Lego mechnical servo motor

[Zerobricks]

THIS TOPIC got me an idea to make a mechanical servo motor using normal power functions.

Because BS is down a video will have to do for now:

[TheItalianBrick]

i'm wondering where it's worth to attempt such a thing, when simply can buy a servo!

I like to find solutions, it's challenging and it can lead to lots of new ideas, but this doesn't look like the case.

Sorry.

[hrontos]

i'm wondering where it's worth to attempt such a thing, when simply can buy a servo!

Let me think.

May be because Lego is about building and not buying?

According to your attitude why to bother to build anything when you can buy a perfect high-peformance RC or beautiful display models?

Edited August 24, 2014 by hrontos

[legomuppet9]

Let me think.

May be because Lego is about building and not buying?

According to your attitude why to bother to build anything when you can buy a perfect high-peformance RC or beautiful display models?

Beautifully said...

Great idea, how does it work when connected to steering I wonder? It shakes a bit at the extremities, so would that affect the steering play?

Edited August 24, 2014 by legomuppet9

[Zerobricks]

Yes its shakey, BUT I think I can reduce the hysteresis by reducing the small crank's length and increasing switches arm length.

[TheItalianBrick]

Let me think.

May be because Lego is about building and not buying?

According to your attitude why to bother to build anything when you can buy a perfect high-peformance RC or beautiful display models?

So why we need to buy an M motor to make a Servo??? we should't be buying motors according to your teaching philosophy!

sorry, it's my really first experience with LEGO, I'm really new to this world and I still need to know how things works!

Edited August 24, 2014 by TheItalianBrick

[hrontos]

So why we need to buy an M motor to make a Servo??? we should't be buying motors according to your teaching philosophy!

It is again not about buying M motor.

Servo is a part that is less common, because it is relatively new.

So for a person with only M motor these solutions and ideas are useful.

For AFOLs it is quite typical, to say I will buy, I will order from Bricklink etc.

For kids it is more about original purpose of the Lego - which is building.

AFOL will sit at computer, order a servo and wait a week to be delivered.

Kid, TFOL or a student with a limited budget will spend that time building alternative solutions using available parts.

I just prefer the second approach. Many nice ideas came exactly from the ability to make a compromise and use what was available.

To the original idea: it is really nice attempt to recreate the servo behavior. The shaking motion can be probably reduces exactly as Zblj suggested.

[TheItalianBrick]

As i said on my first comment (which you probably didn't want to read in the right way), it's very stimulating indeed to find new solutions ect etc, but my questions was if it's worth in this case or not!

so if LEGO is about building and not buying, then please explain me once again why should I buy at first place an M motor!

Buy hey, nevermind me...we all like to explore....and sure we all do it!

[Zerobricks]

Guys dont argue... It was just an idea that popped in my head. Yes Lego servo is smaller better and less noisy...

But it was just to try a concept, which works, even though not the best, but IMO its better than just stalling the motor!

[TheItalianBrick]

You are right ZBLY, anyway there must be a video on Youtube of a different attempt! let me find it guys...

Actually it works, but would be better to reduce the input gear ration!

[hrontos]

so if LEGO is about building and not buying, then please explain me once again why should I buy at first place an M motor!

I am sorry if there is a misunderstanding. I do not suggest to buy M motor. You asked why to built something like this, when you can buy original servo. I wanted to point out, that it is usefull for those who have M motor, which is quite common. I also wanted to make people more think about how to built some something than where to buy something. I will not return to this "buy or build" discussion since this is not very on topic.

[Zerobricks]

You are right ZBLY, anyway there must be a video on Youtube of a different attempt! let me find it guys...

Actually it works, but would be better to reduce the input gear ration!

Yes but that solutions stalls the motor when it reached the end... When a motor is stalled there's a large current going through it, overheating it, and also all that current going to the stalled motor means less power for drive motor(s). My solution doesnt stall, but oscilates which should be less demanding.

[hrontos]

But it was just to try a concept, which works, even though not the best, but IMO its better than just stalling the motor!

That's what I like about the idea. Return to center solutions are quite common, but many of them are based on stalling the motor.

[TheItalianBrick]

That's obviously a good point, but maybe some people only need to switch a switcher, and go back to the center position! A clutch would help a lot Like I needed recently for one of my latest moc and it works perfectly!

[BusterHaus]

Good idea, but the oscillation is probably not desirable. You almost need a ratchet mechanism to lock it in place. But then you'd need a second motor to unlock the ratchet... It's starting to get complex.

[Jim]

i'm wondering where it's worth to attempt such a thing, when simply can buy a servo!

For example:

http://www.eurobricks.com/forum/index.php?showtopic=99312

[Jim]

@TheItalianBrick: Check your PM.

Let's end the "useful/useless" discussion and stay on topic.

Thanks ZBLY for posting this technique

[TheItalianBrick]

Already replayed, plus in this topic I've already posted a different version, including a a solution for not stalling the motor, using a clutch!

Hope this is useful for other people, cos I found it usefull myself in one of my moc. :sweet: