TOPIC:

This is what I use as a standard ESC on all my cars, it can handle up to a 12 turn motor with no problem.



Marius

Put this eBay link up too...

Our enthusiasm in posting has led astray from the original intention of the topic... the introduction!
I'll see if I can move the topic to the technical section from a certain point.

Agemax, would you mind opening a new topic and first post in technical?
I'll then attach the posts from where it got more specific...
Thanks beforehand.

Good idea
It is getting a bit technical.
I wouldn't know how to!
Marius

I have a few buttons that should do the trick.
It should be agemax's topic though and I cannot start another one for him.

Post #2751 and beyond could go to technical. Attached to the (new) first post of agemax.

full wrote:

This is what I use as a standard ESC on all my cars, it can handle up to a 12 turn motor with no problem.

www.ebay.com.au...5ae185a64a
Marius

what on earth is a 12 or a 20 turn motor, do you mean 12X1000 rpm?

The numbers of times the coil inside the motor is "wound up" (=turns) determines the character of the motor.
A motor with many turns has a low top speed but has torque available.
Lower turns mean more rotations per minute thus a higher top speed.
But a decrease in momentarily available power.

Limit for the Grasshopper would probably be a nice 23 turns motor.
Still an okay top speed and nice torque for a bit of off roading.

But you might want to do a suspension mod then first...

This is what it would look like with an electronic speed controller. Although I did not attach all the wiring here :



This ESC is a Robbe Rocar 20 and can be used for a 17T-35T motor.
Not expensive and suits the Grasshopper well.

Thread was split into a topic of it's own.
A few abundant posts concerning that were removed...

agemax wrote:

ok i am starting to get a bit confused now between BEC's and ESC's etc.
can someone please explain these in laymans terms.
i will try to run through the whole wiring on the car as best i can.....

4 AA bateries go to a switch, from the switch it goes to the receiver.
from the receiver, 1 plug goes to the steering servo,1 goes to the speed servo.
the main battery plugs into the speed controller, 3 little wires go to a resistor and 2 wires go to the motor,through a fuse.
also the elusive little red plug from the speed controller that seems to go nowhere

I'll also try to give an explanation...

The vintage set up on your Grasshopper uses a mechanical speed controller or MSC.
Allowing for three different speeds, determined by the angle of the servo.
The power to the MSC comes from the battery pack and it is forwarded - through the resistor - to the motor.
With the rotating MSC also in between and regulating the current that can pass through.
The fuse naturally protects it all from short circuiting.
A sixpack battery delivers 7.2V - using six Sub C batteries at 1.2V each.

In your case the battery holder powers the receiver and the servos. With an on/off switch in between.
Especially older receivers work with a lower voltage (from 4.8-6V) so you cannot apply the power from the main battery.
That is why they get their power from four seperate penlights at 4.8V.
It would most likely get destroyed when connected to the battery pack.

You need something to tone down the voltage from the pack first.
Such an item/regulator is called a BEC (Battery Eliminating Circuit) and it will bring down the voltage to an acceptable level.



The red connector on it can be attached to the 7.2V that comes from the small cable on your MSC.
On the black side you can attach your receiver and it will get the appropriate voltage.
This kind of BEC is external but there are also receivers with this feature built in.
They can regulate the incoming voltage themselves.

Now for the electronic speed controller (ESC)...
This is an electronic unit that is a one piece replacement for this :

- the MSC
- servo for MSC
- battery holder and batteries (not in every case)
- the resistor on the back
- fuse box
- on/off switch (some have a switch - I prefer without)
- a whole bunch of wires

The power from the battery goes to the ESC and this will give a proportional (stepless) amount of that to the motor.
Depending on how much you move the stick on the transmitter.
A slow drive with it is much easier that way. You can make it "crawl" so to say.

It will also have a wire going to the receiver giving it power and sharing info on the amount of throttle you're giving.

An ESC can have several features.
- Pretty much all ESCs have a thermal protection - replacing the fuse box.
- A failsafe will shut off the car when there is interference between the signal of the transmitter and the receiver.
- Automatic set up. Turn on the transmitter and then attach the car battery and the ESC will take that the basic set up.
- A power regulator (BEC) - not all of them have this. The extra cable to feed the receiver will in this case also have the same voltage as the battery pack.

Hope that was helpful. Or at least readable.

agemax wrote:

ok sorry fro being a bit thick here,so if i bought this...



what else do i need to buy, will it work with my transmitter and battery and 480 motor, or will i have to buy a 540 motor?

the spec of my motor is,
JAMARA LIPOWER 480HS
3 - 9v
22000 rpm max
5.8amp max draw.
it dosent say how many turns(?) it has

I think that will work. No need to purchase anything else.
The number of turns is just an indication on ESCs.
It's more about how many Amps they can handle. Guessing about 20A on this one.
You could even run the system on 9V if I'm not mistaken.
At least with a vintage Grasshopper there is extra room in the chassis for a "humppack" at 8.4V.
And I see all the favourable features on the speed controller.

Unless... you're thinking about expanding the hobby in the future.
In that case you might think ahead and get one that can handle more.
On my own cars I use velcro so that I can easily switch the electronics between them.

Quite the post by now...

ok thanks, i think i have got my head around it all now. i think i will get the ESC you suggested as it tidies the car up so much and makes it look far less cluttered and complicated.
saw this on ebay, it looks ok...
www.ebay.co.uk/...2561302080

agemax wrote:

...
will it work with my standard tamiya transmitter?
...

It's a Tamiya transmitter? If you bought the radio as a set, the usual transmitter that would have come with it would be an Acoms Techniplus AP-227 mk3 (very dark grey case, chunky square edged design, analogue volt meter) ...

Regardless, the if your setup works now, it should work with an ESC ... I say _should_ (99.5% certain), because I don't have a ARC-227 RX to test, but I do remember that was what I had with my Grasshopper ("normal" size plugs, but on flying leads, the "standard" wiring order, but no built in BEC).





edit - yep, that's the one