Making a Custom Crossbow Cocking Aid

Over the past ten years the modern crossbow has increased tenfold in popularity. Much of this upsurge is due to conservation departments relaxing the regulations governing their use. Modern crossbows shoot arrows at velocities of more than 300 fps but such power requires bow peak weights exceeding 150-180 pounds pull weight. Hunters line up at sporting goods counters seeking that magic bow only to find out they don’t have the strength to cock it.

Cocking aids are available in the form of hand crank for some crossbows or rope cocking aids in one form or other. The ensuing problem is many of these devices fail to work properly. This is exactly what brings some archers to my gunshop. Here I shall site a recent case where making a better crossbow cocking aid was the best solution. The customer purchased an older model PSE cross- A string cocking aid is common. bow with no provision for a handcrank or standard rope cocking aid.

This crossbow also lacked a provision for an optical sight, a problem I addressed in the July 2011 issue. All rope cocking aids reduce pull weight by 50 percent and make it possible for many older and disabled hunters to continue hunting, so I looked into the possibility of making a workable cocking device to fit this older PSE crossbow. The hooks are stainless steel, bent, curved and polished. The assembly is completed with tool steel axles and pulleys.

The twist allows the pulley to be at right angles to the hook and clear the cocking mechanism of the bow. The T-handles are attached at correct length for the crossbow. Special Cocking Device There are certain mechanical issues that must be dealt with as a crossbow is cocked under great force. In using a rope cocking aid a pair of hooks are attached to the uncocked bowstring. These hooks are pulled with a rope via a pair of pulleys attached to the hooks held by a pair of T-handles.

The rope is then looped around an anchor directly to the rear of the crossbow cocking mechanism. As the hands pull evenly on each handle, force at the laterally opposing hooks draws the bowstring toward the bow’s cocking mechanism. A problem often arises where the rope cocking aid hook and pulley mechanism doesn’t reach freely past the bowstring cocking slot and safety lever. Each crossbow model is somewhat different as are the rope cocking mechanisms.

In some cases there is a mismatch of parts under force and this can damage the bow, the rope cocking mechanism or both. In the case of the older PSE crossbow brought to me, I designed a very different type of hook and pulley system that pulls the bowstring smoothly into the sear and trigger without a hitch. I still used the hook and pulley concept, but in an entirely different way. I began with a fl at piece of stainless steel 1/8" x 3/4" x 3".

The key was making a half-twist in the center of the fl at piece of steel and using a halfinch wide fl at nylon strap in lieu of the commonly-used cord to pull the bowstring. This required a small, fl at pulley at one end and a hook at the other end of the cocking mechanism. The 1/2" diameter pulley is attached to the clevis end via a 1/8" tool steel axle. The axle is attached with silver solder at the corners.

All corners and edges of the entire piece are rounded and smoothed to prevent cord abrasions or part binding. As the shooter pulls the handles, cocking pull force is reduced by 50%. Note how the nylon tape is hooked back around the cocking mechanism of the crossbow receiver. The secret to this design is the halftwist in the fl at steel, which guides the hook and pulley assembly smoothly past the bow cocking mechanism aided by the surface of the fl at cord instead of a thin rope or cord.

This concept worked equally as well on a few other crossbows, cocking them with ease. The captioned photos quite clearly show how this special cocking device is made and used. Conclusions If a vital piece of equipment can rescue an otherwise unusable crossbow for an elderly hunter, it is likely worth the effort. If the crossbow has an optical sight, a stock and trigger, the gunsmith should stand ready to work with it. AG