Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: robertdouglas on October 25, 2012, 09:55:47 AM

Title: Need help designing simple robotic device.
Post by: robertdouglas on October 25, 2012, 09:55:47 AM
Need someone to help us design and build a simple robotic device. 
Basic requirements :

12 volt dc operation
must operate quietly with low power consumption
portable and self contained  (can be connected to a external 12v dc battery)
must have enough power to PULL  a suspened 20lb weight a distance of approx 12 inches then allow the weight to freely move back ,   speed and interval needs to be easlly adjusted ,  ideally with a  simple remote control
here is the biggest issue,  must be very durable and inexpensive with as few moving parts as possible  ,  these need to be used in  extreme conditions,  sun,  sand,  heat,   rain,,,etc,,,,must be weatherproof
we are hoping for a device that is in the shape of a telescoping tube
In a nutshell  its a  heavy pendulum that we need to apply periodic pulling force to keep it swinging with the help of gravity and inertia

we have contacted motion control companines without success,  linear actuators are too slow and also too noisy and expensive 


robert douglas
materials handling

yes we are willing to compensate for a design that meets our needs

please contact us directly   [email protected]  with questions




Title: Re: Need help designing simple robotic device.
Post by: Billy on October 25, 2012, 12:54:50 PM
Need someone to help us design and build a simple robotic device. 

yes we are willing to compensate for a design that meets our needs

please contact us directly   [email protected]  with questions

They do this in clocks. Go look at Big Ben and see how they did this 100 years ago.
Or go to Walmart and buy a suspended swinging baby chair and see how they do it out of plastic.

If you can't get what you need from that,  I will do it for you. Send me a private message and I will provide my background for your review.
Title: Re: Need help designing simple robotic device.
Post by: Soeren on October 29, 2012, 09:22:38 PM
Hi,

[...] must have enough power to PULL  a suspened 20lb weight a distance of approx 12 inches then allow the weight to freely move back ,   speed and interval needs to be easlly adjusted ,  ideally with a  simple remote control
here is the biggest issue,  must be very durable and inexpensive with as few moving parts as possible  ,  these need to be used in  extreme conditions,  sun,  sand,  heat,   rain,,,etc,,,,must be weatherproof
we are hoping for a device that is in the shape of a telescoping tube
In a nutshell  its a  heavy pendulum that we need to apply periodic pulling force to keep it swinging with the help of gravity and inertia
That is very inefficient, all things considered, compared to a slight magnetic push at each second (or each n*2) pass(es) of the center line.

A magnetic push at the right time and strength will compensate for the losses in the system and keep it going without a sound - A neodymium magnet on the pendulum and a a stationary electromagnet, which can be encapsulated in plastic or fibre glass.
The timing is done by detecting the current induced in the coil when the magnet passes it. No moving parts to break or wear down added.

The above is assuming that the pendulum has to be in constant movement once started (manually I suppose) - if used for stop/start action, it will be very slow to get the pendulum up to the wanted oscillations.