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Fine grading with gps


Senior Member
Mar 11, 2007
Waverley NS/Fort Mac AB
Reading this with interest..haven't been on here for awhile..been quite busy of late. I operate a 140 m cat grader with a trimble system. Now and then with the auto on both sides, the blade will jump..but I find this happens when there is less material on the blade. I also find this happens when you are going for example in second gear...just idling along. I find the higher you keep the rpm's the less bouncing\jumping the blade will do.
Now, I am leveling crushed gravel on the Trans Labrador Highway, doing the finish grade. I will level and trimble a section..I always leave a small windrow on the left side of the road after its all to grade...then I will tilt my moldboard all the way forward and brush this windrow from the left side to the right side of the road..this takes all the little washboards/etc that your auto had caused, leaving a smooth finish. Now I have question for you trimble experts...why do I leave the windrow on the left and bring it to the right instead of vice- versa?? Hint: my mast is mounted on the left hand side of the moldboard....lol

Workin for dexters now?


Oct 28, 2012
grade foreman
new to the site here....when you set down on your bench elev. in the morning to be sure your good there...do you also check to see if your slope cross in accurate? you should have to run manual on either side thats the whole point of the system.It may not be real accurate but I use a 4' level and check my machine cross slope and if it's off I rebalibrate.But with 8500 hours thats a lot of hours for a finish machine


New Member
Mar 31, 2024
i wonder if the valve speed is too high, over corrects itself instead of correcting the problem, that would explain the duckwalk, i run both sides on auto with the 140m no dramas at all. thats using uts.
Have you ever benched out both sides of your blade with uts ? Thinking of trying it