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Just realized my old load indicator was way off after a test lift Monday
I've been running the same Grove RT for about 6 years now and always trusted the built in load indicator. Never really questioned it until I picked up a 12 ton transformer at the storage yard near Chattanooga last week. The indicator said I was at 80% capacity but something felt heavier through the controls, like the boom was working harder than usual. So I borrowed a dynamometer from a buddy who does heavy rigging and ran a test lift with a known weight. Turns out the indicator was reading almost 2 tons light at certain boom angles. That's a scary margin of error when you're setting things near a building. I recalibrated it myself using the manual and now I double check with the dynamometer on anything over 15 tons. Has anyone else found their factory load cell drifting after years of use?
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val9496d ago
Funny you mention that - @the_elliot's buddy Dave's story is a good example but the load cell itself probably wasn't the whole problem. Most load indicators on older Grove and Link-Belt machines rely on pressure transducers in the hydraulic system, not a load cell in the boom. Those sensors get sticky and drift over time from dirt in the oil and heat cycles. That's why a 2 ton error at certain boom angles makes sense - the pressure curve changes differently at different positions. A buddy of mine had a 1998 RT that showed 75% at a steep angle but was actually maxed out. He cleaned the transducer ports and changed the hydraulic filter before recalibrating and it fixed it right up. You might want to check those before springing for a new load cell.
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the_elliot6d ago
Was talking to a crane operator buddy of mine named Dave over in Knoxville a couple months back about this exact thing. He runs a older Link-Belt and had a load cell go bad on him during a building job. Said he picked up a 20 ton HVAC unit and the indicator showed 70% but the crane started groaning and listing to one side. Scared him pretty bad. He got a new load cell from the dealer but the calibration was still off by nearly a ton until he dialed it in with a known test weight. After hearing his story I bought my own dynamometer too and now I test mine once a month. Better safe than sorry when you're lifting heavy stuff near people and buildings.
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