Autopilot Angst

[tboussie]

I am retrofitting a Capo 30 (precursor to Olson 911S) for single-handed racing, including the SH Transpac. The boat is 30’ LOA, 7200 lb displacement, tiller steered, symmetric spinnaker, PHRF rating (125% LP headsail) of 123. Electronics are B&G Triton (wind, depth, speed, gps). I am currently working on the autopilot choice and would welcome feedback from the SSS community before I commit to a system.

The rudder tube is enclosed, so I am looking at above-deck tiller drive systems only. After much research I have concluded that my best options include (in order of increasing cost/complexity):
1) Tiller pilots such as Raymarine ST2000+ or Simrad TP32
2) Pelagic Autopilot
3) Raymarine EV-1 (or X5)
4) Simrad SD10 or Octopus RS below-deck cable drive routed to above-deck tiller (driven by Simrad AC12 computer / RC42 compass)
5) L&S 32ST16BP above-deck hydraulic ram + below-deck pump (driven Simrad AC12 computer / RC42 compass / RF300 rudder angle indicator)
6) Any number of below-deck mechanical or hydraulic linear rams coupled to above-deck tiller through Morse cable (driven by B&G computer/compass/rudder angle indicator)

Going through these options,
1) Tiller pilots such as Raymarine ST2000+ or Simrad TP32
I have found these to be okay for motoring and light sailing but not adequate for any serious single-handed sailing and any kind of seas.
2) Pelagic Autopilot
Total kudos to Brian for putting together an inexpensive and robust system. Perhaps he is modest to a fault, but I feel a bit sketchy using this as my primary autopilot system, particularly for Hawaii. I am happy to be convinced otherwise by people with more experience with the system.
3) Raymarine EV-1 (or X5)
It is the only directly tiller-compatible system from a major manufacturer, but I find the drive pretty crappy and the EV-1 SW interface seems to be dumbed-down for the motorboat market. Also mixing B&G and Raymarine electronics seems like a nightmare.
4) Simrad SD10 or Octopus RS
I believe there is a J-88 in the SSS fleet with this set-up (driven by NKE). I really like it because a) it is relatively cheap ($1200), b) the installation is straightforward, c) it has an internal rudder angle sensor which saves me $270 and avoids a vulnerable external sensor mount, and d) it is compatible with the B&G computer system. I worry about the a) relatively low maximum thrust, b) the relatively slow hard-over time, and c) the lifetime of the linkage cable. Input from anyone with real world experience with the Simrad/Octopus system would be welcome.
5) L&S 32ST16BP above-deck hydraulic ram + below-deck pump
The cost ($2400 + $270 for rudder angle sensor) aside, this is my current first choice. The ram is designed for external use, requiring only bulkhead feed-throughs for the hydraulic lines. The pump stays below out of the weather. There is a history of successful integration with B&G electronics, and L&S are widely used in the Mini and other single-handed fleets. My concerns are about a) power draw, b) the need for an external rudder angle sensor, and c) and cost/benefit vs. option 4 above – i.e. is this overkill for my boat. Again, it would be good to get real-world feedback from other sailors who have experience with this or related systems.
6) Other below-deck rams coupled to above-deck tiller
This introduces a wide range of options (potentially good), but introduces additional complexity in installation (potentially bad). A representative system would be a Simrad HLD350 MK2 below-deck drive unit coupled via a Morse cable to the above-deck tiller. What seems straightforward in principle looks to be to be a bit more complicated in practice. I am mechanical, but not infinitely so. I am willing to pay a bit more to avoid excessive installation challenges (i.e. option 5 above). Again, advice from anyone who has undertaken such an installation would be welcome.


All other suggestions/feedback on autopilot is welcome.

Tom

 

[Philpott]

Tom, Dura Mater has a Pelagic. Brian and I plan to take it out onto the Berkeley Circle to calibrate it this Friday. I look forward to a downwind life without fear, without that hyperventilation up on the bow as I feel my autopilot getting distracted and heading up into the wind. DM is 6700 lbs before chocolate and other equipment. You are welcome to come sailing w me to see what you think. Wouldn't you rather spend all that money on a new beemer?

