Thursday around 3 pm a very large cylinder showed up at work, and the customer wanted it repaired the same day. Now, normally we get rush jobs... but this one was not going to be done in an hour and a half.
This was a bucket cylinder off of a Volvo EC700C, here's a picture of the same model of machine so you can get an idea of how large it is.
Now this wasn't simply a re-seal job, nor did we have any seals in stock for it. Some HERO managed to tear off the rod eye, keep in mind the rod is 130 mm diameter ( over 5 inches ) of induction hardened fine grained steel that is friction welded to the forged rod eye. The weld had been cracked, and the company attempted to grind it out and re-weld it. When they had put it back into service, it tore a large portion of the rod out when it failed in a spectacular fashion.
Washing the grease off the cylinder, and the loose rod eye, and removing brackets was 1/2 hour, draining and removing the bolts from the cylinder head and taking the rod assembly out was another hour.
Machining the rod eye back, centerdrilling and tapping was another 1 1/2 hours. Turning the rod back and turning a thread on the end to connect to the rod eye was another hour. Once the eye was installed and tightened on the rod, it was almost 3 hours of welding - initial pass with 1/8th 7018 rod @120 amps, then switched to 1/4" 7018 rod @300 amps.
To cool down the rod, we set up the welded rod assembly in the lathe and set it at a low RPM, with the coolant flowing on it about 18 inches back from the weld, that took over an hour to cool down to the point where it could be re-assembled, and tested.
They wanted it back the same day, but they also didn't want to pay all the overtime for 3 employees to work way late, so they got it on Friday afternoon instead. Had they simply removed it and had it vee'd out and welded properly in the first place, they wouldn't have been down for over a day and a half. To make matters worse, this machine was working at a remote mine site a few hours north, not close to the city.
By the way.... I wouldn't want to know what kind of forces are required to shear off the rod eye.... spectacular by any measure !