Hello all,

I am working on a project that requires a small amount of motion in a very small form factor. I don't think a servo motor will fit so I am planning on implementing a small electromagnet to drive the motion of a small ferrous assembly. From what I can find, a Toroidal inductor seems to be the best fit as the core allows for the creation of a stronger magnetic field if I understand correctly.

Eventually, I'd like to move to a planar magnet to reduce the size even further but for prototyping, a Toroidal inductor is far easier to work with. Am I on the right track?

 

What do you call 'a small amount of motion'?
Amount of movement and size?
Max.

 

From what I can find, a Toroidal inductor seems to be the best fit as the core allows for the creation of a stronger magnetic field if I understand correctly.

I think maybe your misunderstanding. A toroidal coil is used because it tends to concentrate the magnetism in the center of the core. Magnetic field is due to the amp/turns of the coil/solenoid. A magnetic solenoid, to make some thing move, has the turns around the outside, axially, so it will pull the moveable part in. A toroidal coil has the wire going through the center hole.

 

What do you call 'a small amount of motion'?
Amount of movement and size?
Max.

Rough estimates here, the weight of the object would be less than 10 grams and I only need to move it about an inch, two at the most.

 

If rate of movement is not an issue, why not a regular style solenoid coil assembly?
Max.

 

I do not think a toroid is what you want as you are after an external magnetic field to move an armature or something, not one contained in the core.
And a couple of inches is not really a small amount of movement for a small coil. What is "small"??
Can you explain your size limits? Also, does the movement need to have a controlled position or just one end or the other?
What are you actually trying to move?
Really, a lot more detail will help us advise you.

 

I do not think a toroid is what you want as you are after an external magnetic field to move an armature or something, not one contained in the core.
And a couple of inches is not really a small amount of movement for a small coil. What is "small"??
Can you explain your size limits? Also, does the movement need to have a controlled position or just one end or the other?
What are you actually trying to move?
Really, a lot more detail will help us advise you.

Good points, I'll put together a loose spec and post back when I have more information. For now, what I can say is that I just need to move a small 3d printed piece that will have an embedded magnet. The movement doesn't need to be super precise either which works to my advantage.


I'll post back after some experimentation and when I have more details.