les bases du 1/12

[pogache2000]

bonjour a tous

j'aimerais faire une sorte de bible sur le 1/12 en général comme:
un site super :http://www.overrc.com/

les pneus (la dureté)
les marques: JACO, TRC, GRP ou PARMA (pareil), BSR, CRC, CORALLY, SPEED MIND

NOTES FROM OUR TECH DEPARTMENT
COMPOUND Durometer Rating (Tire hardness)
Silver: 25 Soft/Medium
Yellow: 25 Soft/Medium
Platinum: 25 Soft/Medium
White: 26 Medium/Soft
Green: 29 Medium
Gray: 31 Medium
Pink: 34 Medium
Blue: 36 Medium/Firm
Purple 42 Firm/Medium
Red: 54 Firm
2Blue: 55 Very firm

pour les CORALLY: ???

The higher Durometer rating the harder the tire.
High (hard) tires offer less traction but last longer, lower (softer) tires
offer more traction, but wear out more quickly.



les pneus pour moquette et bitume:
pour le bitume : vert av et arr (s'uses vite)
purple av et pink arr (ma préfrérence)
purple av et vert ar

pour la moquette: PURPLE AV ET GRIS OU BLANC ARR

http://www.petitrc.com/_forumphp/showthread.php?t=12783


les traitement pour moquette et bitume

-sur le bitume le "paragon ground effect " marche bien

-sur la moquette: CS ET CORALLY TC2


expliqué le tweak et son importance (les 2 vis sur le té en epoxy)

principe:
a l'extrémite du té (généralement en epoxy) deux vis sans tete sont fixé pour "controlé" les mouvements du pod arrière.




réglage:
le réglage consiste a équilibré le tain arrère pour le rendre sain et éfficace

tu mets ton chassis prèt à rouler avec accu, puce....
sur un plan bien plat tu leves le devant du chassis par son milieu avec un tourne vis. il faut que les deux roues avant se levent en meme tps sinon, c'est que ton chassis est mal tweaké et qu'il te faut ajuster avec les vis de tweak. pour la finesse du réglage, tu mets deux pièces (genre 5 centimes) sur chaque roue. quand tu lèves ton train avant, il faut que les deux pièces tombent en meme tps.
Les américains font comme ça. ça évite d'acheter un tweaker hors de prix.


les moteurs:
quelque que soit la piste ne pas hésité a mettre un moteur puissant car en 4elts la puissance du moteur diminue.


le rapport:
voila un lien de petitrc bien pratique

http://www.petitrc.com/technique/***...l_Rapports.exe

les carroseries: (celles utilisé en compétition)

prtoform spedd12, cefx, parma zetec,???

http://www.petitrc.com/_forumphp/showthread.php?t=33066


les réglages généraux et ceux les plus importants:

??????



les chargeurs, déchargeurs et plaque:

tout les chargeur convienne
pour les déchargeurs ceux qui sont utilisable en 4elts sont: spintec v2, trinity pulse r, la much more ctdx 2
pour les plaques: la tekin doctor 8.0 (elle permet d'égalisé 2 packs en meme temps)




voila j'attend vos idées et expérience (n'hesité pas a rectifié si c'est faux)

[Arn0]

En fait, il y a quelque chose en cours sur ce sujet qui devrait sortir dans quelques semaines.

Voir avec Nicolas Petit!

En fait, il existe déja des sujets abortant la discipline avec des explications sur les pneus, les servos....

Par rapport à ce qui est dit au dessus:
les moteurs:
quelque que soit la piste ne pas hésité a mettre un moteur puissant car en 4elts la puissance du moteur diminue.
- Ce n'est pas la puissance du moteur qui diminue mais celle de l'ensemble des éléments. P=UI avec U diminuant de 7.2V à 4.8V mais aussi P=Cw ...

expliqué le tweak et son importance (les 2 vis sur le té en epoxy)
principe:
a l'extrémite du té (généralement en epoxy) deux vis sans tete sont fixé pour "controlé" les mouvements du pod arrière.
- Un système sans vis de réglages existe depuis un moment (voir Laje Speedevil par exemple)

les chargeurs, déchargeurs et plaque
voir ce document ( http://www.petitrc.com/view_news.php?id=5881 ) dans battery puis Techniques accumlateurs ( http://www.petitrc.com/view_news.php?id=5582 )!

