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Thread: autopilot review

  1. #11
    Join Date
    Jan 2010
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    235

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    Re Bob's comment about needing spare ends for the Raymarine rams is good. However, I cured this problem by buying the RayMarine extension fitting (the shortest is enuf) and drilling a new hole in it (to mimic the position of the hole in the plastic end piece which comes with the ram). The extension fittings are aluminum and hold up well for me. I have also had an occasional problem with strippage of the plastic threads on the stock end cap. The aluminum extension cures that rare problem too.
    Not having Brian's skill with electronics, I just go merrily along with what's available off the shelf. My sailing instruments are RayMarine and they integrate well with the TP4000 and TP4000GP. I often use the "wind mode" (apparent wind setting) on the SHTP. But that method becomes problematic in lite air...less than 5 knots or so apparent.

  2. #12
    Join Date
    Aug 2013
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    199

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    Good golly, is this you, Jim Bates? I've been looking for you since Ben and I chaired the TransPac in 2006!

    Lucie Mewes

  3. #13
    Join Date
    May 2009
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    Bob, do you know which evolution model replaces the X-5 GP? The EV-100 sensor seems to be a much better feedback instrument that the previous fluxgate compass for the X-5 series pilots. It also seems that the only difference between the X-5 and the X-5 GP is the ram. One is more robust than the other.
    Last edited by WBChristie; 08-15-2013 at 01:36 PM.

  4. #14
    Join Date
    Sep 2007
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    I don't know - I haven't looked at them yet. That's interesting about the sensor because I've had trouble with a couple of their fluxgates. I now have two installed and can switch between them if necessary. I assume it's still sensitive to sources of deviation? That's been a challenge on the smaller boats as we add gear.

    Here's a presser: http://www.raymarine.com/news/mynews.cfm?story=7104

    There's also an interesting comparison of the GP vs. non-GP drive motors in this thread, started by our own Slacker:

    http://forums.sailinganarchy.com/ind...owtopic=112693

    Scroll down to post #20 for the details about the motor. Apparently the motor in the non-GP unit costs about four bucks and the motor in the GP costs $300!
    Last edited by BobJ; 08-15-2013 at 06:40 PM.

  5. #15
    Join Date
    May 2009
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    284

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    Thanks, great information there. Apparently the new sensor is not affected by on board magnetic fields.


    At the centre of every Evolution system is the intelligent EV sensor core, a 9-axis sensor that monitors vessel motion in all three dimensions. The innovative EV sensor core combines advanced solid-state sensors with the Evolution autopilot processor into a single easy-to-install housing.

    Mount the EV sensor core above or below decks, the rugged enclosure is fully sealed and built to IPX6 and IPX7 waterproofing and submersion standards.
    EV Sensor Core Benefits

    Precision monitoring of heading, pitch, roll, and yaw allowing the autopilot to evolve instantly as sea conditions and vessel dynamics change.
    Flexible installation options. Mount above or below deck.
    Simple SeaTalkng connectivity to the control head and ACU.
    Solid state sensor technology delivers dynamic accuracy to within 2 degrees in all conditions.
    Auto-compensation for on board magnetic fields and reliable heading accuracy in the northern and southern extremes.
    Fast and reliable heading data for MARPA, radar overlay, and heading modes on Raymarine multifunction displays.

  6. #16
    Join Date
    Sep 2007
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    The new sensor is implemented with 6 sensors, 3 magnetometers, and 3 accelerometers. These are used to fully characterize the magnetic field direction while compensating for pitch, yaw, and role of the boat as well as magnetic declination. The method used to compensate for on board fields is not unlike that used for the old sensor, that is several 360 degress turns are taken at set up to measure static, on board, interference. It will not account for changing fields, like those caused by electrical wiring. One downside to the new sensor approach is that the accelerometers are sensitive to vibration. One thing to be careful about is to try and locate the sensor module where engine vibration is minimized. One might notice an effect where under motoring the unit will wander a bit more than while the motor is off. Another rare failure is that the accelerometers, which use solid state micro machines, have been known to "latch up". They are implemented in silicon will micro oscillating pendulums (dimensions measured in nano meters) and on really rare occasions have become contaminated. You can find these same sensors in your new smartphone. If you have a compass application on your phone you can experience both the good and bad of this technique. Align the phone while level to north. Then try tilting and rolling the phone. You will see compass direction changes and also how long it takes for the compass to recover back to the true course. In the AP 3 more sensors, rate gyros, are added to help with these dynamics, but the experiment shows just how slow the compass is and the challenge the AP has in dealing with sea state. The older flux gate sensor does a good job and has similar response times. It is more expensive to produce however. The rate gyros, now on all three axis, allows RM to compensate steering for a wider variety of sea state. How well they use this new set of information in their algorithms is an experience left to the user.

  7. #17
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    May 2009
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    Brian, I Am interested in the hydraulic ram that you built yourself. In a previous post you mentioned that the RM control box can supply enough "power" to drive a hydraulic setup. Is the hydraulic drive control, for that matter the RM control box simply a "bang bang" output, not an analog output?

  8. #18
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    Sep 2007
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    Quote Originally Posted by WBChristie View Post
    Brian, I Am interested in the hydraulic ram that you built yourself. In a previous post you mentioned that the RM control box can supply enough "power" to drive a hydraulic setup. Is the hydraulic drive control, for that matter the RM control box simply a "bang bang" output, not an analog output?
    Hi, The RM, like all of these implementations, use a PWM (pulse width modulation) or pulsed output. The pulse rates are in the < 1000Hz range. You can hear the RM output pretty well on your SSB or an AM radio. It sounds to be about 300 Hz to me. So it sends pulses of variouse widths that are all on, or all off, and the integration of same by the motor and hydraulics results in what appears to be an analog output. This approach gives the best efficiency from the drive electronics.

    Hope that helps.

  9. #19
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    May 2009
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    Thanks, that does help. Which hydraulic pump did you use? I assume you are using the RM X5 tillerpilot control box to drive the pump?
    Thanks for any input

  10. #20
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    Sep 2007
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    Quote Originally Posted by WBChristie View Post
    Thanks, that does help. Which hydraulic pump did you use? I assume you are using the RM X5 tillerpilot control box to drive the pump?
    Thanks for any input
    I use a small Type 1 pump from RM that does not include the clutch hydraulic bypass valve, so it is a bit less expensive. Any of the various type 1 pumps will work (Octopus/RM/Furuno/Teleflex).

    I drive the hydraulics with two brains, the X5 is my back up and one of my own design is the primary. Both brains also drive the X5 tiller drive. This is another point of redundancy.

    Brian

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