Bought my first TLB (580SE) and the pr. owner showed me how to set the boom lock. Boom up quickly to top dead center then reverse the boom control to compete the setback motion. After initially thinking something had exploded I looked at and figured out the whys and wherefors of the pull of cylinders to TDC then the small push to complete the landing. So my question concerns the unlocking and release of the boom. When I reverse the process (as slow as possible) and the boom drifts back out past that TDC point, it starts falling a short distance before it's caught by the boom cylinders. The weight of the boom,dipper and bucket jerking on those cylinder pins as well as the two top ears on the swing tower seems shocking and excessive. Feels like only a matter of time before something snaps. Are my fears overblown or am I headed down that big bucks highway?
With the engine at ~1100 rpm (low), push out on the lever to unlatch the pin. Then just ease the boom down easy. Mine does free fall a tad, but no big deal. Maybe you have a pin that is more worn than mine, but some loose motion is there on mine also. It's somewhat balanced at that point. Is the bucket and dipper all retracted when you are doing this? After I got used to this I can latch/unlatch it smooth and easy.
yes bucket and dipper are retracted. Travel distance is more than a tad and reaction seems very violent to the point I'm afraid for one of those ears at the top of the swing tower snapping off. When you say balance point that's right after the catch is released.(no fishing jokes
Not trying to be a smart *** but do you have your stabilizers down ? Paul
most assuredly,former crane operator here.
Our C model does the same thing. It seems like the boom falls almost a foot before the hydraulics catch it. I just try to go as easy and slowly as I can so not to beat up the old girl too much.
Same as my old 580B it has got a good bit of sway before the hydros catch it.
it just takes time and practise practise practise trevor b
What is the best way to post a video here? I don't see many on this forum, and I have never tried youtube. I rebuilt the boom cylinders on mine and cannot tell any real difference in the action.
Due to the way the geometry is when the boom is released to drop there is a pressure buildup because of the oil being forced over the secondary relief, when the geometry changes so that the pressure is no longer greater than the secondary popoff pressure the boom stops, although it is abrupt the system is really being cushioned by the secondary, it is not in a free fall as you may assume. I don't believe you are in any danger of breaking any thing, I've seen some awful attempts to lock one up when briefing a new operator or owner. BTW, I have never seen breakage in the area that you fear, as another stated, practice practice practice, and then you'll even make it look bad at times, lol Mel
No worrys, with practice and time you will get the hang of unlocking it and boom down at the right time so its nice and smooth....
As it starts to fall you can reverse the stick slightly again to cushion the fall.