I am surprised that these issues are occurring. I chose this drill because it was meant to be a tried and tested design! When these tabs break are you able to carry on drilling, or do you have to go back to the workshop to do some welding? Don't fancy traipsing back and forth from farm to field every time one breaks. Have just found out today that two of the four wheels are off at an angle due to some frame geometry problems...
Ive been pretty surprised too. Most stuff has now been resolved, but will post an update when we've actually used is properly.
Just a quick note - we have had one of our rear wheel rims replaced as it was welded out of true. It looked like the axle or frame was bent, but fortunately it was just the rim.....id get them to swap the rims around before you go to town on the frame. (I was sure it was the frame/axle too)! There are 2 types weights of wheel BTW, the 6m takes the "13" weight wheel, and the smaller ones "10" weight, I believe. (They sent the wrong one originally).
Good luck,
Tim