Mounting pad for wooden seats

My problematic chair has a solid oak frame but the seat is made from a relatively thin plywood. The seat is mounted using four sheet metal angled brackets to the frame, with only a single wood screw into the plywood seat. This screw constantly works itself loose from the seat.

This mounting pad brings three angled screws into the plywood together with an M5 hex head screw that can be mounted to the angled bracked using a nyloc nut.

Required:

• 1 pcs M5*10 hex head screw
• 1 pcs M5 washer
• 1 pcs M5 nyloc nut
• 3 pcs 3 mm flat head wooden (self tapping) screws

Printed in PETG, 15% infill

The files are slightly updated, compared to the pictures. Screw angle is now only 30 degrees to the normal to simplify mounting into the wood.