Diameter instability correlated with heater power oscillations – missing temperature control visibility #1072
Description
During recent tests from a client, the filament diameter was not stable and repeatedly exceeded the acceptable tolerance range. Instead of remaining constant, the diameter shows a repeating up-and-down pattern over time.
By comparing the provided graphs, these diameter deviations occur at the same time as oscillations in heater power output and motor load. This indicates that the extrusion process is influenced by the behavior of the temperature and pressure control system.
The client sent the following images illustrating this behavior:
Our goal is to conduct systematic tests to understand how the extrusion process responds to changes in temperature and pressure settings and to determine suitable PID parameters.
To do this, we need a clear overview of how the control loop responds to setpoint changes, similar to typical PID response diagrams (step response behaviour).
Our goal is to use tests to create something like this:
At the moment, this is not fully possible because important information about the temperature control is missing from the visualization:
The target temperature is not shown in the temperature graph, so the response to setpoint changes cannot be evaluated.
It is unclear whether the displayed temperature values are raw sensor readings or averaged / filtered values.
If averaging or filtering is applied, the method and time window are unknown.
Without this information, key control characteristics such as response speed, overshoot, and damping cannot be assessed reliably.
Task 1:
Give information if temperature data is averaged and when so how
Task 2:
add a Graph Heating that shows if SSR is on or off