SlotForum banner
1 - 4 of 4 Posts

· Registered
Joined
·
5,158 Posts
good find!

Don't forget the DCC supplies voltage or current to the train motors, a given voltage/power for each step, which has been chosen to result in those speeds.

However, a train has a different inertia, mass, motor and gearing to a car, so the transformation from the train graph to the porsche graph will not be simple.

Also to get the porsche graph for a given slot car will depend on the motor, mass, gearing etc of that particular car, so different slot cars will need different graphs, in an ideal world.
 

· Registered
Joined
·
5,158 Posts
I don't understand what you are trying to do with these graphs, or how they are used with DCC.

the DCC has no idea about what speed the car or motor is going, it can just give voltage, and perhaps detect current draw.

I havent seen anything on the market for slot cars which would give acurate enough slot car telemetry to tell what its acceleration curve was. RC45's method of experimentation is more likely to give perfect results, imho.

Even a speed trap, so you could send the car off at different DCC constant steps, and tell what scale speed that gave, would not show what that step was corresponding to under acceleration.

If the graph is something you can input into the programmer, the new graph WILL give better response than before, but it is unlikely to have anything to do with the speed graph of the resulting car performance.

Also, the porsche acceleration graph response is for someone flooring it and going up the gears. I THINK (but you have the manual!) that the train graph shows constant speeds resulting from each step of the controller. Ie making the travel of the speed knob or trigger smooth and responsive all the way along. If this is what that graph represents, then when you floor the controller, it will applt voltage step 28 straight away (or dependent on some other graph). The reason I dont think this is the graph for that is because it is a graph of steps to speed, and there is no mention of time.
 

· Registered
Joined
·
5,158 Posts
QUOTE I think they are important and the shape is relevant to the vehicle. One can say that the voltage applied is in proportion to the speed. No volts, no speed; max-volts, max-speed - it's not going to go faster.

The graph will be important and make a difference. But if this is in fact a volts to steps graph, then

a - it has nothing to do with what the car does when u floor the throttle (CV3 will, but not the graph; In most cases you may want CV3 delay = 0, to use the car's natural gearing and torque etc.)

b - changing the curve is more like chnging from a 45 ohm to a 20 ohm resistor, or making linear to log curve changes with potentiometers. It is more to do with how much control/throttle distance you have over the car at different speeds.

The porsche acceleration curve is a red herring and not related to what the graph represents
 

· Registered
Joined
·
5,158 Posts
I think RC45 has the only way to work this.

The porsche curve is speed against time

The DCC graph is 'speed' (or probably voltage) against throttle position.

I agree the shape of this graph should probably be convex like the porsche curve, but this is due to voltage overcoming inertia and friction, not to do with acceleration. But any use that these graph shapes have is purely coincidental.
 
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top