Self Steering Build

I’ve been working on the self steering system quite a lot over the last few weeks.  It is taking quite a lot of time to build!

I have built the adjustment dial and corresponding lever out of 10mm RG1000 (recycled ultra-high-molecular-weight polyethylene) sheet.  This involved drilling 60 holes (giving 6-degree adjustment increments) and then finishing the slots with a knife:

I shaped the trim-tab rudder out of 18mm exterior plywood:

The wind vane is 3mm plywood on a hardwood stem.  The base of the stem is mounted in a block laminated from several sheets of plywood.   I have left the vane a lot larger than the original, but will probably have to trim it down to clear the transom and pushpit.  I don’t have access to the boat right now, so I’m not sure of the measurements.

I painted the whole wind vane assembly in white gloss.  The original Quartermaster vanes had  the stem part varnished, which would have looked better but would have taken a lot longer to make and would have been annoying to maintain because the vane is glued and pinned into a slot in the stem.

I started out using some water-based gloss paint but the brush marks were terrible so I switched to a spray can that I found in the shed.

Self Steering Part 1

I am attempting to build a wind-vane self-steering gear based on the “Quartermaster” design from the 1960s.

This is probably the simplest class of self-steering gear: a trim-tab on the main rudder actuated directly by a vertical-axis wind vane.  It was designed for a Folkboat, which our boat was derived from, so hopefully it will work on Lizzie.  This report from 1966 includes a description by the original designer, H K Wilkes who seemed very pleased with the performance.

One of the nice features is that it all just clamps onto the rudder stock, so you can remove it when you don’t need it without leaving lots of ironmongery sticking out of the back of the boat like most self-steering designs.

I’ve come up with a design based on the above report and two photos that I found on the internet.  I’m having to guess all the dimensions and some of the inner workings, so I expect that it might require a few iterations to get right.

So far I’ve ordered the following parts:

  • 10mm diameter 316 stainless rod for the main shaft
  • 25mm x 1.5mm square-section aluminium tube for the shaft housing
  • Plastic end plugs for the housing, which I’m going to drill out as shaft bearings
  • A sheet of 10mm RG1000 plastic for the adjustment dial
  • Fibreglass to cover the water vane, which I’m going to carve out of plywood

The plastic arrived yesterday and I’m now waiting for the other parts.  I just received a very unhelpful text from Fedex saying that they are going to deliver something today, but no indication of what, when or from whom.

In case it is useful to someone trying to Google Quartermaster wind vanes, the “Building Your Own Vane” section on this page is basically describing a Quartermaster vane without using those actual words…