Voici le lien vers tous les sujets techniques 1/12-1/10 sur le forum

[fanaom]

arno un petit cours sur l'utilisation (et leurs influences) des tés asso de differentes epaisseurs svp!!!!
merci beaucoup

[midex]

Bonjour,

je me remets au 1/12e & donc, j'ai besoin d'un refraichissement de memoire sur les vis de tweak :
Les 2 vis de tweak doivent elles etre bien en contact permanent avec le T? Si non, combien faut-il de jeux?

Merci

[Le Fa]

Dans la plupart des cas , ces vis sont vissés sur le T et viennent en contact sur le chassis ... Les visser sans forcer avec une trés légère précontrainte en buté équilibré de part et d'autre ... Ensuite il te faudra pauffiner ton réglage de tweak à l'oeil , avec un banc ou encore avec la méthode des pièces de monnaies qui est pas mal du tout ... Perso je preffère des grosses rondelles bien lourde pour qu'il n'y ait pas de petites frictions perturbatrices comme avec des roulements neufs par éxemple ...En espérant t'avoir aidé ...

[Arn0]

Envoyé par fanaom

arno un petit cours sur l'utilisation (et leurs influences) des tés asso de differentes epaisseurs svp!!!! merci beaucoup

Et pourquoi moi? humm! Je ne suis pas forcement le mieux placé (je ne suis pas parle d'évangile non plus!). Sans pretension, voila que j'ai retenu et pour tout dire, la notice de RC12L3 explique les choses.

Il y existe deux épaisseurs disponible pour les tés: 0.063" et 0.075"

Le 0.063" est celui d'origine des planches associated. Il est à utiliser lorsque l'adhérence est faible afin de faire tenir le train arrière du fait de la plus grand facilité à la déformation. Lorsque le piste est bosselée, il est preférable d'utiliser aussi ce té de 0.063". L'arrière étant théoriquement plus "collé" au sol, l'avant de la voiture aura tendance à un peu plus sousvirer.

Le 0.075" est celui qui sert dans les conditions de piste à forte adhérence et plate. Etant plus épais, la pièce est plus rigide donc moins de déformation aussi bien en flexion que torsion. La voiture sera globalement plus vive et survireuse.

Un autre point avec les tés, il y a 3 trois de fixations avec le pod arrière. Au montage, deux vis sont mises, le trou du milieu restant inutilisé. L'utilisation de ce troisième point tend à rigidifier le té.

En résumé, du plus souple au plus raide:

T-bar 0.063" - deux points de fixation
T-bar 0.063" - trois points de fixation
T-bar 0.075" - deux points de fixation
T-bar 0.075" - trois points de fixation

Il me semble que en Europe, c'est le té de 0.063" très souvent car piste avec adhérence faible-moyenne alors que en Amérique, c'est 0.075" de temps à autre pour les pistes à forte adhérence. Et encore ce dernier point est à modérer car la HB C12 aurait était réglée avec un té de 0.063" à l'IIC alors que l'adhérence était parait-il élevé.

Voici quelques détails complémentaires afin de régler l'avant de la voiture.

On T bar cars, people have started going to softer T bars due to bumps. It helps keep the cars from getting ass happy on bumpy tracks. The .075 will give more steering but being that it bends when the suspension compresses, it has a tendency to make the rear skip in bumpy conditions.

The .063 will give you more rear grip because of the lighter spring tension, it absorbs more of the weight transfer while cornering as opposed to a thicker T bar that would transfer the weight to the outside front tire.

With front springs, .020 is pretty much standard. The use of .018 and .022 are for specific track conditions. .018 would generally be for a lower bite track to help the car roll easier and .022 is for super high traction. There will always be some exceptions to the rules though. I hope this helps.

Jason Breiner

Autre point, des explications sur la position du servo.

The AE dynamic strut front suspension is designed to run with an angled servo. In this configuration you have zero bump toe and an a significant amount of Ackermann.

