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This is a place to share knowledge related to 1/12th scale racing. It is not to be used for conversations.

KITS:
Click links to go to manufacturer product page. If any are missing please add them!

TIRES:
Pre-mounted tires readily available in the US:
Pre-mounted tires readily available in the Europe:
  • Hot Race ??

Gluing your own donuts:
https://www.youtube.com/watch?v=hm7z1rz-74s - Special thanks to Edward Pickering!
Truing tires:
https://www.youtube.com/watch?v=8wqHOLWq6Uc - Special thanks to Edward Pickering!

The following information came from HERE, with some editing and information added. Thanks Christian!

THIS MAY NEED UPDATING FOR THE NEW BLACK CRC CARPET

Brands:
BSR, CRC, Jaco:
Pro One is no longer selling to the public, but it and the brands above are all mounted by BSR and use the same foam. The nomenclature of the BSR vs Jaco/CRC is a little different in a few instances but is otherwise the same. The BSR foam consists of three families, and can be identifed as synthetics, naturals, and blends.

Synthetics - The old school, light weight, easy to true "dry feeling" tires. These include tires like CRC/Jaco Yellow (BSR White), Black, Gray, etc. These tires offer the highest wear rate and lowest grip. Many racers continue to use these nder high bite conditions.

Naturals - These tires are usually the best alternative for low bite and asphalt. They include Pink, Magenta, Double Pink, Lilac (BSR Team Purple), Purple, and other tires. These tires provide a ton of grip, but tend to get sticky in high bite conditions. This rubber does not wear as easily, and the cars will pick up gunk and fibers from the carpet under most high bite conditions. This is especially bad if the humidity is high.

Blends - These are the tires most people run today. They were initially called "JFT foam" by some, as it was believed that the tires were the same as the JFT tires. We can divide the blends further into two groups: high rubber and low rubber content. The high rubber would be the new rear Orange and Red from the BSR family, and the low rubber would be the Green and Blue varieties. When, asked about the difference, John Foister from BSR Tires said they came from the same "family" of foam, but they offered different grip. According to John, the Green/Blue has more bite than Orange/Red, but from track testing Oranges offer more bite than Green (being equivalent to in hardness) when the grip is high and absolutely no grip when it is lower. The Orange foam has a denser pore structure and the tire is not as prone to chunking. It is also important to note is that BSR Blue rears are not the same as the BSR Blue fronts!

JFT:
JFT stands for Japan Foam Tire. They started the new wave of foam tires we are all using now (Blue/Blu, Green/Greene, Dbl Blue, etc). These tires are a little different than the BSR tire family, but work in very similar conditions. They offers four varieties A (asphalt), C (carpet), S (???), and R (???). This does not mean that those types only work on that surface, but this is what they recommend.

JFT uses the same foam for fronts and rears if the color is the same.

A: Used on asphalt, considered close to the natural rubber variety and are named consistently with other natural tires.
C: Used on carpet, considered a blend.
S: Used on carpet?, tires are ???
R: Used on carpet?, tires are ???

For setup, the JFT foam seem to generate more bite than the BSR, therefore the car tends to be a little more aggressive.

Ulti:
Ulti is another Japanese brand that offers an array of compounds. They have their own way of rating tires, and are difficult to equate to other brands. They have 4 different varieties, each in varying degrees of hardness.

J: High rubber content tire, similar to Pink/ Magenta. Soft would be close to a pink. These offer the most bite and are great for asphalt/carpet front tire. (J hard being very popular)
X: "Balanced" blend, similar to JFT Blue/ Green. Soft is equivalent to Green, medium to Blue in hardness. Great for carpet!
Y: High synthetic blend with lower grip, and is not a very popular variety.
Z: A very expensive "special" foam that is supposed to be magic on asphalt. Only make it in soft shore.
European tires:
There are many great European foam tire brands that use their own types of foam, as well as traditional foams. SOmeone with more knowledge about them will need to fill this in!

