Electrically controlled expandable rod

[icydash]

Hey all,

I'm working on a project and could use some advice for a component part. The project is a small robot that's about two inches long. The robot needs to have some kind of microcontroller-controllable retractable/expandable rod or arm that fits within about an inch space, but can expand out to about 3 inches. That arm will have a sensor on the end and reach out and "touch" things. I'm not sure what to do for the expandable arm component. I've been thinking of some kind of electronic antenna-type thing, but could really use some help! Of course the cheaper and sturdier the better (because if the robot runs into a wall, I don't want the arm to bend).

Thanks in advance!

 

[(*steve*)]

See here.

 

[Colin Mitchell]

It's called a SCREW JACK

 

[Colin Mitchell]

You can also use a servo with a crank and push-rod

 

[(*steve*)]

I was thinking about a scissor arm, although you could possibly activate this using a jack screw.

 

[KMoffett]

Google: micro miniature linear servo

Ken

 

[icydash]

Thanks for all the suggestions! I was thinking about something like a scissor arm or jack screw, but I'm not quite sure how to electrically actuate those. The miniature linear servo may work -- with one of those, can I control how far out the pin extends, or is it either (1) all the way out; or (2) all the way in? Do you have any suggestions for a specific part on like Digikey (sorry, I'm bad at looking at the bagillion parts on Digikey and finding the right one!)