I did some poking around the ZZ pcb to figure out why the ZZ is slower than other cars with the same battery and motor. Here is what I found:
With a battery voltage of 1.29v the motor only sees 1.12 under no load conditions (wheels in the air). This tells me that the speed controller on the board has an on resistance of around .5 ohms or more which is pretty crappy. Figures based on a load current of 200ma which I guestimated. There are a couple ways to improve this:
1) Solder additional MOSFETS to the board. This will halve the on resistance for each additional MOSFET. Maybe someone has access to some SMT FETS....I dont. Unsoldering them from a trashed ZZ board is an alternative I supose.
2) Disable reverse. A reversing speed controller is made from a 4 MOSFET circuit called an H-Bridge. Two FETs run forward and 2 run reverse. A speed control with only forward needs only 1 MOSFET and has half the resistance of a reversing one. Reverse is real nice....not sure that I would race with it disabled.
**** HERE'S THE MOD ***** DO THIS AT YOUR OWN RISK....IF YOU BLOW UP...ITS NOT MY FAULT!!!!!!
1) clip the yellow wire right at the PCB.
2) this leaves you with a yellow wire that is connected to the case of the motor (right)
3) Solder this wire to the + side of the battery....look for the red wire and solder it there
4) you will have the yellow wire (case of motor) connected directly to the + side of the battery (right)
5) Charge and run the car....reverse wont work, but you will be faster.
Q: Why does this work?
A: Because you are bypassing the MOSFET that controls reverse. This reduces the speed controllers on resistance by about 1/2 (maybe a little more...too many technical details to write about)
DO THIS AT YOUR OWN RISK....IF YOU BLOW UP...ITS NOT MY FAULT!!!!!!
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More stuff to consider....with reverse disables that means that there is a MOSFET that isnt being used. It should be possible to unsolder it and resolder it across the one MOSFET that is used for forward........just a thought.
dunno if i want a car with no reverse
but heres my experience
i've found that its really easy tofry
a zz board
i fried one just soldering a new antennawire on
i can solder all day on a bit and they workfine
i fixed my zz by replacing the circuit board and
motor with ones from a crappy bullet car
one of the ones withthe led on top
that the steering goes after 1 day
anyhoo
now the thing flies
and the steering is much snapier
its now my favorite car
i ran the led wires to the front
and super glued a couple leds
after scraping the paint off the headlights
guess i'll have to take some pics
i'll try to put them u tommorrow
theres definately something slower
in the zz circuit
i'm getting pretty good at soldering steering wires
heres a tip ... i got a third hand tool with a magnifier
basically its 2 allagator clips and a magnifying glass
on a stand works great and was only 10 bucks
Speed Boosting ZZ PCB Mod
Linear Mode
