The pneumatics panel is completely refurbished all obsolete valves and solenoids are replaced with up to date components as used on the current model of computermatic machine.           




Other components of the machine are also re-piped including the load cylinder, markers and output drive assembly. The load cylinder is also stripped and    re-sealed.














As part of the modification all of the electronic control systems are taken out of the machine and housed in a freestanding control console, this isolates them from sawdust, water and any other contamination. The original TTL control unit which was housed in the machine is replaced with a programmable logic controller (P.L.C.) this unit gives a much higher level of long-term reliability over the hard wired TTL control units. 







From the console the operator can completely control the grading machine. Controls for grade boundary settings, load cylinder range selection and the machine’s speed are all located on the control panels. Also there are readouts for both ‘A’ and ‘B’ transducers, photocells and grade piece and total counters. 

The controls are cover by a transparent lockable hood, which whilst keeping the control panels free from dust, still allows the operator to monitor the status of the machine. 

The console connects to the grading machine via two 36-way connecting leads, these two leads carry all the signals required to run the machine. The standard length is 5 metres.





This picture shows the grade boundary setting panel and the load cylinder range selection and piece counter panels.






An optical encoder is fitted to the top of the first vertical roller.  This replaces the old pulse unit ‘card’ as the machines main pulse unit, being mounted above the roller means that it is not susceptible to getting blocked up with grease or sawdust.





The machine main power supply panel is replaced with a lockable IP66 cabinet. This contains both the main transformer and fuses for the machine, plus a variable frequency inverter unit for controlling the machine’s speed











The existing variable speed gearbox (mechanical type) is replaced with a standard motor, the speed of the motor is controlled by the variable frequency inverter located in the three-phase power supply cabinet.