bow sander for bandfile sanding belts (18" x 1/2" & 13" x 3/8")

Compact manual bow sander for use with bandfile sanding belts, such as those from the Milwaukee M12 bandfile, Dynafile, etc.  It's pretty handy on delicate curved parts or when power might be inappropriate.  The belt is installed and removed without disassembly or tools.

Sizes available:

• 18" x 1/2" (457mm x 12.7mm)
• 13" x 3/8" (330mm x 10mm)

Printing & assembly:

• 4 walls, 4 layers top & bottom
• I used PETG but most filament types should be fine.
• Print out two copies of the same size frame.  Both sides are identical and the ends socket into each other.  
• Two M5 x 20mm screws and nuts are needed for assembly.  (The smaller 13" x 3/8" version uses M5 x 16mm screws).

BOM/parts:

• 18" x 1/2" sanding belts https://amzn.to/48BLoO0
• 13" x 3/8" sanding belts https://amzn.to/48BqxKK
• M5 screws & nuts kit https://amzn.to/48gaQZC

Usage notes:

• The belt slides into the slot between the two frame halves.  After both ends of the belt has fully passed the narrow slot, wrap one end of the belt around the end and then tension the frame by pushing the it against a solid surface and slide the belt on the opposite end over the end.
• In use, you can firm up the belt by tugging on the back/upper side of the belt.