“MORE INFO, PLEASE!”

Is this arm intended to be used within a gravitational field?

NO

You are in CNC and robotics.

Try google for "Robotics" and you will find dedicated groups. They have tried it all and would have some designs ready.

I think one robotics site falls under GlobalSpec - but it was a while back.

If you use series of linear motors then it is possible to build such device. You can also push through pneumatic pressure and pull back through wire and small motor. Remember that length will also cause problem and motors placed at far distance will be a serious problem.

Another good mechanism is screw in a screw. Last thing first and then next. Look to Telescopic Antenna that are motorized. Perhaps a spring can also push and pull the rod from inside the telescopic rod.

You have to have some good mechanical idea for doing all this.

OK, a couple of questions back at you.

1. Does the arm (or whatever) telescope (extend) from a base unit, grab an object and then retract to deliver the object?
2. Or do you intend this device to have its own movable base, navigate to a location, extend to grab the object, retract, and, finally, navigate its way back to you?
3. Are you in a wheelchair or otherwise handicapped?

It would be very helpful to know the complete story regarding why you want this device. What type of terrain? Through different passages/rooms? Does it need to see or do you need to see what it sees? Is this just an industrial device? All of these questions drastically affect the design. We can shoot in the dark, but it's easier when the lights are turned on.

If you are unwilling to give us these details, that's OK. However, you would probably be much more successful Goggling robotic sites that can supply information, and you can pick and choose what fits your needs in private.

A long thinwalled strong Bamboo sliding thru 2 loose-fit bamboo bushes.

At fore tip end have a snap-action mechanism under ready-to-act springs' pressure.

Trip this small hinged holdback detent from backend passing thru bamboo. Nylon string?

And the snake you catch would go nowhere but back at your control!

Total price DIY =<$1

Great. In my childhood I bought that snake thing which extends and contracts easily and was hardly of any price. I also like that bamboo rod idea.

How come you talk so much about bamboo?

Now he said no silliness!!!

Denso has an excellent selection of robots. They are used for placement of computer components on boards to placing 10 lb stacks of lead plates in auto batteries. I do not understand your application, but your gripper or other end of arm tooling may cause you problems. If you just want a single linear motion, you might check on a linear servo, but you will have to use some type of guide rod since it uses a screw motion to move in and out and the rod end of the servo needs a stationary point to work. They are very fast, precise, and robust.

Thanks for giving me more things to research!

Dear Gerard,

I am calling the banks, pharmacies and jewelers in your area. Me thinks me smells a rat.

I can remember seeing somewhere an extending arm made from a strip of thin steel formed into a semicircular shape, something like a steel tape measure but with a deeper formed section. It was self supporting over a long distance but retracted back into a small roll. I can't recall the name or where I saw it, can anyone else help?

I think you are refering to snake arm robot.

No that's not it, it was nowhere near as sophisticated as the snake arm & not steerable.

Roboarm was a nice development but it is no longer produced now. I think inventor closed the production long ago. They were really nice thing. I used them for a training class in Singapore. It was having five axis stepper motors and a gripper.