CTP Autopilot problems

[johnmyjo]

Help Please our CTP autopilot will not hold a course for more than a few minutes and veers off to either port or starboard and will not correct even after going a complete circuit.
I have contacted the manufacturer and followed their instructions several times to no avail. It is on a PDQ 36. It does not hold on flat water motoring or any point of sail. As a last resort I reinstalled an old Autohelm wheel pilot and it worked.

[CSY Man]

Originally Posted by johnmyjo

Help Please our CTP autopilot will not hold a course for more than a few minutes and veers off to either port or starboard and will not correct even after going a complete circuit.
I have contacted the manufacturer and followed their instructions several times to no avail. It is on a PDQ 36. It does not hold on flat water motoring or any point of sail. As a last resort I reinstalled an old Autohelm wheel pilot and it worked.

Old or new generation CPT?
I had 3 of the old ones, constant problems, one of the issues was a burned out motherboard. After a few years with the CPTs I sold the last one and installed a WP32, much better.
Heard good things about the latest generation CPT and if that is what you have, it should stile be under warranty.
Use a handheld compass to check for magnetic interference maybe..?

[Bill O]

Keep the CPT motor/wheel mount and switch the brains out for a pypilot.


Wouldn't even bother trying to fixi the original computer when a much more advanced AP computer (pypilot) is available at a very reasonable price.


Here is a video of

video link

a CPT using a wiper motor to run a large steel boat.


We have one running a below deck hydraulic pump for our AP for several years now and works great.


Bill O.

[johnmyjo]

Problem solved?? I disconnected my solar panels and it works . I don’t know why

[a64pilot]

Originally Posted by johnmyjo

Problem solved?? I disconnected my solar panels and it works . I don’t know why

My guess would be something in you Solar system is outputting RF interference, I don’t know why, but don’t think it’s a panel or it still would be?
You can get RF shield wire to cover the CPT wiring, but I’ve never had good luck with that myself.

[BugzyCan]

Do you have a volt meter on your battery bank, and can you check the voltage on it the next time CTP goes wonky? Maybe there is a voltage fluctuation causing it, or perhaps a bad battery(s).

[johnmyjo]

I thought that it was fixed but I spoke too soon. It worked under sail but today motoring it pulled to starboard as soon as it was engaged. The only electrical item connected was the engine alternator. Could it have an influence.It is 10 feet from the control box.

[Bill O]

Have you changed anything electrically related just prior to the CPT malfunctioning?
If you have an older CPT, it is more than possible that the main board in the control box is malfunctioning. Do you have another one to swap out and check it?
Not to sound like a broken record but the pypilot could be an easy/inexpensive fix (~$100) then you will be up and running again. Doubt you'll be able to service yours for less and you would also have more of a state of the art AP brain.


Bill O.

[hpeer]

Originally Posted by Bill O

Keep the CPT motor/wheel mount and switch the brains out for a pypilot.


Wouldn't even bother trying to fixi the original computer when a much more advanced AP computer (pypilot) is available at a very reasonable price.


Here is a video of

a CPT using a wiper motor to run a large steel boat.


We have one running a below deck hydraulic pump for our AP for several years now and works great.


Bill O.

^DO THIS^

The PyPilot will use it’s internal gyro compass OR you can connect it to a GPS puck antenna, like you use for a PC.

It comes with a little pocket remote, but will also work via its own wireless from your iPhone or a computer.

I can help talk you the modifications if you desire. It’s really quite simple. In th e end all you are filling with the CPT is using the drive motor. The circuit board and relays are now redundant, as is the CPT control head.

You need to buy both the autopilot computer and the drive controller.

$180

https://pypilot.org/store/

[a64pilot]

If someone would build a box that would replace the CPT box, but be an autopilot that could be connected to a plotter I’d buy it.
I don’t think I’m alone either, the CPT drive has plenty of power and speed for me without all the complexity and power drain of a below decks autopilot, plus the 5 min change out to a back up one.
It’s only draw back is that it’s just a simple heading hold autopilot.

I think there would be a market for it, I wonder why CPT doesn’t do this?

[Dsanduril]

Unbalanced DC electricity creates a magnetic field that can hugely effect AP fluxgate compasses. The higher the current the greater the effect.

Since you report problems that seem to be “fixed” by removing charge sources I would suspect positive and negative are not flowing together (when +/- cables travel closely together the magnetic fields cancel each other).

Since it used to work I see two options; a change in wiring, or a bad connection somewhere has changed how current flows. If the latter I would start to look at negative connections. Depending on how things are wired there could be current in the negative bonding wire to the engine block that didn’t used to be there.

That’s my 2 cents, you could confirm by taking the alternator offline while motoring (with care, in a way that won’t destroy the diodes). If that resolves thing then start looking at main power cabling (or look at moving the AP compass either temporarily or permanently).

[hpeer]

Originally Posted by a64pilot

If someone would build a box that would replace the CPT box, but be an autopilot that could be connected to a plotter I’d buy it.
I don’t think I’m alone either, the CPT drive has plenty of power and speed for me without all the complexity and power drain of a below decks autopilot, plus the 5 min change out to a back up one.
It’s only draw back is that it’s just a simple heading hold autopilot.

I think there would be a market for it, I wonder why CPT doesn’t do this?

I think that’s exactly what we are recommending with the PyPilot. It connects to OpenCPN. That’s the plotter.

CPT has tried to modernize this controller. But Sean with PyPilot is way ahead. Sean does NOT have, nor seems to be interested in the drive end. But you could use the Pelagic ram OR the CPT drive (old, don’t know about new).

There is a convergence here that really neat.

[maelduin]

Did you just install it? If so, have you tried reversing the direction?

[Exile]

Originally Posted by a64pilot

If someone would build a box that would replace the CPT box, but be an autopilot that could be connected to a plotter I’d buy it.
I don’t think I’m alone either, the CPT drive has plenty of power and speed for me without all the complexity and power drain of a below decks autopilot, plus the 5 min change out to a back up one.
It’s only draw back is that it’s just a simple heading hold autopilot.

I think there would be a market for it, I wonder why CPT doesn’t do this?

Take a look at Pelagic (https://pelagicautopilot.com). Sophisticated compass and also steer-to-wind function, but designed for tillers or below deck rams. The electronics are completely standalone (not designed to connect to a plotter). I'm looking into it as a backup to my aging B&G controller that would either connect to my existing ram or be tied into a 2nd one. I like the idea of the CPT as a backup as well, except in the event of a failure with the steering system (Edson chain/cable).

[Exile]

Originally Posted by hpeer

But you could use the Pelagic ram OR the CPT drive (old, don’t know about new).

I didn't know that Pelagic made below-deck rams, only tiller actuators.