Familiarity breeds contempt, the old saying goes. But when it comes to high-performance rock drills, the opposite is true: familiarity with these machines brings positive results, including higher productivity, lower maintenance costs and reduced downtime.
Today’s drills – whether top hammer, down-the-hole (DTH), or rotary – are modern marvels of design, engineering and metallurgical research. They are the heart of quarries. When your drills are not working, everything comes to a stop – or at least slows down enough to significantly affect your operation’s production and profitability.
Yet, some companies do not give these machines the respect they deserve, instead treating them as a second-tier machine in an operation. With regular, preventive maintenance and attention to the details, drills can do their hard work for months and years at a time. Without proper care, however, trouble can result.
How they work
Lack of attention can often be attributed to the fact that many service technicians spend a lot of time on machines that are more familiar to them, such as trucks and loaders.
Due to the stressful tasks they perform, and the unique engineering that goes into them, drills are tough to properly maintain, even with sufficient training and that all-important familiarity.
Just as important as caring for the drill itself is to ensure that drill operators and service technicians are properly trained on the maintenance of the drills in your operation’s fleet as well as how they work.
Every manufacturer should provide training on the use of its drills, along with instructions and operation manuals. Employees need to pay close attention to these instructions. Without proper training that is updated periodically, operators and service techs cannot gain the intuitive understanding of their drills that is absolutely necessary to keep these properly running.
And having employees that get high production from a drill is very important. But it is even better when they can spot things that may be going wrong on the machines and are then able to tell a service tech about it, before a small problem grows into a big one and causes extensive downtime. Instead of spending their time troubleshooting a balky drill, well-trained service techs can diagnose a problem more quickly and spend their time fixing it.
Cleanliness next to profitability
One of the simplest and most overlooked preventive maintenance methods is simply to keep the machinery clean. Excessive dirt can build up on drill components such as pumps, motors, valve bodies, hydraulic tanks, cooler packages and fast-fill stations. Excessive dirt that is allowed to build up around pumps, motors and valve bodies will cause them to run hotter, which will reduce the life expectancy of these components; it may also bind up mechanical linkage, causing improper operation.
Dirt that is allowed to build up around hydraulic tanks and fast-fill stations will allow the introduction of dirt into your system on hydraulic tanks through their breathers. On a fast-fill station, it occurs through the couplers used to transfer fluids. It is important for the caps on your fast-fill station, to be kept in place and fittings to be cleaned before use.
But perhaps the most important thing you can do to keep your drills up and running for years to come is to develop and maintain a preventive maintenance schedule.
Under such a schedule, filters and fluids must be changed regularly and according to a manufacturer’s specifications. Basic mechanical checks should be done at regular intervals to keep the machine running properly and within specification. Whether a preventive maintenance schedule is developed on an hourly basis or on a bi-weekly basis, it is one of the best ways to ensure proper operation of your machine. Such schedules, when followed, will increase your drill fleet availability because they allow you to repair and adjust items before they turn into costly downtime. A preventive maintenance program allows you to be proactive instead of reactive.
Begin maintenance the day before
The day before you take a drill into the shop for its scheduled maintenance have your service tech do a quick inspection. This allows the technician the opportunity to talk with the operator who is running the machine, to see if there have been any problems with it since the last round of maintenance. It also helps the technician to identify any parts that may need replacing. Those items can be obtained before the scheduled maintenance begins, so your technicians can actually work on the drill instead of searching the warehouse for parts.
Although drill units can differ according to the methods they use to drill and break rock, they all share the need for clean oil. Any machinery with moving parts needs oil so pay attention to the manufacturer’s oil recommendations. Most of us would not dream of driving the family car without regular oil changes ? so why would we take a chance on our drills, where the stresses are greater and tolerances smaller?
Oil samples can be a great benefit to maintaining the availability of your drill fleet. Whether done through an outside source or completed at your own facility, taking samples will help you track the condition of your drill’s components. Keeping a trend of your oil allows you to see spikes that can mean the beginning of a component’s failure, and also allows you to be proactive and stop problems before they arise.
Companies should also track component hours. This allows you to budget what it is going to cost per year to maintain your drill fleet, as well as enabling you to remove and replace parts before they fail. Components that reach their life expectancy can be changed out during preventive maintenance, which will limit your unexpected downtime.
Pre-shift and post-shift inspections should be done with each shift. A pre-shift inspection is for the benefit of the operator and maintenance; it keeps the operator from running a piece of equipment that might be deemed as unsafe for operation. It also gives him confidence in the equipment after he has done his inspection and found no deficiencies. For the maintenance department, it may allow for small problems to be fixed before they turn into much larger issues. Post-shift inspection allows the operator to see if any problems with his equipment have developed throughout his shift and allows them to be addressed by maintenance before the start of the next shift.
Tips for drill maintenance
No two maintenance programs are exactly the same. Everyone works under different conditions and each business has different needs, capabilities and resources. However, there are a few basic ways to keep your drill maintenance program running as efficiently as the rest of your operation.
? Create and maintain a preventive maintenance schedule; be proactive rather than reactive.
? Change filters and fluids according to the manufacturer’s specifications.
? Inspect the drill for problems, both at the beginning of the work shift and immediately afterwards.
? Create an independent, company-wide team of operators, technicians and supervisors to audit your preventive maintenance program on a quarterly basis and to make sure drill inspections are done consistently.
? Ask the manufacturer to inspect the drill and audit your preventive maintenance.
? Make sure all drill operators and service technicians are up-to-date on the drill’s operation and take advantage of any training offered by the manufacturer.
? Schedule regular oil sampling and make sure all oils are clean and uncontaminated.
? Track major component hours so you are not surprised by the need for replacement.
? Analyse your maintenance data to generate useful reports on scheduled maintenance, daily and long-term operating costs, and historic trends of maintenance and repairs.
? Keep in mind that good brakes are more useful than good airbags and always work to avoid problems before they cause your operation to ‘hit a wall.’
Bill Hissem is a senior mine applications engineer for Sandvik Mining and Construction. Bill Burgee is a training and technical specialist for top hammer drills for Sandvik Mining and Construction. Rick Carrick is a Sandvik Mining and Construction product specialist.
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