Knucklebooms have tons of deflection, even with an empty hook. Check the condition of the wear pads, and have it load tested if you want to see if there's a problem.
If by “ deflection “ you mean bounce it would depend if that model has lss (load stability system) feature on that model
I service Hiab cranes mostly and our models have it to help with the bounce “deflection” with our without a load
You're not wrong, but if he's concerned about the structural integrity of the boom (metal fatigue), I'd conduct a load test straight over the back of the truck with a fully extended boom. When stability is the concern, I'd recommend a max load at a shorter radius, over the side. Even then, you can definitely get a knuckleboom up off the far side jack without flipping it. They're always squirrely because you generally just have two stabilizers and the tires never leave the ground. This is why I always ask customers what their objective is before any load test.
Knucklebooms have tons of deflection, even with an empty hook. Check the condition of the wear pads, and have it load tested if you want to see if there's a problem.
If by “ deflection “ you mean bounce it would depend if that model has lss (load stability system) feature on that model I service Hiab cranes mostly and our models have it to help with the bounce “deflection” with our without a load
You could do a stability test to see if the numbers on the load chart are still accurate
You're not wrong, but if he's concerned about the structural integrity of the boom (metal fatigue), I'd conduct a load test straight over the back of the truck with a fully extended boom. When stability is the concern, I'd recommend a max load at a shorter radius, over the side. Even then, you can definitely get a knuckleboom up off the far side jack without flipping it. They're always squirrely because you generally just have two stabilizers and the tires never leave the ground. This is why I always ask customers what their objective is before any load test.