Sewing Seam Allowance Marker

This is a seam allowance marker that I drafted for sewing patterns so that you can add in a seam allowance from 3/8" to 1 ¾".  Other seam allowance markers are usually in mm and I needed to make one in inches.

You will need 3 M3 screws (1 is 8mm, 1 is 12mm and 1 is 16mm), 1 M4 (yes M4) washer and at least 2 M3 nuts (you can add additional nuts to the screw holding the slide and the dovetail together to make it easier to turn without using a tool).

The M3 screws I used were allen hex head to give more space for grabbing the head of the screw and turning the screws by hand.   One M3 nut can be added to the small opening next to the pencil hold and you can screw the M3 x 12 through the side screw hold and through the inserted nut to hold a pencil/pen.  Use the M3 x 16 screw and the M4 washer (yes M4 so that it is large enough to cover the entire hole) to go through the screw hole in the slider and into the dovetail.  Then you can slide the dovetail into the main body.  The final M3 x 8 screw is used to hold the wheel in place with the second nut to hold it in place.  Don't tighten the screw too much or the wheel won't turn easily.

In order to make it easier for my wife to turn the screw to loosen the slide to adjust the width of the seam allowance you are going to mark, I added 2 additional M3 nuts (not listed above) to the M3 x 16 screw that goes through the M4 washer, the slider and the dovetail.

Attached is a 3mf project file exported from Prusa Slicer with organic supports set up for the slider.  All other parts do not need supports.  Here are the settings I used:

Print Settings:

0.20mm Quality

Organic supports on the slider only

15% Adaptive Cubic infill (you can use any infill type you want)

Hardware:

M3 x 8 allen hex head screw (quantity 1)

M3 x 12 allen hex head screw (quantity 1)

M3 x 16 allen hex head screw (quantity 1)

M4 washer (yes M4 so that it will easily cover the slide screw hole)

M3 nuts (at least quantity 2, I used a total of 4)