I'm trying to automate a process wherein individual small parts must be weighed one after another for identification / sorting.
The parts would be fed to the scale using a conveyor. A mechanism is in place to feed the parts one at a time (i.e. sufficient spacing between the parts).
I know that it is possible to have weighing idlers on industrial conveyors but their precision and repeatability seem to be inadequate for precision weighing. The parts range in weight from 100mg to 30g so the only type of scale that I've found that has sufficient precision (10mg or better) are precision/laboratory scales. For example: Torbal Precision Scales.
I can imagine a solution wherein a lightweight flat surface (e.g. plexiglass) could be laid atop the scale plater upon which the feed conveyor would deposit the parts to be weighed. Then, after a stable weight has been read by computer via the integrated RS-232 port, a motor controlled "sweeping mechanism" could brush off the part from the plexiglass plater onto a discharge conveyor system for routing into one of many possible part bins.
Given this, I have two questions:
- Is there a technology that I'm unaware of that could achieve individual small part weighing that would be simpler than stated solution?
- Would the plexiglass platter (used to create a larger flat surface) cause too much pre-loading to the load cells, thereby affecting the scales performance / durability in any way?