Wheel vs Quadrant Autohelm

[baltics2]

I have a Raymarine wheel driven autohelm on my LM30. It is fine under the motor in light conditions but struggles with more than a little chop. I think this is in part down to the degree of slop in the wheel / teleflex system. Is this common experience? I was wondering about switching to a direct to quadrant ram and wondered if anyone had experience of this and what the pros and cons might be.

Alec

[Brian & Glenda]

Our 1983 LM32 came with what I believe is what Raymarine calls the Raymarine SPX 30 Auto pilot system, which in my case consists of a ST6002 Autopilot Controller on the dash (and it's S100 Remote Control - very handy for adjusting the autopilot's steering from the cockpit or when on deck) and another computer under the helmsperson's feet that runs the whole thing. It steers the vessel through what they call a "Drive Type 3 - Linear" ram that drives its own quadrant and rudder position sensor attached to the rudder post.

The system seems to work very well when motoring in all manner of seas, but I don't use the autopilot when sailing; although it is possible to set it up with links to wind instruments so you can do same and it supposedly will follow the wind shifts appropriately to prevent accidental tacks and gybes. The flux gate compass is mounted in the cabinet under the starboard berth, just aft of the aft head partition.

I can dig out more details if you wish, next time I'm down on the boat... should be this Easter weekend... I have to take some pictures for another member regarding the windlass mount...

Hope that helps, cheers, Brian.

[baltics2]

Hello Brian

Thanks for coming back on this. Interesting to get your feedback that the system you have copes well in all seas. I suspect what I have is a cheaper drive solution, but otherwise the components are similar.

I would be very interested to see what the installation looks like at the rudder post.

Kind regards, |Alec

[jandane]

Hi Alec. In general all autopilots are fine in flat sea. When the waves come in and the bow swings from side to side allmost all hobby systems are coming short. The autopilot is coupled to the compas or the navigator. In order to correct a course, at first it has to discover a change from the given/set course. Then it corrects back over corrects and you are sailing +/- 40dg from your track. I do a lot of sailing in rough weather/seas and my experience with a tiller mounted Raymarine ST2000 is, that when wind is less than 10knobs (5m/s) it is fine for motor. The moment the wavetops turns white I always steer by hand and am able to predict and foresee the motion of the boat in a coming wave.If you want something to use ind more heavy wind and for sail, a wind rudder is the solution

[Brian & Glenda]

Here are two photos of what's under the rear deck and connected to the rudder post on the Danish Delight's autopilot.  One photo is taken from the port side, the other from Stbd. In the photos I've labelled the two 'quadrants' as upper and lower arms.  They are really just levers welded to a collar that is firmly affixed to the rudder shaft.  They are not arc shaped quadrants.

After reading Jandane's comments:  Perhaps I was overly generous when I said it worked "very well when motoring in all manner of seas."  The level of efficiency certainly does vary with wind direction and sea state.  If the wind is on the bow and the waves are also pounding the bow, it certainly does tend to veer off course, but it usually corrects itself and we rarely (if ever) have found ourselves "+/- 40dg from your track" as Jandane suggests, but this system is not a tiller pilot like the ST2000 he refers to.  It is a much more sophisticated system.  In calm seas and whitecaps coming at you from any direction it holds it's own.  If the tops of the waves are blowing off ... and the boat is headed into the seas, it would struggle; but I prefer to be in control in such situations, and would not rely on the autopilot in such conditions. 

We did a nice broad reach in ~20 - 25 kn winds and following rolling seas - crossing the Strait of Georgia from the Sunshine Coast to Vancouver Island a couple of years ago; much of it on autopilot and all went very well until as we neared the island, the bow started rounding up.  It turns out that the main had started to overpower the jib in changing wind conditions, thus rounding us up; so we put a reef in the main, and all was well after that.  Sadly, autopilot won't trim or shorten the sails for you!   But it is fun though tiring to surf those big rollers manually!

I have additional photos from similar but slightly different angles if you want to see more about any aspect of the system.

