[BTCC]

Hi there

I've been a slot car user for a while and I've seen many posts about brakes. Currently I have a SCX/Scalextric classic setup with stock controllers and wall warts, and I'm wondering about brakes. From what I have read I think its to do with the controllers but I'm still a little confused on the whole topic. If someone has a moment could they explain how they work and what you need?

thanks,
Mark

 

[JohnP]

Hi Mark

When you release the trigger on your controller to slow for a corner, the car continues to coast even though no power is being supplied to the track. In this situation the car motor is still turning, effectively acting as a dynamo and producing electricity.

If you now place a resistive load across the motor, it will have to work harder to turn and consequently the car will slow down quicker.

A braking controller has an extra contact which places a short circuit onto the track rails when the trigger is fully released. This loads the motor producing the braking effect described above. More sophisticated controllers include an additional variable resitor which allows you to adjust the braking strength.

You'll need to wire the track accordingly too - perhaps someone else on the forum can point to the wiring diagrams...

Hope that helps

 

[RichD]

Go here: http://www.hoslotcarracing.com/ and look under "Controllers".

 

[pault86]

Hi BTCC,

If your track is not already wired for brakes it is not hard to add them. You will need to build a driver's station that provides the correct electrical connections between your track, your power supply and a controller wired for dynamic braking. This schematic from Fergy's company shows all the connections and adds a direction switch and a switch to turn braking on or off. I just built a driver's station like this and I was surprised how much difference turning braking on or off makes with some cars.

You'll notice that even with brakes there are still only two wires that go to the track. In the scematic these are the two wires that come off the center poles of the double-pole, double-throw direction switch.

The schematic also shows the inside of the controller so you can see what happens when you let up on the trigger. As JohnP described, letting up on the tigger just connects the track common wire with the brake wire. This feeds the voltage the car's motor is producing as it coasts back to the motor but with the opposite polarity, which counteracts the dynamo effect of the spinning motor and causes the car to slow down more quickly than if it was free to coast.

If this still doesn't make sense just post a reply and I will make a simpler diagram - without the direction and brake switches - that will hopefully make things clear.

Paul
Circuit TrustChrist

 

[RMMseven]

The answers about brakes are excellent so far and there are a few other things to consider if you have never experienced using brakes. I have found a wide range of opinions on using brakes, some will say they can't live without brakes and others seem to find them useless or they may even hate them, that's becasue there are other things to consider such as the track layout and the cars being used.

Today's cars with very strong traction magents slow down very rapidly so the effect of adding brakes may not be that noticeable. Initially many people do not like the effect of brakes and it may take some practise to utilize them effectively but once one is used to them they won't know how they got by without them. Some cars have good braking and others seem to have very little even with the brakes on the controller connected.

I also think the track layout makes a difference. A track with a long or very fast straight going into a tight turn gives the greatest difference between brakes and no brakes especially with a car without magnetic traction.