APPENDIX B ■ APPENDIX B
Finishing the Coupler
The cross axle slot on the printed coupler is the right shape and a tight enough fit to hold a Lego cross axle
without adhesive (see Figure B-11). Not only is this more attractive than the coupler in Chapter 20 , but the
cross axle can be forced out and replaced with one of a different length if needed.
Figure B-11. The Lego cross axle fits snugly without epoxy
Figure B-10. Tapping threads in a 3D printed coupler