EDIT 7-24-2016 So I've gotten a lot of emails over the last two years from people who suffer from hand tremors or know close friends/family that do and would like to see updates for this design. I have news... sorta, in an engineering course I worked with a group of several students to improve this design and make it manufacturable. the improved design is more stable from a physics standpoint but doesn't use any 3D printed parts. I am working to adapt the design to a printable form factor and publish it online for all to use.So these were created for a science fair project I did with the objective to try to develop several different types of drinking cups for people with parkinsons or suffer from a severe intention tremor. My grandfather, who has a severe intention tremor, burned himself trying to drink coffee one day and thats what inspired me to create these cups. I only had my printer for a month before the fair, so I did not get to develop these as much as I had hoped to. In a later version there may be a better handle, better fluid containment, less of a pressure difference upon pivot, increased degrees of freedom. Heres the catch, If I hear that any one of you makermen and women think that this is a great idea, and say so in the comments, then I will complete my designs for these cups more proactively. In the fluid series I have developed a unique mug that is intended to use a non-newtonian (shear-thinning) to simulate a slosh tank (what they use to counter earthquake vibrations in tall buildings) within a large outer apparatus. As a result the inner cup pivots in the opposite direction to counter the effect of some minor translational and rotational oscillations due to hand tremors. My axis series: http://www.thingiverse.com/thing:277956The Non-newtonian fluid I used was a silicone lubricant, It demonstrated the desired effect for shear-thinning which I believed would most benefit the design. however, I think plain old water my also work, as long as the fluid in the inner cup isn't particularly dense. There is a cap for the bottom included because there was seepage in my design. just glue one of these things to it and you should be fine. (yes I know its ugly, but the whole thing is anyway) I printed with PLA .4 fill 3 layers, everywhere .2 think If you are considering using these products then I recommend 4 layers on top solid infil every few layers <.2 thinkness and vapor polish it