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Ah, now that sounds a bit better,
sounds like you right uA, the RX board needs 3V and the motors would like 6V. The answer is simple. Dual power rails. 3V for the Rxer and some drive fets with 6V for the motors.
BTW, what are the specs on the fet’s you use.
is the a PDF datasheet for them ?

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Sounds strange, the behaviour sounds almost as if the battery is flat. Or to be more specific, the motor drive circuit is drawing more current than the battery can provide, thus staving the receiver of current. This in turn shuts down the
drive transistor, the available current is restored and the rxer can now turn on again…
thus it appears to shudder.
More current sounds like the answer, but I’m not sure why there is a difference between the battery holder and the original home made pack is.
Did you try to restore the original configuration you had working to see if you could
get back as you had it before.

Tampering with the ferite slugs is just asking for trouble unless you know what it is you’re tampering with. Generally, I don’t, but I own and know how to use a spectrum analyser, so I’m exempt from murphy’s laws of random tampering.

Overall, I think you have some sort of power supply or current drain problem. Sounds more like not enough than too much ?

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What size LED’s are you using bithed ?
I would have though you’d be using blue SMD leds
for the clearance you need/want ? It also looks like you’re using 3V lithium button cells to power them. Are you using any current limiting resistors on your LED’s etc ?

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though call…
I like mini-Z, mini-X performs better, and the HPI RS4 is better again, but damn expensive.

Others are cheaper, and a compremise.

Fast, Cheap, Reliable ….. pick two !

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well you’d be very upset to know they (wireless) sell for $50 in HK. But the cheap option is look out for some cheap cams either new at DSE/jaycar/oatley or keep an eye out on http://www.vkham.com classifieds. Then just buy the 2.4GHz modules from jaycar or oatley. Or if you really feel up to building some circuits, try minikits. something like 444MHz. You’ll get a speel about being a licenced ham radio operator,
nobody cares anymore, just say yes :-).
Might also like to try some of the TV senders either UHF or 2.4GHz.

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I’m not exactly sure. I’ve seen many different types in Hong Kong (RC heaven). But I haven’t looked at web pages much. microrccenter.com has a good forum with other vehicles.
The stuff I’ve seen in hong kong includes
BCG clone tanks,
Clone combat tanks (like jaycar sell)
Digi Q tanks
~1/50th scale RC tanks
~1/20th scale plastic BB firing tanks
and even some massive 1/8th scale tanks.

There are probally a few others I’ve forgotten about.

I’m not sure why some of the webshots pics don’t work… might like to just try follwing the links below.

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oh, just got a look at that ‘bit’ heli … Hmmmmmm. bit parts… yes…. I think he might have done better by getting some plywood to build his new bit blades. Looks a lot like my smart tech heli.

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[Dr Evil voice]
ONE MILLION RPM !!!!

Mahahahahahahahahahah 👿

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Hahah, I love the pics, looks like some classic engineering happening there.
If one terminal is grounded to the chassis, that’s another way of sheilding RF from getting out of the motor. It basically will stop sparklys appearing on your TV. I actually meant 3 capacitors. one from terminal to terminal and one from each terminal to the chassis of the motor.
I actually did a pic today that shows two capacitors to the chassis from each terminal.

http://community.webshots.com/s/image7/7/63/38/98576338dcWGKm_fs.jpg

They’re ceramics and the one between the terminals
isn’t there… hmmm. I should be soldering on in there. 🙂

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Barbarians ! 🙂
We really need to bring back the cane and get rid of barbaric punishments like detention.
Apart from trying hard not to laugh the cane was cool. 5 minutes and you’re outta there free to reak havoc on the world again. 👿

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I’m not sure how I put mine together, I have vauge memories of having problems and re-arranging the spacers etc. to make them work.
A picture says a thousand words…

Edited by – trash on 06 November 2003 16:09:31

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The capacitors are used to reduce noise.
They aren’t necessary, but better to have them than not. The capacitors are usually “monolithic” type, usually 0.1uF or 0.01uF.
You could also use greencaps/polyester etc, but they are much physically bigger, monolithics are small, and you may even care to look for SMD type components if you want to get really small.
You may also find capacitors placed between each terminal and ground.

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Do teachers still yell at students ? wow, I didn’t think they were allowed to even look at them ? Seems tame compared to one of my teachers who’d throw a blackboard duster at you. But we always knew the only reason that would happen was if you deserved it.
That doesn’t mean that some/most teachers have deep psychological problems. Once you get past the hype of HSC and on to uni/tafe, you get rewarded for thinking about tiny motors and how to use them. It’s called Applied Science and the reward is call a Degree. The only reason teachers yell there is because their coffee is too hot when they sip it. :D:D

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oh yeah, the future’s so bright, you’ll have to wear shades !

