Basics of Crossbow
Various manufacturers are attracted to crossbow design over the past few years. The crossbow design can be made simple through the path of least resistance. A strengthening flank is covered on both sides of the stock of crossbow. The combination barrel is served by the aluminium assembly which is flat. The nose of the forestock is set with the bow or prods and to its right and left flank pieces, ¼” plate steel is pinned. On the both sides of the shoulder extension, the walnuts stocks were trimmed and inserted. There exists friction as the barrel comes in contact with the string. Hence, shoulder slides are added to the both sides of chase so that string wear is reduced and bolt velocity is increased. Delrin could be used to serve this purpose as it has inherent llubricity.
The open sights of crossbow consists a strap made with aluminium and the receiver is mounted with an alloy rear ring. Each of these brackets is threaded with head cap screws so that sighting beads are provided. The rear unit is either raised or lowered according to the requirement of specific range. We cannot use telescopic rifle sight on a crossbow mainly because of three reasons.
1. The effective range of weapon is limited to fifty yards and hence an expert hand or practiced naked eye is required
2. A trajectory of 15 yards or more is sufficient to reduce the point of impact from line of sight. This adjustment range is restrictive or is a tedious process.
3. The field of view is narrowed and there is a chance of increment in weight
This articles addresses with two different crossbows- one is easy to assemble and can serve as a target piece, second is for multipurpose and has many features suitable for “range shooting”.
Step-by-step procedure of building crossbow
This procedure outlines the simplest way and safest way of building crossbow. One should be careful in cutting the aluminium stock and scribing the outline. The first step is to join all the pieces and this step will take a considerable amount of time with the file. Care should be taken while designing trigger guard which is considered as the centre spine’s weak spot. It should be made such that it is not thinner than 7/32”. The parts can be trimmed using a band saw which comes along with a metal-cutting blade. After making the sockets ready, the aluminium centre spine is clamped with one of the flanks and the alignment is rechecked with the help of a template. The corresponding holes must then be drilled into the flank piece.
6×3/4” screws must be used for locating pins temporarily and the second flank piece is then clamped again. Make sure that all the three pieces are mated evenly and then drilled. In order to make the steel trigger components to move freely within the stock, they should be thinned by 1/64”. Drillings must be made at pivoted pins in the left and right flank pieces. In order to drill them accurately, a trigger-housing template must be used. According to your requirement, you can also install a safety mechanism which can be set into slots that are cut through central spine.
The inner surfaces of the barrel must be bevelled before assembling the stock and the edges are rounded. Roughing can be done through a file or a grinder and emery cloth can be used for smoothing the metal. The extra-fine polishing must be saved for future purposes after pinning and bolting. The next process in the making of crossbow deals with setting the bolt tang to which wooden slides are added followed by cutting, fastening and shaping.
Photo source: http://www.burlingtonfreepress.com/story/sports/2014/10/25/crossbows-spikehorns-may-store-deer-hunters/17944357/
The front piece of crossbow is bent into a frame according to the configuration in order to make the bolt to pass through it. A short cap screw acts as a bead and machine screws are fitted on the top of the forestock. The screws can be adjusted up or down according to the sighting range. A lighter bow must be made to increase the string life of crossbow and a cocking lever is needed to pull into the intended position. In the stationary part of the lever, a pair of slots is fitted into the forestock of crossbow.
A prod is held by an aluminium block which is fitted with hard rubber strip. Another prod is fitted to the rear side of the socket that provides additional cushioning. The metal block is fitted tightly with a cap screw which is threaded into a hole at the nose of stock. After installing the prod according to the instructions, you can enjoy the pleasure of stringing it. Bastard string along with Dacron cable is suggested for muscular men and this string can be easily slipped onto the prod. This completes the making of crossbow.