OpenMarine

Hi all,

I'm busy getting my boat ready to cross the Atlantic in December.  We are a 2017 40ft Nautitech catamaran, with a standard B&G setup. However, I want to have the redundancy of a second autopilot in case of mechanical or electrical failure. I was considering going for a passive "Hydrovane" system, but it's v. expensive and difficult to fit to a catamaran. 

At the moment, i'm thinking of going for a Jefa DD-1 direct drive as it's over the 100 m.Kg I need for the boat. https://www.jefa.com/ftp/steering/brochu...ochure.pdf

I'd then love to couple this with Pypilot, so I can have a completely independent system in case of a NMEA backbone failure (say from a lightning strike). I also think the OEM stuff is seriously overpriced these days.....

For getting Pypilot to work with the DD-1, I assume i'm correct that the missing piece of the puzzle would be the motor controller?  It looks like these aren't available to buy at the moment, so i was wondering if there is a step-by-step guide to building one.  I'm pretty handy at building systems (designed and built my own watermaker with Aurduino controller), but i'm not an electrical engineer by background, so don't have the skills to easily take a proper schematic and translate that into an Aurdino / ESP32 build. I'm good with online tutorials (so know enough to be dangerous).   :-)

So my questions:
- Is a DD-1 + PyPilot (with compass, rudder sensor, etc) a good backup option?
- Are there any easy guides for building an appropriate motor controller?

Thanks so much in advance

Casp.

Check out the schematics:
https://github.com/pypilot/pypilot_schematics

It is possible to use an arduino driving hbridge.

I plan to bring my store back in a few weeks. I am taking a break to focus on improving the software right now.

Thanks Sean, I may well buy one...

Although i'm now thinking of a plan B and following your example of creating something to go on the steering wheel using a wiper motor and a belt drive.
Again, i'm after a system purely as a backup in the event that I had something catastrophically go wrong with my L&S actuator that I couldn't repair. A drive attached to the wheel feels like it's always going to be smaller and more efficient as the steering has already been geared down to be managed by a human.  


Thanks

Casp.

its hard to get the same rudder movement speed if you drive the wheel unless you spin it really fast.

you may have to reduce sail in rougher weather if your motor isnt fast enough.