How to Protect the Feed Sensor, Protect Quality and Save Money at the Paver
BY John Ball
When the feed sensor costs between $1,500 and $2,000 to replace and you have one on each side of the screed, you want them to last throughout the paving season. Here’s how to increase the chances of protecting the feed sensor from contamination, and protecting the quality of your mat at the same time.
The typical feed sensor sends a beam to the top of the head of material at a rate of 10 times per second, reading the material’s height. It sends a signal to the controls system to help you monitor and maintain the correct height, also assisting in the correct speed of mix entering the augers. The sensor is your constant eyeball on the mix to help you maintain quality. If you close that eye with a patch of asphalt and goop, yet still try to use faulty readings, you’re paving blindly.
To keep the feed sensor clean, wipe it with a rag doused with some brake cleaner at the end of every paving shift. Do this while the equipment is hot to help get any stray material to wipe away easily. Do this as part of the daily equipment shutdown routine.
The endgate will get messy after a full day of paving and grabbing shovelfuls of mix from the auger area, but make sure routine care and cleaning keep the mess from building up. Arrow A points to a collapsed spring that will prevent the screed from floating properly; this will result in a line in your mat. Arrow B points to an ineffective light. This needs to be cleaned so it can swivel back to its appropriate position to help nighttime crews see the mat. Arrow C points to a missing knob on the crank. A worker can cut his hand or snag clothing on this. You’ll notice that the caps are missing on top of the cranks as well, which allows shoveled asphalt to dribble and fall into the tubes, clogging the gears inside. Even if you have to use a quick fix of duct tape until new caps come in, you can prevent a clogged mess from freezing your endgate. Arrow D points to the feed sensor housing discussed in this article. Don’t let a time or two of overflowing material cause springs to collapse and lights to get stuck in ineffective positions. Fix problems before they become safety or quality hazards. Photo courtesy John Ball of Top Quality Paving.
Also at the end of the day, take a look at the feed sensor wires. Inspect these to make sure they aren’t being stretched and cut. Make sure they aren’t pinched between the tow arm and the frame of the tractor at the end of the day.
Another way to keep the feed sensor clean is to use best paving practices.
When the paving crew begins the first pull of the shift, it’s typical to fill up the augers and overfeed the extensions. Train the team to be careful with this excess of material. Don’t overfeed so much that the head of material rises too high and touches or clogs the feed sensor. Definitely don’t let the mix rise above and bury the feed sensor.
Also pay close attention to the endgate when paving alongside driveways. Crews have a tendency to pile up mix—because they don’t want to run out—and overfeed the head of material in preparation for sliding out to accommodate the driveway. You definitely want more material here so you don’t starve the area or create too much handwork for the crew, but you must keep an eye on quality.
The inner circle of this tube is the ceramic feed sensor, which is supposed to be white. It can be replaced when it stops working, but that will cost the company anywhere from $1,500 to $2,000. Use brake cleaner to wipe this down at the end of each paving shift. Photo courtesy John Ball of Top Quality Paving.
As you slide the extension back in at the end of the driveway, watch out for the head of material because it will rise again. This is another chance for it to get too high and come up to contact the feed sensor.
By keeping your eye on the feed sensor, you give this tool its best chance to keep an eye on your material. Let the sensor do its job to help you pave a top quality mat by keeping it clean and clear of the mix and muck that could lead to its expensive replacement.
John Ball is the proprietor of Top Quality Paving & Training, Manchester, New Hampshire. He provides personal, on-site paving consulting services around the United States and into Canada. For more information, contact him at (603) 493-1458 or tqpaving@yahoo.com.