I have a RM SPX-5 Wheel drive autopilot without a rudder sensor. Does it make any sense to add a rudder sensor? Thanks.. Jon
Rudder Sensor with Wheel Drive unit?????
- Thread starter PGIJon
- Start date
Raymarine says:
-- Smart Rudder Sense(TM) technology enables precision steering without
the use of a rudder feedback sensor; ideal for outboard engines and
installations that cannot fit a rudder sensor.
However, does this mean that it doesn't "use" the rudder position data as part of it's calculations, or does it simply use it to display the rudder position? I can't believe it wouldn't use this precise data (if available) and instead rely solely on software to "calculate" the rudder position.
A question for the Raymarine software designers.
Good Point MZ4... I'm going to to post this on their forum and see what they have to say... I'll post the response here.
Actually found this Q&A on their website which seems to suggest that adding the sensor would be a good idea. Which seem to contridict their product bullet points: Smart Rudder SenseTM (SRS) enabled - Rudder Reference Transducer not required. Located here... http://www.raymarine.com/view/?id=855
Q: I am installing an SPX-10 with Type 1 linear drive and 7001 display on a wheel driven 36' sailboat. Is it necessary to install the rudder reference sensor?
A: Always. With a rudder reference sensor in the system, the autopilot has more information available, where the rudder is located, that will allow better operation, mainly in unsettled seas.
Q: I am installing an SPX-10 with Type 1 linear drive and 7001 display on a wheel driven 36' sailboat. Is it necessary to install the rudder reference sensor?
A: Always. With a rudder reference sensor in the system, the autopilot has more information available, where the rudder is located, that will allow better operation, mainly in unsettled seas.
I would not put one on unless you can't get it to drive a straight line.. If it hunts or waggles slowly, a rudder position sensor would help. My old RM 4000+ was not able to drive a straight line (even in calm while motoring) until I installed an RPS.. after that, it drives really fine ! Don't add it unless ya need it. The 34 autopilot has the toughest time sailing at a 45 deg angle with the waves.. like lots of helmsmen do too!.. My old 4000+ would crater immediately before the RPS.. again, the SPX is supposed to be smarter and not need one.. but if it needs one, put it on.
EDIT: I fought with tuning constants for 5 years before I gave up and put in the sensor!
EDIT: I fought with tuning constants for 5 years before I gave up and put in the sensor!
I have the SPX-5 on my boat and added a sensor only because I found one unused on a consignment table with out all the hardware very cheap. I love electronic gadgets and toys so I said why not. It is neat to see the rudder angle on the head unit but I haven't noticed a significant difference in operation. Personally I wouldn't cough up the big bucks for a brand new unit.
Yes absolutely. Raymarine has not done well at coming up with an AP that can do well without a rudder reference.. What they did do well with is now making it an "optional purchase" instead of "standard equipment"....
no rudder sensor
I have the EV100 with no rudder sensor. I very light wind the boat sails in an S pattern. This is because the motion sensor is slow to notice a change in direction so it over corrects one way then the other. This does not happen in moderate to high winds. I assume the rudder sensor would improve this.
I have the EV100 with no rudder sensor. I very light wind the boat sails in an S pattern. This is because the motion sensor is slow to notice a change in direction so it over corrects one way then the other. This does not happen in moderate to high winds. I assume the rudder sensor would improve this.
Re: no rudder sensor
I assume that the SPX "learns" where the center of the tiller is by taking an average over time and converting that to an electrical signal. After all, most of the time you'll be going straight. Makes sense.
With the sensor, it would already know where center is, and full left/right rudder. I would think that if a deviation is detected, it would favor the sensor [maybe].
Another variation would be forward prop walk. Right handed props creep the boat to the right when motoring, and you compensate by giving a slight left rudder. I wonder how the SPX figures out the difference between motoring and sailing.
I'm sure it's a great AP.
I assume that the SPX "learns" where the center of the tiller is by taking an average over time and converting that to an electrical signal. After all, most of the time you'll be going straight. Makes sense.
With the sensor, it would already know where center is, and full left/right rudder. I would think that if a deviation is detected, it would favor the sensor [maybe].
Another variation would be forward prop walk. Right handed props creep the boat to the right when motoring, and you compensate by giving a slight left rudder. I wonder how the SPX figures out the difference between motoring and sailing.
I'm sure it's a great AP.
I guess I'm going to have to make this optional/required purchase... Here's RM's replyYes absolutely. Raymarine has not done well at coming up with an AP that can do well without a rudder reference.. What they did do well with is now making it an "optional purchase" instead of "standard equipment"....
Reply by Underway - Raymarine, US 27 Yes, it is not required for all installations because there is a gyro compass on board of the X5 course computer, that provides virtual rudder reference data. This doesn't always give the pilot the best data for some boats and causes the issues you are explaining in less than ideal conditions. So, I would recommend adding a rudder reference sensor for better functionality with your vessel.