McElroy Discussion Forums

I have two pendents that show the graphs up side down, by this I mean positive pressures are recorded below the zero line. I think this is because they are older versons, is this correct?

Without seeing the graphs, I would have to assume that it is doing what it's supposed to do.

First of all, it is a feature of the TracStar™ Coach™ as well as the McElroy Joint Reporter program. Remember the Coach™ pendant allows the user to change carriage control direction, so depending on how the carriage direction is setup, you may have one Coach™ showing pressure at the top of the graph, and another machine showing just the opposite.

Secondly, we need to report the carriage open/close shift sequence, which involves a change in carriage control direction. In order to report such a change on the graph, we chose to split the graph into two halves, one for each direction.

It was not “negative pressure” you saw. It was simply a change in direction. Both halves of the graph are reporting positive pressure, and indicating a change in carriage direction. We felt that this is a much better way to report the shift sequence.

Try it and see how it works. You are supposed to reduce pressure in the heat-soak cycle (to drag pressure) before you shift the carriage to neutral. If instead you shifted to neutral first before switching to drag pressure, then the graph will not show a change in pressure, indicating pressure is trapped in the carriage, and therefore an incorrect shift sequence.

I hope this helps.