WMT 2019 Factory Line

[peter]

2019 Winter Project
Milk Shake F
actory Line
The line runs from under the left hand side out into the rear centre of the
> viewed area.
>
> Line operates as a straight line similar to the Underground
>
> train comprises small tank loco 3 x tank wagons and brake van.
>
> Operation – when button pressed the Yard Lights at the Factory come on the
> train enters into the open and stops at the factory to load ?unload and
> then returns to tunnel and light go out end of program
>
> control either by Raspberry Pi as per underground or by conventional means
>
> Baseboard to be 2 inches above existing level
>
> would need a revised staion for cliff lift
>
> also safety power brakes in track to prevent over runs

[TerryJC]

I have some questions about the requirement:

1. Am I right in saying that there are only two stops on the layout; at the factory and in the tunnel?
2. Will there be any traffic lights?
3. You mention the possibility of controlling the system manually instead of using a Raspberry Pi. Does the WMT already possess the required hardware?
4. Will there be a Guard Rail Button to start the sequence, or will it simply run on a timer?

[peter]

The train is parked in the Tunnel and when the Button is pressed the Factory Lights come on and the train drives into th Factory and stops a suitable time to simulate unloading before reversing out into the Tunnel and stopping out f sight

As this is a private line I did not envisage signal lights but it is a possibility maybe a flashing warning light, will discuss with Geoff.

we have some equipment but not all and this was a proviso in case the problems we have were not overcome
however there is no drag involved and therefore unlikely to be the same problem and perhaps including the automatic warm up would also be possible

Yes it is to be operated by Push Button and I see the sequence as Go There , time delay and Return Stop sequence and await Button press/ or apply automatic repeat sequence

How does that sound
Remember this is advance warning and all thoughts on how to improve the attraction are welcome

[peter]

The train is parked in the Tunnel and when the Button is pressed the Factory Lights come on and the train drives into th Factory and stops a suitable time to simulate unloading before reversing out into the Tunnel and stopping out f sight

As this is a private line I did not envisage signal lights but it is a possibility maybe a flashing warning light, will discuss with Geoff.

we have some equipment but not all and this was a proviso in case the problems we have were not overcome
however there is no drag involved and therefore unlikely to be the same problem and perhaps including the automatic warm up would also be possible

Yes it is to be operated by Push Button and I see the sequence as Go There , time delay and Return Stop sequence and await Button press/ or apply automatic repeat sequence

How does that sound
Remember this is advance warning and all thoughts on how to improve the attraction are welcome

[TerryJC]

Peter,

I'm not sure why your posts are coming out twice

Your explanation is fine and all I wanted to do was to ensure that the Requirement was well understood by both sides. The reason I asked about the conventional control kit is that this project might have been better done that way, since the requirements are much simpler than the Underground system. However, if you've got to buy some kit then the Pi solution is probably the better one since Clive accidentally bought two sets of modules for the Underground

I would imagine that there will be no need to decelerate the train in the tunnel; a track break would be fine. If you can confirm that then only one sensor would be required; at the Factory end. (There are two sensors in the Store, but one is currently serviceable. (I might be able to diagnose and repair it.))

Assuming that the above is acceptable, then the only costs associated with the new layout would be wiring, an SD Card (we may have sufficient in the Store) and sundries such as resistors, capacitors, header pins, and terminal blocks etc.

Let me know if the team are happy with the requirement to date and / or have anything to add and I'll rough out a design.

[peter]

I think we are on the same wave length

I dont envisage the train travelling very fast and the total length would be qite short only 4 - 6 foot at most hence the lighting and possibly the warning light
so yes the only slowing down visible would be at factory end of the line
will discuss tomorrow with Geoff and keith

Peter

[TerryJC]

All,

The following is an extract from the Comments section of the first draft program that I have just uploaded to GitLab (see viewtopic.php?f=27&t=205):

Code: Select all

#!/usr/bin/env python3
# milkshakecontrol.py:
#                Wimborne Model Town
#      Milk Shake Factory Railway System Control Functions
#
#  **********************************************************************
# This program carries out the following functions:
#   With reference to this diagram:
#
#     Out -->                                                   <-- Back 
#
#  Tunnel End                                                  Factory End
#   ==  =============================================================  ==
#      ^                                                    ^
#      |                                                    |
#    Track                                                Sensor   Track
#    Break                                                         Break
#
#   1. On the press of a button on the guard-rail:
#
#   2. The Trackside Lights are switched on.
#
#   3. The train starts inside the tunnel and picks up speed in the Out direction 
#      taking approximately 2 seconds to reach full speed.
#      
#   4. The train then maintains a set speed down the track until it passes the Sensor,
#      when it reduces speed over approximately 2 seconds and then stops at the
#      Factory End.
#
#   5. After approximately 5 seconds, the train accelerates over approximately 2 seconds
#      and returns to the tunnel where it is stopped by the track break.
#
#   6. The Trackside Lights are switched off.

Please give the timings some thought:

• Is the acceleration / deceleration time OK? This is what was used for the Underground.
• I will be putting a timeout into the code to ensure that the motor drive stops if the sensor is missed and / or after the track break is passed. Do we have any ideas how long it will take to run from one end to the other? This can be tuned, but I'd like to start with a reasonable figure.

[Geoff]

Hi, at this stage it is impossible to give approx. time for slowing down or length of running time, due to variations in the speed of the locos.
Geoff

[TerryJC]

Sorry,

Perhaps I didn't explain myself very well. I think maybe i was under the misapprehension that the track was complete and only waiting for my hardware (see viewtopic.php?p=2987#p2987). The total time to run is unimportant and can certainly be adjusted in situ, si it's not a problem yet.

What I was wondering with the question about acceleration / deceleration is the time to change the speed. The software will take into account the variations in the speed of the locos, but do you envisage a slow lumbering start up or a nippy one like the Underground?

Again it can all be tuned later, but I wanted a starting point.

[peter]

My thoughts on this would be a slow lumbering style but the locos are quite nippy so may need some form of resistor adding to loco
will talk to Geoff Monday

Peter