Quote Originally Posted by Michael R 1974 View Post
Interesting machine. I'd be worried about that method of agitation though. The builder really needs to analyze the resulting negatives for development uniformity.

In his meticulous testing, Richard Henry constructed an automatic agitation machine, although it was only for agitation and did not automatically pump chemistry in/out. In testing for uniformity and agitation patterns with inversion agitation, he found that not only were complete inversions required, but that when inversions are machine controlled some rotation about the tank axis was required in order to "randomize" the agitation.
This was exactly the question I had when seeing the machine's agitation. Because the motion is always the same will there be the possibility of something like like "surge marks?" With people the motion will always be different.

Then there is the problem of the tank not being fully inverted. If you look at a diagram of Kodak's recommended method, not only is the tank inverted but it is also given a swirl each time.

One other point. Since highly conductive solutions will be used has the unit been tested for electrical safety?