Tire Diameter:
If you are racing on carpet, you have to evaluate how much grip your track has. If your track is low to medium grip, you can run bigger tires. If you are on higher bite you have to cut them smaller, there is simply no way around it. Bigger tires are needed for asphalt, especially in the rear. The larger tires provide much needed lateral bite.

Carpet (mm):
Low - Medium Bite
Front: 42.0 - 42.5
Rear: 42.5 - 43.00
Medium - High Bite
Front: 40.5 - 41.0
Rear: 41.5 - 42.0
Big Race
Front: 39.5 - 40.0
Rear: 40.5 - 41.0
Asphalt (mm):
Parking Lot
Front: 43.0 - 44.0
Rear: 44.0 - 45.0
Prepped High Bite
Front: 42.0 - 43.0
Rear: 43.0 - 44.0

Tire Saucing:
Most facilities have moved towards odorless traction additives such as SXT. Some of additives evaporate very quickly and some do not. This seems to be something that is also dependent on tire compound and ambient temperature. For example, saucing a Green compound seems like it never dries, especially when tjhe temperature is lower. We have found that wiping the tires off 15 minutes before we go run allows the sauce to cure, which makes the car come in much quicker with Green rears. Blue compounds on the other hand, do fine when wiped off right before hitting the track.

Saucing half front and full rear is a good initial starting point. If the front of the car is too agressive you can sauce les than half, or for a shorter amount of time.
Tire Fuzzing:
In conditions of increasing grip, foam tires will somewtimes get sticky and pick up fuzz and debris from the track. This is highly dependent on the rubber sedan tire that is being run at your local track and the compound/ type of foam you are running on you car. The softer the sedan tire and the harder/higher rubber content in your foam tire, trouble with fuzzing seems more likely to occur.

There are ways to get around fuzzing under most conditions, and usually involves the selection of the correct foam compound. The more fuzz you get, the softer/lower rubber content you want to run.

Examples:
Problem: Car fuzzes with Lilac/Team Purple fronts and car starts pushing.
Solution: Use a softer front tire and or different family of foam. Replace it with Blue or Double Blue front.

Problem: Car loses rear bite 6 minutes into the run. Blue rear tires look almost clean but have small carpet hairs.
Solution: Use Green rear tires. The softer compound wears instead of getting sticky, minimizing fuzz.

Tire Selection:
Starting out, pick 2 tire compounds for the front and rear. The following should have you covered 99% of the time.

Rear - Green and Blue (BSR) or Green and Light Blue (JFT)
Front - Blue and Double Blue (BSR) or Blue and Dark Blue (JFT)

You may wonder about other compounds out there and if they might be better, trust me, they probably won't be. Even if there are other tires that can be as fast, the synthetic family wears out really fast and the high natural rubber will probably fuzz on you over an 8 minute run. The blends family seems to be the most versatile foam type available today. They last awhile, and sticking to them will make your process of tire selection simpler.
Tire Charts:
BSR/CRC/Jaco



Contact



Corally



JFT (Japan Foam Tire)



Ulti



Enneti (Xceed)



ELECTRONICS:
ESC:
As of now, ROAR is staying 1S (3.7V nominal; 4.2V fully charged) for 1/12. There are many 1S ESC's with a built in BEC so nothing else is required to power the receiver and servo.

If you don't want to lock yourself into a 1S specific ESC, you do have other options! It is possible to use your 2S ESC without a booster or receiver pack, and the ESC simply supplies the lower voltage. If that does not appeal to you, you will need to use an Rx pack or booster. The Rx pack and booster will both supply the receiver with a higher voltage than the 1S pack.

If you decide to use an Rx pack, MAKE SURE TO REMOVE THE RED WIRE FROM THE ESC PLUG THAT GOES INTO THE RECEIVER!!!

If you choose to use a voltage booster, it works exactly how it sounds. Instead of plugging the ESC into the receiver, it plugs into the booster, and the booster plug goes to the ESC, supplying the higher voltage.

1S ESC:
If there are any missing please add them!!

If anyone would like a need for a chart comparing the ESC's specs PM fenton06 and I'll get one made and put in here!
DISCONTINUED 1S ESC:
If there are any missing please add them!!


