linear actuators on aliexpress

[FabianT]

any chance you could repost the link?  it has ... in it

Sorry, haven't been here in a while. Winter in Sweden .

Here is the link (still shows ... but works for me?!):

https://www.aliexpress.com/item/40002079...4c4dktEZwx

Mulitple different speeds, length and thrust.

Worked extremely well during the three months that I've been using mine.
Edit: The most notable difference to the autohelm/raymarine is the noise! They are really really quite. And the noise it makes is much nicer to life with!

[southwest24kn]

I am testing this one:
https://www.aliexpress.com/item/1005002249127759.html
Purchase option selected: 12V 100N 60mm s, Stroke 250mm

Just on the tabletop test bench for now but seems to be fast (much faster than Raymarine ST1000), quiet enough and with sufficient torque.

From memory one purchaser opened it up and confirmed it had decent metal gears.

[seandepagnier]

I am testing this one:
https://www.aliexpress.com/item/1005002249127759.html
Purchase option selected: 12V 100N 60mm s, Stroke 250mm

Just on the tabletop test bench for now but seems to be fast (much faster than Raymarine ST1000), quiet enough and with sufficient torque.

From memory one purchaser opened it up and confirmed it had decent metal gears.

What about the linear movement?   Is it recirculating ball or lead screw?

I got the version with 170mm/s and it feels perhaps too fast after all, but I will try it with a balanced rudder.

[southwest24kn]

I am testing this one:
https://www.aliexpress.com/item/1005002249127759.html
Purchase option selected: 12V 100N 60mm s, Stroke 250mm

Just on the tabletop test bench for now but seems to be fast (much faster than Raymarine ST1000), quiet enough and with sufficient torque.

From memory one purchaser opened it up and confirmed it had decent metal gears.

What about the linear movement?   Is it recirculating ball or lead screw?

I got the version with 170mm/s and it feels perhaps too fast after all, but I will try it with a balanced rudder.

Hmmm don't know.
Any way to tell short of dismantling it to look inside?

[seandepagnier]

I think you need to open it so you can see the threads to be sure.

[Vlisie]

For Europeans, I ordered my actuator at Botland actuator, these look the same as those found on Aliexpress only even cheaper. Especially if you include the extra costs (tax, delivery). I will test this actuator and post my experiences here.

[seandepagnier]

Some months ago I ordered a linear actuator from aliexpress. I recently have been sailing using it, and it has the specifications:

speed: 170mm/s
force: 50N
range: 300mm

https://www.aliexpress.com/item/2255800497051447.html

This turns out to be a quite fast movement speed, and to compound matters, the distance from the attachment to the rudder is only 14 inches instead of the usual 18 or 24 inches. What this means, is it is too fast, as half-speed movement for 200 milliseconds already makes the boat react significantly. I would have done better with a lower speed! Anyway I will increase the distance (and leverage) at the reduction of speed. It can do full range of rudder movement in 1.5 seconds, as beyond 25 degrees or so the rudder stalls (useful for braking but pypilot doesnt know about that yet)

The motor did not seem to get warm at all in use. This is sailing speeds 8-10 knots.
To get acceptable steering I had to adjust the default gains to be much lower.

ap.pilot.basic.D = 0.0192
ap.pilot.basic.DD = 0.0088
ap.pilot.basic.FF = 0.4943
ap.pilot.basic.I = 0
ap.pilot.basic.P = 0.0017
ap.pilot.basic.PR = 0.0017

Compare these to the gains on your boat.

[sd_tom]

I don't see clutches mentioned here.. do they back drive when de-energized enough to be used as below deck?

[seandepagnier]

I don't see clutches mentioned here.. do they back drive when de-energized enough to be used as below deck?

There is no clutch.   There is a simple ball joint (tiller pilot pin) that snaps in place so can quickly be connected/disconnected manually.

[sd_tom]

Ok thanks.  If I go below deck I need a very compact linear actuator due to a very pinched stern (Catalina 38).  The most compact hydraulic ones from raymarine and l&s are still a bit too big so always on the hunt for non traditional options.