I don't tilt and move it a lot. I do sometimes have to look at the air sac so I can see veins or whatever else. They were saying here somewhere to mark with a pencil the air sac development to see that it is growing. I did that and when the chicks in side got to a certain stage I had to rely on the air sac growing. I ended up with 3 or 4 pencil marks by the time they were done.