Tell Me More About Miniature Motors

I haven't played with anything that small, but I've used several titchy little motors from people like Portescap. Burns your fingertips when you try to stop them by grabbing the shaft. Pokey little blighters!

The motors in mobile 'phone vibrators are pretty small, and you get quite a buzz ...

I'm not sure this is exactly hands-on in the usual sense;

http://en.wikipedia.org/wiki/Nanomotor

You're not going to break a tub w/this are you?

Hi,

what really do you want to know, this is not clear from your statements.

I am very familiar with these motors, I am using these since now 30 years, I was near the development of the Faulhaber "Pennymotor" (see at Faulhaber website "brushless") that is 1 to 2 mm thick and 8 to 12 mm in diameter.

If you ask Faulhaber, Portescap (now part of Danaher) or Maxon may be they can send you one. If they don't I can look what I have. But first: specify your needs, what is the intended use.

Or take apart al the video players, CD players and similar device, usually there are these and the fareast makes inside.

These motors are magnificent as they have only copper and insulating laquer in the winding. This makes these motors easy to calculate and easy to use as servo motors.The winding is (most) a cylindrical shell. This winding is made with an angle to the circumferential direction of 45 to 80 degrees so that the current has a high share of axial component.The permanent magnet may be inside or outside the shell and is generating a perpendicular magnetic flux. The axial component of the current with the perpendicular magnetic flux is generating the torque.

As in any motor one limit is thermal: two thermal resistances and two thermal time constants, one winding to case, the other case to environment. Temp limits can be up to 200°C.

Another limit is maximum speed: bearings are one factor, available voltage and voltage limit in the commutating electronics or mechanical commutator is the other factor. The driving voltage ahs to overcome the induced countervoltage and the resistive losses in the coil.

The third limit is the current limit (by heat generated in the coil and limited cooling).

Torque/current is the k-factor and is the same as induced voltage/speed, speed in rad/s.

Above 500rev/sec we normally switch over to air turbines in our experimantal work with high speed airbearings that rotate up to 7000rev/sec for micro milling and grinding.

RHABE

Well , smallest motors i have encountered is one found in mobile phone for vibration and watches for setting analog dials , but miniturised motors only seen on televisions , internet and read in magzines , applications too may be limited to there size or we look for applications specialized for those .we need miniture sensors , ckt , to control motor

up to 0.014 mNm at speeds up to 15,000 rpm

- sounds like the sort of thing one might find in the retractable-tray-loading-facility in a CD-rom drive.

Modelmakers use small motors. Check out Z-gauge trains for examples.

http://en.wikipedia.org/wiki/Z_scale

I remember reading somewhere about some guy (in the USA, I think) who won a competition to make a minute working motor. Took years to make. Apparently he brought one to the UK, and it got crushed when someone was trying to focus a microscope on it . Just had a quick look round Google, but couldn't find it - does anyone know any more about it?

In 1959 William MacLellan built a 1 millionth of a hp motor (1/60000 inch diameter) in response to a challenge by Richard Feynman. A book called "The Story of Measurement contains a picture of the latter looking at it thru a microscope !

That sounds like the one - thanks.

Glad to help. The book is a great read as well (Author -Andrew Robinson).

I know nothing about this sort of thing, but, someone borrowed my camera at work the other day and broke it (I think they dropped it). We decided to take it to bits to see if there was anything we could fix: no chance. The lens housing has several tiny motors and gears: I can post you the "remains" if you send your address to me via private message.

If your interested in real available miniture motors check out the following link:

http://www.newscaletech.com/

Their motors are based on ceramic technology and work well.

I was afraid by your title. You know, the type of questions ''Tell me about the quantum computer''.

I have worked with Smoovy BLDC motors in the past. My main problem with them was the plastic planetary that had to be run-in to provide the rated maximum torque.

Currently use 6mm diameter step motors.

Planning to use ultrasonic motors soon.

Some obvious and less obvious notes to ease the transition to the micron world:

• They are somewhat robust, but care is very important.
• Get them with a harness/flex attached. BLDC and steppers have many pins in a small space. A pain for prototyping.
• Any contaminant, misalignment, friction, etc., while barely perceptible at best can be greater than the motor torque. (cyanoacrylate fumes, machining errors...)
• Plan for 100% inspection.
• Off the shelf hardware like screws, bushings are less common to difficult to find.
• Tooling design may be inherent to the design.
• Get a good loupe for the good eye you have left.

The source you quoted are of good Swiss quality, Good Asian sources are also possible, and some with small quantity capability.

Many modeling and R/C sites sell vibrator pager motors without the mass, gears and how to's. These can be a good cheap source for hands-on destruction.

I have seen the NEW SCALE motor operate and belive they live up their data sheet. My suggestion is that you call them directly and talk to them about your application. Quick articles and data sheets never give you the entire story or answers for that mater.

A reply to all that posted here, thank you for your input, All posts had some interesting information in them. I did not ask from a profesional angle as we use 25mm diameter 2 or 4 pole stepper motors on our equipment, I was just being nosy and will look at the equipment suggested for further real life instances for their use.

Maybe then it will also become clearer to me what they are capable of in strength terms, still not sure about that.

In reply to the nano motor post in specific, I once saw an article about nanohairs acting to electric charge in a bending kind of way. This stuff was put on a conveyor and created a beltless and roller less conveyor system that was multidirectional as well. How cool is that?

Thanks all and have a good day or what is left of it for some of you.

Somewhere in CR4 is some great stuff about conveyors/linear motors and stuff, but I don't recall where. I like the sound of electrostatic hair conveyors ( though I might have to be more careful than most near one).

Why?, no mechanical rollers and such to get your tail trapped.

"Somewhere in CR4 is some great stuff ..." see thread http://cr4.globalspec.com/thread/13709/New-Web-Based-Encyclopedia

I too have an interest in mini motors.

Keep the ideas flowing.

Wat's your need?

There is realy many types and sizes.

These are happy times for small mechanics, as some can still manipulated .