Steering Systems
I anticipate that there will be various steering systems; tiller, tiller pilot (auto-helm), sheet to tiller, vane and emergency rudder.
Vane Self Steering
My plan is to use the vane system from Chantilly which needed some modifications after running it in and make a servo pendulum system as the rudder on Mischief is hung on a skeg so doesn't suit a trim tab.
If it looks familiar it is strongly influenced by my experiences with other similar system.
Vane Self Steering
My plan is to use the vane system from Chantilly which needed some modifications after running it in and make a servo pendulum system as the rudder on Mischief is hung on a skeg so doesn't suit a trim tab.
If it looks familiar it is strongly influenced by my experiences with other similar system.
A while ago I bought a solid oak door off ebay, after making a tool cabinet I still had quite a bit left over. The door was only 3/4" thick but took two of us to lift it into the car.
I planned one of the planks to make the pendulum.
There are currently four designs for the connection between the vane and the pendulum. These are drawn out in Visio and, if practical, built. So far design 1, bike cable drive to actuator arm with threaded rod push / pull arrangement, has been binned. I am on design number 2, cable drive directly to the pendulum aero-foil and this is looking hopeful, albeit that the wind vane will need to be relocated.
Bike brake cable drive is looking hopeful as a solution.
Redesign
3/2/2018, trial fit of steering on Mischief
Dry fit of the hardwood bracket was positive.
I re-wired the tiller pilot supply so this is looking like a viable option as well.
Final fit was OK, I thought that I had a near perfect fit but when I started to tighten things up there was a slight gap. Mastic sealed it and it seems to be very solid. Next will be to try the pendulum hanger.
Pendulum and Vane dry fit went well. Having the mast down
made things a bit awkward but I can fit and remove the gear whilst on board the
boat. There might be a problem with the starboard cable as it leads to the
outboard gear. Having a central strut in the push pit doesn’t help.
Hopefully the pendulum is long enough to allow some adjustment!!
First wet fit went well.
With 1/2 a knot of tide running over the servo pendulum blade a force of about 5 kg was generated at the tiller line connection point. This equated to less than 0.5kg of force at the servo drive point. This bodes well for trials but I will need to shorten the hinge swivel section to that it doesn't go into the water. Then I'll need to shorten the servo blade as it is far too long. The cable route to the swivel hinge section will need some thinking about as the port cable bending radius is going to be a bit tight depending upon the angle of the vane.
February '19 update
The oar and the hinge are just about the right size. Now the task is to work out the control lines. At this point there is string everywhere while I try and work out how to transfer the maximum power and scope to the tiller. I am veering towards using side arms to transfer motion from the base of the hinge to blocks mounted on the taff rail. Pictures to follow.
March '19 update
Slight adjustment to the oar and now the cable line-up. I tried the system out on Friday 1st March but there was almost no wind, definitely not enough to move the vane, let along the oar via the cables.
On Saturday the wind was too gusty to make much progress (or take photos) but the system did work up wind, albeit the course was far from straight. It looks like some damping on the vane is required and feedback to the oar. I'll consult the books.
First wet fit went well.
With 1/2 a knot of tide running over the servo pendulum blade a force of about 5 kg was generated at the tiller line connection point. This equated to less than 0.5kg of force at the servo drive point. This bodes well for trials but I will need to shorten the hinge swivel section to that it doesn't go into the water. Then I'll need to shorten the servo blade as it is far too long. The cable route to the swivel hinge section will need some thinking about as the port cable bending radius is going to be a bit tight depending upon the angle of the vane.
February '19 update
The oar and the hinge are just about the right size. Now the task is to work out the control lines. At this point there is string everywhere while I try and work out how to transfer the maximum power and scope to the tiller. I am veering towards using side arms to transfer motion from the base of the hinge to blocks mounted on the taff rail. Pictures to follow.
March '19 update
Slight adjustment to the oar and now the cable line-up. I tried the system out on Friday 1st March but there was almost no wind, definitely not enough to move the vane, let along the oar via the cables.
On Saturday the wind was too gusty to make much progress (or take photos) but the system did work up wind, albeit the course was far from straight. It looks like some damping on the vane is required and feedback to the oar. I'll consult the books.
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