Both of these "Technic Links" come in the NXT retail kit and the Education Resource Set. How have you used these unique parts and can you point us to any of your NXT creations that use them?
I find them rather limiting - I guess the idea of it is that it has multiple degrees of freedom in the 'ball joint' similar to what people have in their skeleton.
I tend to use beams / leftarms with non friction pins instead - they are more effective and dont come apart as easilly.
On the other I have used it for cosmetic reasons - e.g. to support a pivotable robot head from either side to make it tilt left and right.
I tried to use those in the construction of a mono-motor biped, but it didn't work out very well. Not that it was those technic links' fault, more just non-stable construction on my part (it was my 4th creation).\
They seem like they may have been designed for train wheels. However if you hook one end up to a motor and do a partial turn, you can achieve either a pushing or pulling action at the other end of the beam.
I've seen this before in the the pen assembly of The NXT Step Idea book's Marty robot. In addition, I've seen it used in the "Orange Book". There was a small humanoid robot that could open its mouth or raise its eyebrows - both mechanisms augmented by this type of beam.
I used them one to articulate an animatronic eyeball project. I never got around to taking video / photos as I couldn't quite get it to work properly. The ball and socket was just a little too flimsy for me and the thin arms were difficult to constrain.
I've used them as a structural to hold items together (not to keep them rigid or solid, but to keep them from expanding to far).
I've also used them to secure NXT cables. You can run a piece on two of the black friction ball pins. Then connect the piece across them. Run the NXT cable under the piece. It keeps it from flapping around. You can run a couple under one piece this way.
Anonymous said…
Two of each are, of course, needed to construct Alpha Rex. I presume that is the reason they are included in the retail kit.
I use them to raise a hidden part on a explorer robot. The explorer (spy) robot's purpose is to explore unknown terrain and therefore has to estimate the size of obstacles to see if it can climb over, has tot try to run arround an obstacle or can pass underneath an obstacle. The hidden part infact contains the ultrasonic sensor and by highering or lowering the part a different angle from the sensor to the ground plane is obtained which makes it possible to estimate an obstacles size. The beams give the freedom of movement needed to obtain the angles. From an estaetic point of view, I think they give that extra technic (mechanical) look to a robot.
I use them to raise a hidden part on a explorer robot. The explorer (spy) robot's purpose is to explore unknown terrain and therefore has to estimate the size of obstacles to see if it can climb over, has tot try to run arround an obstacle or can pass underneath an obstacle. The hidden part infact contains the ultrasonic sensor and by highering or lowering the part a different angle from the sensor to the ground plane is obtained which makes it possible to estimate an obstacles size. The beams give the freedom of movement needed to obtain the angles. From an estaetic point of view, I think they give that extra technic (mechanical) look to a robot.
there are many ways to use it, but you need to fix the rest of the construction first. They originate from a car front steering, so that the wheel can not only steer side ways, but also move freely up and down, see the large racecars.
Martyn
Anonymous said…
I used two of them to transfer the spinning motion of two gears to the flapping motion of the parrot I made. It turned out alright, but I found that they didn't hold well if the motor spun too fast.
Comments
I tend to use beams / leftarms with non friction pins instead - they are more effective and dont come apart as easilly.
On the other I have used it for cosmetic reasons - e.g. to support a pivotable robot head from either side to make it tilt left and right.
Tim
--
NXTMonger
nxtmongersworld.blogspot.com
I've seen this before in the the pen assembly of The NXT Step Idea book's Marty robot. In addition, I've seen it used in the "Orange Book". There was a small humanoid robot that could open its mouth or raise its eyebrows - both mechanisms augmented by this type of beam.
damo
I've also used them to secure NXT cables. You can run a piece on two of the black friction ball pins. Then connect the piece across them. Run the NXT cable under the piece. It keeps it from flapping around. You can run a couple under one piece this way.
Martyn
http://nxtgallery.com/index.php?page=viewbot&id=147010386
Bu92
http://www.youtube.com/watch?v=eRBV37GN0Fc
P.S
Could someone please to a post asking what 'Technic Axle Joiner Double Flexible' (45590)(name from peeron.com) is used for?