Random part of the day: Linear Actuator 10-15 M

I’ve heard this mentioned, but never seen one in person, or video of how it works. I’m guessing you hook an axle up to the orange bit, and rotating it causes the shaft to extend or retract, depending on whether you rotate CW or CCW. And that Fabuland bulldogs would put it to an entirely different and more nefarious use.

Part exists only for 42131 (which contains 6). This means 1397 sets. 1340 members own this set. This means 57 sets extra (i.e. people owning multiple copies). Would be good to own just one but there is just too much good stuff to buy nowadays - must prioritize for the upcoming 42145.

*** the piece is not rare - it has appeared in many sets over the years in two different lengths (10-15M and 15-23M) it is however new in this colour (black and dark blueish grey) for 42131.

@PurpleDave: Assuming it works like element 4612100, you're spot on. Interesting that this one has you stick an axle into it, while 4612100 has an axle sticking out that you attach something to.

Linear actuators, when paired with PF or other motors, are an alternative to pneumatics. IMHO they’re more reliable, but some applications are more genuine with pneumatics.

@TheOtherMike:
I was actually thinking about that at a show last weekend, but in relation to motors. Motors also typically have an axle socket rather than an axle stub. My initial thought was that, if you break an axle off in the socket you might be able to extract the broken piece and recover the motor, where breaking the axle off a motor renders it largely useless. But I just realized two other effects. One is related, which is that you aren’t going to whack the socket against a table and snap it off, but you might do that with an axle stub. A few members of my LUG have had trains derail off the table nose first and shear all or part of the top pin off their 9v motors, which you can’t remove or replace. At that point you can only hard-mount the motor to a short car so it doesn’t need to pivot on the pin. The other issue is that a stub needs more space to build out from, if you’re not just putting a gear on it. You’d need either an axle joiner to extend the axle, which means you need two studs of clearance just for that. A socket lets you pick the length of your axle so you don’t need a joiner, or so you can place it wherever it’s most convenient. You can still use a 2L axle to have a stub axle if you want, but you can’t invert a stub to make a socket.

This is the newer version that comes with the 42131 CAT. The older version has a light grey casing.

I wonder if there is any difference from the previous version 61927 apart from the colour, maybe Lego just discontinued it and then realized it's pretty useful so needed to bring it back! Mainly used in lifting bulldozer blades, crane booms and excavator arms, although a different use found for lifting skips in 42024 and container in 42078.

@PurpleDave: Those are some good points. I hadn't realized motors have a socket now, all the Lego motors I have are years old and have stubs.