Used to Maya to learn the basics (more tuts) then I switched to Blender, free and open source and got better modeling toolkit than Maya IMO.
Yes, I keep it stuck on the top. There won’t be timeline animation, as the user holds a key, a tooth rises with the spring in tow, as the user releases it, all pops back to idle. so continous location from the tooth and continous scale from the spring.
Another thing: Can I do this: order UE to fit the image from this object to this? That way my problem would be solved. Like, fill the spring in a container and I scale the container that has its top restricted or so?