micro_Amps
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Yes, absolutely, they all make a difference.
Gearing adjustment is needed if you have a winding track, tires need to be changed depending on the speeds you want to do around corners (to stop flipping), suspension helps more on the higher speed (and heavier) dual cell cars, and where the surface you are driving on is slightly rough.
You will probably find your 4.2 is a little underpowered on a standard car, (better for a dual cell or fet mod car) but at the higher speeds I find the soft sticky tyres in the rear, and the medium to hard on the front allow high speed cornering and good traction.
It takes a bit of experimentation, but the different hop-ups can make quite a difference.
:)uAI’ve posted this before, but here is a pic of the “Voltage regulator” charger I use.
Its a twin LM317 regulator, with 2x 555 timers doing the timing control. Switchable using rotary switches in steps from 1 minute to 4, at voltages of 2 to 12 volts output.I also use a Pirahna delta peak charger.
:)uA
This is getting a bit techo fo rthe general chat section, how about we move it.
Dave, delta peak chargers do amazing things for BCGs
:)uA
No Jamie, dont touch that one or you wont be going anywhere. Its in parrallel with the larger 100uF electrlytic cap.
:)uANo Jamie, dont touch that one or you wont be going anywhere. Its in parrallel with the larger 100uF electrlytic cap.
:)uAQuote:the button on the back is for choosing between the A B C frequencies… A is the only one that should work i think, with the older Bits anywayNope, not quite.
The a,b,c switch on the back is for the different types of cars, standards and boosters.
a – standard single speed cars
b – booster car, push top button to go on boost
c – booster car, on boost all the time.The range on my 4B was crap too, until I changed the aerial to a telescopic, now I dont use anything else.
:)uAQuote:the button on the back is for choosing between the A B C frequencies… A is the only one that should work i think, with the older Bits anywayNope, not quite.
The a,b,c switch on the back is for the different types of cars, standards and boosters.
a – standard single speed cars
b – booster car, push top button to go on boost
c – booster car, on boost all the time.The range on my 4B was crap too, until I changed the aerial to a telescopic, now I dont use anything else.
:)uARemove the steering cover at the front and check the steering spring, it will be bent. If you straighten it the car will run straight.
Check directions for this in the “Tech” section at the top of this page.
Goodluck.
:)uARemove the steering cover at the front and check the steering spring, it will be bent. If you straighten it the car will run straight.
Check directions for this in the “Tech” section at the top of this page.
Goodluck.
:)uA:blush: thanks merc-blue.
Im sure there will be at least one other BIT tech head (who is based in Melbourne) who will come along too. (hey ph :smiley2:)
If you can get this up and running it would be great, there seems to be many more active Melbourne people now than there was, say, 6 months ago.
:)uAb007a, what you are saying is correct, but the Tomy (& clones) Rx circuits are just not that carefully set up in the first place, and significant gains in range can be obtained with just few mods and a little tuning.
Whilst the ‘super regenerative’ receivers are a simple and highly sensitive RF receiver, the assembly and tuning seems to be a bit ‘hit and miss’ from the factory, no doubt they are made at break neck speed.
Appreciable range gains are possible just by doing one or more of the following,…..
– remove the ‘cripple’ cap from the Rx (if it has one)
– remove the cripple cap from the Tx (if it has one)
– lengthen the Rx aerial (length, ie distance up from the ground is crucial, a length of Cat5 wire or #9 guitar string is excellent)
– lengthen the Tx aerial (again, greater distance from the ground allows wider transmission radius), although a correct aerial replacement would also require the inductances in the final aerial circuit to be changed. The original wire aerial droops down toward the ground and by doing this reduces the range.
– rutune the variable inductor on the Rx pcb. These seem to be only ‘roughly’ tuned and even if the aerial is not replaced, retuning this can increase the range.
– increasing the power supply to the Rx pcb. A dual cell car, or a Rx pcb with the DC-DC converter changed to a 5V one, has significantly greater range.Conversely, increasing the Tx output does not really have a great effect on range, its the Rx sensitvity, that makes the most difference. A higher power Tx will make a difference but it also causes more interference to cars on nearby frequencies, which is undesirable.
Sheilding the Rx from unwanted stray signals would be a benefit, but there are all the above ‘issues’ that can be addressed first(for little or no cost) that will add meters of distance to the range of a micro rc car.
Recently I had a car here that the owner (Barto) complained of short range. It was true, the car only went about 1 to 2 meters before stuttering to a halt. All I had to do was remove the Rx criple cap and retune the vari-inductor and the range increased to the length of my house, (10 meters plus) and it took 5 minutes to do.
:)uAb007a, what you are saying is correct, but the Tomy (& clones) Rx circuits are just not that carefully set up in the first place, and significant gains in range can be obtained with just few mods and a little tuning.
Whilst the ‘super regenerative’ receivers are a simple and highly sensitive RF receiver, the assembly and tuning seems to be a bit ‘hit and miss’ from the factory, no doubt they are made at break neck speed.
