Steering - Base Mount - Angular joint design

Steering - Base Mount - Starboard

ATR5-b1′s steering is actuated by a 1.5hp retrofitted winch. A previous post detailed the steering requirements [120lb-in torque, 540 degree total rotation] and the winch spool mount [wherein the spool is bolted to a rectangular aluminum assembly which is in turn hose-clamped to the steering wheel].

The winch base — containing the motor and planetary gearbox — must be affixed to the chassis framework to provide the leverage to actuate the steering wheel. Moreover, the winch must be positioned at a precise height and angle (stern 28 degrees below the horizontal plane) to properly engage with the spool gear. Tri-joints can only produce right angles (90, 180, 270, 360 degrees). As a pair of points define a line, one solution is to affix an angled rod extending from the winch base to the framework at two points. The first point defines the height and, for a fixed horizontal distance between the two points, the height of the second point defines the angle.  The (crude) design drawing [above right] depicts the design [starboard side view]. For a given vertical error in hole position, the angular error will be inversely proportional to the horizontal separation; this is why the framework mounting rods are separated by an extra 1/2″ rod. The machined reality is pictured as well [above left].  The complete steering assembly, as successfully tested, is pictured at various angles below. Note that this assembly lacks the position feedback that will be required for proper automation.

Steering - Base Mount - Isomorphic (Starboard Stern)

Steering - Base Mount - Bottom

Steering - Above Bow