i made a guide using several layers of red electric tape. i set needle on 1/4" line of drafting ruler and mark the line on the tape and the carefully slice thin strip til i have a clean, straight edge. care is taken to not scratch the needle plate. i want no adhesive of any kind on the black enamal portion of my machine deck. so, red tape is only adhered to needle plate which can have adhesive cleaned off if needed. over the years the adhesive becomes gummy or otherwise nasty & i remove all and repeat the process.