Flexture Joystick Bipod

This is a novel design for a printable joystick bipod that utilizes compliant mechanisms (flextures) for movement control.

Design

The mechanical design of the flexture allows for fine grain control of vertical and horizontal movement via the joystick while minimizing rotation and forward-aft movement. 

Course height adjustment is done via a captured nut mechanism between the legs. A 180mm screw with 120mm leg segments will allow for 100mm of height adjustment (minimum height of 160mm and a maximum height of 260mm).

Friction and backlash in the movement control system is very low due to the use of compliant mechanisms. The flexture mechanism is also biased such that the joystick will be centered within the movement region with ~10lb attached to the top of the bipod.

The design includes two risers for a 17S footprint adapter (eg. Area419 ARCALOCK clamps): 

1. Version A is a two part design that that “clamps” around the flexture to reduce forward-aft movement, at the cost of additional friction.
2. Version B is a floating design that adds no additional friction to the design.

Does it actually work?

Yes, with caveats. Not recommended for competition use unless you can improve upon my design.

Pros: 

• The flexture mechanism works amazingly well and is extremely smooth with roughly 8 inches of both vertical and horizontal range at 50 yards.
• Effectively zero backlash in the joystick.
• Very lightweight assembly at only 1.2 lb, including the ARCA mount.
• Total cost of ~$100 (the ballscrew can be replaced with a lead screw).
• Both the movement range and joystick stiffness can be customized as part of the design.

Cons:

• The base of the bipod does not move with recoil, so it essentially pivots where it stands. Forward and rearward movement therefore changes the point of impact. This makes it impossible to shoot free-recoil. Version A of the riser was intended to address this, but the extra friction caused the joystick to stutter.
• The flexure mechanism still allows for a bit of rotation. This is useful as the design doesn't allow for individual leg height adjustment, but also means a bubble level or electronic cant indicator is pretty much required.

Bill of Materials

• (2) spherical bearings (12mm ID, 22mm OD, 10mm width) - $9 on Amazon
• (8) ball bearings (16mm OD, 6mm ID, 5mm width) - $12 on Amazon
• ~1000mm hollow carbon fiber rods (12mm OD, 10mm ID) - $46 on Amazon
• (1) ballscrew (10mm OD, 8mm ID, 3mm pitch, 180mm length)
• (1) M6 set screw (5mm length)
• (8) M6 bolts/nuts (20mm length)
• (16) M6 washers (to sandwich ball bearings)
• (4) M3 bolts/nuts (20mm length)
• (3) M5 bolt/nut (16mm length, optional, for ARCA mount and joystick joint)

Note: I have no idea where to source the ballscrew from, as I already had this one on hand that was savaged from somewhere a long time ago. If you modify the design, keep in mind that the OD of the ballscrew must match the ID of the hollow rods, and the OD the hollow rods must match the ID of the spherical bearings.