Mechanical help involving servo & limit switch on helmet

Hi,

I’m an electrical engineering student with a little experience and a passion for tinkering, but I’m not that great at mechanical designing. I’m working on a project to build a helmet where when I press a button a motor drives a face mask open and up sliding back across the top exposing my face, then when I press the button again I’d like the mask to close back up.

Surprising I found a guy who built a costume where the helmet does this, but there is no info available on how he managed this. I’m not sure if he used servos or a motor and limit switches.

http://www.youtube.com/watch?v=iS2yRKO-5qk&feature=related
I’ve included a video of this guy’s costume where the helmet opens and closes for an example of what I’m looking to do.

The helmet I am building is a two piece helmet so whatever he used I can see working for me, but I don’t have any other info on how he did it.

Would it be easier to accomplish this with servos or I imagine with a small logic circuit, two limit switches, and a dc motor? Also what are some ideas on the mechanical side as to how to make this work? I’ve thought of a track system in the helmet but am having a hard time and space is an issue as it’s a helmet. I would greatly appreciate any help.

Hello.

It’s difficult to help you much with your problem as you’ve described it so far since you have a very specific problem (you have a particular helmet, and probably some specific idea of the performance you want), but you’re only giving very general information. You have to figure out more details yourself first, and then you can ask some specific questions that someone might be able to answer. Even in your seemingly more specific question toward the end, you’re asking for a somewhat subjective call about how easy something might be. Do you actually know what the “small logic circuit” would be?

You could begin by considering the parts in this small walking robot tutorial:

pololu.com/docs/0J42/1

That gives you some benchmark for size and complexity, and you can think about whether you could make something smaller without servos. Or, if there is a limitation to the approach, you could ask more specific questions, such as can you get a multi-turn micro servo (no) or a stronger or faster servo (yes, but it will be bigger). Once you start thinking about these specific questions, you should be able to help yourself more, too, since things like the size and strengths of various servos are available all over the place.

- Jan