[Swansea Hackspace] Project

[Justin Mitchell]

On Tue, 2016-03-08 at 23:41 +0000, jody thomas wrote:
> Hello I was wondering if you could help, I'm designing a product. It's
> going to be like the grabbers elderly use but motorised. Similar to
> robotic arms used in manufacturing. I need to know how to move the
> claw, i have looked online and have seen alot of servos being used but
> I need to be able to control it using buttons and run of batteries. 
> Thank you for any help 

A simple enough project in principle, there are lots of grabber/claw
designs on thingiverse that you can download and 3D print or laser cut. 

They tend to use a single servo as the motor, you then need a very small
amount of computer power to run the servo, one of the small Arduino
family boards will do the job, even just an 8-pin ATtiny85 chip will be
enough.

One IO pin to the servo, one or two for buttons, and the battery.  You
can either have two buttons: one open, one close.  or have a single
button that whilst held makes it close slowly, and when let go makes it
open slowly.

how strong the grip is will depend on a mix of the design of the claw,
and what size/strength of servo motor is used.
 
hope that helps