PALLET Hopper/MAGAZINE Drive Upgrade: From Clunky DOL Control to Smooth VSD Performance
This project involved upgrading a hopper drive system that was originally controlled direct-on-line (DOL). While functional, the existing setup was harsh in operation, with abrupt starts and stops that created a clunky feel and unnecessary mechanical stress on the system.
Peak Control upgraded the hopper motor to VSD control, introduced independent brake control logic, and modified the PLC program to suit the new drive behaviour. The outcome was a much smoother and more controlled hopper movement, with better stopping performance and improved overall machine operation.
The Problem
The original hopper drive arrangement used DOL starting, which meant the motor was effectively running at full speed immediately on start. This created several issues:
Harsh starting and stopping
Clunky machine movement
Increased mechanical shock on the system
Limited control over acceleration and deceleration
Poor coordination between motor operation and brake timing
The existing system did the job, but it lacked the level of control needed for smooth, modern machine operation.
The Upgrade
Peak Control carried out a full control upgrade to convert the hopper drive from DOL to variable speed drive operation.
The scope included:
Installation and commissioning of a VSD
Reworking control to suit drive-based motor operation
Adding independent brake control
Updating the PLC program to manage motor run, direction, and brake timing
Setting and tuning acceleration and deceleration parameters
Testing and refining operation onsite
Because the original system relied on a much simpler control method, PLC changes were required to ensure the drive and brake operated in the correct sequence and delivered smooth, reliable performance.
Key Improvements
The upgraded system delivered several immediate improvements:
Smoother hopper movement
The VSD allowed controlled ramp-up and ramp-down, removing the harsh, on/off feel of the old DOL setup.
Independent brake control
Brake timing could now be properly managed instead of relying on abrupt motor stopping, resulting in better control and cleaner stopping performance.
Reduced mechanical stress
By softening starts and stops, the upgrade reduced shock loading on mechanical components.
Improved operator feel
The machine now runs in a much more controlled and professional manner, making operation feel cleaner and more refined.
Better long-term reliability
With less harsh movement and improved motor control, the system is better positioned for long-term reliability and reduced wear.
Technical Summary
This project required more than simply fitting a drive. To achieve the desired result, the system needed proper integration between the VSD, motor brake, and PLC logic.
Peak Control updated the control philosophy so the PLC could coordinate:
motor run commands
direction control
timed brake release and reapplication
smoother acceleration and deceleration
safe stopping behaviour
This ensured the upgraded system operated as a complete solution rather than just a hardware change.
Outcome
The hopper now runs smoothly and predictably, with significantly improved start/stop behaviour compared to the original DOL arrangement. The upgrade transformed the feel of the machine from abrupt and clunky to controlled and refined.
This project is a good example of how targeted automation upgrades can deliver a major improvement in machine performance without requiring a full machine replacement.
Suggested CTA
Need to modernise an older machine?
Peak Control can upgrade outdated motor control systems with VSD integration, PLC modifications, and practical onsite commissioning to improve performance, reliability, and operator experience.