One note of correction to what I said earlier... it turns out my drive unit is a Type 1 linear drive, not a Type 3 as originally noted.  Here is a link to Raymarine's current drive units... I haven't compared the specs of the one on our boat, to these specs though...  www.raymarine.com/view/index-id=579.html

We don't have any slop in our teleflex system... and I've never had to adjust it, but there is lots of advice on the internet on that topic.  Perhaps if your system is similar to ours (It sounds like you may have Raymarine rotary drive, instead of the linear drive we have) if that were fixed, it may perform similarly.  I can see how a rotary / wheel drive autopilot may strain the teleflex more than the linear drive does. 

Hope that helps,
Brian.

Attachments:

[jandane]

Brian - what is the name of your autopilot. I can only find the hydraulic device on your link.
Sorry...I just have to read the post again. St6002. Thanks

[Brian & Glenda]

The drive unit I have is electric rather than hydraulic. It is similar to, if not the same as the Type One under their Mechanical Linear tab in the provided link. I thought the link would take you directly to that tab, but apparently not. My drive unit bears a label professing it to be a Type 1. It being electric is one of the reasons I rarely use the autopilot while sailing. (It burns 18 to 36 watts these specs say.) I prefer sailing to motoring whenever I can, and like to save the batteries for running only the essentials while sailing, enabling a longer time at anchor. My solar panel helps in this regard... but I really should invest in a larger battery bank than the one currently on the boat.)

I believe that some components of my autopilot system are now obsolete. (including the ST6002) If considering a replacement unit for your tiller autopilot ... best talk to a rep to see what's available and perhaps compatible with the rest of your system.

Brian.

[jandane]

Thanks. For this season I will leave it. I have just installed waterheater, electric toilet, holding tank, Dometic CRD50 cooler and a bow thruster plus redone lids and floor with new varnish, so......

[baltics2]

Brian, Jandane Thanks for coming back on this and particularly for those annotated photos Brian. That looks all very familiar and is very helpful. I suspect I have essentially the same Raymarine system as you, with the exception of the drive.

Interesting to hear that you have no slop on your wheel steering which suggests we shouldn't need to live with what we have. Ours is like an early '70s Datsun. And the play is giving the autopilot a hard time. It sounds as if I need to start with the steering box.

I have been following Classe Mini and am envious of sophisticated autopilots they run and which seem to cope with all levels of sea. And the price of the kit is pretty much the same as bog standard Raymarine.

Ah well, back to restitching the foot of my main. Only three feet to go.

Kind regards

Alec

[Brian & Glenda]

I found this on the internet, relating to installing a Teleflex steering system. Perhaps the adjustment of the nut as described under Section A of Page 2 has worked loose?

www.m2omarine.com/fckimages/pdf/MECHANICAL/11.pdf

Hope that helps, Brian.

[Brian & Glenda]

I should have added that I don't know if this is the correct instructions for the model of Teleflex on your boat or my boat, but I expect that adjusting same would be similar on all models.

[johnwebb]

I have been doing things to my LM32 for some time and have got nice holding tank and water tank gauge, holding tank deck pumpout and instruments sorted. I am now playing with autopilots. The boat had a Raymarine ST4000+ with tiller ram going to an extra stubby tiller with excessive play. I did attach a wheel actuator I happened to have in the garage, left over from changing to a ST6000+ (?) on a Dehler 36. This worked but very badly due I am certain to the backlash in the wheel steering, I had assumed this is in the wheel box but need someone to watch the rudder end of the cable to be certain. The manufacturer of the box ignore my emails for help! I am experimenting with going back to the tiller without play but am not hopefull it will be good enough and really want the operational simplicity of the direct rudder actuator type, push a button to engage. My experience of the ST6000+ is that it will be extremely good so assume it's successor will be as well. It had acceleration sensors so detected yaw before it was obvious, had a built in arse! They really worked. Hence I am very interested in Brian & Glenda's pictures.