Circle router jig for Bosch GKF 12V-8

Hello,  

A Bosch GKF 12V-8 is a little bit challenging for milling a circular holes. None of the jigs for circles fits it. Therefore, I designed my own jig. The input requirement was a wide range of radius - usable for small tweeters and 15" woofer without any modification or new parts. Also, should be printable on 220x220mm buildplate and stiff enought to prevent wobbling.  

The distance between center pin and the center of the spindle is min. 52mm max. 454mm  (+/- 1mm).  The exact diameter is related to mill size so its better to write a spindle-pin distances. 

The construction consist of 4 parts : 

Jig - back - ( circle jig_plate2.stl )

jig - front - ( circle jig_plate1.stl )

jig - nut - ( circle jig_plate1.stl )

jig - pinholder - ( circle jig_plate1.stl )

For circle jig_plate1.stl must be generated a support touching a builtplane. For circle jig_plate2.stl is not necessary. 

The original pad on router is attached via 5 pcs Torx screws. The jig is designed to use those screws for attaching to the router. 

For connection pinholder and nut you will need : 

1pcs M6x25 metric hexbolt 

1pcs M6 nut

I used broken 3,125mm mill as a center pin. Feel free to use any pin with 3mm diameter. 

The pinholder can be used in three setups :

1) pin in a hole closer to curved end - facing towards spindle  - allows to mill small radius (approx. 48mm) to medium size radius (approx. 280mm)

2)pin in a hole closer to curvedend - facing towards outside - allows to mill medium radius (approx. 103mm) to medium size radius (approx. 220mm)

3)pin in a hole closer to plain end - facing towards outside - allows to mill radius (approx. 118mm) to big size radius (approx. 235mm)

Printing settings : 

0,4mm nozzle

0,25mm layer height 

10% infill

Silver PLA Devil Design

5 Perimeters

3 Solid layers TOP/BOTTOM