Mounting the Autohelm 4000 rudder sensor
I have not actually used my autopilot yet but mounting the sensor was no problem.I used a jigsaw to cut a tapered piece of 1/8" alloy plate approx 8" long, radiused at one end for the sensor base ( and drilled accordingly for the screws) and with two holes at the other end to match the two 3/8" studs that protrude down from the rudder top bearing housing. Note that the two studs on the port side on my boat are not parallel to the boats centreline on my boat and the end of the plate needs to be "skewed" to accomodate this offset. I suspect that every boat is different here and that you will need to shape the bracket for your own boat. 1/8" alloy plate is easy to shape with a coarse 3/8" round file so on-boat modification is simple.I then had to bend the bracket twice to get a 3/4" offset between the end in order to get enough clearance between the top face of the steering quadrant and the mounting face of the bracket, which is the bottom face, because I mounted the sensor upside down. This is permitted in the manual.I have a 6" vice, a large hammer and a block of hard wood which made bending simple enough.I then bolted the bracket under the two studs, using suitable ss washers for packing. One day if I get bored I will mix some epoxy putty and bed it properly, as the fibreglass surface is not very even, but in reality there is very little stress on the sensor.I mounted the nylon ball joint on a small piece of alloy plate that fits under the two existing but unused 3/8" machine screws at the back of the quadrant. The nylon ball joint sits just outside ( aft) of the two machine screws, which are 2 3/4" apart.The sensor is mounted with the arm trailing aft (in its centre position) so the threaded link rod runs athwartships when the wheel is centred.It will save you time if you clearly mark the sensor body and arm when the arm is centralised, as trying to do this with the moulded in marks on the unit when you are lying halfway through the access door in the rear bunk is not easy. I found it easier to completely remove the access door and its frame by removing the 4 screws securing the fram to the bulkhead.All you have to do then is cut the threaded rod to length and don't forget to reverse the sensor wires on the back of the control panel (because you have fitted the unit upside down, which effectively is back to front).If any one wants a picture or drawings I could knock some up.I will let you know how it works!CheersAl