Crossbow Trigger Mechanism (simple But Sturdy)


Today we make a trigger/lock mechanism for a rather powerful crossbow, would also work for BB guns though.
Both of my BB guns use this design. And here we go:

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Step 1: Templates, Material and Tools


- Screwdriver

- Dremel rotary tool + cutting wheel

- Jig saw or small metal saw

- Pair of pliers


- 5mm Alu plate (scrap metal or wood), for a stronger bow, alu or brass

- 2-3mm Alu (for the base plate and cover)

- Tension-spring (appr. 20mm, 0.5 to 0.8mm wire-thickness

- 4x 5-8mm screws (2 holding the spring and 2 as stoppers) M3 will do

- 5x 12mm screw (for mounting the 2 trigger parts plus cover-plate)

- 6mm plastic spacers (or metaltubing, scrap-wood or whatever)

- M3 nuts

Step 2: Instructional-video and Fabrication-steps

1. Print 2 baseplates and the other 2 parts on paper, then use a scissor to cut them out

2. Transfer the outlines to the metal, then mark+drill holes (3mm for M3) and saw out the 4 parts as shown

3. Attach the tension-spring as shown

4. Screw in the stopper-screws

5. All other screws into the flipped coverplate, spacers on, make sure the 2 lock parts are where they belong

6. Screw on the M3 nuts, check if there is enough room for smooth operation, and its done.

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    7 Discussions


    4 months ago

    great design! can you share the sketch with dimensions? thanks!


    1 year ago on Step 1

    Hi Can I know the exact dimensions of the required size of the trigger like the picture


    1 year ago

    Não consigo fazer o download em PDF


    3 years ago

    One of those projects I've always wanted to do. Unfortunately I always have too many other projects taking up my time. One of these days maybe I'll get to it? I still have a bow I need to restring.