The prod is from the company Barnett. It is for the Commando or the Wildcat. The draw weight of the prod is not high particularly. The prod is in one piece, not in two pieces like most of the crossbows. I made the channel groove from steel, and likewise the trigger mechanism.
At the rear end of the channel groove is a stage, where the string is hung up. To releases a shot, the string is pressed upward. That is actually quite simple to make, and functioned also quite well. It is however not particularly careful for the string and I think that thereby the crossbow shoots inaccurate. You can see the details in the pictures further down. I am however on the search for a better alternative, therefore I made also this webside, and I hope that new ideas come.
In addition I am on the search for a prod (more power). Either a guidance for the building of or one to buy. In any case one should be it glass fiber or carbon fiber elbow, and no steel. If somebody has a tip, please send me an email.
To improve the draw weight, I made the draw lenght approximately 5 cm longer than with the crossbow of barnett. The difference of the Energie is enormous. The kinetic energy of the arrow has approximately 80 joules. The arrow has a speed of 70 - 80m/s depending of the weight. I calculate the speed with the application Arrowmatcher.
For cocking the crossbow I need however a cocking lever. The draw weight is approximately 80 kg. That is enough to shot thru a piece of wood, which is 3 - 4 cm thick. The crossbow shoots unfortunately inaccurate. At 10 m the arrow hit a circle whith a diameter of 2cm, depending upon arrow (longer arrows are more exact). And also only, if I shot always with the same arrow. I would like to improve that. I use the same arrows, as bowmen, where I cut the shaft. The nock do not have a slot for the string, it has simply a flat surface.
For the interested ones I made photos of the parts of the crossbow. The pictures can be clicked , to get it the large size.
stretched trigger mechanism. you can see the stage for the bow string
stretched trigger mechanism with unscrewed side plate, I think, you can recognizes the principle here very well
Trigger Mechanism in pieces
The side plate unscrewed
the trigger unstretched
A sketch of the trigger mechanism . The Lila dash line shows the mechanism after a shot was done.