 

[BobJ]

Random thoughts:

I agree about the ST-1000 or ST-2000 - okay for motoring inshore and light upwind only. I used a ST-2000 for awhile.

I've sailed on a J/88 with the Simrad TillerPilot driven by a B&G MFD (Zeus?) mounted in the drop board. This was better than trying to slide aft every time you wanted to adjust the TP (or tack or jibe). We were sailing with a big masthead ass'y in light air and this combo worked pretty well. I think you'd want a spare Simrad TP for Hawaii - it seemed a bit light and exposed. One advantage is the Simrad TP will work autonomously if there's a problem elsewhere in the system.

Chris here has the other J/88 with the SD-10 mounted in the back of the cockpit and controlled by an NKE system. My understanding is it took awhile to get dialed in but I haven't heard about any problems since. I think he has Brian's Pelagic AP as his backup. Chris will probably chime in here.

I have Brian's Pelagic drive unit, controlled by my Raymarine EV-200 (primary) or X-5 (backup). His drive is quiet and silky smooth compared to the Raymarine cockpit drives, but there are a couple issues calibrating it with the EV-200. It's probably fine if you use it with an X-5 or with his own controller. I'd trust it on a Hawaii race before the Ray drives. They're okay if you maintain them and carry spares. My experience is that one Ray drive *might* get you to Hawaii if it was just serviced and you keep the boat balanced.

I don't think a hydraulic drive would be good for Hawaii, given the power draw. The Minis use them in combo with electric cockpit drives (usually the Ray drive) to save power. If you do a Morse cable to a belowdecks drive you need a way to release it quickly. I bought the EV-200 (instead of the EV-100) because it has a clutch circuit. This opened up the option for a belowdecks drive if I cut into the rudder tube (and I might).

I agree about Ray's EV systems being dumbed down. The X-5 is the better unit - those contemplating a Raymarine system would do well to track down an X-5 (or X-10) while you still can. The X-5/10 can also work over SeaTalkNG (NMEA 2000) so you can use Ray's newer instruments. I'm in the process of converting everything over - the "backbone" architecture of their new stuff is a big improvement. Those interested can come and take a look in Vallejo this weekend.

I still have an ST-4000 somewhere: It's a stand-alone controller (no ACU) with belowdecks fluxgate and the same Ray Q047 cockpit drive. It's not a gyro but it was okay for my boat - it was my backup to the X-5.

If I had your B&G instruments I'd probably use Brian's drive, either with his controller or with a B&G MFD. As he'll tell you, the drives are just +/- pulses. They're agnostic as to bus language.

 

[Daydreamer]

Watching this thread with keen interest.

I have a Raymarine ST 2000 on Nightmare and the same full rudder tube.

Upwind around the bay it does ok. It wanders more in the swell but keeps me going in the general direction so I can reef etc
Reaching it is pretty slow to react so it will occasionally round up. This was my experience returning from the Farallones.
Off the wind with a masthead symmetrical I am not sure where I trust it. From 150 to 175 off the wind and with the swell it seems to do well enough to get the kite down.

My ST 2000 said it has auto sea state, that it learns. I am not convinced.

I have no instruments either so will be building a complete system.

 

[tboussie]

Random thoughts:

Chris here has the other J/88 with the SD-10 mounted in the back of the cockpit and controlled by an NKE system. My understanding is it took awhile to get dialed in but I haven't heard about any problems since. I think he has Brian's Pelagic AP as his backup. Chris will probably chime in here.

I don't think a hydraulic drive would be good for Hawaii, given the power draw. The Minis use them in combo with electric cockpit drives (usually the Ray drive) to save power. If you do a Morse cable to a belowdecks drive you need a way to release it quickly. I bought the EV-200 (instead of the EV-100) because it has a clutch circuit. This opened up the option for a belowdecks drive if I cut into the rudder tube (and I might).



Bob - thanks for your input. Some follow-on observations.

I am working on an electrical budget including autopilot draw. The hydraulic systems do draw more power, but then again they are more powerful. It is difficult to know just how much power (maximum thrust in AP language) I will need for my boat in the anticipated conditions. Feedback from similar boats would be appreciated.

