the inability of the National Associations to look forward, and set future standards.

This will work best if a National Association, and preferably IFMAR, makes a new set of Rules that we can all use. Allowing people to just fiddle around and come up with something, doesn't work. As I said, look at the two years of upheaval we have had over BL, and ask yourself if ROAR/EFRA/JMRCA had led the way with Rules, wouldn't we be better off?

IFMAR made a set of TC Rules in 1995, and everyone followed them to the letter (and mm!). Manufacturers were delighted, racers knew where they stood, and the class settled down very quickly.

Personally, I see that many new drivers are joining 12th from TC because they are able to use all their existing kit, and if they had to buy LiPo, BL380 and receiver packs, they would think twice. Another reason 12th is popular is the stability of the Rules. Cars that are three years-old are just as competitive as this year's, and you can run the same major parts year after year - contrast that with the 6-month turnaround of new TCs!

I am sure that inventive minds need something to work with, so I'd propose another class - Open. Start with simple Rules (min weight 450g, max volts 3.7, any motor, any cell type, etc.) and offer it to the market (the racers). If it has legs, it will get entrants, if it doesn't, it won't. After a couple of years a consensus may emerge, at which point make it into the new class a couple of years after that.

The last thing we need to do is to allow tinkering with the Rules based on a whim, and on continuous tinkering to keep things in line. That's what's happening in TC, and we now look like having to have at least six different types of chassis across the World (foam/rubber, LiPo/NiMh, six cell/five cell) and Lord-knows how many different cells, tyres, motors, etc. Just how attractive does that look when you're staring a $600 investment in the face, and what's it going to do to prices when the volumes decrease?

12th's stability also allows people like BMI to invest in the market for minimum development. Would Jason have come in at this level if it was changing and developing fast to accommodate new Rules? Would AE bother for the size of market? Would IRS and others like Dave survive if all his tooling investment were in jeopardy?

12th's attraction is its simplicity and stability, and the forthcoming changes to TC in the US and Europe are making it ever more attractive. Don't threaten the businesses we know and love, like BMI and IRS, by making the class less stable. Please, let's not screw up the best opportunity we have ever had to put 12th back where it was 15 years ago - the premiere, and best, RC Electric Class.
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Old 01-16-2008, 02:23 PM   #3786
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Quote:
Originally Posted by Lost Aggresiva View Post
With all this talk of LiPo/Brushless, I thought I'd throw this in as well. One of our local racers has been experimenting lately trying to find combinations that work for 1/12th scale. This past weekend he ran a 1 cell LiPo with a 8.5 brushless motor. The lap times were the same as a 4 cell powered stocker. The only problem seems to be some speedos have an issue with the BEC and the low voltage. But I'm thinking a receiver pack is well worth racing all day with one battery.

Just my $0.02.
The Rx pack will fix the bec issue. You should be able to gear up to a insane degree with that power system and get back to 19T speeds. BL motors are not as limited as BR motors with regards to gearing. You can gear up until you start overheationg the motor.

I gear a 10.5 on 4 cell at 37/88 with 1.75 tires. If you gear your 8.5 on 3.7v at 40/88 you should be going about the same speed as me.
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Old 01-16-2008, 02:33 PM   #3787
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Originally Posted by SlowerOne View Post
These are great ideas, and I hope they remain just that - ideas. The upheaval we have recently had over LiPo and BL in TC has its foundations in the inability of the National Associations to look forward, and set future standards.

This will work best if a National Association, and preferably IFMAR, makes a new set of Rules that we can all use. Allowing people to just fiddle around and come up with something, doesn't work. As I said, look at the two years of upheaval we have had over BL, and ask yourself if ROAR/EFRA/JMRCA had led the way with Rules, wouldn't we be better off?

IFMAR made a set of TC Rules in 1995, and everyone followed them to the letter (and mm!). Manufacturers were delighted, racers knew where they stood, and the class settled down very quickly.

Personally, I see that many new drivers are joining 12th from TC because they are able to use all their existing kit, and if they had to buy LiPo, BL380 and receiver packs, they would think twice. Another reason 12th is popular is the stability of the Rules. Cars that are three years-old are just as competitive as this year's, and you can run the same major parts year after year - contrast that with the 6-month turnaround of new TCs!

I am sure that inventive minds need something to work with, so I'd propose another class - Open. Start with simple Rules (min weight 450g, max volts 3.7, any motor, any cell type, etc.) and offer it to the market (the racers). If it has legs, it will get entrants, if it doesn't, it won't. After a couple of years a consensus may emerge, at which point make it into the new class a couple of years after that.

