This is the method I devised so the blobs could 'dance' smoothly. Originally the plan was to have them swaying, but because the Newplast is so hard and the blobs are so chunky, I couldn't bend their bodies side-to-side enough. Instead I decided they should turn from side-to-side - but how to do that without grating their plasticine bottoms all over my lumpy set floor?
Washers and petroleum jelly was the solution I came up with. I used rubber washers for the bigger blobs and a little steel washer for the small green blob. I coated the washers in petroleum jelly so they would glide smoothly, then put the washer over the tie-down hole on the bottom of the blob before fixing it to the set floor. It seemed to work - there was only a minimal amount of grated plasticine left on the set floor when I'd finished animating. This method also made the blobs appear to be floating slightly above the ground, and what could be more alien than that?
Here is a photo I took of the set just after I finished animating to show my terribly high-tech set up. Yes, that's TWO angle-poise lamps with daylight bulbs, I bought the second one especially for this project. I glued the lamps in position with a hot glue gun this time, after having a few problems with slowly drooping lamps and mid-animation collisions between my head and the lamps in the past. The knobs on the lamp that are supposed to tighten and hold the lamps in position are less than useless. It's going to be a fun job trying to pick all the hardened glue off the lamp joints though... ho hum. The pot on the left contains my modelling tools and the tray on the right has the replacement mouths on it. At the bottom left you can just see my camcorder on it's tripod, and left of that, out of shot, is a small foldable table with my laptop on it.
The other thing I'd like to mention is the importance of having your animation space set up in an ergonomically friendly manner. The first two animations I made, I had the table far too low which meant I spent hours stooping over and kneeling down, even shuffling around on my knees between my laptop and the puppets. Big mistake. I felt no pain whilst I was animating because I was so absorbed in what I was doing, but the next day I woke up to find that every muscle in my body ached and I physically couldn't straighten my knees or spine which made me walk like a very old goblin.
Now I have raised my animation table by about 8" so I don't have to stoop at all when I animate. Unfortunately my laptop is still on a low table, but I put a dining chair in front of it so I can sit down to check a frame instead of bending over. Now I don't get back or knee pain from animating, although I do end up with a bruised arse from all the getting up and down. Ideally I'd get a taller table so I don't have to keep sitting down every few minutes, but I don't know where I'd find a very tall, very narrow foldable table. I think next time I'll just put a cushion on the chair.
So yes, make sure your animation table is tall enough or you'll pay for it next day!