Regarding the J-88 with the NKE/Octopus set-up, I would like to talk to Chris about his experience to date, so if you see him please encourage him to contact me (tboussie at gmail dot com).

The nice part of the below deck drive linked to the external tiller via a cable is that you can physically engage/dis-engage the drive at the tiller, just like you do with a tiller pilot or the X-5. No need for a clutch and the associated drag and current draw. The only pre-packaged systems I am aware for this kind of set-up are the Octopus RS and Simrad SD-10 (actually both Octopus products, the SD-10 is just re-branded for Simrad). I have considered building my own system with a more powerful / faster drive, but I have struggled to find a push-pull Morse cable with a 10-12" throw. Also the mounting issues are non-trivial. And I have no time.

Tom

 

[BobJ]

If I finally go to a belowdecks drive I want to be done with the cockpit drive issues which have plagued me for years. I'm willing (read "thrilled") to power a clutch circuit to get there.

Also, make sure your Morse cable's quick release at the tiller is really quick. I've had too many close calls when Bay racing to count, even just getting to the tiller quickly enough to lift the drive off the pin. I'm talking myself into cutting that rudder tube as I write.

 

[Wylieguy]

I have a brand new in-the-box Raymarine Smartpilot X-5 Tiller system with an ST6002 Control Head that I might be willing to part with if the price is right. Any offers? Pat Broderick. my last name with no "K" at sonic dot net All lower case.

 

[todd22123]

Random thoughts:

I have Brian's Pelagic drive unit, controlled by my Raymarine EV-200 (primary) or X-5 (backup). His drive is quiet and silky smooth compared to the Raymarine cockpit drives, but there are a couple issues calibrating it with the EV-200. It's probably fine if you use it with an X-5 or with his own controller. I'd trust it on a Hawaii race before the Ray drives. They're okay if you maintain them and carry spares. My experience is that one Ray drive *might* get you to Hawaii if it was just serviced and you keep the boat balanced.

As he'll tell you, the drives are just +/- pulses. They're agnostic as to bus language.

Bob- What issues did you have using Pelagic drive unit with EV-200? Are you using the option of setting "hard over" time, rather than separate rudder reference indicator?

Alpha has a rudder post drive with what appears to be a simple and functional mechanical disconnect. I have never seen it in person, but it seems that one could use this for below deck drive w/o clutch.

http://alphamarinesystems.com/alpha_30002.htm

 

[Ragnar]

If you plan to keep the boat a while, I would pursue option 5 for reliability. Seems like everyone fusses with their electric drive units, but I don't see or hear about much fussing with hydraulics. Like the electric drives, cover the hydraulic rams somehow. Zimaz had this setup & it ran for years. The rudder angle sensor was mounted in the cockpit alongside the ram. The tradeoff in my mind with hydraulic vs electric drive is reliability v amps. Power consumption is higher with hydraulic in part due to the solenoid needed to stay open with the hydraulic option. Someone found a system that was able to bypass this and thus draw less power to drive the pump, but I don't know the system.

If not, buy a couple of Simrad TP's and be done with it. Or a TP and Pelagic. You will need at least 2 drive units. I would take 3 if coming back on your own bottom. Test it a while in rough conditions to test your mounts & connections & make sure you can repair these at sea. I would guess Pelagic's drives are more reliable, but these need more real world testing.

You don't need an AP connection to your instruments to go to Hawaii. Compass course is fine. There are advantages to using a true wind function, but that is tough and costly to do well.

 

[BobJ]

1) On the EV-200 (and I assume the EV-100), the dockside calibration includes a step which requires moving the drive to one stop (hard over) and then to the other stop. With the Pelagic drive you can only do this with it engaged, using the controller's buttons (you can't force it by hand). But you can't use those buttons while you're calibrating so it's a catch 22 with the Pelagic drive. I have to calibrate the pilot with the Ray drive and then change to the Pelagic. That's do-able if you have both drives.

