The right side twine knotter on my NH275 baler misses a bale every so often. The left left side knotter is almost bulletproof. I recently noticed the knife arm on the left (good) side has just a little play in it, but the right side knotter has much more play in it compared to the left. Could this be the source of the right side not tying as consistently as the left?. I did break down for $20 to buy a new roller for the right side knife arm but have not installed it yet. I am thinking the old roller may be worn and a new roller may eliminate some play. If this does not help (and a knife arm is not supposed to have a lot of play in it) what else can I look at to reduce play?