If anyone would like a need for a chart comparing the ESC's specs PM fenton06 and I'll get one made and put in here!

Voltage Boosters:
If there are any missing please add them!
Servos:
BODIES:
Black Art (CRC - US Dist):
  • Audi R8C - BA002 - .020 Thick



  • Black Market (Mohawk 12) - BA005 - .020



  • Lola B10 - BA006 - .020 thick
  • Toyota TS030 - BA008 - .020 thick

    Lola - black/red, TS030 - green/pink


PROTOForm:

Reflex Racing/RSD:

SUSPENSION ADJUSTMENTS:
Pan Car Front Suspension Tuning:
DISCLAIMER : The following tuning advice was written based on the tuning experience of the author and may not hold true for all cars, drivers, or surfaces. In the end the best tuning advice is to experiment and make changes one at a time so you can track your changes and find the car balance that works best for your driving style. One real world test is worth a million ‘expert’ opinions.

Front End Type:

All popular modern pan car front suspensions are very similar, with a few exceptions such as Speedmerchant New School but most of the info in this wiki applies to them as well. For the most part, they consist of a rigid bottom arm, an upper A-arm, and a kingpin with a spring. There are different flavors of this general design, such as the CRC Dynamic Strut that uses a threaded kingpin and upper pivot ball instead of the Associated style that uses a kingpin that goes through the entire steering knuckle assembly, but their operation is the same with the rigid lower arm and the upper arm controlling the arc of movement as the suspension is compressed.

Assembly:

More so than in almost any other part of the car, the front suspension of your 1/12 car must move absolutely free. Reamers and hobby knives are important here, as any binding will cause the car to corner unpredictably. A little play in the suspension is a good thing, and racers will often find that ‘worn in’ suspension pieces function a little better than new.

Springs:

Besides tires, spring rate is the most important part of deciding how your car will handle through corners, but are somewhat complicated. As a general rule of thumb, a very hard front spring will have somewhat less steering grip than a softer spring with the same suspension setup and tires, but not as much as in other classes such as touring or offroad. On carpet, springs of different tension can be used to tune how your car will maintain or lose energy through corners with the following general rule of thumb:

Hard Spring (0.55mm or harder): Less overall steering, quick reaction to driver input, less on power steering, harder turn-in with potentially lazy mid-corner and exit.

Soft Spring (.45mm): More overall steering especially at low speed, slightly slower reaction to driver input, more on-power steering, less aggressive turn-in but can ‘hook’ and give better mid-corner and exit.

It is worth noting that front springs from different suppliers are often very different, in both height, wire thickness, and coils for a given spring height meaning that a “medium” spring from one manufacturer may be the “hard” spring for another. To make accurate changes you may want to use one spring maker and stick with their line.

Another aspect to pan car springs is that they can get “blown out” and collapse, no longer as stiff or as tall as they were. These should be replaced with fresh springs to ensure consistent handling.

Dampening:

This is generally a minor adjustment, but adding dampening tube fluid to the front kingpins of a 1/12 car can give it a little more initial steering. Often unusual compounds see use here, such as Losi Smart Diff Grease or Associated Green Slime being a popular front kingpin lube.

Caster and Reactive Caster:

Caster is the angle of the kingpin, almost always angling back to the rear of the car, with a typical range from 0-10 degrees. Increasing your caster will typically result in less turn-in but a little more control, more steering exiting the corner, and somewhat increased straight-line stability with less tendency to wander because a wheel running caster will tend to straighten itself. Less caster will usually give you more off-power steering, but often with correspondingly less on-power when accelerating out of the corner.

Running reactive caster attempts to use both of these aspects to increase overall steering: when the car loads up on the outside front tire, the caster angle decreases, increasing the front end ‘hook’ as you enter the corner and then giving you the high caster on-power steering as you exit and weight is transferred off the front end. More reactive caster means more overall steering, but can mean you may have to adjust your driving style to drive more ‘ahead of the car’, needing to predict where the front end will grip.

