Candyman,
I build a shaft for the AT Pro -- a complete shaft, with an upper that can be made "counterweight-ready" (i.e., a threaded fitting installed in the butt end that allows one of my counterweights to be attached). That counterweight, I'm nearly certain, would really help, with your achy elbow. The reason I say that is, your "achy elbow" is likely tendonitis, similar to "golfer's elbow" or "tennis elbow." And that form of tendonitis is often caused by "repetitive motion" (swinging a golf club, or tennis racket, or metal detector), COMBINED with tight grip pressure. And what is the cause of the tendency for tight grip pressure on a detector? The cause, is the fact that the machine is NOSE-HEAVY!
When a machine is nose-heavy, you must fight to counteract that nose-heaviness by applying force with your hand and wrist, a "torquing, upward-directed" force that you exert to lift the coil and keep it floating. And so, the more nose-heavy the machine is, the more force you need to exert, and the more force you try to exert, the more you tend to grip the handle of the machine tightly -- and hence, tendonitis can eventually begin to flare up.
The cure for tendonitis is rest, and then to keep it from recurring, you need to reduce your grip pressure. And the best way to reduce grip pressure is to balance the machine, SO THAT your hand/wrist are not having to lift the coil, but instead you leave that job (lifting the coil) to the COUNTERWEIGHT. Think see-saw, or teeter-totter. If you have weight (a child) that needs to be lifted at one end of the see-saw, you simply place weight (another child) on the opposite end of the see-saw. In a rough/rudimentary way, that's relatively analogous to what counterweighting does for you, on your detector, to lift the coil. You can achieve somewhat of the same effect with a harness (i.e. letting the harness help lift the coil), but to me, a harness is cumbersome and restrictive. That's why I feel that counterweighting is the better option.
Make sense?
Steve
