Fletcher Moorland have been supporting Dematic CDU repairs for many years. When an OEM withdrew a critical component from production, our ability to support CDU repairs was in jeopardy.
In essence the CDU unit is a 5Hp linear motor mounted onto a chassis which contains a low profile drive and a CPU control PCB. It was the low profile drive (driveblok) manufactured by Parker Automation that was withdrawn from production. We contacted many companies across the globe for this part but non were available.
The driveblok was not just a 5Hp drive, it had a low profile design to fit into the chassis, more importantly the automated sorter system it drives uses the Parker software to control the entire sorter. It uses analogue sampling of speed, voltage, power and current and sends this information to the sorter through the onboard control PCB. This meant we could not just fit an ‘off the shelf’ drive.
The challenge to continue supporting CDU repairs was put to our ‘obsolescence engineering’ department. Their aim was to retrofit a drive and control stage to the CDU so it had the same fit, form and function as the original.
Their project plan was as follows
- Source a drive unit that would fit in the confined space of the CDU chassis
- Reverse engineer the CPU control on the CDU
- Develop a software conversion PCB to take the original commissioning and operation software and convert this to the new drive software
- Develop a ‘real time’ analogue data sampling PCB to sample the speed, current, power and voltage of the CDU
- Build prototype PCB’s
- Connect the prototypes to a CDU for acceptance testing
- Write software code to control the new design
Once the considerable R&D engineering project had been completed, a new PCB layout was drawn up and we had bare PCB’s manufactured ready for population at our electronics workshop.
The first retrofit unit has just passed all testing and the project has been signed off for release to our customers.
We are now back in a position to continue supporting CDU repairs for years to come.
The original CDU control with obsolete driveblok
Newly designed retrofit control
Discussion
No comments yet.