Jaemus
Experienced Roboteer
Joined: 01 Apr 2009
Posts: 2674
Location: NSW
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I like Glen's idea, the mechanical simplicity of that cannot fail, it would be a bit like hokey pokey or pokey dokey or whatever you called it
warning light wont help you as you really want to be able to slam the thing back and forth
quick story, the original version of Das Boot (then called Venator) had a drill powered threaded rod type lifter, in which i put some limit switches, and also the drill was controlled by a servo switch setup it was awful and killed itself almost immediately in combat. such things can't be trusted imo!
Das Boot's version just uses a scooter motor that doesnt mind being stalled for lengthy periods, so I slam it around like nobody's business
if i was to do an electronic setup for a brushless driven lifter, my vote would go to an optical position / angle sensor (encoder) like Jake mentioned, with an Arduino and some code that goes along the lines of zeroing the signal to the brushless controller if its going in the up direction and it's nearly at or beyond a point slightly before fully up, only then allowing signals in the down direction until its back behind the limit point. Can do one for the down direction too but that can affect you being able to easily position it fully down, so in that case I'd set it up so it reduces 'throttle' to a few % for that direction after a similar limit point, so it closes softly for the last cm or so of movement, but allows it to keep trying to turn gently even after it has stopped mechanicially. Arduino's are cheap and pretty easy to wire up for RC signal inputs and outputs so you should be able to cook one up as a signal interceptor type arrangement without too much wheel reinvention, i'd say. _________________ <Patrician|Away> what does your robot do, sam
<bovril> it collects data about the surrounding environment, then discards it and drives into walls
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