Tag Archives: Hebridean

Maintaining the Hebridean

Last summer I noticed a few problems with my Hebridean self-steering gear. This post is a (belated) log of the things I did to fix it up, and may be of interest to other Hebridean owners.

The first problem I noticed was that the Hebridean’s trunk could collide with the fairleads I put in the mount to allow the steering lines to cross over (described in this video). This is a simple error of planning on my part, but at some point there’d clearly been enough force on the pendulum to split the mount.

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This problem will go away when I turn the mounting blocks upside-down (described below) but in the meantime it’s a fairly simple job to glue the mount back together. I also have quite a bit of spare oak planking from the Hebridean construction that I can use to replace it if necessary.

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You can’t have too many clamps!

The mount itself has developed a distinct curve. I’m not sure what’s caused this. There may have been a collision with my boat when I wasn’t around, or there may be some systematic pressure on one direction.

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The curve has affected the mounting bolts too.

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I haven’t done anything to fix this curve yet.  It doesn’t affect operation.

A much more serious problem is that the carbon push rod that connects the wind vane to the pendulum had split at both ends and come unglued from the plugs that attach it to the rest of the linkage.

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This is much less likely to be a problem with the later versions of the Hebridean, as John Fleming is now using cross-woven carbon tubes and supplies ferrules for the ends of the rods, as seen in this photograph of Emmelène’s mark 2 Hebridean.

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I fixed this using epoxy to re-attach the tubes, and then adding a whipping to keep the tube ends together.

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I noticed that the top of the push rod was colliding with the turret tube at the extremes of movement, and this may have contributed to the splitting. This was easily fixed with a few washers, but it does show that it pays to watch all the parts of your self-steering gear as it operates.

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A much less serious problem is the mascot. I bought a “pen topper” in the form of an RNLI lifeboatman’s head from an RNLI shop, and he’s been sitting on the end of the vane’s connecting rod for some years. For some reason, local birds have decided to eat his face!

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Unfortunately, this item isn’t in the RNLI shop any more, so I’m on the look out for a new mascot.

Here’s a problem I have not yet fixed. The weight of the Hebridean rests on a pin that keeps it floating on the blocks that are clamped by the mount. This forms a bearing that wears at the pin when the Hebridean is steering. A few months of use and the pin looks like this:

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Emmelène‘s Hebridean has a two-part solution for this. Firstly, he has a HDPE washer between the pin and the blocks. (HDPE is what plastic milk cartons and chopping boards are made of.) This more or less eliminates the wear. But an extra clever thing is that his blocks are mounted upside-down from Tammy’s, so that the top edge protrudes from the mount, making room for the washer. Here’s Tammy Norie’s mount (during fitting).

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And here’s Emmelène’s mount.

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Simple and effective. I’ll be copying this arrangement on Tammy. It will also eliminate the collision between the Hebridean’s trunk and the fairleads that caused the mount to split.

I hope this is of interest, at least to other Hebridean owners. I welcome comments!

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Filed under Repairs and Modifications, self steering

The worthy Hebridean

Two years on from building a Hebridean self steering system, I talk about the latest modifications, and show how well the system is working in practice.

9 Comments

2017-09-01 · 19:53

The Trials of my Hebridean

I have finally edited the video footage of my various trials of my Hebridean self steering system during and after my Netherlands cruise. This is a system I built over two weeks in July. Here’s the result.

Here are a few things I mention in the video that are worth repeating.

  • When I set off, my Hebridean was not complete and I had no experience with wind vanes.
  • This is a story about my Hebridean on my boat.
  • Very small boats and junk rigs may require mods to the plans.
  • I should have spent more time experimenting with the bungee.
  • Don’t copy me until you have tried the system according to the plans.

Thank you everyone for your help and support with this project. Special thanks to John Fleming for showing great patience when dealing with me. Paul Thompson for keen technical insight. And Stephen Crowther for useful observations and support.

I’m sure the story’s not over yet, but part one is complete.

9 Comments

2015-09-14 · 21:42

Neaped

I went out for a day sail on the Deben with my friend and housemate on Sunday. It was a pleasant and relaxing day with gentle north east winds. A good job too as we were both a little, er, tired from a party the night before. High tides were at 06:00 and 18:30, so we rode the tide out into the sea and then back home.

The sea was smooth and the winds light, so I tried my Hebridean with the unbalanced pendulum in the light wind conditions.  It worked fine, as long as there was enough wind to fill the sail.  I’m still surprised.

