R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

    Hide Wikipost
Old 10-28-2016, 12:43 PM   -   Wikipost
R/C Tech Forums Thread Wiki: 1/12 forum
Please read: This is a community-maintained wiki post containing the most important information from this thread. You may edit the Wiki once you have been a member for 90 days and have made 90 posts.
 
Last edit by: fenton06
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:

Print Wikipost

Reply
 
Thread Tools Search this Thread
Old 05-13-2009, 09:32 PM   #31336
Tech Champion
 
Scottrik's Avatar
 
Join Date: Sep 2004
Location: Billings, MT
Posts: 6,123
Trader Rating: 239 (100%+)
Default

A lot depends if you can toggle the low voltage cutoff on and off or not. For example the LiPo-capable Novaks you can turn off the LiPo mode and eliminate low voltage cutoff. The Tekin and LRP/Nosram esc's can also be run in a non-cutoff mode. I've yet to try my KO BMC's and am concerned they may not support 1s LiPo.

The 4-cell Novak (unfortunately discontinued) doesn't have LiPo cutoff and is absolutely "plug and play" with the boosters. The others that I've seen used with boosters all have needed work-arounds to function correctly. Nothing major, but not as convenient as the Novak. Now if the Novak didn't take up half the chassis area of my 1/12 chassis...
__________________
Congressmen should wear uniforms like NASCAR drivers so we can identify their corporate sponsors.

THE REVOLUTION WILL NOT BE TELEVISED -Gil Scott-Heron (1949-2011)
Scottrik is offline   Reply With Quote
Old 05-13-2009, 09:35 PM   #31337
Tech Adept
 
silverfrancis's Avatar
 
Join Date: Jan 2009
Location: Sydney
Posts: 119
Default

Well how about this esc, yeah racing brainless esc 35A? Has anyone tried this or know whether it works with one cell lipo.

Also i still don't understand what you mean by booster or receiver pack.
__________________
For Technology news visit: www.technific.com
silverfrancis is offline   Reply With Quote
Old 05-13-2009, 10:35 PM   #31338
Tech Champion
 
Scottrik's Avatar
 
Join Date: Sep 2004
Location: Billings, MT
Posts: 6,123
Trader Rating: 239 (100%+)
Default

Quote:
Originally Posted by silverfrancis View Post
Also i still don't understand what you mean by booster or receiver pack.
The single cell LiPo batteries (1s) are substantially less voltage than even the 4-cell packs we have traditionally used. The voltage is so low that most of our electronics (receiver/servo/PT) will not function at the voltage provided. Even those that WILL work (an example is the 4-cell specific GTB and Spektrum receiver) the voltage is so low that the servo is very very sluggish.

A booster is an electronic circuit that takes the voltage available from the battery and bumps it up. As an example, the King Hobbies unit I've been using takes any voltage 3.7-4.2 volts input and outputs a steady 5 volts which is enough to power the electronics.

A receiver pack is, anymore, a small capacity 2s LiPo battery that is carried on the car specifically to power the receiver/servo/PT. The down side to this is that this is a second battery that needs to be charged, etc. The 2s LiPo also is generally too high voltage for receivers/servos and have the potential to burn servos out, so a voltage regulator should also be incorporated.

Receiver packs can also be made from 4 or 5 very small NiMH or NiCd cells which eliminates the over-voltage situation but creates (arguably) even more maintenance in addition to the charging regimen that would be required.

Receiver packs are nothing new. Not too long ago before NiMH battery capacities grew to such high numbers as we've seen the last several years folks running 1/12 Mod ran receiver packs because the high current load of the low turn brushed motors could cause voltage in the main pack to drop low enough that the PT wouldn't pick up or the car would steer to one side or the other as the driver applied power when the receiver wasn't getting enough juice, etc.

My own feeling is that adding a receiver pack completely eliminates any and all of the convenience advantage LiPo batteries offer and, in fact, adds complexity to the point of "why bother". I HAVE used the voltage boosters successfully and am convinced they are the way to go.
__________________
Congressmen should wear uniforms like NASCAR drivers so we can identify their corporate sponsors.

THE REVOLUTION WILL NOT BE TELEVISED -Gil Scott-Heron (1949-2011)
Scottrik is offline   Reply With Quote
Old 05-13-2009, 11:56 PM   #31339
Tech Adept
 
silverfrancis's Avatar
 
Join Date: Jan 2009
Location: Sydney
Posts: 119
Default

How about the yeah racing esc. It says it can run 4 to 9 NiMh Cells or a 2-3 cell lipo. If i use the one cell lipo in association with the booster will i be able to run it.