As grip increases, less reactive caster is the normal tuning change made to keep the front end of the car from gripping too hard and oversteering and prevent traction roll. Static caster adjustments are still used to change the cars on power / off power steering balance.

Reactive Camber and Front Roll Center:

Reactive camber or camber gain is how much camber is added the front wheels as the suspension compresses. This can be increased or decreased by changing the angle and length of the top arm. Short, angled arm = more. Long, flat arm = less. More reactive camber will typically cause the car to “roll up” on the outer front wheel, transferring more weight in a turn and give more steering up to the point at which the tire is overloaded. This is generally more front grip and weight transfer than wanted on carpet, and as a result most cars run a flatter longer front arm.

Roll Center is the point on which the car will twist laterally or ‘roll’ during cornering. This can be raised or lowered by changing the angle and length of the top arm, with a short angled arm raising is slightly and a long flat arm lowering it. From what I have calculated most modern 1/12 cars meant for carpet have a roll center somewhere around the height of the chassis plate or just below it, but due to the lower arms being rigid and flat the roll center cannot be under the bottom of the tires like it often is on a touring car.
These two are inexorably linked in pan cars. Top arm length can be changed by the top arm mount in or out using shims or a CRC Long Arm kit, but is generally a minor tuning choice. Tuning of roll center with shims is usually a minor tuning choice in a pan car with a rigid bottom arm due to how the car cannot gain extra mechanical advantage on the lower arm as you can in a touring car, while reactive camber can be a significant driver of the car’s performance. In a modern car running on carpet the kit setup is usually perfectly fine.

Front End Alignment:

Static camber is the angle of your front wheels at rest, typically somewhere from 0 to 1.5 degrees on a pan car depending on surface, tire choice, and other factors, but a good starting point is usually somewhere around 0.5 degrees. More camber will typically give more steering, but many racers use static camber to ensure that their tires wear flat even if that means not having exactly equal camber on both sides of the car. This is adjusted by threading in and out the upper turnbuckle or pivot ball.

It is also worth noting that when running on high grip the flex and deformation of your chassis, suspension parts, and front wheels can become significant and cause uneven front tire wear. Some troubleshooting of the right combination of static camber, camber gain, caster, and tire/rim choice may be necessary to ensure even front tire wear.

Toe-In:

The front toe is one of the more easily adjusted aspects of the car and can have a significant effect on the attitude of the car due to it being a quick way to moderately adjust Ackerman without making significant other changes. With nothing else being adjusted, going from zero toe to toe-in will give a car a harder turn-in and will tend to scrub speed with the front end as opposed to using drag brake. This can be necessary when racing in Super Stock or higher power classes and will allow you to drive more aggressively, and can help the car track straighter under power. Toe-out will tend to make the car coast more through corners due to reducing the steering angle of the outer front tire. If a car has too much off-power steering but is otherwise stable, adding toe-out can calm the car but may the car to wander on the straights especially if the front end setup is very soft.

Ackerman:

Ackerman is the difference in steering angle between the two front tires during a turn. It is the result of how during a turn the inside of the car experiences a tighter circle and needs correspondingly more steering angle, but is also an important tuning tool. More Ackerman means having more inside wheel steering angle relative to the outer wheel, less means that the difference in steering angle is smaller.

To add or remove Ackerman, using a servo horn that spaces the links further apart (such as a Kimbrough Small Servo Saver, the outer holes on a Tamiya or Xray servo saver) will have more Ackerman than a servo that puts the links close together (Kimbrough Medium inner holes, Tamiya or Xray inner holes.) The rule of thumb is that a servo that puts the ball studs close together but spaced away from the servo horn will have less Ackerman than one that spaces them far apart and close to the servo horn. Ackerman changes will have the same effect as changing toe with more Ackerman being effectively toeing the wheels out and less toeing them in, but will not affect the straight-line attitude of the car.

