Wheel rotation speed

Thank you John,

I use 3DC for long time and really didn’t notice that improvement! Besides the glasses other deseases are coming to my attention…



I’m having a bit of bother with my current attempt at a diesel engine. I’ve used the trainworks ‘engineer’ plugin to make the frame+wheels+conrods, then modified the position of the conrods to attach some counterbalance weights. I’ve reset the animation using the animate rods plugin and the animation looks OK to me in 3DC and in Decapod’s ‘Shapeviewer’. In MSTS however, the wheels and rods turn veeeerrry slooowly……. though apparenly in the correct manner.

The model started off as a 6 wheel unit. As part of the modelling, I’ve deleted the middle set of wheels, leaving the axle driving the counterweight via the conrods. I don’t see that this should be a problem as I’ve done something like this with a different model which seems to work OK. I’ve tried leaving the wheels named as per the ‘engineer’ plugin ( ie Wheels1 contains two ‘wheel’ objects) and naming the Wheels as Wheels11, Wheels12 etc. with no obvious effect.
Do the wheels groups have to be in any particular order or place in the hierarchy?

This is the first time I’ve done anything with the animation plugins and I won’t be surprised if I’ve missed something obvious……..


(I posted the same query on the UKTS 3DC forum a few days ago but got no replies <!– s:( –><img src="{SMILIES_PATH}/icon_e_sad.gif" alt=":(" title="Sad" /><!– s:( –> )

Check the animation properties so make sure you don’t have the default 100 key frames still set.

Alternatively, if you have used 16 keyframes they you need to edit the resulting S file so that the line

animation ( 16 30


animation ( 16 60

For pure wheel/rod animations you really only ever need 8 keyframes, 16 or higher should really only be needed when there are pistons and connecting rods.

Hi Paul

Thanks for the prompt reply. I was fairly sure that there were only 8 frames in the animation – this shows up in the animate rods plug-in and I didn’t change that value – I’d noted your comments from other threads about that aspect of the animation process.
(edit: properties for model show as 8 frames, 4 frames per second)

The ‘.s’ file has;

animations ( 1
animation ( 8 30
anim_nodes ( 22

and the wheels and conrods have parameters;

anim_node WHEELS1 (
controllers ( 1 tcb_rot ( 9 slerp_rot ( 0 0 0 0 1 )
slerp_rot ( 1 -0.3826834 0 0 0.9238796 )etc

There are also lines for the other groups in the model, though no parameters for them – I guess this is OK? For example;

anim_node MAIN ( controllers ( 0
anim_node GROUP (
controllers ( 0

I noticed in the animation section of the ‘.s’ file that there were two ‘anim_node’ lines for MAIN, one before the wheels and another after. Both have the value controllers ( 0 ). The model hierarchy has a group ‘Main’ below the project name and above all other groups+objects, and there is an object called ‘Main’ within this group.


That should all be OK.
The only other thing that affects wheel animation speed is the wheel radius in the Engine section of the ENG file.

There are 2 wheel radius entries, the first in the wagon section is for bogie wheels, the second in the engine section is for driven wheels.
Make sure this is half of the wheel diameter on the model.

Aha! That’s it!

On checking the .eng file, there were no entries for the WheelRadius in either section. I’ve edited them in and the animation now works in MSTS.

It looks as if the Trainsim Wizard isn’t writing those particular lines when it generates a .eng file – I haven’t noticed this before as I’ve used another .eng file as a starting point. Is it supposed to? Not a big deal – just wondering whether my copy of the plugin is corrupted and should be replaced.

Anyway, thanks again for the help!


Hi John,

the exporter does not generate eng or wag files. Those files are an art of its own so its best to use a copy as starting point.


Hi Roman

The ‘Trainworks’ wizard ( one of Paul Gausdens plugins) – if you have it – has options to create .eng file, cabview and sounds. I think it copies these from one of the default MSTS loco’s and makes appropriate adjustments.

It’s handy to use the wizard to set up the ‘headout’ position, the exhaust smoke position and the filling point. Also, the cabview files are a good starting point if one is making one’s own cabview – at least the right file structure is in place. It also does LOD levels. The basic 3DC exporter doesn’t do this of course.

Whilst I’ve used the wizard before – and generated .eng files with it <!– s:) –><img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile" /><!– s:) –> – I hadn’t used the .eng file subsequently so hadn’t noticed any issue with wheel diameters

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