Also i was wondering if i was to pair a 13.5t with 4 cell NiMh then what is the lipo equivilant?
__________________
For Technology news visit: www.technific.com
silverfrancis is offline   Reply With Quote
Old 05-14-2009, 12:24 AM   #31340
Tech Regular
 
Join Date: Feb 2009
Posts: 398
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by silverfrancis View Post
How about the yeah racing esc. It says it can run 4 to 9 NiMh Cells or a 2-3 cell lipo. If i use the one cell lipo in association with the booster will i be able to run it.

Also i was wondering if i was to pair a 13.5t with 4 cell NiMh then what is the lipo equivilant?
Look at the RPM per Volt for the 13.5t and find out the RPM with a 4 cell then a 1s and adjust accordingly. Prolly a 10.5? I think the Schumacher site list's speed passions RPM per Volt with there Turn Limit.

I'm sure there is a better way, but that is what I would do since I don't know it.
JoshM20 is offline   Reply With Quote
Old 05-14-2009, 12:46 AM   #31341
Tech Adept
 
silverfrancis's Avatar
 
Join Date: Jan 2009
Location: Sydney
Posts: 119
Default

Is yeah racing and speed passion the same?
__________________
For Technology news visit: www.technific.com
silverfrancis is offline   Reply With Quote
Old 05-14-2009, 12:57 AM   #31342
Tech Regular
 
Join Date: Feb 2009
Posts: 398
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by silverfrancis View Post
Is yeah racing and speed passion the same?
No, Speed Passion is imported by Schumacher and others I think.

Not sure who it's really made by, but I've heard good things about the motors.
JoshM20 is offline   Reply With Quote
Old 05-14-2009, 12:59 AM   #31343
Tech Regular
 
Join Date: Feb 2009
Posts: 398
Trader Rating: 7 (100%+)
Default

According to them the 13.5T is a 3600 kV motor

So a 1s Lipo on a 13.5T will = 13,320 RPM
4 cell NiMH is 4.8 Volts IIRC 13.5T = 17,280 RPM

Novak's New Ballistic 8.5 on a 1s Lipo = 18,500 RPM

Speed Passion Makes a 9.5, I will have to call Schumacher Tomorrow and see if he has the kV rating for it.

Last edited by JoshM20; 05-14-2009 at 01:17 AM.
JoshM20 is offline   Reply With Quote
Old 05-14-2009, 01:02 AM   #31344
Tech Adept
 
silverfrancis's Avatar
 
Join Date: Jan 2009
Location: Sydney
Posts: 119
Default

Ok so for the yeah racing esc to work with a 1 cell lipo i have to use a booster and up the voltage past that of 4 Nimh cells to work. Is this the case?
__________________
For Technology news visit: www.technific.com
silverfrancis is offline   Reply With Quote
Old 05-14-2009, 01:20 AM   #31345
Tech Regular
 
Join Date: Feb 2009
Posts: 398
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by silverfrancis View Post
Ok so for the yeah racing esc to work with a 1 cell lipo i have to use a booster and up the voltage past that of 4 Nimh cells to work. Is this the case?
I don't think so, I always knew it to be that booster/rec packs were used to power the servo/PT/reciever. I don't think it boosts the voltage to your ESC/Motor.

I'm not 100 % on that though.
JoshM20 is offline   Reply With Quote
Old 05-14-2009, 04:32 AM   #31346
Tech Champion
 
Scottrik's Avatar
 
Join Date: Sep 2004
Location: Billings, MT
Posts: 6,123
Trader Rating: 239 (100%+)
Default

Quote:
Originally Posted by JoshM20 View Post
booster/rec packs were used to power the servo/PT/reciever. I don't think it boosts the voltage to your ESC/Motor.
100% correct.

The unfortunate thing re: the Yeah Racing esc is that you've headed off the beaten path a bit...YOU may end up being the guy who experiments with it and figures out what (if anything) will make it work with the 1s LiPo. Thus far the esc's I've SEEN work with the 1s setup are the Novak 4-cell (easiest) and the Tekin RS (simple workaround that supposedly won't be necessary once the new firmware is out). I am aware from my racing friends in Denver that they've figured out how to work around the LRP/Nosram esc's too (probably a similar process to the Tekin). I believe I've heard that folks have made the SpeedPassion work too.

I know nothing about the Yeah Racing esc and know of nobody who runs one. In fact I'd never heard they had an esc until you asked. As I said, I'm guessing you're going to be the test subject.
__________________
Congressmen should wear uniforms like NASCAR drivers so we can identify their corporate sponsors.

THE REVOLUTION WILL NOT BE TELEVISED -Gil Scott-Heron (1949-2011)
Scottrik is offline   Reply With Quote
Old 05-14-2009, 04:34 AM   #31347
Tech Addict
 
Join Date: Dec 2005
Location: Belgium
Posts: 526
Trader Rating: 6 (100%+)
Default

Quote:
Originally Posted by JoshM20 View Post
I don't think so, I always knew it to be that booster/rec packs were used to power the servo/PT/reciever. I don't think it boosts the voltage to your ESC/Motor.

