which motors do you use

[mirojr]

Hi

 

I wondered what peoples experiences with using motors in projects has been.

 

Mainly my issues are ease of use and cost.

 

I really like the lego motors but they are more expensive, but they are easier to build as I don't need glue guns or other things.

 

At school we have a shed load of cheap motors that sit in a little plastic housing with a sticky pull off base. These are cheap and cheerful but not ideal if I want to add them to a lego setup for gears etc. They do have a nice little push on toothed wheel that seems to fit ok with lego stuff, but not perfect, and without decent attachment to other lego parts a bit of a pain.

 

I wonder what people use in regards to motor projects?

 

Thanks

[FN-GM]

@SimpleSi will be able to help

[SimpleSi]

The cheap little motor tend to run too fast as they are ungeared.

 

For robotics I just use these sort

6V Geared Motor with Dual Shaft

as they are geared down and have 5mm shaft ready for wheels.

 

More expensive but metal geared

Micro Metal Gearmotor - Pimoroni

 

 

I also like these

Data Harvest - KNEX education control motor KX92845 : KX92845

as they are ready to go to interface to K'nex for fairground ride type projects

 

I'm thinking that if a sec school had a 3D printer, they could make some gears to fix on the cheap motors to interface to technics maybe?

 

Simon

[pcstru]

Cheap Servo's are also worth considering. They come with a built in gearbox AND positional sensor but can be modified for continuous rotation. You do need some interfacing - PicAxe 08's and a couple of other components probably being the cheapest option.

[mirojr]

The cheap little motor tend to run too fast as they are ungeared.

 

For robotics I just use these sort

6V Geared Motor with Dual Shaft

as they are geared down and have 5mm shaft ready for wheels.

 

I'm thinking that if a sec school had a 3D printer, they could make some gears to fix on the cheap motors to interface to technics maybe?

 

Simon

 

 

 

I think I can get these at cpc. Do these look the same:

 

MC018-1A - MULTICOMP - MOTOR, 3-12VDC | CPC

 

I just need to locate wheels. Do Lego wheels fit?

 

What do you use for a chassis ?

 

I had been using Lego gears with a cheap motor, but its just not very good. Mainly because of the inability to properly seat the motors on something.

 

It takes a lot of messing and time is something I never seem to have a lot of.

 

Thanks

Edited May 18, 2014 by mirojr

[mirojr]

Oh it mentions 'our wheels' on the link you sent!

[SimpleSi]

4tronik have wheels that fit as well.

The CPC ones are the same sort but I prefer more highly geared ones myself

[mirojr]

This cpc one is 180:1

 

Just no wheels ha ha.

[SimpleSi]

No its 180 RPM (prob 50:1 gearing down from 9600rpm)

 

Which is pretty much the same as the 4tronix one - I prefer more highly geared (better torque at low speeds) but the 200rpm range ones are the most common

 

- - - Updated - - -

 

I'm just in the middle or playing with PWM freqs as I've found that I can can better torgue at low speeds if I lower the PWM freq

 

Simon

[mjs_mjs]

It also depends on what you're trying to achieve. For continuous rotation like RC cars, then small DC motors are the way to go, but for control applications there are two other types of motors, Stepper motors and servo's (ok so not strictly a type of motor).

 

Servo's are usually small geared DC motors with additional feedback circuits so that they have the property of always trying to match their input position data. From a programming POV they are very useful as i can set their value and forget about it - on the assumption that the motor will achieve the position i set. Hence they are used alot in amateur robotics, RC cars, RC planes. They also don't usually need any additional circuitry, just power and a PWM control at 5vTTL, making them uber simple to implement on Arduino and the like.

 

Stepper motors are very good when you need high torque and good precision, ie inkjet printers, 3d printers, laser cutters. They have no feedback usually, so additional sense circuits are needed for control applications. They also often need current sensing drive circuits so become complex to implement quickly.

 

For a RC car i'm probably go for a servo for the steering and a DC motor for drive.

 

 

What kind of projects are you looking into?

[mirojr]

No its 180 RPM (prob 50:1 gearing down from 9600rpm)

 

Which is pretty much the same as the 4tronix one - I prefer more highly geared (better torque at low speeds) but the 200rpm range ones are the most common

 

- - - Updated - - -

 

I'm just in the middle or playing with PWM freqs as I've found that I can can better torgue at low speeds if I lower the PWM freq

 

Simon

 

I am reading it from cpc catalogue it does say 180:1 probably a typo as most of the others are 48:1 but I have seen these Battery Operated Gearbox - BO Series - VIGOR PRECISION LTD|????????

Which has 180:1 ratio option

So there is a chance the catalogue is correct

[mirojr]

And looking at that other link you sent. Micro Metal Gearmotor - Pimoroni

 

That gives Ratios and rpm so it looks like it could be 180:1

 

That aside do you use a L293D in your circuit? :-)

[SimpleSi]

Yes if want to reverse them - just a ULN2003 as a buffer when reverse not needed.

 

Simon