The last thing we need to do is to allow tinkering with the Rules based on a whim, and on continuous tinkering to keep things in line. That's what's happening in TC, and we now look like having to have at least six different types of chassis across the World (foam/rubber, LiPo/NiMh, six cell/five cell) and Lord-knows how many different cells, tyres, motors, etc. Just how attractive does that look when you're staring a $600 investment in the face, and what's it going to do to prices when the volumes decrease?

12th's stability also allows people like BMI to invest in the market for minimum development. Would Jason have come in at this level if it was changing and developing fast to accommodate new Rules? Would AE bother for the size of market? Would IRS and others like Dave survive if all his tooling investment were in jeopardy?

12th's attraction is its simplicity and stability, and the forthcoming changes to TC in the US and Europe are making it ever more attractive. Don't threaten the businesses we know and love, like BMI and IRS, by making the class less stable. Please, let's not screw up the best opportunity we have ever had to put 12th back where it was 15 years ago - the premiere, and best, RC Electric Class.
But it never happens like that because all change in this hobby is consumer driven.

A group of guys get together in a parking lot and start racing thier Tamiya TL01's. A few more join in and the word gets out. Thats how sedans got started as well as Rebuildable stock motors, 19T, LiPo and BL motors.

When there is the demand for a new class the santioning bodies react and create rules.

Also, if ROAR and IFMAR had made BL rules 3 years ago we would be in big trouble today. ROAR and IFMAR had no knowledge of what BL motors rules would need to be. Neither did the motor manufacturers. We would be racing bonded rotor, 10.5's in stock and 8.5's in 19T. The rotors would be degaussing and exploding all the time and BL may not have taken off.

Its took 3 years to get the worlds first set of complete BL motor rules and it could not have happend faster. There are still areas in the rules that will have to get revised over time as things no one though about pop up.
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Old 01-16-2008, 02:52 PM   #3788
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ROAR did the right thing in my book by waiting. TCs had been out for several years before IFMAR adopted a rules set for them as well. There were many different TC designs out there with different widths and wheel bases all over the place. It wasn't until a standard started to emerge from the manufacturers side that a rules set was adopted. LiPo and BL are an even more varied issue then TC was and it took time before enough was known about the technologies to see which way they were headed. Had they made rules earlier more people would have been upset as the technology changed and rules changing with that would have had even more people needing to buy a new "stock" equivalent motor then are having to now.

I don't see people moving into 1/12th because they can use their same TC equipment. Only about half of the equipment can truely move over. The servos are much different in size and once you convert a pack from 6 cell to 4 cell going back to 6 to run it in TC becomes a problem. Often even the recievers are not carried over since not as many people run a micro reciever in a TC as do in 1/12th. Depending on which LiPo technology is adopted for 1/12th would determine how much carry over there is between 1/12th and TC. If 1/12th started using 7.4v LiPo and countering the added voltage by going to a smaller motor then now even your battery pack can be interchanged between 1/12th and TC.

I'm not saying to tinker with the rules based on a whim. I'm saying now is the time to start looking at alternate ideas for the good of the class. Now that ROAR has officially adopted LiPo and BL, how much longer do you think manufacturers will continue to do R&D on nickel based batteries for RC applications? We face the eventuallity of 4 cell racing as being the only form of nickel based racing occuring. 4 cell racing will have to adapt or stagnate and die. Personally I would rather see it adapt.

For an open class I would rather keep it at 4.8v but lower the minimum weight to keep the people trying 3.7v competitive. You would have 2 choices: a) more power with 4 cell Ni based but be heavier. Or b) lighter weight but with less power with LiPo. At least that wasy I could keep running without needing a reciever pack. 3.7v will make a reciever pack pretty much mandatory.

Anyway...this is a discussion best taken to another thread...sorry we got off topic.
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Old 01-16-2008, 03:27 PM   #3789
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Old 01-16-2008, 04:45 PM   #3790
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One last post here on "Jason's Thread". This should be taken to another before we fill up this one up.

I can certainly respect everyone's opinions and ideas. I have been racing 12th scale for 21 years and I am not looking to tug the rug out from underneath it.

If you have an open mind, consider this: 12th scale cars can be built using today's 18th scale equipment, have comparable speeds, for less money, less maintenance and still remain very simple.

I haven't had the time lately to finish testing this project, but it has already gathered lots of interest and info.