We passed Tide Mill Yacht Harbour at about 17:30 and deliberately grounded about 6m from the dock that Steve Crowther has generously lent me just to the north.  While we were tidying up the boat I gradually paddled her closer and eventually retrieved the mooring lines with the boat hook.  We then pulled her in tighter to the shore as the tide rose, in order to get an accurate time when we could bring her alongside the dock.

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The answer was 18:26, almost bang on the day’s high tide of 3.5m.  This tallies with my earlier estimate that the mud there is 2.8m above chart datum, adding Tammy Norie’s 0.6m draft gives 3.4m. I suspect her draft is a bit over 0.6m with two people on board.

This means that Tammy is unlikely to get off the dock on days when the high tide is less than 3.5m at Woodbridge.  For example this Thursday 2015-09-08 the high tide is just 3.28m.  Plenty of water at the weekend though!

Careful calculations, planning, execution, and shenanigans with the mud are all part of the fun.

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Filed under Logs

Replacing the pendulum on the Hebridean

After spending a good 100 hours constructing my Hebridean wind vane I grew quite frustrated when it started to go wrong, especially after such initially promising results. However, after some very useful comments from readers I set about constructing a temporary replacement pendulum.

I started out with some 18mm plywood and a couple of hardwood blocks bought from the local Hubo.

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I didn’t glue the blocks to the plywood, instead using four big stainless steel screws through each, being careful to offset them slightly so they didn’t clash.

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Then I marked off 9mm from each side of the leading and trailing edges, sharpened my plane, and set about adding a 45° bevel to the leading and trailing edges.  The plywood makes this easy to get right since it has a built-in gradient.

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I noticed there was a slight curve in my plywood, but hoped that removing the pendulum balance cut-out would prevent this being an issue. I was expecting to have to add some balance later.

I put on a few coats of Cuprinol Ultimate to help keep the water out.

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I was deliberately doing all the work in Tammy Norie’s cockpit, to see what it was like. Well, this is what the cockpit was like, anyway.

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I attached the pintles and mounted the pendulum onto the Hebridean frame.

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Later that day I sailed from Harlingen to Den Oevre. Actually, I mostly motorsailed due to adverse wind and current, and the need to make the weather window in the North Sea. But I did spend about an hour trying out the Hebridean on various upwind courses in what was about a force 3 or 4.

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It seemed to work really well. With the linkage disconnected the pendulum was stable and would return to the centre position. With the linkage connected and the vane in place, but no tiller connection, the vane behaved itself very well. Attaching it to the tiller worked just fine and the boat steered nicely. There was no obvious lack of sensitivity, though truly light wind tests have yet to come.

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After picking up Martin Roberts at Den Oevre and motoring out past Den Helder we reached our departure point, and I set up the Hebridean for downwind.

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It worked well, and continued to work for the entire 36-hours that followed, taking us across the North Sea. For the second half of the trip it was set to a dead downwind course and took us through some pretty big and steep wave conditions.

The only problems were with the control line setup. I’d used some simple twine to attach various blocks and eyes on a trial basis, and these chafed through after 24 hours of continuous action. This put us off course temporarily on a couple of occasions but nothing serious went wrong.

We didn’t disconnect the Hebridean until we had to cross the infamous bar on the river Deben, and I lifted it off completely when we put in to Tide Mill yacht haven. Looking at it then, it was clear that the plywood had curved further, but unlike the original pendulum this didn’t cause any noticeable problems.

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I spent a lot of time wondering about all this and discussing it with my crew.  We went over all the suggestions, John Fleming’s instructions, and John’s feedback during the journey.

Our theory is this: John mentions that he expect instability that is dampened when the Hebridean is connected to the tiller.  The thing is, the Coromandel has a small rudder and a very light tiller.  We suspect that it’s simply not providing the damping that John expects, so that the pendulum flips out.  Added to that, my pendulum seemed to develop a clockwise bias, and that made it always flip out in one direction almost immediately, overwhelming the vane.  The simple unbalanced pendulum doesn’t require damping to stay in line, so it behaves much better on my little boat.

It might also be insensitive and fail in light winds, but it seemed to be doing the job in F3.  I’ll know more when I try it out around the East Coast this month.

Anyway, I think we have discovered something important about the Hebridean and my boat, making the whole thing much more feasible for my Jester Challenge attempt.  I now believe it can be made to work. And I’ve also proved I can repair it in the cockpit!