Turning Circle / Steering Angle:

In offroad or even touring car you can set up the car to use the full angle of the steering 100% of the time. You will almost certainly not be able to do this in 1/12 scale. It goes without saying that as you turn up your steering angle you will gain steering often to the point of the car being undriveable. The quickest way to set the steering correctly is to set the sub-trim in your radio such that the car tracks straight and the servo horn is straight up and down, then set the endpoints equally such that they don't quite hit the steering bump-stops, then turn down the dual-rate or total throw from there. A typical starting point is somewhere between 45 and 60% of the total steering throw, or a 4-5' turning circle.
SOMEONE ELSE DO THE REAR TUNING SECTION! AND A TROUBLESHOOTING TREE! FEEL FREE TO MAKE YOUR OWN CHANGES!

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Old 05-02-2005, 08:48 AM   #12946
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Sweet webmaster contacted. Thanks.
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Old 05-02-2005, 09:31 AM   #12947
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Quote:
Originally posted by PMK
As I said I didn't peel the plys away to totally destroy the chassis plate since I plan to repair it. It does seem odd though that with visible plys of 90 and -45 that they wouldn't stack some 0's and 45's in correct sequence to do it proper. But after Going by your info, and what is visible on the edge of my plate, I"m guessing they must be setting more plys 0, 90. And these all must be unidirectional layers.

And by the shape of the chassis perimeter it is somewhat derived for maximum efficency in cutting the most plates from raw stock.

The quasi-isotropic chassis I layed up is extremely rigid,hopefully not beyond some magic point.

In your research for carbon fibre subcontracters, are any having difficulty get raw carbon. It seems the carbon shortage is starting to happen. I got a call from my dad 2000 miles away wanting to know if I had sources for a certain weave his friend needed for a job. My source was dried up for twill also. Some of the composite specific magazines have been thinking this would happen at some point. I wonder where the RC car world will fall on the ladder of importance for carbonfibre.

PK

PK
Several years ago I was contracting with Composite Craft for special channel stock. Because rigidity was of the up most importance, they were laying up the fiber in a quasi-isotropic layout. If you are going to create one piece, flat chassis plates for RC car racing applications, the first thing to remember is the surface you will be racing on. Carpet racing requires a very stiff chassis because there is so much grip. For that application, you will see the kit manufactures laying up very thick, 2.5 - 3.0 mm plates. I think that if they used quasi-isotropic methods, they could lay up thinner chassis plates.

On asphalt racing, you need flexible chassis plates. At the ROAR Nationals in Portland last year, the manufactures that made their kits with the thick chassis plates came out with special, one off, thin plates to give their team drivers an edge. Some of those chassis are available now for the weekend racers who are moving from carpet to asphalt. CEFX has the optional, thinner, asphalt chassis available.

What is driving the carbon fiber shortage?
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Old 05-02-2005, 09:31 AM   #12948
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Default Re: 12th scale website

Quote:
Originally posted by Jeff Brown
hey guys, back years ago I used to run a 12th scale only website. Buddy and I were thinking about putting it back up online. Just wondering if there would be interest for it.

Setups...... reports..... tips and tricks...... racers rides.... everything. All just 12th scale. Thanks.

