Milling Machine Pre-Check Walk Around
Opinions below are from a Kennametal District Rep who used to operate several milling machines:
- Inspect conveyor belts for tears and missing chevrons. These issues pose down time due to belt breakage and the missing chevrons reduce the efficiency of the machine by holding material in the cutter box thus increasing tool wear.
- Inspect and clean water filter and spray nozzles lack of water will increase tool wear and cause rotation issues.
- Inspect drum kicker paddles worn or missing paddles reduce the ability of the drum to eject material onto loading belts thus increasing tool wear and reducing production.
- Inspect tool holders for wear attributed to loss of tooling or inconsistent heights. Maintaining these to the optimum condition allows for a smooth pattern, smooth operation, and even tool wear throughout cutter box.
- Warm up machine prior to operation which includes engaging conveyor belts and cutter drum and also suggest to turn water system on briefly for a visual check to insure nozzles are working.
- Walk the cut area in front of machine to find and mark any foreign objects such as manhole lids, water valves, drain grates, etc and mark so that machine will not hit. Carbide tools cannot handle the abrupt conditions.
- After entering cut find a happy medium on track speed so that the belts are not overloaded and the engine RPM is not pulled down allowing for a productive cut.
Note: Most newer machines have a sensor that will not allow engine to be pulled down eliminating damage and allow for maximum HP to be applied to the cut.
- When tools must be checked, focus on the carbide when changing because this is the business end of the product and tools prematurely changed is money wasted.
- When truck has been loaded allow the conveyor to run until material is removed so all product possible is ejected from cutter box eliminating premature tool wear. Also suggest while the conveyor is being emptied place water spray in manual mode allowing water to be sprayed on tools to cool and turn back to automatic mode once conveyor is shut off.
- After end of the day suggest to run all modes in the high range which includes the conveyors, cutter drum, water spray for a couple minutes before final wash down so a pre check can be performed the next day before operation.
Note: My preference is to change all tools in the evening and the sort used tools for next day’s run and use them as spotters when tools have to be changed. This allows for a seamless start to the day and thus eliminating premature stopping of the machine to check tools. Clearly my preference!