Artist in need of help

[dmhmaestro]

Hello all... ive been redirected from another forum that i also asked...

Im making this sculpture and i need variable speed motor... i need it to spin about 50 rpm- 80 rpm... i dont know exactly... i must improvise speed to achieve the desired result.... This is the thing i made and it isnt working... because the motor is brushless.... The thing on motor is barbq stick with magnet and counter weigh for stability...

http://oi67.tinypic.com/n4dok.jpg

They told me it was maybe stepper motor?

http://www.ebay.com/itm/Geeetech-ste...IAAOSwBLlVEoS~

I need exactly name of the controller and motor so i can order it on ebay... thank u all very much!

[Mjolinor]

It is a NEMA stepper motor and to make it rotate you need some electronic circuits. These can be (but are not limited to) Raspberry Pi, PC Arduino and a miriad of other options that would be far too long to list.

What you choose to drive it with does depend on what you want to do with it but whatever you choose it will need programming in order to work.

[dmhmaestro]

It is a NEMA stepper motor and to make it rotate you need some electronic circuits. These can be (but are not limited to) Raspberry Pi, PC Arduino and a miriad of other options that would be far too long to list.

What you choose to drive it with does depend on what you want to do with it but whatever you choose it will need programming in order to work.

im very suprised that it is that difficult to achieve... we see tons of motors and just this task to make it variable rpm becomes so hard... I really need this because im making something extraordinary ...

I need detailed guidance in how to make this motor... The motor will not have much friction in its purpose it will have contact with ferrofluid and thats it... So , i would need to buy stepper motor and what more? couldnt i just buy some know controller?

something like this?

http://www.ebay.com/itm/4-phase-5-wi...4AAOSwgQ9VuCmy

[Mjolinor]

Yes you could just buy that and you could manually control the rotations and positions. If you are happy doing that then you are sorted but most people using steppers want them to rotate at very specific, repeatable speeds between known start and finish points.

None of it is difficult, in fact it is quite trivial but solving a problem without having the problem defined is never possible no matter what it is.

[awerby]

If all you're trying to do is rotate a turntable at a variable speed, you don't need a stepper motor or the associated electronic circuitry that makes it run, which can be fairly expensive. All you need is a simple DC motor with a potentiometer to limit the voltage it gets. The less voltage one of these motors gets, the slower it goes. There are also more elaborate speed controllers that modulate current as well as voltage. You can run it off a battery or through a "wall wart" transformer. In the RPM range you're talking about, you probably want a gear-motor, which trades some of its excess speed for torque. Here's a selection to choose from: https://www.surpluscenter.com/Electr...DC-Gearmotors/

Andrew Werby
Juxtamorph.com

[dmhmaestro]

Yes you could just buy that and you could manually control the rotations and positions. If you are happy doing that then you are sorted but most people using steppers want them to rotate at very specific, repeatable speeds between known start and finish points.

None of it is difficult, in fact it is quite trivial but solving a problem without having the problem defined is never possible no matter what it is.

The problem with this motor is that it isnt precise enough.... ive watched video on youtube and it only has about 10 levels and the rotation is not fluid... its very jerky

[dmhmaestro]

If all you're trying to do is rotate a turntable at a variable speed, you don't need a stepper motor or the associated electronic circuitry that makes it run, which can be fairly expensive. All you need is a simple DC motor with a potentiometer to limit the voltage it gets. The less voltage one of these motors gets, the slower it goes. There are also more elaborate speed controllers that modulate current as well as voltage. You can run it off a battery or through a "wall wart" transformer. In the RPM range you're talking about, you probably want a gear-motor, which trades some of its excess speed for torque. Here's a selection to choose from: https://www.surpluscenter.com/Electr...DC-Gearmotors/

Andrew Werby
Juxtamorph.com

There is a bunch of items in the link u sent me... can u please be more specific so i can check the motor i need?

I though this is going to be so easy task... i just need small motor to rotate at variable speed and i cannot find the answer to my quest, and its holding my project down

[djprinter]

You could just use RC parts from hobbyking.com.

you'd need 3 things:

1) brushless motor http://www.hobbyking.com/hobbyking/s...00kv_17g_.html
2) brushless speed control http://www.hobbyking.com/hobbyking/s...EC_2_3S_V.html
3) servo tester (to adjust speed without hooking it up to a RC radio) http://www.hobbyking.com/hobbyking/s...vo_Tester.html

Shouldn't cost you more than $25 for all of this

[dmhmaestro]

You could just use RC parts from hobbyking.com.

you'd need 3 things:

1) brushless motor http://www.hobbyking.com/hobbyking/s...00kv_17g_.html
2) brushless speed control http://www.hobbyking.com/hobbyking/s...EC_2_3S_V.html
3) servo tester (to adjust speed without hooking it up to a RC radio) http://www.hobbyking.com/hobbyking/s...vo_Tester.html

Shouldn't cost you more than $25 for all of this

thanks a bunch!

The only problem is that shipping to my country is a bit expensive... can i find the items on ebay? and if u would help me i would be so grateful.

The sculpture im making is so good and im waiting in anxiety to finish it

[awerby]

I can't tell you what motor to buy, since you haven't told us whether this sculpture of yours is a 5 ton piece of stone on a 2-meter turntable or a 2 gram piece of foam on a 5 cm disc. The torque required from the motor is going to be different in these two circumstances, and the price of the former will be considerably higher than the latter.

Andrew Werby
www.computersculpture.com