Got a little problem here, and wondered if anyone had the same trouble. I have been taking my excavator proficiency test which goes a little like this. Dig a 20' trench 3'Dx3'W Make a 90 deg. trench adjoining 40' L x 3'D x 3'W Contining make the trench depth 5' with a 1:1 slope V-ditch for 40' finish with a connecting 13'x13'x 5' box at the end of the V-ditch. too easy. Heres the problem. Why the heck cant I keep grade on this!!! I'm out of the machine every time before i move and can't seem to keep from falling down toward my machine. I have to keep adding dirt which is making me fall behind on my times.:Banghead Heres the real puzzler. I was just screwing around with a mini ex 331 bobcat. Shot grade one time and followed it out without leaving the machine any more. Dead nutz. WTH!!!! ointhead Same with a combo. Never had a problem. One check of the grade stake and I had it dialed I carried grade. No worries. Some say it's an illusion with the rounded windshield. Thats my theory. Any else have problems like this starting out or is it just one of those machines that are hard to master?
I find shallow (3' is pretty shallow for most excavators) easy to overdig. Find some reference on the bucket, stick, whatever to use to keep it at ground level, I find that helps. I've even been known to dab paint or a piece of tape where I can see it.
Yeah I never shoot anything of mine until its all done. Anything within 15 centimeters with my 385 is grade. Im usually under 10. It's all about the reference points. Tip of teeth to start of bucket is 55 centimeters. Top of bucket is 200 (2m) centimeters (half it for 100cm/1m). First bucket pin is 2.5m, linkage pin is 3m and aux hydraulic block is 3.5m. Anything inbetween you just look and go oh well 2m is here, so 180 is 20cm less then that...
What I've found helpful when grading a trench with little fall is to put the Bucket flat on the bottom. start where you know where the grade is good and just slid it towards the machine while keeping the bucket flat on the bottom of the trench. As long as you keep the bucket flat you should not slope it down as you pull towards the machine. It works for me. usually once I get a 10'' section done I can just eye ball the remainder pretty good.
I agree with dirtman on the bottom of the bucket. I also pick a spot on the stick according to the depth of the trench and grade along like that it's usually pretty close, but on occasion I will get a little crazy and go too deep, then put too much dirt back in, then take too much out.......times like that require a 5 minute brake or the situation usually escalates into a real mess