I've had a Raymarine one for years (well, I've got through 3 now), but it finally gave up last year (horrible corroded mess inside!) But it was never much use when the engine was in the well, as the compass is on the inboard end of the tillerpilot, too close to the engine, and gets a lot of magnetic interference. This only became a problem when I changed engines from a Mercury 2-stroke to a Yamaha 4-stroke.
But the Simrad ones have the compass at the outboard end, further from the engine, and seem to work fine. I'm glad I changed!
Hi Geoff, I’m sorry to learn that you are in administration 😂.
This is the first time I’ve seen compass location being a deciding factor in choosing an autopilot. Very interesting.
For anyone owing a tiller autopilot, I highly recommend a cover to help keep the electronics dry
On the corrosion issue, I learned of and purchased from eBay a waterproof cover for my Autohelm tiller pilot. In practical boat owner forums many report problems with water ingress. The cover stops that and gives you a more reliable and longer lasting setup. They’re still for sale. The price is £15. My cover is well made, fits perfectly and show no sign of fading or degradation after being in use for many years. There’s also no need to remove the cover when the sun comes out, as the autopilot doesn’t overheat with the cover on during warm sunny days. And no, it’s not my aunty that makes them 😀.
I've got a background in electronics and have been asked on a number of occasions to look at various bits of "yachty" electronics. To date I've repaired three Autohelm 1000/2000s and two TP22 including my own, both of which had the same fault.
So here's my two pence worth. Mechanically the Autohelm 1000 and 2000 are the same, and are superior to the Simrad in that they have a recirculation ball drive on the ram which is smoother, more reliable (and more efficient) than the nylon nut and leadscrew used on the Simrad. In this respect the Autohlem is better. Internal construction is somewhat similar in that there's a drive PCB, compass, motor/gearbox and ram. Moisture proofing, and water ingress prevention, is again something that is the pretty much the same for both units. What depresses me is that neither manufacturer make any attempt to protect the components and tracking on the board with a coat of lacquer or varnish. All the components, PCB track, connectors etc are exposed to the air around them so subject to corrosion. To prolong the life of these things try to keep them dry, and keep it in the warm at home over the winter.
The biggest difference (aside for the compass location already mentioned) is how the two units handle a stall condition on the ram. The Simrad has two magnets and two sensors in the gearbox that detect gearbox movement and direction. So if the electronics is calling for the ram to move and applying power to the motor, but the gearbox isn't moving (because it's at end of travel or stalled for some other reason), it will beep and turn off drive after a couple of seconds.
By contrast the Autohlem/Raymarine units have NO stall detection/protection circuitry. When first fixing an Autohlem 1000 I thought this very strange so did a bit of investigation. I found a post where someone had challenged Raymarine about this, and apparently the Raymarine response was that if the ram was stalled, the off course alarm would sound and the skipper would then intervene to correct the situation. What actually happens when you stall an Autohlem 1000/2000 is that they pull big currents from the supply 10-15A or so. If (when?) this happens for any length of time then either the breaker in the supply trips (or fuse blows) or the transistors in the motor drive circuit get so hot the solder melts and they fall off the circuit board. Two of the Autohelms I fixed had transistors rattling around inside where they'd unsoldered themselves off the PCB. I'd guess it takes about 10-15 seconds of stalled ram for this to happen. In both cases, replacing the transistors with new devices (less than £5 for the bits) brought the units back to full operation.
Overall the Raymarine/Autohelm unit does feel slightly better made (and I think is generally more expensive), but the lack of stall protection is a MASSIVE drop off in my opinion. However, once aware of this limitation then the Autohlem unit would probably be my choice because of the better ram implementation.
One final point, the Simrad unit (or at least the TP 22) is quite sensitive to dips in the supply. Like the Autohelm unit, current spikes can easily be 10A when the motor initially starts (or if stalled), and if this causes even a brief dip in the 12V supply the unit will beep, reset, and generally not work properly. I recently had a problem where I thought my TP 22 was playing up, but when I tried it at home on a solid supply it worked perfectly. The issue was traced to a slightly poor contact on the "Autohelm" breaker circuit.
Apologies if I’ve rambled on a bit
I'm looking forward to trying it out in a couple of weeks time but am expecting it to work as by all accounts it solves the problem of motor interference.
I was recommended to get a cover for my ST1000 autohelm and bought one of these.
Although it didn’t get a lot of use it was good to be able to keep the water away from the selection buttons and hopefully help to keep the unit dry. It was well made, easy to fit and didn’t hamper using the selection buttons.