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Filed under Constructing the Hebridean, Netherlands Cruise 2015, Repairs and Modifications, self steering

Constructing the Hebridean day 13

I’m in the final stages of my project to construct a Hebridean wind vane self steering system. I brought the pendulum home to Cambridge so that I could work on shaping it into the computer-generated profile recommended by John Fleming in his plans.

You may recall that earlier I made a template from the plans out of a piece of thin plywood.

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I also experimented with using a router to get the basic shape of the profile, then planing to finish the job.

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I would have continued with this technique, but I don’t have a router or any other suitable power tools in Cambridge.  I did look in to using a CNC router at Makespace to get a perfect profile, but in the end I just went to Mackays and bought a plane and sharpening stone (things I wanted anyway) and did the job by hand on my dining room table.

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I started by getting the bottom end of the pendulum into the correct shape.  This end is going to be cut off since the pendulum is way too long for Tammy Norie, so I could afford to get into practice.  I applied greatest pressure with the plane at this point and eased off towards the top, so that less wood was removed.  I then moved up the pendulum, using the template as a guide.  This gradually copied the shape from the bottom end up along the whole plank.

To fine tune the shape, I used a marker pen to mark where the template was touching the surface.  It was then easy to plane away the mark and take another look.  This gradually corrected the profile over the whole pendulum.

I did about three hours of planing last night and another two this morning, followed by about 30 minutes of sanding, with this result.

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It’s very close.  There are some minor wobbles that I’ll correct, but I think the job is done.  So I’d say allow six hours for planing your pendulum.

I had to sharpen the plane about once per hour, and especially when it was new. This video on how to sharpen a plane was very helpful, and allowed me to get a very good cutting edge.

I’m also left with about a third-of-a-plank’s worth of oak shavings!

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Filed under Constructing the Hebridean, Equipment, Repairs and Modifications, self steering

Constructing the Hebridean day 12

This past weekend I sailed from Fareham to Emsworth and back with a friend from Cambridge, and while aboard (and under way!) I assembled and attached the incomplete pendulum and was able to test some aspects of the Hebridean wind vane self steering gear that I have been constructing since last Monday.

Before setting out, I finished making and attaching the counterweights. These balance the vane and push rods so that wind pressure is able to twist the pendulum. John Fleming’s plans involve creating counterweights by setting lead shot in polyester resin. But Dad has a better idea. He found a couple of old doorknobs and we filled them with lead instead.

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I tapped 10mm threads into the handles, then tapped 6mm threads into some 10mm threaded rod, so that the counterweights could be bolted to 6mm threaded rod on the Hebridean.  This also allows for some adjustment in their position with lock nuts.

I attached the upper counterweight to the vane and fiddled with it until the vane just returned to vertical.  It’s then that I found out exactly what the “grub screw” is for.  It tilts the upper counterweight arm so that you can get the vane vertical.

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The lower counterweight balances the push rod mechanism.  You need to detach the vane and pendulum, but hang the pendulum push rod so that you get the right weight.

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You then position the lower counterweight until the main push rod moves up and down with minimal force.

With these things done, I took the frame and pendulum aboard Tammy Norie. While underway I attached the pendulum sides and hinges.  Drilling oak with a little hand drill is slow going, especially when the helm is tacking every few minutes!

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The results were very satisfying. I was able to get the pendulum into the water while under way and see how it moved the whole gear when twisted.

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This kind of testing also revealed problems.  I left the end of the extension proud of the trunk, to keep that end of the cross-lap joint strong.  Unfortunately, it clashes with the mount and prevents the pendulum being fully lifted out of the water.  I’ll need to trim it down.

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There’s another issue with the pivot and mount.  I made the mount as a sandwich (as recommended) but this means that the split pins keeping the pivot in the mount clash with the sides, preventing the Hebridean from rotating.  I’m not sure what John intended here.  I notice that his boat has the mount in a different orientation so perhaps he didn’t notice this problem.

Later on I was able to attach the whole push rod linkage to the pendulum.  Once that was done it was possible to steer the Hebridean by wiggling the vane counterweight rod.

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I even have a video of this bit!

Unfortunately, this last test was taken just before we had to moor up, so I didn’t have time to test using actual wind. As it was we only just got unloaded before the tide dried out Tammy. We even had to push the rowing boat through the mud to get home.

I’ve taken the pendulum back home to Cambridge to shape it at home when I’m home from work.

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Filed under Constructing the Hebridean, Equipment, Repairs and Modifications, self steering