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The tamiya motors sound like a really simple problem that I was having with my mini-Z. The batteries weren’t fully charged and the torque required to overcome friction just wasn’t quite enough. I replaced the battery charger and it doesn’t happen anymore.
I’ve seen those 4WD tamiyas somewhere too, but they didn’t grab my attention. I think I saw them in KL where they were probably asking some rediculious price.
There is another type of 4WD car the is much better than Mini-X. I’m supprised that I never see them mentioned here.
HPI – RS4’s. They are better than mini-Z and mini-X, but the cost is more expensive and I’ve been waiting for the price to come down.

http://www.hpiracing.com/kits/micro/micro-m.htm

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1mm w@nkel rotary. heheh, that sounds very cool too… do you have a URL for it ?
I just had to type wqnkel for myself too.
Invent an 1diot proof system and nature will find a better 1diot !
I wonder if idiot gets censored ? 🙂

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They run on lighter fluid and they run at about 40000 rpm. Hmm, might have to gear that down a bit. But I’d guess that you’d just simply have the same setup as a diesel electric train to get the best performance, else you’d have to consider a gear box etc.

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lilnismo it sounds like what you want is simple surface mount LED’s that you can get from jaycar, farnell, RS, wes, oatley electronics, even dick smith or any mobile phone shop. They tiny and don’t draw too much power. (20mA each).

I have some electroluminecient panels that I bought in Hong Kong. They sound like just the thing your looking for. $3 each.
All ELS’s require about 100 volts AC to drive them and only a tiny amount of current.
A simple switchmode boost circuit works well.

Oatley eletronics used to sell them a few years ago, might care to give them a buzz see if they still have any in stock.

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You can also find cheapo 640 x 480 type digital cameras getting around like the ones jaycar sell.
Even a web cam can be used to capture a picture and most internet cafes have those these days.

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Finally I have had some spare time to complete my entry.

The base construction is a clone semi trailer.
They have some rather dull controlers so the first thing to be replaced was the radio control
circuits. Nothing special there.

For the job at hand, more torque and more traction is required than the standard clone semi can offer. A clone tank motor was used for the job, it has enough basic torque to start with.
The base 2.4 volt batteries are ripped out and a
3 Volt lithium battery dropped in. Now we have some serious moving power.
Next thing was to get this power to the ground.
Lots of power is no good if you can’t transfer it.
The standard clone truck has 2 plastic drive wheels, the other drive wheels are just dummy wheels. I added a few extra gears and now we have twice as much traction. Four wheel drive.

Next was to add some nice special effects.

Headlights, Highlights and Tail lights.

The headlights are the 8000mcd white 3mm LEDs.
The Highligts are optic fibre driven by a clear yellow LED.

The tailights are also optic fibre driven by two
high brightness LEDs. The LEDs are glued to the under side of the trailor while the battery that powers them is glued inside of the trailor.

It’s now all ready to come together.

Wheels… lots of them !! 26 in all.
If these were real double wheels then this little beast would have 50 tyres in all.

True to life, the bit beast takes a bit to get off the mark. But once moving, there is no stopping it. The trailers follow very well and the whole train is quite manouverable. It’s quite capable of sharp turns, but trying a full 180 degree turn can result in a rollover.
Yes, you can reverse, ever wondered why real road trains never reverse ?

The end result is a very big micro vehicle !

I wanted to add optic fibre side lights down each side of the trailors but the fibre doesn’t disperse light very well and the effect was not worth the effort.

Edited by – trash on 27 October 2003 11:01:58

Edited by – trash on 27 October 2003 11:06:18

Edited by – trash on 27 October 2003 11:24:23

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Even if they aren’t torquey, then it’s just a matter of design application, much like a traction engine in a train.
It is designed to power some sort of generator to create electricity. If it doesn’t have enough
power to drive a car, then the generator charges
a small battery or capacitor and uses that to drive an electric motor with more torque or traction. A bit like the hybrid electric/fuel cars getting around now.

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It cost about $10 per metre. I got it from the states. I have 100ft of it currently in transist.

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I have some muscle wire nitinol on the way from the USA. Also know as SMA (shape memory alloy).
Basically you heat them and they change shape or length. Easiest way to heat the wire is pass electric current through it.

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Ok Aaron,
it’s still a little vauge to me why you’re tinkering with something which seems to be inside the stereo where you don’t need to get to it.
But dealing directly with the problem…
the answer is simple. If the pin is connected to the audio line when the socket isn’t in use, then you need to deal with it. With your multimeter, measure the resistance/impedence between the audio and ground. There should be something there less than 10Kohms (high impedence).
If this is the case then you need to test the pin to make sure it goes open circuit when the plug is inserted. (>1 Megaohm)

To the sense pin you solder a choke. A big one,
but something that is practical… 100mH etc.
DSE sells chokes, look for the highest value in the smallest size practical.
On the other side of the choke you solder a 1uF capacitor to ground.
These two components are acting as a low pass filter. Hopefully low enough to pass DC and not
audio. I haven’t worked out exact values because it’s not all the critical. You basically want DC and not AC to get through.
Next is to solder a small diode 1N418 or even a 1N4004 to the choke and capacitor. The Kathode,
(end with the stripe) is soldered to the choke/cap.
The other side of the diode you solder a BC558
or similar transistor. (a PNP type).
The center pin (Base) is the one you solder to the diode.
The Collector you solder to ground.

The last pin left is the Emitter. This pin will be connect to earth when you put a plug into the socket.
You may need to also solder a 560 ohm resistor (depending on the voltage) to a positive rail and the emitter to pull the line high. But this depends on what the transistor is trying to ground.

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If you need help laoding it etc, just let me know. You can get everything you need from jaycar.
Programers, chips, circuit boards, components etc.

[Author]

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