2) Because the EV's are dumbed-down, you have to lie to the computer to get the drive to respond fast enough. The Ray drive and Pelagic drive are both 5-7 seconds lock-to-lock. If you calibrate the ACU for that speed it's way too slow - you have to tell it the hardover time is 11-12 seconds so it thinks it has to respond faster. The Pelagic drive is still too slow to respond - the response of the Ray drive (when the ACU is lied to) is closer to normal.

3) Not a drive problem but to deceive the ACU in (2) above you can't have a rudder reference. If it sees a rudder reference it won't let you set the hard-over time.

Hey, you asked . . .
___________________

Ragnar, glad to see your post. I've been trying to click the "Read More" button on your blog but it doesn't work. I know there's more to the story - very sorry.

 

[todd22123]

1) On the EV-200 (and I assume the EV-100), the dockside calibration includes a step which requires moving the drive to one stop (hard over) and then to the other stop. With the Pelagic drive you can only do this with it engaged, using the controller's buttons (you can't force it by hand). But you can't use those buttons while you're calibrating so it's a catch 22 with the Pelagic drive. I have to calibrate the pilot with the Ray drive and then change to the Pelagic. That's do-able if you have both drives.

2) Because the EV's are dumbed-down, you have to lie to the computer to get the drive to respond fast enough. The Ray drive and Pelagic drive are both 5-7 seconds lock-to-lock. If you calibrate the ACU for that speed it's way too slow - you have to tell it the hardover time is 11-12 seconds so it thinks it has to respond faster. The Pelagic drive is still too slow to respond - the response of the Ray drive (when the ACU is lied to) is closer to normal.

Agree this is bizarre, and it is what I have found, as well. In order to have the AP respond faster, the hardover time is set longer on the programming. Less intuitive that whatever preceded it, some type of boat response or gain setting, if I recall correctly.

The piece I still do not understand is, since the drive is "agnostic", why do they respond differently to the current from the controller?

Assuming what you say is true, "The Pelagic drive is still too slow to respond", does this make the Pelagic drive less attractive as a backup for the Ray drive, at least for anyone who has the EV-200 controller?

Thanks,
Todd

 

[BobJ]

I wouldn't say that yet. I need to do more extensive on-the-water testing, hopefully with Brian aboard. He's only seen his drive work with the X-5 - my EV-200 is new.

 

[WBChristie]

Agree this is bizarre, and it is what I have found, as well. In order to have the AP respond faster, the hardover time is set longer on the programming. Less intuitive that whatever preceded it, some type of boat response or gain setting, if I recall correctly.

The piece I still do not understand is, since the drive is "agnostic", why do they respond differently to the current from the controller?

Assuming what you say is true, "The Pelagic drive is still too slow to respond", does this make the Pelagic drive less attractive as a backup for the Ray drive, at least for anyone who has the EV-200 controller?

Thanks,
Todd

The drives are geared differently. It takes more current to move the Pelagic than the Ray.....so a "burst" of current/voltage (its a pulse width modulated system) will not translate to the same movement/stroke even if the hard over time is the same at full voltage.
In the case of switching between the pelagic and the ray, you would have to have set the hard over time for each so that the same response would be achieved from both drives. Experiment by switching between the drives and playing with the hard over time. Then write down the different hard over times for each drive and change the hard over time when you change the drive.

 

[WBChristie]

1) On the EV-200 (and I assume the EV-100), the dockside calibration includes a step which requires moving the drive to one stop (hard over) and then to the other stop. With the Pelagic drive you can only do this with it engaged, using the controller's buttons (you can't force it by hand). But you can't use those buttons while you're calibrating so it's a catch 22 with the Pelagic drive. I have to calibrate the pilot with the Ray drive and then change to the Pelagic. That's do-able if you have both drives.

2) Because the EV's are dumbed-down, you have to lie to the computer to get the drive to respond fast enough. The Ray drive and Pelagic drive are both 5-7 seconds lock-to-lock. If you calibrate the ACU for that speed it's way too slow - you have to tell it the hardover time is 11-12 seconds so it thinks it has to respond faster. The Pelagic drive is still too slow to respond - the response of the Ray drive (when the ACU is lied to) is closer to normal.

