3DTS Donner Pass Cab Forward Wheelslip issue, any fix?

[richpeo]

Hello,
As stated in the title when using the SP Cab Forwards adding more than about 14% regulator in any cut off setting results in the drive wheel set under the smoke box spinning wildly whereas the under cab set are gripping normally, is there a fix?
Thanks

[eric]

I don't have that set, but does it do that at speed? I've seen other locomotives with excessive wheel slip at low speed but it goes away at higher speed and once things are in motion.

[eric]

Just saw a related topic elsewhere. Advanced adhesion might be causing slip where it didn't happen before. Try turning that off if it's enabled.

[richpeo]

Thanks for that, unchecking advanced adhesion has cured the issue!

[ngc427]

I found a relatively more robust solution to this issue! The weight of the trailing "engines" was set to 10 tons, upping it to 50 tons solves this issue, while also being able to keep the new advanced adhesion settings.

Going into the "3DTS_CABFORWARD" directory in your TRAINSET folder, find the "Rear.eng" files, and change the line "Mass ( 10t )" to "Mass ( 50t )".

[Melkor]

Thank you! This worked for me as well, I was hoping an update like this was possible vs. turning off the feature

[Melkor]

After some time I found this still behaves unrealistically if you put way too much throttle on, I tried editing the front and back to distribute the weight and that seems to feel much more realistic, so 150t for each is what I ended up on. With that I can't get any "impossible" wheelslip even if I try, with advanced adhesion.

[R. Steele]

I find it hard to accept that you will ever get reliable physics just by arbitrarily changing mass of different parts of the model. OR's advanced adhesion is predicated upon the user providing accurate data for OR to simulate the physics of the machine. You may get one aspect of the model performing correctly only to find something else is not true to reality,.

Try doing some research on this steam locomotive and also on OR physics on Steamer_CTN's website >>> https://www.coalstonewcastle.com.au/physics/

PDF for the 4294 cabforward >>> https://www.asme.org/wwwasmeorg/medi...steam-loco.pdf

[Melkor]

Yes just as a naive adjustment, "distributed weight is better than not" ...maybe I don't mean to say accurate, but it doesn't behave goofy that way and the 150t is based on the total tonnage from wiki, not necessarily arbitrary. This way the loco is drive-able and feels similar to the cab forward for railworks/ts classic...but of course could be improved.

[ngc427]

After some time I found this still behaves unrealistically if you put way too much throttle on, I tried editing the front and back to distribute the weight and that seems to feel much more realistic, so 150t for each is what I ended up on. With that I can't get any "impossible" wheelslip even if I try, with advanced adhesion.

Thank you for the tip! I just knew that the weight was definitely involved, but I hadn't tested specific values super in-depth, I'll give this a shot!