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
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.
I have zero problems with all the ones i had/have.
If you are talking about a parallel offset boom, it's probably a gray market machine.
Yanmar B7 ?
Does the boom like this and is the machine a shade of teal?
Yes the teal B7 is one of the ones I was looking at
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.
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.
Thanks for the info.
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
Thanks all of you for the useful information. Dave
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
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.
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.
Hmm... Interesting that you would say that...
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.
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.
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.
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.
Here is what I am familiar with. I agree with heymcall in that the problems are all operator and owner caused. I will say that I've never seen one of these machines being sold used where the intermediate boom section was tight.
I agree with JohnC. The potentiometers / wiring/ computer - are a mess to deal with. Mine were disabled, I started to go thru and fix the system. Decided instead that I would never take my eyes off the bucket when my hands were on the joysticks. However I much prefer this style offset boom to the normal mini boom that swings in front of the cab. I use the offset boom rarely, but find it much nicer to use than pivoting the std style mini boom and then rotating the house and looking sideways at where your digging. There’s a lot of joints to wear out n get loose though!!
Oh and by the way - On mine some one had run the bucket thru the front window into the door corner post and up near the top of the right corner post on the cab. So be careful if you end up with one! Price was right though!! Took some creative body work to push it all back out - those cabs are not made out of car body sheet metal, pretty decent stuff, seemed like 14 gauge.
Ok guys the style with the vertical pins in the intermediate section are the style I was asking about. I didnt know about the TAK style where the base slid over to the side.
I've seen this style of boom often referred to as 'Z' style. I worked for a sewer and water company for a while that used a number of Komatsu PC75's and PC125's for water main renewal work in places like back alley's and on tight city streets. They were alright for this kind of work but the mechanic always had to chase after operators to grease everything as some people don't know how to do that and also make sure they weren't pounding on the old cast iron pipe to break it in to smaller pieces as he had to get a replacement boom piece on one of the machines because he suspected somebody was busting old pipe with it.....just to make it fit better in the scrap bin..... He said he tried welding it and even sent it out but I guess the damage was done and who knows it could of been a manufacturing defect. I don't see as many of these machines for sale in Western Canada anymore since the earthquake in Japan. I would of liked one of the PC75's with a monoboom (regular boom) they were pretty nice machines.
Hi John C. just wonderin if the potentiometers are shutting down the hydraulics on my pc75uu, i have never had a problem with the articulating boom, but now the hydraulics are shut down. nothing else is affected,(engine wise etc.) any ideas??
Potentiometers only limit (stop) boom up and left shift (toward cab).
If the linkages are bent and have moved outside of the calibrated position the computer will shut down all hydraulic controls. If a wire is cut or shorted it will also shut off your hydraulics.
And, on my Komatsu machines, there is an override toggle switch to allow maneuvering when the system is out of range or broken. And never is travel affected, or swing, on mine.
I've not seen that on any of the gray market machines. Where would one look to find that switch?
They hide it under the seat!! Seriously, it’s there but very inconvenient to get to Also shows it in my manual