On asphalt this is a good thing. It makes the inside wheel turn in hard on low speed corners giving you more steering.

On carpet this is a bad thing because the traction is much higher. You do not need as much Ackermann. All Ackermann does on carpet is hurt corner speed and make the car hook into corners because its dragging the inside wheel past its optimum slip angle.

Running the servo flat generates a lot less Ackermann. This reduces wheel scrub and increases corner speed. The think to watch is the bump toe. The front suspension was not designed to accommodate a servo in the flat configuration so you have to compensate for this.

This is gone by running taller ball studs on your steering spindles. If you run the middle holes on a small Kimbrough servo saver with medium height IRS ball studs on the spindles you will have a small amount of bump toe in. If you run the holes closest to the servo output shaft you will have zero bump steer.

If you do not do this you car will go horribly pigeon toed as the suspension compresses and this will kill your lap times.

So...

Asphalt: Servo Angled
Carpet: Servo Flat (with corrected bump toe)

Adrian Martinez

Et un petit lien pour l'effet des réglages

Si les pilotes de CF passent par ici, est ce qu'ils pourraient corriger au besoin? Par exemple,M@t avec sa L4, Philippe avec SE, Michel (DT10D) avec diverses voitures... doivent être des mines intarissables sur les réglages.

PS: dans le premier message (#1), des liens ont été ajoutés!

[fanaom]

la je dis >>>> MERCI !!!!

[twister34]

Envoyé par Le Fa

Perso je preffère des grosses rondelles...

Chacun son truc

[Reporter]

http://www.carsrcracing.co.uk/?page_id=65

Starting 12th scale with L4 based cars

Article and photos by Trevor Coult
Additional photos by Paul Lomas

Quite a few new people have been starting 12th scale at our club recently. Most have bought new or second hand Associated RC12L4s, or other cars with a T-bar and Associated front end. Most of these people have asked me various questions about the build and/or running of their cars. I’m not sure why they have chosen me to ask their questions to, I’ve only been back racing myself for a year after a two decade layoff, but I’m always happy to answer them if I can or direct them to a person who can. Maybe I appear to be less intimidating than approaching the many team drivers at the club even though they would be just as happy to help.

As a result of this I wondered if there was any resource on the internet that gave people answers to the questions they were asking and couldn’t find one, or at least none that gave all the information in a single place. So I thought I would try to create a resource myself containing the answers to some of the questions I’ve been asked, and some of the things I’ve learnt in my first year back racing a 12th scale. As I’m no expert not everything is likely to be absolutely correct or the best way of doing something but I’m sure it will be tuned and improved over time. I’ve used a second hand L4 that I had lying around for a lot of the photos as this would probably be the same as a lot of beginners. The rest are of the L4 I currently use.

Thanks to all the people that have helped me with setup and parts in my first year, in no particular order, Kevin Creaser, Mick Ramsbottom, Andy Griffiths, Glyn Ward, Mark Jewitt, Mick Farrell, Peter Winton, Alan Curry, Fred Hatfield, Keith Robertson, Paul Lomas and anyone I may have forgotten.

I’ve split this into sections so a beginner can look at it a bit at a time, or just go to the section relevent to the question they have.

Here it is…

Chassis Preparation

Associated Dynamic Strut Front End Building

T-Bar Building and Mounting

The Rear Pod

Differential Building

Shock Building

Servo Mounting

Wheel Mounting

Cell Building

Electrics and Wiring

Bodyshell Mounting

Overall Car Setup

[Arn0]

J'ai traduit ce document http://richardchang.com/hobby/rctips_112_summary.pdf en français, la traduction a été faite de manière un peu rapide par manque de temps mais l'idée est là. Il s'agit d'un résumé sur l'influence des réglages de géométrie, huile, ressorts, pneus. C'est peut être le genre de feuille (ça tient en une page) qui peut être intéressant d'avoir dans ses affaires.

