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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.

Front - Green and Blue (BSR) or Green and Light Blue (JFT)
Rear - 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!
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:

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Old 10-15-2013, 10:36 AM   #39961
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The lubricant prevents metal-to-metal contact; that's how it reduces wear and friction. But this contact is necessary to get the required friction from the balls to the ring.
I believe that's why silicone lube is used on the diff balls. It doesn't form the anti-friction layer between the balls and the rings like Moly would, but still provides lubrication from the balls and the spur gear - which under power is in constant contact with the balls. Using Moly would cause considerably more slipping due to how it forms a low friction layer when under pressure between two surfaces. Silicone moves out of the way for the most part.

Or at least that's how it was explained to me by some gray beard when I first got into RC.
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Old 10-15-2013, 11:03 AM   #39962
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well ...it isnt the spur bearing thats gone on the car

..rebuilt the diff, all is well smooth as silk etc.. for some...weird reason..its the wheel/tyre itself?! plastic must of gotten so bent or something but i cant see any visible crack marks or stretching ..really..really odd lol

oh well
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Old 10-15-2013, 11:11 AM   #39963
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what diff lube do you use?

I have some Corally lube, I hope it's ok. I only put a very small amount of it on each hole. When I saw the video I realised I used way to much before which didn't help the diff working like it should :roll:

now the diff is rebuilt and tightened correctly

holding two wheels and try to move the spur makes the diff looser than holding the spur + right wheel in one hand and try to move the left wheel
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Old 10-15-2013, 11:17 AM   #39964
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Originally Posted by PurcyP View Post
well ...it isnt the spur bearing thats gone on the car

..rebuilt the diff, all is well smooth as silk etc.. for some...weird reason..its the wheel/tyre itself?! plastic must of gotten so bent or something but i cant see any visible crack marks or stretching ..really..really odd lol

oh well
It is not unusual for rims to get bent in impacts as they are designed to flex. Sometimes they don't spin true even right from the factory. Try swapping the rim to the other side and see if the wobble follows it. If it does the rim is bent or cracked. If it doesn't it is likely your hub is bent.
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Old 10-15-2013, 11:35 AM   #39965
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yea the wobble followed, rim is bent and now in the bin.
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Old 10-15-2013, 01:46 PM   #39966
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If it is just a slight wobble it should be fine so long as the foam spins true. Also make sure you are not getting confused by glue overlap...sometimes that makes it look like the rim is not spinning true.
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Old 10-15-2013, 02:51 PM   #39967
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are the front suspension mounting points of the xray x12 the same as a associated/speedmerchant/yokomo and others cars? or they have their own mounting points?
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Old 10-16-2013, 04:52 AM   #39968
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Originally Posted by Clegg View Post
I believe that's why silicone lube is used on the diff balls. It doesn't form the anti-friction layer between the balls and the rings like Moly would, but still provides lubrication from the balls and the spur gear - which under power is in constant contact with the balls. Using Moly would cause considerably more slipping due to how it forms a low friction layer when under pressure between two surfaces. Silicone moves out of the way for the most part.

Or at least that's how it was explained to me by some gray beard when I first got into RC.
The materials used in Kimbrough molded and Robinson machined spurs have sufficient lubricity for this, with the advantage that they don't trap dirt as much. The machined spurs are quite slippery!
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Last edited by howardcano; 10-18-2013 at 03:22 AM. Reason: Changed machined spur manufacturer from Kimbrough to Robinson.
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Old 10-16-2013, 05:39 AM   #39969
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Originally Posted by InspGadgt View Post
If it is just a slight wobble it should be fine so long as the foam spins true. Also make sure you are not getting confused by glue overlap...sometimes that makes it look like the rim is not spinning true.
oooh no, it was really..out of kilter lol
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Old 10-16-2013, 09:12 AM   #39970
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Originally Posted by Pulse_ View Post
what diff lube do you use?

I have some Corally lube, I hope it's ok. I only put a very small amount of it on each hole. When I saw the video I realised I used way to much before which didn't help the diff working like it should :roll:

now the diff is rebuilt and tightened correctly

holding two wheels and try to move the spur makes the diff looser than holding the spur + right wheel in one hand and try to move the left wheel
My process for lubing balls is to put a dab of silicone lube (Associated stealth Lube) slightly bigger than one of the balls in the palm of my hand then rub the balls into it. (I believe this is called the Cleveland Gayte method) Then drop the balls into the spur. That gets enough on the balls to lubricate properly without having excess on the spur that will make a mess and attract too much dust/grime. If you see grease coming off your spur you are using too much.
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Old 10-16-2013, 11:13 AM   #39971
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Does anyone have a Set-up sheet for the CRC XI car in a PDF file? I am looking keep my set-ups from track to track in order.
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Old 10-16-2013, 11:25 AM   #39972
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Originally Posted by dr_hfuhuhurr View Post
My process for lubing balls is to put a dab of silicone lube (Associated stealth Lube) slightly bigger than one of the balls in the palm of my hand then rub the balls into it. (I believe this is called the Cleveland Gayte method) Then drop the balls into the spur. That gets enough on the balls to lubricate properly without having excess on the spur that will make a mess and attract too much dust/grime. If you see grease coming off your spur you are using too much.
Ok this confirms I had way too much grease before rebuilding it

