All,

This is copied and pasted from a Facebook post. It contains two YouTube links that may not come through, but you should be able to copy and paste them into your browser if not.
It is from the page SV Thank You George, if you want to search for the page on Facebook to get more information.

It addresses problems encountered with the ram travel stops on the Raymarine ST 1000/2000 models. The rams hit the travel stops pretty hard which leads to damage.  I do not personally own one of these units, but since so many members do, I wanted to share this article/post.

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Here are some notes on my installation of Dennis Meulensteen's fabulous fix.

First, the problem is that the Raymarine ST1000/2000 apparently has a design 'deficiency'. Somehow it doesn't contain discrete sensors to tell itself when the ram (the arm that pushes/pulls on the tiller to steer the boat) reaches the extreme end of its extension or retraction. This ram, rams into the end of its rail track inside. That's how it stops itself. Bang. Those ends do have a rubber gasket pad. But the effect is still very physical - you can feel it when you hold the unit in your hands. The owners manual in fact states that the "drive unit thrust torque" is 125lbs (57kg)!

I was wondering how the Raymarine 'knows' when it does get to the end of its ram's run (to pause the motor and hold it in pause while it reverses the polarity of the current going to the motor in preparation for the next actuation.) I know next to nothing about electricity and circuitry (as you will read) but I'm imaging that the the motor, when the ram rams into itself, either experiences an amperage spike or something in the current gets back to the brains in the processor.

However this is, owners' Raymarine ST1000s have been 'wearing out'. It looks like either the belts or gears that make up the drive mechanism strip or break free from the repeated trauma. I guess it also can't be good on motor longevity.

So, Dennis Meulensteen has put a lot of work on coming up with a fix that I understand is based on Gary Malm's pioneering efforts on this.

Dennis Meulensteen
https://youtu.be/qt5CePdEEX0?si=4X7i-5wOSo1hHRMG

Gary Malm
https://youtu.be/z18CR3eBDCE?si=fyRKOdRbpjk6xTPr

So, I followed Dennis's instruction and within 2 days one of the components, a 3D-printed part, was in my hands and the other bits from Amazon arrived soon afterwards.

In disassembly, I noted that the ribbon cable from the compass unit really is delicate - it was the one thing I felt most anxious about.

I searched for any wear, or worse, bending/fracturing of the end plates of the internal track ram. Mine were fine but some folks' get really bashed up.

It's the little things. Had to drive across the city to 3 Ace Hardwares to find the teeny machine screws/nuts (Amazon disappoints) that attach the switches.

I proceeded to assemble the mechanism using a ballpoint pen spring (as instructed). Except my spring sprung out repeatedly. Of course I snapped a picture and messaged Dennis and spent a teaching day at the university distractedly imagining how I'd have to glue in a fix or come up with a different mechanism. When I got home I discovered I'd install the switch upside down, so, I flipped it around, and it worked perfectly as Dennis designed. It's actually one of the best parts to the thing - a switch that elegantly tames a steel driven ram pushing at 125lbs, turning an internal "bang" into a "click" with nobody getting hurt.

I also discovered how careful I needed to be with the wire switch actuation arm. You bend it into shape manually following the prescribed measurements. The first one I fabricated attached to the rail it ran on but after a few tries, it fell off. I needed to make another one with a teeny bit more grab-radius where it grips the rail.

Though not in the official instructions, I also ground out a little extra clearance where the wire arm passes through. I also noticed that my wire actuator arm passed very close to a bare lead of one of the diodes. So, I threaded on a bit of black shrink tube insulation.

I'm really 'uninformed' when it comes to electronics. I have to repeat out loud to my self that a 'closed' switch is one that actually passes a current. I barely know what a diode is, never mind the cathode from the anode and how those relate to current flow direction.

I assembled the whole mechanism and tested it using my bench power supply. I attached power leads directly to the Raymarine's motor. I got the motor to actuate the ram but, bang, it rammed into itself at the ends of its stroke. Clearly my circuit was not working.

More photos and texting. I disassembled and tested each component with a multimeter, for continuity and polarity of current. An utter mystery - everything checked out. It was the story of my electrical life - nothing I have ever disassembled to fix - going all the way back to the family toaster when I was 7 - ever worked again.

Dunno how I realized. I'd excluded the full circuitry of the whole unit (including the additional switches) by powering the motor directly. I moved the 12v leads to attach to the 12v plug. Duh. Worked perfectly.

I hope this helps someone here.

Todd T.