November 12th, 2009

Remote Windage Adjustment System for F-Class Rests

We saw an interesting gizmo on Peter White’s front rest at the recent California Long-Range Championship. Peter, who won the F-Class division, has fitted a remote drive system that allows him to adjust his Sinclair windage top without moving from his shooting position.

Remote Windage Adjustment drive

The windage control cable (actually a McMaster-Carr flexible drive shaft) attaches to the right side of the windage top in place of the regular adjustment knob. It then circles back to the shooter, and is clamped at the end of the pedestal leg (near the vertical adjustment speed screw). A large, knurled knob is attached to the end of the flexible drive.

Remote Windage Adjustment drive

Remote Windage Adjustment driveWith this set-up, Peter can adjust windage easily with his left hand, while keeping his right (trigger) hand in place on the rifle. In addition, he can fine-tune his vertical using the rotary knob (speed screw) on the threaded shaft for the rear-most rest “foot”. The flex-drive adjustment system places his windage control right next to his elevation fine-tune control, so both windage and elevation controls can be manipulated with the “free hand” from the shooting position.

Peter fabricated this system himself from less than $60 worth of parts. All you need is a McMaster Carr flexible drive shaft ($50-$60), an adjustment knob at the shooter’s end, and a small bracket to hold the adjustment knob securely.

Many F-Class shooters have fabricated a similar remote windage control system. If you have basic mechanical skills, you can build your own system in a couple hours (with the correct parts). Or, Leroy Johnson of Johnson’s Precision Gunsmithing, jpgrifles [at] yahoo.com, can build you a working system, if you send in your windage top. Leroy explains that “the various windage tops all have slightly different configurations, so the price depends on how much special work is required.”

Peter’s Parts List and Tips
Peter White offers some advice on building a remote windage control: “The parts were obtained from McMaster-Carr, www.mcmaster.com. The flexible drive shafts come in various lengths and diameters. When using the smallest diameters in this application the bend radius is critical as the cable wants to kink in one direction of operation. The tape you see on my rig covers a couple of stiffener rods. I have seen others using a longer cable with a larger bend radius with no need of a stiffener. Others have employed jacketed cables that have a much higher torque rating (but also much higher cost).”

Products Needed (Total = $49.31)

Part Number Description Price
3127K22 Panel-Mount Flexible Drive Shaft, 18″ Overall Length, 0.130″ Shaft OD $42.31
2577K18 Stainless Steel Knurled-Rim Knob W/Set Screw, 1/4″ Unthreaded Through Hole, 1″ Diameter $7.00