This is part 3 of 3 on a € 6,- DIY model train speed measurement device.
Traincontroller 9 has a semi-automated speed profiling option for use with a ‘third party device’. Well … that ‘third party’ … that’s us! With our brand new built Arduino speed measurement device described in part 1 and 2.
The TC measurements are done one by one. When we press START the engine starts to run with a speed and direction set by TC. Our device performs the speed measurement while the train passes by. When done, we press STOP and TC shows a field where we can enter the measured value. We now press START again to start the next measurement. And so on.
Despite the operator interaction, measuring a complete speed profile this way takes far less time than it would otherwise, because the device performs the measurements with high accuracy over just a very short distance.
The steps to take to profile an engine with an external speed measurement device are:
- If your Command Station has the option to select the DCC output voltage, set it to the desired value and from there on never change it again.
- Set your loc decoder’s CV3 (acceleration) and CV4 (deceleration) to 0 (or to 1, if 0 gives problems) and ensure that ‘traction control’ is enabled (refer to your decoder’s user manual how to do this).
- Tune CV2 (minimum speed at step 1), CV5 (maximum speed at step 28) and CV6 (medium speed at step 15) such that you derive speed values that you like, using the measurement device. Example: 4, 80, 40 km/h. Also measure the backward max speed … this may differ some.
- In TC9, go into Edit Mode and double click the engine to profile in the ‘Engines+Trains’ window to open its properties window.
- Click the ‘Speed’ tab and enter the maximum speeds you just measured in the ‘Forward’ and ‘Backward’ fields.
- Now click the ‘Automatic Speed & Brake’ button and in the new window click ‘Advanced Fine Tuning’. We’re in the speed calibration window now.
- First click the ‘Threshold Speed’ tab. Move the green slider to forward speed step 1. The engine now runs at the minimum speed we just tuned with CV2. Click ‘Store’. Do the same backward.
- Now click the ‘Speed Profile’ tab and from the ‘Measurement’ drop down select the one with the tools icon, where the tooltip says ‘Measurement of the complete profile with a third party device’.
- TAKE CARE: Set both the ‘Run Out’ and ‘Pause’ fields to zero. If there is a non-zero value in the ‘Run Out’ field, your engine will keep running after you pressed ‘Stop’ … we don’t want that.
- We’re ready to start measuring. Place the engine such that the forward direction is towards the measurement device. Just a few cm away is fine at low speeds; this will give nice short measurement times. Now press ‘Start’.
- The engine now runs through our measurement device. Once it is fully out, press ‘Stop’, read out the km/h value, enter it into the field presented by TC and click ‘OK’.
- Click ‘Start’ again to start the next measurement (this will be backward). And so on … until 14 forward and 14 backward measurements are done. Take care to let the engine run a bit further away as the speed increases … we need to give it some room to accelerate.
- When the speed calibrations are finished, select brake compensation measurement from the drop down.
- Enter the brake ramp distance you use in the majority of blocks and set the slider to the speed with which you usually enter blocks where you want the train to stop.
- With a few iterations, tune the ‘Brake Compensation’ forward and backward values such that the engine stops accurately at the distance specified.
The video shows the whole process.