Offsetting boom problematic?

[davo727]

On a few of the Midi size excavators that have the stick that will move to the right to dig next to a foundation--- are these setups ok or problematic? Avoid? Thanks, Dave

 

[heymccall]

You dont give model examples.
I've got TB180FR and TB53FR machines nearing 10k hrs with no offset issues of consequence. These are conventional booms with a slewing arms at the base, offsetting the whole boom/ arm assembly. But, used like a battering ram, I've replaced one stick (sheared at the boom tip pin) and had to redo the anchor hole for one of the slewing pin bores in the main frame.

On my 3 piece boom stuff (PC128 & PC228), electric wiring to sensors, and all the vertical pins and bushes by 6k hours.

But, our guys beat the hell out of these things. Used as designed, the only drawback is the initial expense.

 

[rondig]

I have zero problems with all the ones i had/have.

 

[hvy 1ton]

If you are talking about a parallel offset boom, it's probably a gray market machine.

 

[davo727]

Yanmar B7 ?

 

[hvy 1ton]

Does the boom like this and is the machine a shade of teal?

 

[davo727]

Yes the teal B7 is one of the ones I was looking at

 

[crane operator]

A guy here in town has a tak one, and the pins and frame where the offset is have given him trouble, but we are mostly all rock digging here. He said its awfully handy in the right spot, but not as robust as a fixed boom.

 

[John C.]

People that smash the sides of the boom and stick into something are the biggest problem. The bearings in the secondary boom are the next issue. The electrical things can be real head scratchers.

 

[davo727]

Thanks for the info.

 

[Jakebreak]

we have one on a 314c cat its handy so far we haven't had any problems with ours the one thing I noticed is that it is a heavier setup compared to a regular one I feel that it doesn't quite have the grunt that a regular excavator that size has

 

[davo727]

Thanks all of you for the useful information. Dave

 

[cuttin edge]

Another option I find handy is a swing boom. We have them on our rubber Track machines, and our 308 cat. You can situate yourself to dig along a foundation or around a corner. The 308 has over 5000 hours with no issues

 

[John C.]

I didn't have time to fully compose my thoughts on these machines when I had to leave to go to a funeral, "way too many of those these days".

The articulating boom machines in this country, for the most part, came in through the gray market and as such were not exposed to the safety scrutiny associated with use in the USA. The problem with them is that the bucket is totally able to smash into the cab and endanger the operator that isn't cognizant of this fact or is inattentive to operation at inopportune times. The manufacturers saw fit to install a safety system composed of analog potentiometers and digital encoders tied to a programable logic controller to prevent this safety issue from happening. One of the things they did to kind of hide the real reasons for the safety feature was to put a display panel in the cab and use the system to monitor the depth of cut the machine was digging. All this was useful in a trained operator's hands but unfortunately the panels were in a foreign language and there was no printed materials available explaining operation and repair of the systems. As I stated earlier the most common damage to the system is the rods and potentiometer mounted on the stick end of the boom would get damaged and the machine would stop working because the PLC did not know where the boom and stick were in relation to the cab. The only fix available in those times was to tie wire or weld the linkage in a place where the system worked and hope the operator does hurt themselves. The problem with doing that is you have now disabled a necessary safety system which is a willful violation of state and federal regulations and now may carry a felony charge and likely jail time if someone were to get hurt.

I've inspected my share of these machines to the point that I won't have anything to do with them anymore. I only have to glance at the front of the cab looking for a dent that straight lines just above the top of the kick window to know the system is disabled. You tell me you are thinking of buying one and I'll say do what you want, but my recommendation is to steer clear.

 

[heymccall]

Never had one with a 3 piece boom strike the cab. I have, however, repaired the wiring, and replaced a few potentiometers. And, I can't believe my operators are smarter than the ones that you've been around.

Ironically, I've had more, than I care to talk about, cab strikes due to bucket couplers spacing the bucket out further, on conventional excavators.

 

[doublewide]

Hmm... Interesting that you would say that...

 

[crane operator]

I just wanted to clarify my post above. The guy here in town that has a tak, has the type of boom where the whole boom shifts to the side, its not one like what hvy 1 ton posted where the stick has a extra hinge so you could dig around a corner. I think tak calls it STS.

He had troubles with one of the two pivot pieces, but I'm not sure which one, and had to have the assembly replaced. I can probably find out more if you really need to know.

 

[heymccall]

On my 9600 hr, 2007, TB180FR, the same one that sheared the stick in half, they beat so hard with it that the bore in pic 2 was egged to point that the retainer sheared.

 

[John C.]

Those photos are different that the articulating booms I am talking about. I'll hunt around to see if I can find a photo in my files.

 

[heymccall]

They are more prone to vertical pin bore excess deformation when used a a drop hammer. Again, used as intended, they're no more upkeep than a regular hoe.