Raymarine ST2000 Installation Advice

[thompsontwins]

Hi all,

Looking to buy a Raymarine ST2000 for my LM24. Has anyone got any advice or photos on best place to mount? Was an extension required? What were the pitfalls, if any?

I feel starboard side may be best mounting choice as all the electrics are on that side of the boat.

Paul

[Sula]

Hi Paul,

I assume you are talking about the ST2000 tiller-pilot (I've been confused in the past by someone talking about a Raymarine auto-helm with the same or similar model number, but it turned out to be a model of the type (directly) driving wheel-steering.)

I would have thought the ST1000 would be adequate for the LM24 (and LM27), but you pays yer money . . .

The auto-helm doesn't care what side of the boat it is mounted on, so long as the unit itself is kept away from magnetic fields (e.g. lumps of ferrous metal, electronic equipment, cables carrying heavy electrical currents) as these cause false readings in the compass inside the auto helm body). I think as default it is set up to be used on the starboard side, but it is a simple operation (described in the manual) to reset it to operate on the opposite side so it e.g. pulls to steer to starboard rather than pushes. (Other brands of tiller pilot - e.g. Navico - are likewise.)

It is important to get the lateral distance from the tiller correct (see manual for the spec), or as near as you can get it, otherwise you won't get full tiller travel in one direction. Note, though, you can buy (or an engineer could make) an extension to the auto helm driving shaft (available in different lengths) if you have to mount it further away from the tiller than specified.

The fore-and aft distance from the rudder pivot line is less critical, but if it's too far aft of that specified the loads on the auto helm will be much heavier (not so critical if your auto helm is a more powerful than needed for your boat). In theory it could also mean that at full autohelm deflection your rudder will being pushed beyond its stall angle (rule of thumb circa 20 degrees to the water flow - but 'it depends'), but I've only ever experienced insufficient 'throw' in extremis, rather than excessive throw. If it's too far forward it can't turn the tiller far enough side-to-side. Measuring the specified distance is straightforward on the LM24/27 as the rudder post is (if I remember correctly) vertical - you can just measure from the centre of the top of the rudder post. (People with non-vertical rudder posts often fail, I've noticed, to appreciate this is not the case for them.)

Note that the brass socket that autohelm locates in is subject to repeated rocking forces. If it is mounted in a thin panel, such as the GRP surface of the cockpit coaming, the socket really needs supporting over it's length by e.g. a small and supported block of hardwood mounted behind the panel, or some resin filler built up around the socket and bracing it against the sides of the coaming (the latter probably the easiest in the narrow confines of the interior of the coaming). Also check carefully the external diameter of the socket before drilling. If I remember correctly it is 1/2 inch, i.e. 12.5mm and NOT 12mm or 13mm. That 0.5mm caused me some grief on a previous on a previous boat. (Having proudly fashioned a teak bracket to mount it, it being the weekend and no 1/2" drill bit to hand and in a rush to complete the job, tried to force the socket into a 12mm drilled hole resulting in my lovely teak bracket splitting and becoming good for only firewood.)

The height and depth of the tiller at the relevant point along its length is a key constraint/parameter.

I've used an ST1000 and ST2000 (no difference in installation terms) on my LM27 (and similar on other boats). Despite being very familiar with them and their installation, getting the set up right on my LM27 has proved a rather trying saga. I hope my recounting of some of it at length can help you avoid similar pitfalls

On my boat the previous owner had mounted the (physical, not electrical) socket for the auto-helm on the starboard side (presumably because, like your boat, this is closest to the electric supply), in the top of the coaming at the rear of the cockpit. It was unsatisfactory because the socket for the auto helm (non-tiller end) had been placed too close to the tiller (laterally). This meant (a) it couldn't move the tiller far enough to starboard, but had more than enough travel to port); and (b) the auto helm wasn't horizontal (as it ought to be for optimum leverage and compass operation) and sloped up at quite an angle to the tiller, tending (usually at the most inconvenient moment) to lift the tiller on its hinge rather than push it away to port.

I drilled a new hole in the coaming at the back of the cockpit the correct distance from the tiller. (Rather than messing about filling the old hole I just bought a new brass socket (at Raymarine prices!) for the new hole, then had two in the aft coaming. In order to get the autohelm horizontal I also moved the pin on the tiller that the autohelm drops onto from the top of the tiller to underneath, using one of the extortionately priced brackets sold by Raymarine (someone handy with metalwork and access to the appropriate tools could knock one up in short order). Unfortunately, I then discovered that with the autohelm now horizontal, the bulge under the autohelm body(containing the compass?) fouled the coaming.

