Hi,
I am working on an installation that needs to do the following:
a metal-round object around 5-10cm square with the weight of no more then 0.5k-1k will be connected to a string lifted in air around 30-50cm above ground and will be release on another object down below which will make the object below resonant. This action of dropping and lifting back up the metal object should be made with a either a servo motor or a dc motor?
I wanted to ask what is your recommendation for such a project? What motor shall I use? I guess I will need to power it separately from the arduino? (The arduino will give the command to lift and release the object) What other things I should consider?
Does the "round square ball" have to be dropped repeatedly, like ringing a bell, or is it dropped once for some sort of test and then the test setup reset?
Maybe some sort of electromagnet that can pick up the "round square ball". That way the ball can literally be dropped.
So you have a 1 kilogram object that you lift from the "ground" to about 400 mm ( I think better in mm). Then you want to drop it in what I would call "free fall" i.e. nothing slowing it down from gravity.
Not perfect but you could have a free spinning spool on the motor shaft. It would be held to the shaft by a magnetic brake. When the break is released the spool will free spin dropping the 1k object. As I said this is not perfect but it can be easily repeated.
If the actions do not have to be repeated, simply have a blade swing by and cut the string holding the 1k object.
BTW I'm guessing English is not your first language. Don't let those who criticize your terminology other you.
The action should be repeated in some intervals. I'll say about 3 seconds intervals or the time it takes to release the object and bring it back up. So it should be repeated action of releasing the object and pull it back up and releasing again and back up etc etc
That is true. Although I do know I should work harder on my english
Your English is much better than my 2nd language I worked with folks in France, Germany, Poland, Sweden and Japan. I tried to learn a little French....then a little German... then just gave up. So you are doing much better than I did.
Expanding on the spool approach.
Say you have a free spinning spool (pully etc) on the motor shaft. with a spool being moved by an RC servo.
RC Servo pushed spool with attached gear so the gears are engaged. Motor lifts weight.
At the top the RC servo pulls the spool and gear so the gear is no longer engaged, the free wheeling spool drops your weight.
The same thing could be accomplished by building a clutch from two steel plates. The face of one having a cork layer attached. Much longer life and much less noise.
I bought a product, material and samples from an estate auction. I attempted to get documentation form the family, but never succeeded. It did exactly what you have drawn, but using the cork faced clutch. Had to scrap the project.
Thanks for your replay! I will try your idea asap!
edit: Just one question - there is no way using only servo motor to push and turn the spool and to lift the weight of the object?
I cannot think of a way to make the spool concept work with only one motor. Keep in mind, most servo motors are limited to < 1 revolution. Often only 90°. The "spool" motor must make many turns to lift the weight. Spool motor could be a simple DC motor with a shaft long enough to hold the spool and connection.
You could use a solenoid to engage and disengage the spool.
