So I'm looking at a couple 6 ton machines, the HR20 Terex, and the PC60 Komatsu, among other machines in this arena of size (finally took people's advice and narrowed the search for an excavator for the largest machine I could haul with my current set up). Both machines are in the same weight class, and given the little different boom geometry of the Terex I figured you'd see a bit different digging performance, (in terms of length of reach, depth etc.) but surprisingly they are all pretty close except for one stat, vertical wall digging depth. (The HR20 obviously trails by about 10 percent or so although slightly greater at reach at ground) But they are all really really close except vertical wall digging depth. Here's some stats from both of their spec sheets Weight, HR20 13140 lbs, PC60 14021 lbs Max digging height, HR 20 18' 2" PC 60 23' 5" Max reach at ground HR20 21', PC60 20'10" Max vertical Wall digging depth HR 20 5' 10", PC60 11'6" Max Digging Depth HR20 12' 3", PC60 13'5" Max Dumping Height HR20 12' 8", PC60 16' 5" So the question I have is it's about the vertical wall digging depth which is HALF that of the PC60, which seems odd to me with the rest of the statistics being so close. Is this just a boom geometry thing? Does this statistic really matter in general use? I'm just going to be digging 6-8 foot foundations so I'm not worried about the dig depth it will work either way, but I'm wondering if that one specification is pointing out a deficiency that will show up in work with the machine. In comparison all the other SK60's, EX60 other excavators all have similar stats to the PC60 so what is it with the Terex that makes it be that far off in the specifications? Any thoughts on whether this is something that actually matters or just a quirk in the geometry. Thanks for the help and ideas! Sources http://www.equipmentcentral.com/north_america/data/new_equipment/PC60-7B KUSS106-03.pdf http://www.w-equipment.com/machiner...luaWdyYWFmbWFjaGluZXMvSFIyMC5wZGY=.pdf/32803/
The brochures show the Terex having a swing boom, the Komatsu a standard fixed boom which makes the boom longer, mounts back over the ring bearing, so yes I would think the geometry is enough different to explain the different specs.
That's what I figured, my question then I suppose is it something I'll notice, and is it a severe disadvantage to have the boom up front on a swing like that? thanks
Well, the boom swing is pretty handy if you need to dig next to obstacles like trees, fences, walls, etc. You offset the boom and you dig right up next to and inline with let's say a retaining wall, and have sufficient swing to sidecast the spoils or load out. On the other hand if you don't foresee needing that feature, the standard boom will be more rigid, have fewer places to loosen up and as you see better straight vertical digging ability. Just really comes down to what kind of work you foresee doing. If it's pretty much just normal excavator work I would go for the straight boom over the swing boom, but that's just me. Hopefully some more experienced owners/operators will chime in here with some opinions.