OpenMarine
Linear actuator for outboard - Printable Version

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+--- Thread: Linear actuator for outboard (/showthread.php?tid=3814)



Linear actuator for outboard - adamjs16 - 2021-12-22

I want to use PyPilot to construct an autopilot, for my outboard on my dingy.

In terms of linear actuators, it seems I have two options. Both have built in rudder feedback and end of travel switches.

  1. pcnautic bare tiller drive
  2. Many options are avaible on Aliexpress (some of which listed here)
The pcnautic looks like a good unit and seems like the safe option. However, I have recently lost my job and I'm looking to save money. There are so many options on Aliexpress, it is hard to know where to start. None of them have many reviews so it is hard to judge the quality.

I would appreiciate some advice on which option to take. I would like to know if there is much of a difference in quality between pcnautic and aliexpress. Could anyone recommend or send links to actuators on aliexpress that have been tested? I know a few have been discussed on the thread I linked, but they are all different, which has just made me more confused.


RE: Linear actuator for outboard - seandepagnier - 2021-12-22

I ordered one a few weeks ago from aliexpress but it has not arrived yet.

There were dozens of possible options to choose from. It's difficult to test them all, but ideally I would like to compare several.

Please post your experience if you order one of these.


RE: Linear actuator for outboard - PaddyB - 2021-12-23

Some links in this thread to what looks like the pcnautic/pelagic ram but without endstops & position feedback . I have the pcnautic which seems great but haven't tested it yet.
https://forums.ybw.com/index.php?threads/rant-raymarine-st1000-tiller-pilot.510265/page-5#post-7757322


RE: Linear actuator for outboard - adamjs16 - 2021-12-23

I am considering getting this actuator from AliExpress.

However I'm unsure what spec is best. My boat is a 4.35m dingy with a 30hp outboard. It's top speed is about 25 knots. This is very different to the other boats I have seen PyPilot implemented on.

Which option for speed and torque do you think is best?
70 mm/s 200N?
45 mm/s 400N?

I will of course post results when I get this working. Will be interesting to see how PyPilot handles a reasonably fast dingy.


RE: Linear actuator for outboard - rastam4n - 2021-12-23

(2021-12-23, 01:23 PM)adamjs16 Wrote: I am considering getting this actuator from AliExpress.

However I'm unsure what spec is best. My boat is a 4.35m dingy with a 30hp outboard. It's top speed is about 25 knots. This is very different to the other boats I have seen PyPilot implemented on.

Which option for speed and torque do you think is best?
70 mm/s 200N?
45 mm/s 400N?

I will of course post results when I get this working. Will be interesting to see how PyPilot handles a reasonably fast dingy.

I have pypilot connected to an electric hydraulic pump which steers my 200 hp outboard. Works great at speed but only in calm water, in rough water there is too much saturation and pypilot fails with a hard right turn.... so be careful!


RE: Linear actuator for outboard - Onno - 2021-12-24

My biggest concern this aliexpress type mentioned: 8    Inner tube material      Aluminum Alloy
I think they mean the pushrod, that should be stainless steel in our salty conditions.
For example this type from the same shop mentioned the stainless steel: 8    Inner tube material           Stainless steel


RE: Linear actuator for outboard - NWRoamer - 2022-01-19

I'm working on a similar project, using a pre-built PyPilot from Sean to steer an electric trolling motor in my fishing boat. I'd suggest you get under way at the max speed you'd feel good with autopilot on and use a fish scale to measure the max force it takes to turn the tiller. I tested mine, and it took about 3 pounds to turn. Remember that because of P-Factor (prop torque), one direction may be easier than the other, so you may need to test both port and starboard turns. 3 pounds is only 13 newtons, so in my case any strength actuator would do it.


RE: Linear actuator for outboard - emiliano_az - 2022-01-23

Hi all, I am new to pypilot and trying to figure out what component I should buy. About the linear actuator what is the minimum and best speed? What about 40-50 mm/s?


RE: Linear actuator for outboard - adamjs16 - 2022-01-23

I will definitely measure the torque needed to steer the tiller before buying the actuator.

That is a good question. It seems like that is the speed people are going for but I can't find a definitive answer.


RE: Linear actuator for outboard - rastam4n - 2022-01-23

Re: Speed of the actuator, I use a 70mm/s actuator, it was actually too fast for my setup, as I am mirroring the movement of my main engine. Basically, the autopilot moves the main engine to steer with a electric hydraulic pump, and the actuator moves the auxiliary engine at the same (close to the same) time. I had to slow the speed down using software, otherwise the Auxiliary engine would always try to beat the main engine to the new position. I figure I am using about 1/3 of the speed. Having a little extra is not bad though, so I would recommend 70mm/s, and you can always slow it down in the settings if you have to.