We will race for the very 1st time this week end at the french championship



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Old 10-18-2013, 03:31 AM   #39973
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Default SSE Dash-P3

Just wanted to share a picture of the latest version of the prototype car my friend and I have been working on for the last year:


Small Scale Engineering Dash-P3

This Sunday the car will make its big race debut in the spec (10.5 blinky) class. This is our 3rd prototype chassis. The 2nd chassis will also be driven on Sunday by my partner in this project, and Small Scale Engineering owner and engineer. The race is outdoors on tarmac.

There are quite a lot of parts you'll recognise, and some oldskool design philosophies with only a few minor innovations. Speedmerchant and Tamiya parts feature. We've really tried to keep the car simple yet effective.

Our goal here has been to eventually put the car into production. This makes troubleshooting with the design very time consuming. Because usually when you have an issue you just think no problem I'll change that part for one off this car, but in this situation I have to give consideration to tooling and parts and materials costs, etc.

Still, it's coming along, and maybe in 6 months we'll be Australia's only RC car manufacturer. Bugle Boy Racing is making bodies for us, they just won a World Championship, well kinda, they made the geared diff in Hartson's Associated 4WD.
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Old 10-18-2013, 04:47 AM   #39974
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Just wanted to share a picture of the latest version of the prototype car my friend and I have been working on for the last year:


Small Scale Engineering Dash-P3

This Sunday the car will make its big race debut in the spec (10.5 blinky) class. This is our 3rd prototype chassis. The 2nd chassis will also be driven on Sunday by my partner in this project, and Small Scale Engineering owner and engineer. The race is outdoors on tarmac.

There are quite a lot of parts you'll recognise, and some oldskool design philosophies with only a few minor innovations. Speedmerchant and Tamiya parts feature. We've really tried to keep the car simple yet effective.

Our goal here has been to eventually put the car into production. This makes troubleshooting with the design very time consuming. Because usually when you have an issue you just think no problem I'll change that part for one off this car, but in this situation I have to give consideration to tooling and parts and materials costs, etc.

Still, it's coming along, and maybe in 6 months we'll be Australia's only RC car manufacturer. Bugle Boy Racing is making bodies for us, they just won a World Championship, well kinda, they made the geared diff in Hartson's Associated 4WD.
I like it!

I notice that the links are mounted under the "ears" on the chassis and rear pod. Was this done for more ground clearance, or to lower the pivot points, neither, or both?
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Old 10-18-2013, 05:01 AM   #39975
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I like it!

I notice that the links are mounted under the "ears" on the chassis and rear pod. Was this done for more ground clearance, or to lower the pivot points, neither, or both?
The centre ball is still mounted the regular way, so the link balls are still at a normal height to line up.

There is a significant advantage with ride height. The outside of the chassis underneath the links is usually scraped up when we run on asphalt. This arrangement significantly reduces that problem.

Necessity is the mother of innovation here though. The car was originally designed as an inline car for one reason: the cheapest graphite sheet we could get wasn't wide enough for a latitudinal mounted battery. After some initial testing I decided that we had to mount the battery cross-ways to make it easier to drive in low grip conditions and for newer drivers (which was the market we wanted to aim for). This is the arrangement we came up with.

The ears as you called them at the front double as positioners for the battery, meaning the pack doesn't slide around like it does in some other cars. (Also it's much easier to tape the battery in without the shock in the way, and the chassis is narrower than the pack which keeps it in tighter.)

The car can still be converted to an inline configuration without needing any additional parts. Removing the ears front and back allows the side links to be mounted in a conventional way out of the same holes as the ears mount on. The side-springs sit on top of the rear of the links in this case.

If you want to see what lead us to this point, I've been blogging about it on my club's website: http://www.morcc.com.au/smf/index.php?topic=4255.0 There are additional pictures of the previous iterations of the car, some early engineering diagrams and some of our inspirations.

p.s. You know it's going to say "I like it!" -- Howard Cano (ROAR '93 IC8 National Champion) on the box now right?
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