Here are some quick facts without getting into too much details:

If someone wanted to start out racing a conventional 12th scale (starting with nothing), you could spend $1000 to get rolling, but not have everything you really need. If you started out with a 2C Lipo 12th with 1/18th scale motor & esc, you could get started for about $700 and have most of everything you need.

An average weight of 810g conventional car consumes tires, parts and bodies at a much higher rate then my proto-type 410g car.

My proto car is too fast with the motor I put in it. I am putting in much less motor here shortly to retest. With the exception of it being too fast, it seemed to handle a med-low carpet just fine. When I get it all dialed in, I could send it to Jason and Adrian for some asphalt testing.

Here's another question that we should really be asking ourselves: how much longer are they going to be building sub-c sized cells? We are foolish to think that the rc market is driving the cell technology when in fact it is the cordless tool market and/or wireless devices such as laptops & cell phones. NiNH will die on the vine like the NiCad in time. I think we should open our eyes & minds and consider some options before we get painted into a corner.
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Old 01-16-2008, 05:05 PM   #3791
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I do agree with you brian to an extent. Lipo is coming and we will have to make them work in 1/12th scale. as much as i dread that day it is coming and sooner than most would like. The cars can be modified slightly to accomodate a lipo without added weight. On the otherhand,360 motors are not the way to go from what i have seen. Not enough weight on the rear tires will yield very little forward bite and sidebite. We could go lighter than where we are now but 360 is way too small. I can see the cars being ok on carpet because you have higher traction than outdoor asphalt. Low to medium bite asphalt has much less traction than carpet of low traction.Keep in mind that alot of tracks in other countries do not allow traction compounds. I can set up a 360 motor in the car to see what it does in my own car to make sure that i gave it all i could but i just see too many issues with going to such a tiny motor.
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Old 01-16-2008, 05:12 PM   #3792
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It used to be thought also that having the wing mounted directly to the wheel hubs gave more traction as well. Full sized F1 ran that way for a year or so. But later testing revealed that more traction was gained by attaching the wing to the chassis.

It would be interesting to do a weight comparison between a 4cell pack with ESC and 540 sized motor and a 7.4v LiPo pack with a ESC and 380 sized motor.
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Old 01-16-2008, 05:31 PM   #3793
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It used to be thought also that having the wing mounted directly to the wheel hubs gave more traction as well. Full sized F1 ran that way for a year or so. But later testing revealed that more traction was gained by attaching the wing to the chassis.
Sorry--this is not correct. Hub mounted wings were banned by the FIA as the original "moving aerodynamic aid" after several catastrophic failures (particularly the Loti) on systems that were not as robust as the ones developed by Chaparral. This was, of course, pre ground-effect era. Designers would have continued to run hub-mounted wings given the option as it allowed softer spring rates and more mechanical grip. The ground-effect era may have rendered it a moot point re: this advantage as springs then needed to be stiffer anyway to support the multiples of car weight generated by harnessing the ground effect to create downforce (as the twin-chassis Lotus was quickly banned as "moving aerodynamic aids).
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Old 01-16-2008, 05:47 PM   #3794
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Hey Mr. Jason,

What are the odds of creating a special thread in the BMI site forum to discuss matters re: POSSIBLE futures of 1/12.

Some keys from the above posts:

1/12 will likely be forced to LiPo or some similar technology at some point down the road.

Doing so will likely require some redesign. Quite likely major redesign to take full advantage of the technology.

If doing a re-design anyway, why not take the next step at the same time?

I don't think the balance would be affected as much as many are thinking here. By going to the 380 motor and LiPo battery we would be able to use the smaller (lighter, smaller footprint) esc's we're seeing for mini / micro racing. The SUBSTANTIALLY reduced weight (note Brian's test rocket...I mean mule) is at roughly half what a current car runs) will allow a much lighter servo as we'd be needing less oz-in, etc. A further benefit is these smaller components seem to be costing less than the TC leftovers and pre-miniaturization and marginally digital electronics we're currently saddled with.

Lighter cars, easier on tires, easier on bodies, easier on parts, easier on everything including the racer's wallet.

I think we miss a REAL opportunity by dismissing this out-of-hand when we could be really getting out in front of changes that will probably be forced on us anyway (LiPo) and managing that change to our benefit.
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Old 01-16-2008, 05:48 PM   #3795
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I stand corrected. I do remember reading it somewhere though which spawned some testing locally back in the pan car days. We tested mounting the wing on the pod vs mounting a wing to the rear body posts and had some interesting results. In the end the idea was abandond for us due to it not being as durable and the pain in the butt it was to mount to the body post like that.
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