Jeff

Jeff, that would be a wonderfull thing. The previous website for the USTC has been dormant for over a year. The moderator of that site hasn't been very active and the USTC wan't offered this year. A site such as your offering would be a good place to resurrect 1/12 scale as a major racing vehicle in the US. It is growing as the number of cars showing up at the club races I attend is up. We are seeing a lot of people the raced touring cars move over. They are having enough fun that they a loosing interest in the touring car to run the 1/12. I hope you do it.
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Old 05-02-2005, 09:43 AM   #12949
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hey guys I am the owner of 12thscales.com I didnt know if there would be any interest in the site, so I stopped working on it. What do you guys want it to contain. I started racing 12thscale around 1992 and still have original associated 12E's, corally's and so forth. You name it, I got it. I just replied to an email I was sent, so let me get working on this site and get it up to the forefront for all 12th scale racers. Im game.
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Old 05-02-2005, 09:48 AM   #12950
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Quote:
Originally posted by woody1
hey guys I am the owner of 12thscales.com I didnt know if there would be any interest in the site, so I stopped working on it. What do you guys want it to contain. I started racing 12thscale around 1992 and still have original associated 12E's, corally's and so forth. You name it, I got it. I just replied to an email I was sent, so let me get working on this site and get it up to the forefront for all 12th scale racers. Im game.
LOL that was me. Wow fast response. Yeah get it going man. Looks nice!
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Old 05-02-2005, 09:51 AM   #12951
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Originally posted by revzalot
LOL that was me. Wow fast response. Yeah get it going man. Looks nice!
Im on it, it will be fully functional this week.
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Old 05-02-2005, 07:34 PM   #12952
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Quote:
Originally posted by Crashby
Several years ago I was contracting with Composite Craft for special channel stock. Because rigidity was of the up most importance, they were laying up the fiber in a quasi-isotropic layout. If you are going to create one piece, flat chassis plates for RC car racing applications, the first thing to remember is the surface you will be racing on. Carpet racing requires a very stiff chassis because there is so much grip. For that application, you will see the kit manufactures laying up very thick, 2.5 - 3.0 mm plates. I think that if they used quasi-isotropic methods, they could lay up thinner chassis plates.

On asphalt racing, you need flexible chassis plates. At the ROAR Nationals in Portland last year, the manufactures that made their kits with the thick chassis plates came out with special, one off, thin plates to give their team drivers an edge. Some of those chassis are available now for the weekend racers who are moving from carpet to asphalt. CEFX has the optional, thinner, asphalt chassis available.

What is driving the carbon fiber shortage?
Carbon fibre is somewhat of a commodity. At the present time aerospace is using a large portion of raw carbon for the aerospace weaves and filament wound components. Aerospace comes first with commercial second. Since our cars are fast but not quite measured in mach we fall into commercial carbon fibre. It may not affect RC but it is causing problems for others that utilize carbon for products produced.

Now something worthy. Knowing that manufacturers produce and sometimes offer as option different thickness chassis plates, if a softer plate is desirable for outdoor, and stiff is good for indoor, what allows the several cars that supposedly have a stiff chassis to work well outdoor. The BMI comes to mind first. They feel it forces the suspension to work rather than allow the chassis to be a suspension component. Any thoughts?

And Crashby are you allowed to discuss what the channels were used for? And I agree that a proper orientation could prove to be as stiff while lighter. If I do another, I will aim for about 2/3's the weight of an oem plate and slightly more rigid. Time will tell.

PK
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Old 05-02-2005, 07:43 PM   #12953
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Old 05-02-2005, 08:01 PM   #12954
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Default Re: Rollout?

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Originally posted by RC Professor
Can anyone give me a starting point for rollout? I'm interested in rollout for both stock and 19T motors. I'll be running outdoor asphalt, but I don't know what distance the running line is. I do know that it takes us about 16 sec. a lap running 19T touring, if that's any help.

Thanks for any suggestions,
Brian
To calculate roll-out, I believe that tire circumference is necessary.
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Old 05-02-2005, 08:12 PM   #12955
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Old 05-02-2005, 08:14 PM   #12956
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hyperform racing is right.most manufacturers are using component grade carbon fiber(fibers layed at 0 and 90 degrees).i am using quasi isotropic on all of my kits and it is very stiff.i have been using it for the past 2 years and have had alot of success with it.the reason quasi is more expensive is because the fibers are layed at 0,90 and 45 degrees which means that there is alot of wasted material because of the sheet corners get cut off on the 45 degree layers.but with the quasi isotropic material you get incredible torsional strength.however,i have been experimenting with different types of carbon fiber and i am actually having panels made now that far exceed the strength of the quasi isotropic i am using now.unfortunately it is quite a bit more expensive but being that i do not farm out my work,i should be able to absorb most of the costs.
there has been a shortage in carbon fiber.apparently the government uses alot of it and they get first dibbs on it and they did demand alot of the raw material which did hurt the availability of it.im sure it will let up in the near future but it kinda sucks for right now.
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Old 05-02-2005, 08:48 PM   #12957
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Quote:
Originally posted by PMK
Carbon fibre is somewhat of a commodity. At the present time aerospace is using a large portion of raw carbon for the aerospace weaves and filament wound components. Aerospace comes first with commercial second. Since our cars are fast but not quite measured in mach we fall into commercial carbon fibre. It may not affect RC but it is causing problems for others that utilize carbon for products produced.

