Grader hire contractor Brett Chivers is consistently achieving better results than competitors using total station positioning thanks to Topcon’s unique GNSS and laser transmitter technology, mmGPS.
Mr Chivers first adopted Topcon’s unique mmGPS solution seven years ago and says he hasn’t looked back since. “I first used it while working on the Bendigo Freeway in Victoria and a colleague recommended I purchase a system, not just for the technology but also because of the backup support provided by Topcon’s Australian dealer, Position Partners,” he said.
“I purchased a system and went on to win more work for a later stage of the same project. Once a client sees the system’s performance and the results it can deliver, there’s no going back,” he added.
Topcon mmGPS is the only system of its kind worldwide that utilises a combination of GNSS positioning and a high precision laser transmitter to
achieve +/- 3 millimetre accuracy for fine grading, kerbing and slipform paving applications.
Unlike a total station setup, which can be used to achieve similar accuracies, Topcon mmGPS does not require users to complete resections every day, enabling the grader to continue working without interruption.
“The only time a total station setup will win over the Topcon mmGPS system is when the job requires working under a dense tree canopy or under cover when you can’t receive GPS signal,” Mr Chivers explains. “Other than that, I don’t think it can be bettered.”
Mr Chivers is proud to be a self-sufficient contractor that is able to setup and check his work without needing the help of surveyors. “All I need is the design files loaded onto my machine and access to the network and I can set up my laser and get to work,” he said.
“The surveyors are very impressed with the levels I can achieve with this system as it’s always well within their benchmark of 4 millimetres.” he added.
In the seven years he’s been using the technology, Mr Chivers has developed his own unique way of checking levels without using a GPS rover or relying on a surveyor. He explains that the key to success lies in taking the time to setup and check your position and calibration regularly.
“I check my benchmarks against a couple of RL points a few times a day using the blade of the machine rather than a rover,” he said. “You do get a bit of variation in the satellites throughout the day as they rotate around the earth, so I verify my position information at around 10am, lunch time and then again at about 3pm.”
Using a block of concrete or a pit lid as an RL point, Mr Chivers positions the grader blade on the point to check horizontal and vertical levels and account for any variation in satellite positioning.
“If the height is a little out, I simply go into the machine setup settings on the Topcon control box and edit the height so that it’s right,” he said. “I find using the blade of the machine so much more accurate as you have a more solid reference point to check against, whereas a rover might sink into the ground a little and be a few millimetres out.”
Mr Chivers also takes the time to calibrate his machine sensors a couple of times a day to ensure they are working at optimum performance. “If I notice that one side of the blade is cutting a little deeper than the other, I’ll quickly recalibrate the system to make sure the settings are all correct.”
“Regular position checks and calibrations are essential to getting the best results from the system. It doesn’t take long to do them and it saves a huge amount of time in the long run as you are grading accurately the first time and eliminating any rework,” he added.
Mr Chivers also takes great care of his laser transmitter and has it regularly calibrated at Position Partners’ Sydney service centre. “The laser is a high precision, sensitive instrument and short of putting a seat belt on it in my car at the end of the day, I make sure it’s well looked after.”
For technical help, Mr Chivers uses Position Partners’ remote support service, Tokara Link. This enables Position Partners technicians to login to the machine’s control box remotely to change settings, update software and troubleshoot without having to visit the machine in person. The small Tokara Link modem also enables Mr Chivers to connect to a GPS network on site without any additional hardware.
“Tokara Link is fantastic if I ever do run into technical difficulties, as I don’t have to wait for someone to come out on site and help me. The support team gets back to me very quickly and has me back up and running in no time. I couldn’t ask for better,” he said.