New (to me) pedestal and wheel

[gbraun]

Converting my Islander 32 from tiller to wheel. Was given an old pedestal and wheel. Began to disassemble the guts today, and am surprised at what I find. The axle that supports the wheel has a spocket, with chain, but the assembly also has a hollow rectangular "tube" hanging from it, that extends down most of the length of the pedestal, and a second sprocket!. See pictures attached. Can anyone tell me how this arrangement is supposed to function? I was expecting a top sprocket, with a length of chain, but not a loop of chain around two sprockets. Can't see how cables would attach. Until I took it all apart, I assumed that the rectangular thing was maybe a wiring channel. Also - can't see how to actually remove the axle for cleanup. Can't see how the sprocket can come off the axle. Has a set screw, but also a little knob that mates with it. See the picture. Any suggestions.?

[Rachel]

Do you know what type it is? If it's Edson they have quite a bit of technical information available from their website, including worksheets on tiller-to-wheel conversions:

http://www.edsonmarine.com/support/techsupport.php

Rachel

[earlylight]

My guess is that the second sprocket may get driven by an autohelm of some type.

[Hirilondë]

My Edsen pedestal has a sprocket on the shaft that attaches to the wheel just like in your picture. A section of chain goes over/around it and has lengths of cable attached to both ends. These cables go through the cockpit sole inside the pedestal, around shieves attached to the bottom of the sole and to the quadrant. I have no idea what the other components you describe are for. The auto pilots I am familiar with use an arm on the rudder post as the link between the motor/drive and the rudder. I would think using the steering as a link would add unnecessary resistance.

[Chris Campbell]

I can't tell for sure from the pictures, but it looks like the lower sprocket is attached to a pinion gear which drives the rack that is in the same picture with it - is that the case? If so, then The ends of the rack would have been attached somehow to the top of the rudder to drive it from side to side (cables, chain, mechanical attachment that allows for fore-and-aft movement or some other method). If not, I'll keep guessing!

[gbraun]

Chris - I think you could be right, there is a gear in there that's part of the lower spocket deal. No matter, I've figured that I'm just going to heave out the internal assembly, whihc will leave me with an empty pedestal with a spocket for chain/wire.