3) Not a drive problem but to deceive the ACU in (2) above you can't have a rudder reference. If it sees a rudder reference it won't let you set the hard-over time.

Hey, you asked . . .
___________________

Ragnar, glad to see your post. I've been trying to click the "Read More" button on your blog but it doesn't work. I know there's more to the story - very sorry.

So, Bob you have a feedback sensor on the ray drive but not the pelagic? Does the pilot work better with the feedback sensor for you?

 

[BobJ]

I had a rotary rudder sensor installed with the X-5 but had to disconnect it to trick the hardover time in the EV-200's ACU. If I change to a belowdecks drive I'll try to use it again. Yes, the X-5 seemed to work better with it.

The best setup I ever had on this boat was the old S1G with rotary reference installed. I did the 2006 SHTP race with it, slept with the kite up, etc.- no problems. It's been all downhill from there (going downhill from there?)

 

[WBChristie]

Have you tried the ACU-200 with the feedback sensor? I understand that the hard over time cannot be changed with the sensor wired up to the ACU-200 - but I'm curious how the ACU-200 performs with the feedback sensor wired in.

 

[BobJ]

I never got that far since I had to disconnect the sensor to get the drives working properly. As you read on the Raymarine Tech Forum (and thanks for your input over there), this has been on ongoing saga.

Thanks for the insight on the gearing differences between the two drives - it confirmed my suspicions. Now I know what sequence I need to go through to make it all work. If the Ray drive wants the hardover time to be set to 11 seconds, what would you guess it should be for the Pelagic - 16-18 seconds?

 

[WBChristie]

I never got that far since I had to disconnect the sensor to get the drives working properly. As you read on the Raymarine Tech Forum (and thanks for your input over there), this has been on ongoing saga.

Thanks for the insight on the gearing differences between the two drives - it confirmed my suspicions. Now I know what sequence I need to go through to make it all work. If the Ray drive wants the hardover time to be set to 11 seconds, what would you guess it should be for the Pelagic - 16-18 seconds?

That seems like a good number to try....but one of the reasons I'm curious about the feedback sensor being connected, is that the response might be different with the sensor in the system. the x5 sensor should wire up to the acu-200. My biggest frustration with the evo pilot on my Hawaii trip was that it would give the drive a small correction, but in effect the drive would not move because the "bump" was not big enough to translate into actual rudder movement. All the while, the ACU would assume that the drive had moved, eventually causing a pilot fault due to max rudder applied - but in actual fact the rudder hadn't moved. VERY frustrating. My assumption is that the feedback sensor should fix this - but making assumptions with this drive is dangerous. The Ray people dont seem to understand what I'm telling them when I try to explain this. Maybe I need to articulate it better.

 

[BobJ]

The rudder reference clearly worked with the ACU-200 but I'll have to keep disconnecting it when switching drives (to change the hardover time), which might be more trouble than it's worth. But I would install one on your boat - it does help.

Just for comic relief - The other wrinkle is that I'm currently set up to switch between the X-5 and EV-200 "on the fly." I had the same setup with the X-5 and ST4000+ where I could put one on standby and engage the other. Two fluxgates but the rudder reference and drive were connected to both ACU's. It looks like I may need to rethink this.

(Tom, sorry to throw your thread into a cocked hat.)

 

[tboussie]

The rudder reference clearly worked with the ACU-200 but I'll have to keep disconnecting it when switching drives (to change the hardover time), which might be more trouble than it's worth. But I would install one on your boat - it does help.

Just for comic relief - The other wrinkle is that I'm currently set up to switch between the X-5 and EV-200 "on the fly." I had the same setup with the X-5 and ST4000+ where I could put one on standby and engage the other. Two fluxgates but the rudder reference and drive were connected to both ACU's. It looks like I may need to rethink this.

(Tom, sorry to throw your thread into a cocked hat.)

Bob - no problem. The more info the merrier. It does confirm my instinct to stay the hell away from the Raymarine AP (with apologies to all the RM devotees out there), or more generally from mixing AP components.

Tom