My Pfaff Grandquilter 18.8 has been misbehaving - missing stitches. Checked all the usual - tension, needle, levels of the quilt and bars, ensuring the rails were spotless. The missed stitches were not consistently at one area across the quilt - sometimes near the left, sometimes near the right end. Always on the left/right axis, not the front/back movements.
Talked to my local vendor, and the new encoders have a spring-system that holds the encoders down on the rails. Also discovered that there are 'tires' on the encoder - 4 o-ring-type-thing-ma-hooties. Brought home new 'tires' for the encoder if mine looked damanged.
Back home, we took some bits apart to get to the encoder, took the encoder off. Examined the 'tires' - don't see any lint, threads or damage. But as he's taking it apart and then putting it back together, decides that maybe a low-tech solution might work ... something is needed to add downward pressure to the encoder to keep it in firm contact with the rails.
I had seen a spring kit on the interwebs that someone was selling a few years ago, no longer in stock and can't find any other references to it. The dealer is going to check to see if she can get some. In the meantime, we rigged up an elastic to try to keep the encoder with just a bit more pressure.
After everything was back together, stitched for two hours, not one single missed stitch!
Hooray for engineer farmer husbands - finding a way to fix stuff :)