Joints and Physics (Hydraulic Arms)

I'm fairly new to Construct 2 and was wondering if anyone knew of an example that demonstrates how a hydraulic arm might work. For example, you push a button and it changes the length of a line used in a distance joint to effect the arm itself (think of how the hydraulic arms on a garbage truck affects the position of the door)? Also, an example of how a joint would work if it were controlled by rotation (such as a wrist). I'm working on some robotics as part of a game and it'd be much more realistic with this effect. Thanks!

AhemExcuseMe - i tried doing this some time ago (trying to make legs that walked) but was very unsuccessful due to the odd workings of physics and revolute joints.

i tried to make an example of this using physics and joints but after fiddling with it for some time i decided that simulating a hydraulic joint was much easier than trying to get the picky revolute joint system to work. sometimes the joints of the arm piece would get "pushed out" of where its joint was (attached to the base), and when changing the height of the arm it didn't push the upright piece like i had thought it would.

here's what i came up with:

dropbox.com/s/7cv9qr7910xaoh8/hydraulicarms.capx

if you want to try and fiddle with it, remove the pin behaviour from the arm1, add physics back and update the event sheet to reinclude revolute joints. maybe you will have some ideas that i did not!

i did learn a new expression that may or may not help with my legs project though <img src="smileys/smiley36.gif" border="0" align="middle" />

Thanks wretchedshark! I tried to look at this file, but I have build 114, so it doesn't open. Do you have a beta version? It says you have build 116.

yes, i got one of the beta releases to look at another user's capx

scirra.com/construct2/releases