RC Tips 1/12 français

[pogache2000]

alors la chapeau


c'est ma feuille de chevet...

merci mille fois

ce mec merite un oscar

[Eric S]

Merci Arno! Il merit bien un RC Cesar et un RC Oscar

Enorme ton travail sur Petit rc, MERCIIIIIIIIIII

[Reporter]

Des explications intéressantes au sujet des réglages et comportement de la voiture

Décrochage en virage
http://www.petitrc.com/_forumphp//sh...ad.php?t=39715

Un sujet général sur les réglages
http://www.petitrc.com/_forumphp/showthread.php?t=3936

[Reporter]

Front End building “Tips and Tricks” from the Maverick Team:

Smooth, smooth, smooth: One of the biggest differences between the Fast Guys and the Slower Guys, is the amount of “binding” in the suspension components. The Fast Guys will often take hours to assemble a front end. Polishing, grinding, trimming, sanding, and hand fitting each part so that it works freely and smoothly through it’s intended motion.

In the front end, the difference can be huge when comparing a “worked” version, or a quickly put together version. It’s amazing how the same pieces can work so differently, depending how they were assembled. (Keep this in mind when asking someone at the track what front springs they use … Green springs on a front end that’s binding, will be like purples on a front end that’s smooth.)

A word to the wise: Wear a dust mask when sanding or grinding any plastic, fiberglass, or carbon fiber. Always wear some form of eye protection when polishing, sanding, or grinding on parts. Do not hold small parts by hand when cutting, always use pliers or some other way , to keep your fingers away from the cutting device. Clean your hands thoroughly with soap and warm water when done.

Polishing king pins: Although the kingpins look good in the package, their finish can be improved. Use a polishing cream or paste, like “Mothers Mag”, a Dremel Tool or drill press, and a soft cloth.

Spin the kingpin in the Dremel, or drill press, at slow speeds and polish for a few minutes using the polishing compound and cloth. Switch ends and repeat.

Wash the kingpins thoroughly with soap and warm water.

Pivot ball fit in arms and eyelets: The hard coated, teflon impregnated, aluminum pivot balls are made by IRS and are of excellent quality. Use a good pivot ball installation tool when installing and removing the pivot balls to extended their life.

The pivot balls should fit into the lower a-arms and upper eyelets without being too tight, or too loose. Either way is not good, they must be just right for the best performance. If they are too tight, which is often the case due to the plastic injection molding process, there are a couple of tricks to make them fit better.

First, simple snap them in and out a couple of times. This will often be all that’s needed to free them up.

Second, “lightly” polish the balls. Use a 4-40 bolt, a 4-40 nut, your polishing compound, a soft cloth, and a Dremel Tool or drill press. Be very careful when working with the pivot balls, not to scratch or gaul the inside where the kingpin rides.

Upper Eyelet Mods: The upper eyelet is a part that usually needs a little modifying to work well when increasing the travel of the front end.

The kingpin will actually hit the upper eyelet, causing binding. This binding is the same as having the spring get stiffer as it compresses. Only, it does not always do the same thing every time. Not good for consistent handling. (see "upper eyelet hits kingpin" picture below)

The modification is an easy one. Use an Xacto knife and carefully trim away some of the plastic on the outside half on the top, and the inside half on the bottom. Think of a crescent moon shape as you’re trimming the plastic, that’s what the area should look like when it’s done. (see "trim away gray area" picture below)

Another way to accomplish this, is to mill down the upper eyelet. A milling machine is preferred, but with some careful cutting with a Dremel tool, you can achieve good results.

This modification is not as easy, and takes a little more time. You’re actually going to remove a lot of material from either the top of the Eyelet, or the top and bottom of the Eyelet. When you’re done cutting, use an Xacto knife to clean the flashing off the edges of the Eyelet. Please be careful with your fingers when performing this modification, use extra care. (see "upper eyelet side view" picture below)

With either Upper Eyelet mod you choose, the important thing is not to take too much material away. Too much means you’ll have slop in the upper eyelet and upper pivot ball. You want to remove just enough so the kingpin will not contact the upper eyelet, on the top or the bottom, when the suspension is fully compressed. (It’s ok if it does contact a little at the very top. You will not be using all this suspension travel on the track.)

Steering Block Mods: The steering block is another part that needs some modification to get rid of some binding when increasing suspension travel.

