mini 4x4 Racing - xtreme li'l machinz

GEAR RATIO | CHASSIS | BATTERIES | CHARGERS | MOTORS

GEAR RATIO Stock gear ratio
· 5:1 (blue/green) best for super technical course
· 4.2:1 (red/flesh) average between 5:1 and 4:1
· 4:1 (black/flesh) best for soft speed course
· 3.5:1 (cyan/yellow) best for speed course

Modified gear ratio
· 3.8:1 cyan/flesh
· 4.1:1 cyan/green
· 4.3:1 black/green
· 4.5:1 red/green
· 4.6:1 blue/flesh

8T pinion gear is used.

Note on modified gear ratio: The gears MUST mesh properly with each other or else the teeth would be damaged. There are some gears that mesh differently on different chassis. Do not use modified gear ratio unless proper meshing is achieved.

CHASSIS The ones I'm familiar with.
VS chassis - for light set-up but brittle material and noisy, front ∓ rear slots for easy installation of Side-X's, narrow
SUPER X chassis - very stable but weak "wing", more slots, motor accessed under it, wide
SUPER TZ chassis - basic, no slots for rear bumper, strong "wing", narrow
SUPER TZ-X chassis - SUPER TZ ∓ SUPER X combined, ideal chassis (for me), stable, stronger wing compared to Super X, but very noisy, narrow
SUPER FM chassis - for technical courses, motor adds weight to the front, pulls the car instead of pushing it, but no slots for rear bumpers, narrow

BATTERIES · For better performance of batteries, cycle them before first use.
How to cycle: Charge the batteries to their full capacity, then discharge them (use flashlight, discharger, breaking in motors...later). Repeat 2x (3 all-in-all).

Ni-Cd Nickel Cadmium - "memory effect", limited current rating
· To avoid "memory effect", always drain the batteries (avoid overdischarging the batts because this will cause polarity reversal).

Ni-MH Nickel Metal Hydride - more sensitive to overcharging compared to Ni-Cd's, more cycles
· For maintenance of Ni-MH's, drain them once a month or after 20 cycles.

· When charging, always see to it that the temperature of the batts are "tolerable" (one way of knowing this is holding the batts). If its too hot, stop charging and continue after they cool down.
· It is not advisable to use quick chargers (ones which charge batts in 15 mins). It will shorten the battery life.

STORING RECHARGEABLES: NiMH and NiCd batteries, start to lose power when stored for only a few days at room temperature. But they will retain a 90% charge for several months if you keep them in the freezer after they are fully charged. If you do decide to store your charged NiMH cells in the freezer or refrigerator, make sure you keep them in tightly sealed bags so they stay dry. And you should also let them return to room temperature before using them.

Myth: Quick charging NiMH batteries will reduce their life.
· For batteries that are designed to be quick charged, for example, Sanyo, Golden Power, Energizer, that is absolutely not true. It is important to use a battery charger that has been specifically designed to rapid charge NiMH cells. Actually there is a much greater likely hood of reducing the life of a NiMH battery by using an "overnight" charger than by using a smart fast charger. Overnight chargers rely on the fact that you will unplug them after a number of hours. If you forget to unplug them they can continue to charge the batteries longer than they should. Overcharging WILL reduce the life of batteries. - SOURCE: GREENBATTERIES

CHARGERS Ni-Cd ∓ Ni-MH chargers:
· Many of the inexpensive NiMH battery chargers are simply NiCd chargers that have been modified slightly. Typically a 5 hour NiCd charger has a switch that allows the charge time to be increased from five hours to eight hours. Thus a 5 hour NiCd charger becomes an 8 hour NiMh charger. As we mentioned above, we do not recommend this type of charger design. While it is less expensive to manufacture than a smart charger, it can lead to overcharging and battery damage.
· Most NiMH smart chargers have actually been designed to detect when a NiMH battery is fully charged and then shut off or go into a trickle charge mode. Because of the more complex circuitry, this type of charger costs more to make, but should lead to greater battery life. Some of these chargers only cost slightly more that the "dumb" chargers. We strongly recommend investing in a smart charger for your NiMH or NiCd batteries.

SMART CHARGER: A charger with microprocessor control. A smart charger can determine when a battery is fully charged and then depending on its design, either shut off entirely or switch to trickle charge.

SOURCE: GREENBATTERIES

· I recommend using the MW 1-Hour Charger. A smart charger with a capacity of 4 AA's and 4 AAA's. It uses a CPU-9798A microprocessor. The batteries undergo a 4 step process.
1. Discharge
2. Fast Charge (0% - 60%)
3. Boost Charge (60% - 95%)
4. Trickle Charge (95% - +100%)

Trickle Charge: Replaces the loss in capacity due to self discharge. Theoretically a trickle charge is a charge rate that is high enough to keep a battery fully charged, but low enough to avoid overcharging. If trickle charging is used then the charge rate should be very low or only intermittent. The best smart chargers will only send an occasional pulse charge to the battery once it is charged. They do not apply a continuous low rate of charge.

BATTERY CHARGER CALCULATOR

MOTORS Tuned Motors (Atomic, Rev, Torque) usually for technical courses. I prefer Atomic than the rest because of its actual speed and torque.

Dash Motors (Plasma, Jet, Ultra, Mach, Hyper2, Hyper) are used in speed and complex courses. For complex I use Hyper2 and Ultra/Jet for speed courses. Actual speed of Plasma, as I've noticed, is slower than the rest. I've heard that Mach has a great potential but the drawback is that it doesn't last long. This leaves us the Jet and the Ultra. Both are the best but comparing them, I prefer Jet because Ultra has no "holes", it is difficult for the dirt to come out when cleaning it.

Breaking-in Motors: This part is very essential so read carefully.
1. Install the motor on the chassis (remove all gears in contact with the pinion gear of motor). Put the batts in then turn it on for 5 mins. Let it rest for 5 mins or until the motors cools down. You may repeat it 2 more times.
2. Assemble the car complete with gears and tires. Put the car on something so that it won't run away (spray can cap, cup. Put tape around so it won't fall off as shown here ). Turn it on again for 5 mins. You may repeat it 2 more times. Let it rest again in between.
3. Let the car run on the tracks for 2 mins for a couple of times.
4. Soak the motor in oil preferably Inox or WD40 overnight inside a film canister (you can get this for free at any film developing center). Let it drip and shake off excess oil. Save the oil for later.

On Pinion Gears: I recommend using metal pinion gears. It is strong, thus will last longer than the plastic. The temperature build-up from the motor will cause the plastic pinion gear to move usually towards the motor, making the car to stop in the middle of the race. So not to damage the gears in contact with it, always grease them.

· Use heat sinks to lengthen the performance of the motor during runs (also helps batteries to last longer).