Puckers usually are caused by how tight the quilt sandwich is put together. I would look into spray baste instead of pins for sandwiching the quilt before quilting. I had the worst trouble keeping puckers out before I went that route. Since then I've purchased a mid-arm machine on a frame. If you're wanting a sit-down sewing machine for quilting - look for one with the largest throat space as possible. I've used a new Babylock and an old 401A Singer - both did fine.