If you compress the suspension, you’ll see the upper eyelet and the inner top of the steering block will make contact with each other. (see left picture below)

Trim the steering block with an Xacto knife half way around it, where the upper eyelet hits it. (see the right picture below)

The idea is to increase the clearance between these two parts. You want to remove just enough so the steering block will not contact the upper eyelet, when the suspension is fully compressed. (It’s ok if it does contact a little at the very top. You will not be using all this suspension travel on the track.)

But, make sure you cycle the steering through it’s throw, and that the steering block has clearance throughout the steering travel you intend to use.

Kingpin Lube: There are a lot of products out there that can be used for kingpin lube and add dampening to the front end. (It’s like changing the shock oil in your side shocks, to suit different tracks and racing conditions). Our favorite is 1/8 Scale Buggy differential lube. It comes from a few different manufacturers, and in a variety of viscosities.

We use the Mugen or Ofna brands, anywhere from 1000 to 150000 thickness. The higher the number, the thicker the lube.

Use a very small amount on the kingpin, above and below the pivot ball. Work the suspension throughout it’s motion and wipe off any excess lube. Install the spring, spring bushing and e-clip, and you’re ready to race.

Wolfe spring rates: We almost always use Wolfe Standard Rate springs for our front ends. Starting from the softest, the rates are; white, red, green and purple being the stiffest. (For extreme tuning needs, there are other rates available. Wolfe also makes a line of progressive rate springs.)

Caster Blocks: Choose a good quality caster block, such as the IRS or SRP versions, to start with. Unfortunately, there are times when the Associated and aftermarket parts don’t fit together as desired.

Sometimes there is binding in the movement. Sometimes there is excessive slop in the parts fit. And, sometimes it all goes together perfectly the first time.

Dry fit the caster blocks, hinge pins, caster shims, and upper a-arms. Check the fit of this assembly carefully. I’ll spend some extra time on these pieces, ensuring the proper fit. Ideally, what you’d like to have, is the upper a-arm move freely, so the spring and dampening can do their job without any influence from these parts.

Please keep in mind, if you have to choose between binding and slop, a “little bit” of slop is better than binding.

To fix binding, polish the hinge pin so that the a-arm moves freely. When assembled with the caster shims, the arm may be tight between the block ends. Carefully sand a small amount of the end of the a-arm, where it contacts the caster shims.

Fixing slop in the IRS caster blocks (and please think about this first and take your time while trying this) takes a little more work. To take out slop in the caster block and hinge pin, I’ll put a slight bend in the hinge pin 1/8” from each end. You should barely be able to notice the bend, but when the hinge pin slides into the caster block, it will bind itself, taking out the slop. Make sure the a-arm moves freely on the hinge pin.

To fix slop between the a-arm and the hinge pin is really tricky. You can try slightly bending the caster shims to put slight pressure on the a-arm, reducing the play.

These fixes will need to be checked after each race day. After many races, or after hard crashes, you’ll need to purchase new parts and freshen up the front end.

Wolfe 1/18” front axles: Spacing the tires on the front axles is one more tuning aid to make your car faster. You can shift both tires out to widen the front track width, or move one out at a time.

Experiment with moving two shims at a time, until you find a set-up that works well for you.

Like the Wolfe Instructions say, the axles are a tight fit in the steering blocks. There really is only one easy way to insert them, and that is to press them in with a vice.



Basic Front End Set-up: Without knowing what style of track you’re running on, what kind of tires, body, and what the rest of your set-up is like, it’s really hard to give a base set-up to try.

I’d suggest starting very close to the set-up you’re were running, and tune from there.

At the risk of getting it all wrong, I will suggest this starting set-up from most foam tire, average size oval tracks.

Left Side: Green Spring, upper arm located in the inner middle, or top hole on the caster block. 0 or 2 degrees of caster. Camber setting straight up.

Right Side: Red Spring, upper arm located in the outer middle, or bottom hole on the caster block. 2 or 4 degrees of caster. Camber setting 2 degrees in at the top of the tire.

If the steering seems to aggressive, switch the springs from side to side.

~Good Luck, and have FUN, with your R/C racing~