The evolution of my trains

[agrimes]

Ok. So you have a train truck assembly part. it's pretty mediocre, and has some problems, such as uncontrollable free spin around the axis.

Now a small electric motor can't spin it hard enough to break the wheels loose so therefore you are leaving lots of potential traction on the table -> FAIL. Any combination of multiple small motors quickly gets out of hand, essentially fail too.

OK, so you put a medium motor on the truck and have plenty of power to break it loose. Then you can scale that up to 2, 3 4, and potentially more trucks to get as much traction as your generators can power.

What I found by doing that is:

-> the throttle is exceptionally touchy, can't shunt, and the wheels always break loose and start slipping, ragardless of the design of the train just above 0.28 on the throttle.

My first response was to create a complex and baroque wheel deslipification circuit. (aka a traction control system). While the circuit successfully stopped the train from wasting energy, it did not unlock any more speed.

What governs the final top speed the trains reach is a mystery to me where a larger, more powerful version of an architecture that reaches 205 mph, will reach only 175.

https://steamcommunity.com/sharedfiles/filedetails/?id=1948106610

A guest on my server likes to use the Norfolk Southern train engine as it is one of the few on workshop that actually work as advertised. I slapped down my normal compliment of micros for the power system. The original architecture tried to figure out how much the traction motor needed for each throttle setting and then throttle the diesel to match. Mine simply implements a control loop over battery state of charge and is so reliable that it can simply be thrown onto just about any design you come across and work as intended.

OK. The original design had a SINGLE traction motor driving all 4 trucks through a few gearboxes. I took away one of the trucks, it now slips at 0.80 on the throttle, or around 3x 0.28, and is much more polite in the switching yard.

On the main line, it can pull a test passenger train up to 105 mph, by comparison my reference 2-truck design with one traction motor each, can only pull the same train and a tender up to 80 mph, with the wind at it's back.

The final top speed of this architecture is a bit lacking so a lot more testing is required...

The goals are to come up with architectural guidelines for achieving maximum pull and maximum speed using conventional drive.

Meanwhile, my obnoxiously absurd gear-drive trains can accelerate to over 270 mph without much effort...

I have a number of other overhauls and refits in my queue, one is a very challenging case,

https://steamcommunity.com/sharedfiles/filedetails/?id=1677492379

Is part of a matching set of awesome rail cars. The work order on that:

- fuel system was totally wack, convert to custom tank from many dozens tank-parts chained together.

- figure out the best traction architecture for this design.

- Update the couplers to be compatible with DONKK standard and crew gangway system without breaking aesthetics.

Very challenging project!

[Overland]

if you want some good traction and prepared to go unconventional, look into a half-track design thats using tank tracks and have the bogeys be guide wheels

youll be able to shunt well with this, plus with a little thinking, you can easily make a road-rail version that couples to rail wheels and can freely off track for transport and storage

magnets can stop free spin too :)