I'm working directly out of the load tables for machine, in which they state does not exceed 87% for hydraulic limited loads and 75% for tipping. I'm curious, as I might get in a pinch and asking for everything, the bucket weighs 2300#. If I get in a bind, what can I expect for additional? Just the 2300#? Not even that? Also, should I bank on the table values or is there generally a bit more in them? Basically I am picking precision goods off a trailer, like transformers. As for spec'ing loads, I have the education and experience, I just need to know how good I want to feel with these tables.
I don't know how exact lift charts are for excavators. My guess would be there on the safe side and more is available. My 057 picked a 8' tonka block over the side in close. Definitely not on the chart. With that being said, if I had a technical lift and my excavator was all I had to do the job, if it was feasible, I would try to simulate the load and movements first before the actual pick. As you know without out riggers, the chart changes fast as you rotate. If you need to travel with the load, ground conditions are a big concern. The chart is for reference to get you in the ball park of capability at a given point. After that it's up to the operator to work within the capabilities of the machine and the site conditions to keep things from getting out of control.
My chart is by the seat of my pants and the fact that what I’m trying to lift is on the ground and my tracks are in the air. That and my coffee is spilling over. Lol
For lifting new transformers I’d stick to the load chart…
As an excavator guy with crane certs, I get really conservative with things that cannot take the occasional unplanned touch ala @HarleyHappy as a track gets air. Moving structures like catchbasins, you can get a lot more optional as long as you are graceful about it. if you have to do it with the wrong tool (excavator), work over the end or the corner, and plan on temporarily landing the load on dunnage to make turns with the tracks unloaded. You can move a whole lot if you follow that rule. Do not FAFO over the side with something that cannot survive an unplanned touchdown.
Seat of the pants is great if the operator is experienced and you're lifting concrete or other items that can be lowered a little faster than usual if necessary. If you're lifting expensive, fragile items or are on a site surrounded by safety guys I'll go with the crane. Load charts become meaningless if you toast a transformer that takes 6 months to replace or get on the bad side of the safety guy. Sometimes it's more about perception and security than cost.
Is the lifting eye on the WB coupler rated for 1500kg?
What also matters is how you lower a load as the CG will shift during non-perpendicular lifts and lowers. With a hoe, I believe the only way to lift or lower a heavy load any decent distance is to use the boom which pushes the load and CG away from you as you lower with boom only. Thus you might pick up a load off a trailer with every last bit of 'oompf' she's got and let the trailer pull away out from under the load. But as you start to lower the load, the CG swings out just enough to start the tip over or safety pressure releases. You can crowd the dipper as you lower but the boom CG is still moving further out. It's not uncommon for forklift drivers to lift a heavy 'near max' load off a trailer (or other 'high' surface) and then when lowering it, the forklift will tilt over forward. This is usually because forklift drivers will start to lift a max load up and then tilt the mast back to level it from the fork flex which pulls the CG closer. As you lower the load, the CG moves forward away from the front wheels. Worst case is when a driver tries to slow the lowering, or even just abruptly stops the lowering, and the momentum just pulls you forward. So, in my non-certified, non-expert opinion, it's not the lift you have to worry about, it's the lowering as the CG swings and the momentum can overcome you quickly. And you won't know it until you're doing it.
It’s a wonder some of us are still walking around at all. I remember having to unload rough cut lumber bundles of trailers, with a 5k forklift. Every week, I would have to take the grate out of the counterweight and jam in the structural Devine diving board. That was so 3 fat guys could sit on the diving board, so I could pick up the bundles from Ethan Allen. I swear they did it on purpose, for entertainment. Our Big Red with the Perkins, we could never keep running. The stuff we did, lifting, loading and driving, should have been the end of us.
No, this is not a FAFO or even a "try it and see" operation. When pushing near max, I would always do a lift and have the trucker pull out so I can immediately just lower very close to the ground. Yes, if I need to travel, I would set the load down first. I try to keep stuff extremely close to the ground, near touching so if balance is lost, it's a pretty graceful touchdown. It sounds like no one here references a load chart. I guess I was taught different being around cranes. We don't guess with a $1M concrete bridge structure. Excavators are tricky because they don't just lift straight up and down, and geometry changes. I've called around for cranes and it's such a piddly job that it doesn't pencil well. I wish I had two ex's with high capacity.
they are about worthless when the geometry changes as you lower things. The very nature of the operation turns into FAFO by that . Look at the chart. Realize that as you " I can immediately just lower very close to the ground. " the chart changes.
If this isn't the truest statement ever made. A load chart in a excavator serves one purpose, either I'm going to try it, or I have no chance. And the number you use is the smallest number on the chart, don't give a rip where it is on the chart, and take another 1500 pounds from that. Example. If the lowest number you can find on your chart is 14k pounds, if what you want to lift weighs 12,500 pounds, let's get it on. If you know for a certified fact it weighs 13k, you are playing FAFO. I don't care how far away, over side, end, in a hole, up in the air. If it weighs as much as the lowest value on that chart, you are eff ing around and are going to find out.
You wouldn't believe the amount of work we do after they have tried with the excavator. Excavators are poor lifters, due to the digging geometry, they don't/can't lift up when close. Which kills their capacities.That and they are built for cycle speed, not precision. It gets interesting tandem picking with a big ex, when you see him go up on his toes. In the ex, you can at least get rid of it in a hurry, in the crane - you're married to it. It gets painful and expensive getting rid of it.
Thanks Op. It takes a few years to learn the hard lessons. Where an excavator kicks butt is with the bucket about even with the tracks, picking a load that is -10. Over one corner, With your tongue like this. Up high they are dissapointing weak sauce. I was working on a bridge job in 2000, and the pilebuck in charge was very skeptical about what I could to with the Komatsu 400 and he was right to not depend on it for much. Looking back I could have learned more from that guy. I said I could help two-pick a girder launcher with a truck crane and we never did that, just like as Crane OP lined out.
I would have sworn I put this in the crane section but here we are. On any machine, CG and load center are the factors. Any excavator would be the same but I do agree that the arm geometry was never intended to be a crane. They dig, thus why they are optimized for max for in the ground. Frustrating. But there is force, then there is counterweight. As in any crane guy here knows how to build the stack, and in my other line of work, use a versa-lift. We can push out the counter and it changes everything. Not the first time I've got nutso and hung a full barrel of lead cuttings on the back of a forklift to get a problem solved. I'd be willing to walk that road if I was in range, but I'm off by a mile in the 322. The last towing guy I talked to wanted big bucks, but I understand they are used to scamming people in a desperate situation. These are planned lifts. I just need to buy bigger toys. GD, an RT crane would pay for itself instantly!