WFTF Target Checker
World Field Target Federation target checking device, plans source code and instructions for manufacture and assembly.
The aim of this project is to provide a means of manufacturing a device that can be used safely to test the operation of knock over style Field Targets during a competition so that target disputes and stoppages can be kept to a minimum.
The device is designed to give an equivalent impact force to an airgun pellet hitting the paddle of a target at 5.5 ft/lbs energy (7 Joules). To mimic the effect of a target being shot at with a WFTF legal air rifle at 55 yards.
Brian Samson demonstrates the device:
Printing
There are 8 parts that need to be printed, the STL files can be found in the STL directory. All dimentions are in mm and the parts are oriented so that no support structures are required.
For best results the parts should be printed in PLA/PHA filament (ColorFabb recommended) The Left and Right hand Cylinder parts may be prone to some curling on the edges and as a result it is recommended that they are printed individually.
Suggested printer settings
- Layer height : 0.12 mm
- Nozzle size : 0.4 mm
- Print speed : 50 mm/s
- Fill Density : 25%
Assembly Instructions
Non-Printed parts required :
- 4mm diameter mild steel bar (140mm long)
- M3 Nyloc nuts X 8
- M3 x 30mm Cap Head Bolts X 8
- Small spring - 10mm x 5mm
- Main spring
- 12.7mm OD
- 1.25mm Wire
- Stainless steel
- 140mm long
- Rated at around 4Nm per cm of compression