Use an animation.
You can learn about rotations from the pdf by neal Hirsig on the Rocket Steam Locomotive.
Unfortunately, the site for Neal is no longer active and the archive link is nowhere to be found.
Thankfully for me, I downloaded all the pdfs to my computer before it went poof but you can find remnants still on the net, as you can see by the links above.
Edit:
Use this to find other pdfs.
https://web.archive.org/web/20170430192538/http://gryllus.net/Blender/PDFTutorials/
See pdfs 11c, 12b, 12c.
for more videos Neal Hirsig’s Videos on Vimeo
You can try to manipulate the speed of the animation but as for the formula to do that, I wouldn’t have a clue,
https://wiki.jmonkeyengine.org/jme3/advanced/animation.html#animation-channel-properties
The locomotive has a speed formula for the rotations in it but how to tie it to jme anim speed is probably doable but may not be realistic. haven’t tried.