Now something worthy. Knowing that manufacturers produce and sometimes offer as option different thickness chassis plates, if a softer plate is desirable for outdoor, and stiff is good for indoor, what allows the several cars that supposedly have a stiff chassis to work well outdoor. The BMI comes to mind first. They feel it forces the suspension to work rather than allow the chassis to be a suspension component. Any thoughts?

And Crashby are you allowed to discuss what the channels were used for? And I agree that a proper orientation could prove to be as stiff while lighter. If I do another, I will aim for about 2/3's the weight of an oem plate and slightly more rigid. Time will tell.

PK
Well... Common theory is that the stiffer the chassis is, the better the suspension will work and or can be tuned. While this theory is true for 1:1 racing and even down to 1:8, any scales lower than that the theory starts to degrade somewhat. My thinking is, and I must say that it is my own opinion, that because 1/12th scale cars are so light and the suspension movement is so minute that the flexibility of the chassis becomes a tuning aid. As far as some of the cars with thick chassis working well on asphalt, I think you have to look at the recent World Championships in Florida or the ROAR Nationals in Portland. All of the top three cars at both events, I think, had thin chassis. At the recent indoor ROAR Carpet Nationals the top three cars had thick chassis.

The carbon channels I had made were of two different sizes that would tightly fit inside of each other to form a rectangular tube. I then cut these up to make a very rigid monocoque chassis for a 1/12th car I designed and was racing back in 1985-86. The design used the Associated independent front suspension with the mono shock. I felt to make the suspension work, the chassis had to be rigid. The cars were very cool looking but... they had too much rear grip and proved to be difficult to get enough steering. So after two years of constant design changes, breathing carbon dust, I gave up and went to a kit and started to have some fun.
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Old 05-02-2005, 08:53 PM   #12958
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I don't want to knock any of the thick chassis cars. Especially the BMI as they are my new found friends!!! I ordered a BMI conversion that I plan on running at the Vegas carpet race and this fall/winter during our carpet season. While I am sure I could get it to work reasonably well on asphalt, it's just too damn pretty to mess it up on asphalt!!!
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Old 05-03-2005, 03:24 AM   #12959
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i agree crashby,flex is definately a tuning option.alot of it depends on the layout of the suspension components and weight distribution.if you cannot get the car to grip in low traction surfaces,flex will give you that needed traction.the bad thing is that it is not consistant.the car never flexes the same twice and will also fatigue the material.in alot of cases it is necesarry but i personally run my cars as rigid as i can.if i need felx i will use it but the rule is,the stiffer the faster as long as it stays on the track.
our chassis for the 1/12th was designed for carpet racing,but because of the placement of the suspension components,it opened a new window of adjustment that allowed it to work extremely well on asphalt.thats all i have to run on .and yes,it gets scratched like a mother but it is so fast.
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Old 05-03-2005, 05:49 AM   #12960
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Some are predicting the CF shortage will be about 18 months, time will tell.

Pro TC are you accomplishing all carbon fab inhouse or just the cutting?

Given time I will form a new plate, however it will not be Quasi. For these lighter cars equal strength in all directions seems overkill and heavy.

As for the oem L4 plate, it may not be Quasi-isotropic but it definately is not molded bi directional @0 90. From the crash damage it obviously has the following schedule of a plain woven exterior a unidirectional 90, followed by a -45, and god knows what's next. I would guess a +45 followed by a 90. I doubt it has any 0 orientation plies as they are just extra weight.

As reference 0's would run parrallel to the motor shaft in my example.

And yes this could all be in error beneath the exposed plies.

And Crashby, on those channels did you deal with Fred at Composite Craft or Kim?

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