I had noted at the outset that the aft cockpit coaming was significantly further aft than the correct distance from the rudder pivot to the auto helm socket specified by the manual, but had stuck with it for convenience. Now faced with the choice of either having to make a mounting sticking up from the coaming and in the way of the mainsheet etc., or shifting the autohelm forward, I went for the latter. I drilled another hole, this time is the side coaming of the cockpit, bought yet another Raymarine socket, and one of Raymarine's premium priced ram-arm extensions (again, easy for someone with the tools and knowledge to make), and unscrewed and moved forward the only recently installed bracket holding the pin under the tiller.

Having gone to some considerable lengths to ensure that the depth and position of the tiller's now underslung 'pin' bracket meant it cleared (though only just) the coaming under the tiller, something in the tiller hinge on the rudder post head got moved, and I ended up with a semi-circular gouge in the aft coaming. Not serious, but very annoying at this stage in the saga.

I was also finding that the very limited clearance between the top of the pin and the underside of the tiller made it very fiddly, and time consuming (especially if one were in a hurry!), to set the auto helm rod onto it.

At this point in the saga life intervened and stopped progress on this and other projects, and even sailing Sula, for a couple of years (though I hope to get back on the case in the spring).

I now have three options to solve the remaining problems -
a) have some sort mounting block sticking up from the aft coaming for the non-tiller end of the auto helm, and refit the tiller pin in the original position on top off the tiller. (This is likely to be the easiest - and therefore most likely - short term option.)
b) make a sideways projecting bracket (or wood or metal) on the tiller, on top of which, in clear air, the pin would be mounted. (This could work with either the aft or side coaming mounting of the auto helm, but still doesn't properly deal with the height issue.)
c) make a new tiller. I don't find the one on Sula aesthetically pleasing, or a convenient height and length for either my default 'bum-steering' (standing in the cockpit, leaning back against the tiller to steer) or steering while sitting on the cockpit seats or coaming. (I've previously made a tiller for a different boat, and enjoyed it, but have less time and patience these days, and I've since had some tools stolen, so this looks a long way off, or never.)
d) my fantasy notion of the auto helm being mounted under the aft deck, permanently connected to an arm on the rudder post, which would be engaged or disengaged with the rudder post in a manner broadly like, but more convenient (electric or cable operated?) than the normal LM mechanism for engaging disengaging the wheel-steering. (Negligible chance of coming to pass!)

I hope armed with the knowledge from this cautionary tale you will have an easier time with what should ordinarily be a quick and simple job!

p.s. Don't undersize the cable providing power to the autohelm electrical socket. It draws a lot of current when pushing/pulling hard. Ensure it is fused (8amp, IIRC) and preferably also switched .

[thompsontwins]

Phew!

The reason I have ordered the ST2000 is that it is on Boat Show offer at the moment, and priced the same as the ST1000. From my research it may be slight overkill, but it will helm quicker than ST1000. As you say, you pays yer money.

Thanks so much for taking the time to reply. What a faff! I suspected there could be pitfalls, hence my question. If I had known beforehand it may have put me off buying one! However, I intend doing more solo sailing, so a tiller pilot will be useful.

Interesting advice on current drain. Maybe the ST2000 draws more than the ST1000?

A lot of planning required, and a measure twice cut once approach. Useful to know your experience, thanks for sharing.

Paul

[Sula]

No, I agree the St2000 is a better choice, especially if it's the same price! Just didn't want you to be laying out extra unnecessarily.

It's not necessarily a huge faff. My tale was a bit of 'I wouldn't start from here . . .' (i.e. trying to just modify the unsatisfactory arrangement I inherited, and doing it in incremental steps, each of which revealed a new complication).

Should be easier starting from scratch, really. Cut yourself out a triangular piece of cardboard with the relevant fore-and-aft and lateral distance requirements, hold it horizontal against the tiller. You'll then know where your 'ideal' theoretical mounting socket and tiller pin would be, and you can consider what adjustments/compromises/extensions/brackets you might need to make/buy to install it in practice.

I doubt the ST2000 will consume much more at all than the ST1000 on average, as this primarily relates to load and time under load. It will draw more current if it is under a heavier load than the St1000 would cope with, and will take less time to move the tiller if loads are near to the a St1000's maximum capability. (i doubt an LM24 will impose such loads except if things are getting out of shape, or the sails are seriously unbalanced.

Decent sized power supply wires will ensure the power of your autohelm isn't constrained by falling voltage under load, and that you are not wasting precious battery power heating up undersized wires.

A tiller pilot will certainly be useful, especially for single handing. One of the most useful things on a boat, in my view (at least for my kind of relaxed cruising, often single or short handed). You'll wonder how you ever managed without!

[thompsontwins]

Thanks again for the update. Liking the cardboard template idea. Just waiting for it to arrive in October.
Paul