Appreciable range gains are possible just by doing one or more of the following,…..
– remove the ‘cripple’ cap from the Rx (if it has one)
– remove the cripple cap from the Tx (if it has one)
– lengthen the Rx aerial (length, ie distance up from the ground is crucial, a length of Cat5 wire or #9 guitar string is excellent)
– lengthen the Tx aerial (again, greater distance from the ground allows wider transmission radius), although a correct aerial replacement would also require the inductances in the final aerial circuit to be changed. The original wire aerial droops down toward the ground and by doing this reduces the range.
– rutune the variable inductor on the Rx pcb. These seem to be only ‘roughly’ tuned and even if the aerial is not replaced, retuning this can increase the range.
– increasing the power supply to the Rx pcb. A dual cell car, or a Rx pcb with the DC-DC converter changed to a 5V one, has significantly greater range.Conversely, increasing the Tx output does not really have a great effect on range, its the Rx sensitvity, that makes the most difference. A higher power Tx will make a difference but it also causes more interference to cars on nearby frequencies, which is undesirable.
Sheilding the Rx from unwanted stray signals would be a benefit, but there are all the above ‘issues’ that can be addressed first(for little or no cost) that will add meters of distance to the range of a micro rc car.
Recently I had a car here that the owner (Barto) complained of short range. It was true, the car only went about 1 to 2 meters before stuttering to a halt. All I had to do was remove the Rx criple cap and retune the vari-inductor and the range increased to the length of my house, (10 meters plus) and it took 5 minutes to do.
:)uAI didnt contact the site because I looked at the payment section and it looks like a pain in the @r$e to make it happen.
I still wouldnt mind getting my hands on one of those mini F1 racers tho.
:)uAI think that was for ALL of them, who would buy that many??
:)uAI like the idea that they went for the old mini version not the new, and that there is so many different types.
I think one will probably end up at my place eventually, bit of a mini fan.
:)uAQuote:bambowhehehe, good stuff.
:)uAMy version was about equivilent to a garden trimmer motor (whipper snipper)
The ‘piston’ was about 25mm accross (1 inch), and the head coil was hand wound enamelled wire about 1mm in diameter, power pulsed with an SCR relay, timing was achieved using a hall effect transistors and rare earth mag on the flywheel. Speed and torque were variable and controlled byvoltage and timing ‘angle’, max revs produced at 8deg BTDC. It was torquey but pulsing 100 amps at 80Hz (4800 rpm) is almost like running fully switched on, and there’s a whole lot more you can do with 100 amps than just spin a plastic piston motor.
It was 2 stroke, firing only once just before TDC. The next version would have had the piston running inside a coil ‘tube’ and fired both directions to produce the 1 stroke cycle.
:)uAMuts, the 4B controllers are lower strength signal than the standard controlers. If you change the aerial to a telescopic aerial it makes it heaps better, almost as good as a normal controller. Have a look at QFM for the details.
:)uAMuts, the 4B controllers are lower strength signal than the standard controlers. If you change the aerial to a telescopic aerial it makes it heaps better, almost as good as a normal controller. Have a look at QFM for the details.
:)uAJust a ‘get together’ or a race day would do me.
If its anywhere near Melbourne, I’ll be there.
:)uAThe Enertec micro flash charger.
They are a dual cell too, twin 40mAH 1/4AAA NiMH cells. Boost is only ‘on’ in forward and if you turn a corner they go back to slower speed whilst turning.
Not easily fet modded, but good fun anyway.
Rear axel is captive, but they have a reasonable motor. Pity they dont go into ‘boost’ in reverse, it would make things easier on carpet.
:)uAHey, those F1 mini cars look ok.
:)uAYes Trash, I have a working model of your idea. I thought it up about 3 years ago. Unfortunately its not that efficient. Magnetic field strength is based on flux density and that means huge currents pulsed into the ‘head’ coil. It creates massive EMR interference and uses heaps of current. I was switching 150 amps and not getting a great deal of power output, it ran at about 4800rpm on a single cylinder.
Fun to build and watch, but ultimately useless.
:)uAMutters, try bending the heatsink tab a little so it doesnt exert so much force on the plastic at the back of the chassis. Other than that, just be careful I suppose.
You cant really glue anything onto it because it slips into the body shell. Id be interested to hear anybodys suggestions for repairing these.
:)uAQuote:ph2t and micro_amps got my attention, some of the stuff you guys are designing and building is off the scale !We’re not sick Trash, a little obsessed at times though I must admit.
There is so much more that can be done to these cars with some techo knowledge, and we aim to figure it out. You are right though, much of the ‘hard core’ techo stuff originates from this forum.
Anyway,
Me……electronics technician, electrician, applied physics (Vic Uni (temporarily)), spend most of my day installing, fault finding, debugging, calibrating and fine tuning, all manner of circuitry from mega large (600Vdc @ 400 Amps) to miniature (micro Amps through SMT).
:)uA -
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