This flyscreen is made to clip over the gasket of your portlight. Its designed in two halves with alignment pins and holes. So you can fit a generic flyscreen in between the two halves. And glue them together with ca glue.

For a oval portlight with the size: 103mm x 313mm

Assembling:

• Cut a over-size piece of flyscreen fabric to fit the 3D printed parts
• Fit the screen on the half with the pins. And clamp it down with some binder clips.
• Glue the screen on the part by placing a couple dots of ca glue on the screen and press it against the part.
• Make sure the alignment pins are sticking out trough the flyscreen grid. With no fabric on the pins. Otherwise cut the tread between the grid that is on or over the pins. 
• Place some ca glue in the holes of the other halve of the assembly. And trace the contour of the part connecting the holes
• Clamp the two part together with the binders clips or some clamps.
• After the glue dried, cut the excess screen off.

Note:

If the print is to big for your printbed slice the print perpendicular to the straight sides and in between two alignment pins/ holes.