Author Topic: Most Economic Linear Actuation?  (Read 1154 times)

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Offline VegaObscuraTopic starter

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Most Economic Linear Actuation?
« on: October 20, 2010, 10:50:07 PM »
In my opinion, one of the most important parts of a robot is the ability to reach out and do something.  Sure, that could be done with a robotic arm, but I think that would seriously over complicate an otherwise fairly simple task.  I want to learn how to cheaply make a pole that extends straight out.  All the linear actuators I see online cost around $100 and are capable of much more powerful feats than most people need.  I want to find a way to create an extending pole (I wouldn't call it an arm) with a stroke of about 1 foot and material cost of about $15.  Does anyone have any idea how to get started?  Am I being too optimistic with my goals?

Offline rbtying

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Re: Most Economic Linear Actuation?
« Reply #1 on: October 20, 2010, 11:37:31 PM »
I'd guess a gear rack + gearmotor would do the trick, with feedback from an encoder?

Offline knossos

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Re: Most Economic Linear Actuation?
« Reply #2 on: October 21, 2010, 03:46:59 AM »
Gear rack + motor was what I was going to suggest too.  Here's a servo-mount gear and a gear rack from servo city.
"Never regret thy fall,
O Icarus of the fearless flight
For the greatest tragedy of them all
Is never to feel the burning light."
— Oscar Wilde

Offline waltr

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Re: Most Economic Linear Actuation?
« Reply #3 on: October 21, 2010, 07:03:27 AM »
A lead-screw is another good way to do a linear actuator. This does have excellent holding without applying power to the motor and can be slow/hi-torque or fast/low-torque depending on the lead pitch.

Offline Soeren

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Re: Most Economic Linear Actuation?
« Reply #4 on: October 21, 2010, 10:05:08 AM »
Yes, plus one for screwing  ;)
For simple apps. a length of cheap threaded rod can be used with regular nuts, however, the thread is not shaped for load bearing, so for powering up, the screw from a scissor car jack is a much better choice - Just look around and you'll find usable screws in different sizes.

An alternative could be a folded arm swinging open by a servo or similar.

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives


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