I'm not 100 % on that though.
A booster will not boost the voltage to your motor, only receiver and servo.

I'm asking myself why nobody has looked into the A123cells as a new battery for 1/12th. 2S gives you 6.6V and they can be charged in 15 minutes.
Atm I'm designing a 12th car using those cells as I dont care much for a 1S lipo pack.
__________________
Make it idiot-proof, and someone will make a better idiot.
Quante is offline   Reply With Quote
Old 05-14-2009, 04:39 AM   #31348
Tech Regular
 
Join Date: Feb 2009
Posts: 398
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by Quante View Post
A booster will not boost the voltage to your motor, only receiver and servo.

I'm asking myself why nobody has looked into the A123cells as a new battery for 1/12th. 2S gives you 6.6V and they can be charged in 15 minutes.
Atm I'm designing a 12th car using those cells as I dont care much for a 1S lipo pack.
A few guys talk about doing it on the thread The future of 1/12th scale... or something like that. Some have done it, I thought about it. Seems like you can do it in a T-Bar chassis, so it appeals me.
JoshM20 is offline   Reply With Quote
Old 05-14-2009, 04:50 AM   #31349
Tech Champion
 
Scottrik's Avatar
 
Join Date: Sep 2004
Location: Billings, MT
Posts: 6,123
Trader Rating: 239 (100%+)
Default

Quote:
Originally Posted by Quante View Post
I'm asking myself why nobody has looked into the A123cells as a new battery for 1/12th. 2S gives you 6.6V and they can be charged in 15 minutes.
Atm I'm designing a 12th car using those cells as I dont care much for a 1S lipo pack.
Quote:
Originally Posted by JoshM20 View Post
A few guys talk about doing it on the thread The future of 1/12th scale... or something like that. Some have done it, I thought about it. Seems like you can do it in a T-Bar chassis, so it appeals me.
Doing a car to satisfy your own curiosity, etc, is probably great but designing one at this point to race competitively (and dream of any sort of commercial success) is going to be like pissing into a hurricane. At this point it appears the decision has been made and 1s LiPo is it.

As far as the A123 batteries, I confess to not knowing a TON about them but for starters even 6.6v (nominal) is way too much. 4-cell / 17.5 (and 1s / 13.5 is VERY similar speed) is really too fast for 1/12 beginners and there's no motor available that would see a 6.6v car running even THAT comparatively slowly. Even a 21.5 would be faster.

Also (and this may have changed) it seems that anybody I'd seen trying A123 cells ended their test description with "if we shortened the race time" because capacity was pretty severely limited. That is decidedly opposite the trend right now since for 2009 all 1/10 classes have INCREASED race time to six minutes. I'm not interested at ALL in decreasing 1/12 race time--8 minutes it's been and 8 minutes it should remain. As it is, we were barely taking 2000-2200mah out of 1s packs running 10.5 at Denver in March so I'd say 20+ minute races running 17.5 could be feasible. Maybe not practical, but feasible...
__________________
Congressmen should wear uniforms like NASCAR drivers so we can identify their corporate sponsors.

THE REVOLUTION WILL NOT BE TELEVISED -Gil Scott-Heron (1949-2011)
Scottrik is offline   Reply With Quote
Old 05-14-2009, 04:55 AM   #31350
Tech Adept
 
Join Date: Jul 2008
Location: Hong Kong
Posts: 233
Default

Quote:
Originally Posted by Quante View Post
A booster will not boost the voltage to your motor, only receiver and servo.

I'm asking myself why nobody has looked into the A123cells as a new battery for 1/12th. 2S gives you 6.6V and they can be charged in 15 minutes.
Atm I'm designing a 12th car using those cells as I dont care much for a 1S lipo pack.
Hi I have a T-bar 1/12 (12x) and I run 2S A123 on it.
Because of the size of the A123, i needed to config the car to have left side: battery, right side: ESC+Receiver+Weights(~60g).

With this config, the L/R weight is about right. the body just fits.

I run the car with a 11.5R @ 6.6V, with rollout ~ 34mm

yes, the car runs for 20mins and the A123 can be fully-charged in another 15-20mins.

BTW: I am just driving this car for fun only... I am a newbie and NOT into competitive racing.

hardmankam is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
New to the forum mig rod Electric Off-Road 1 01-05-2008 05:23 PM
hi i need help and im new to the forum racer4 Rookie Zone 4 01-21-2007 02:37 PM
Why is this forum listed under the On Road Forum? sport10 Onroad Nitro Engine Zone 0 01-11-2007 08:06 AM
Forum Changes... futureal Wisconsin & Illinois Racing 3 10-28-2002 09:26 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 12:53 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net

SEO by vBSEO 3.5.0