Raymarine Wheel drive autopilot on Hunter boat- to upgrade?

kappykaplan · May 1, 2022

jviss said:
I guess he meant "things get a little hinky," as in precarious or unreliable.

Yes.

MikeHoncho · May 1, 2022

jviss said:
I guess he meant "things get a little hinky," as in precarious or unreliable.

When things get hanky “ crazy, spirited, not planned. The CPT has been completely reliable. The clutch ( how I have my system orientated. ) is down low .

dLj · May 1, 2022

MikeHoncho said:
When things get hanky “ crazy, spirited, not planned. The CPT has been completely reliable. The clutch ( how I have my system orientated. ) is down low .

Yes, that does depend upon where you have it set-up. Where it is on my brothers 35.5 it's quite accessible.

I seem to recall we did a "reverse" installation (details are alluding me, we did it a number of years ago now). The layout is very nice in that boat. The initial installation was done long enough ago that CPT had a bit of a funky way they tensioned the belt that would come loose. But subsequently they changed that design and it is now much more robust. We haven't had a problem since the new mounting system was installed. Just a FYI - CPT offered to send us the new mounting designed equipment free of charge. They did that a couple years after we installed the original equipment. They really stand behind their equipment.

I don't own a CPT on my current boat, nor would I go that route in the future on this boat as I have a really excellent linear drive mechanism. But if I ever have a boat that may need this type of autopilot, I would not hesitate for a second to get a CPT.

dj

MikeHoncho · May 1, 2022

I’ve considered reversing the drive motor so the clutch is to the stern.

dLj · May 1, 2022

MikeHoncho said:
I’ve considered reversing the drive motor so the clutch is to the stern.

That's how we did the installation. Never has been problem in that geometry - very easy to just reach down and pull... I seem to remember that's called a reverse installation, but that might be related to the Combo of side plus geometry - it's too long ago now for my memory to have those details clear.

dj

p. s. The new mounting bracket they make for this is really nice (I use the term new rather loosely)

dLj · May 1, 2022

capt.amory said:
Thank you :-D I have decided on the CPT as well. costs $2000 it generates 4-5 times the torque that a typical wheel drive pilot uses

"The CPT can produce up to 86 ft-lbs (116 Nm) of torque to your vessel's steering wheel. This would be the same force as hanging an 86 lb weight (or two 5-gallon water jugs) from one of your wheel's spokes one foot out from the center. Other wheel pilots may typically only produce 30Nm, or 22 ft-lbs of torque."

You won't be disappointed. I know several full time cruisers crossing oceans with these and I've heard nothing but praise.

dj

MikeHoncho · May 1, 2022

I recommend orientating the drive so the clutch is facing you.

jviss · May 2, 2022

So, a sidebar, but I read the CPT web site - I think all of it - and there's a nit I'd like to pick. It could be a misunderstanding on my part, or I could be right. And, we can all have a good argument/discussion about it here, unless the OP objects, at which pint I will desist.

Don't get me wrong! I'm not knocking the CPT pilot. I respect that they've developed a robust, "bullet proof" pilot that is strong, reliable, repairable, essentially waterproof, and that they've been in business with this for a long time. That's a testament to the product and the satisfied customers.

The website says this, as an answer to a "common question:"

(here's the page: Common Questions)

How is the CPT different from other autopilots?
The CPT is a rugged stand-alone autopilot that keeps a vessel on a magnetic compass course. With your boat on course, set the CPT and it will steer and keep your boat on that course, rain or shine. It is a course-keeping autopilot. For simplicity and reliability it does not have connections to rudder transducers, GPS, or other electronics. The CPT is designed for immersion and cockpit mounting, and is powerful enough to steer heavy displacement boats.

The teeth on the belt, wheel, and clutch eliminate slipping. The simple to use manual clutch engages the drive, and also provides emergency overload protection.

Please be aware that a magnetic compass course is not the same as a GPS course. In keeping to a good average compass course, your vessel will still be subject to drift from wind and currents. This is apparent when observing your GPS over time, and on a passage you will still need to navigate and make periodic adjustments.

The point I will quibble with is the use of the term "course." Based on what I infer about the design of this pilot, it is not a course-keeping pilot, but a heading-keeping pilot. The CPT will keep you on the heading that you are on when you enable it. It will not, can not, hold a course, magnetic or otherwise, since it has no data about current, COG, or anything else like that. So, if you rewrite this answer substituting "heading" for 'course,' it is correct.

Interestingly, they state correctly that it holds a heading on the "Features" page:
"Flip the toggle up to hold heading and the autopilot will maintain the current heading." And even the legend on the control panel says "HOLD HEADING" and "STANDBY" for the two positions of the toggle switch.

So, generally correct, except for whoever wrote that answer.

That said, it would be cool if there was an option to turn over control of the wheel drive to an autopilot computer, and if there was a magnetic clutch option. The former would probably be easy to accomplish, and you could add a toggle switch for "CPT of EXTERNAL" computer.