Y seams not withstanding . . .i used to struggle getting 1/4" seams . . .tried various feet, etc. then, an experienced piecer pointed out, it could be my thread and machine needle. Sure enough, my needle was too large . . .it displaced the threads in the cotton weave . . .and my thread, too thick, was keeping the cotton weave displaced by filling the gap the needle made.
I switched to Schmetz Microtex 70 needles and 50wt Aurifil thread and my seams have been spot on since.