Letting 4 wheels rotate 90° with 1 motor

[Legoman021]

Hi there! I want to make a 4 wheeler from Lego Technic that can rotate his wheels 90°. The problem is that I want to do this with a servo motor, but in only have 1 of them. Do u guys know how I could solve this problem? Thanks!

Legoman021

[Mr Jos]

By using axles and gears you can link the servo motor to all 4 wheel hubs to steer them 90° at the same time.

[Jundis]

Hi @Legoman021

Can you maybe make a sketch or even post a pic of what you want to do exactly?

For what I get from your question, you should try to use turntables. Depending on the wheel size, there are bigger and smaller ones available. The grey part should be attached to you chassis, the black part to you wheel. Then you use gears to interconnect the black parts to drive them simultaniously.

 

[Legoman021]

Thanks @Jundis and @Mr Jos for replying. What i forgot to say, is that I want my wheels be be quit far apart, and that gear trains are probably not gonna work. I tried laying out what's my plan to put it in the file, but the file is to big. The wheels are probably gonna be around 45 studs apart.

[Johnny1360]

Either linkages and gears, or motors on each wheel, without knowing what or how dense the build is between wheels it would be hard to say which is best. You really need to see the big picture to decide.

Edited August 21, 2022 by Johnny1360

[suffocation]

45 studs apart with one servo motor can still work using a standard rack & pinion solution, provided the model isn't too heavy. Otherwise, as Johnny1360 said, you're probably better off connecting the servo motor to a linkage built with liftarms and/or towball arms. You can see something like this, albeit without the servo, in 42068.

[Jurss]

It seems, that this will be pretty big, heavy machine. For one servo it would be pretty hard or impossible to rotate 4 wheels at once. Servo at all is one of the worst motors.

Linkage also won't be straight forward, to have 90' rotation. I think so.  It would be better to use some standard motor, and do turning with gears, also using turntables on top of wheels.

[Mr Jos]

One servo motor will indeed not have enough power to rotate 4wheels of a heavy machine. If speed is no issue, use a normal motor and gear it down before sending the movement in 4 directions. Is it some sort of portal bridge or something?

And about files being to big, don't try to upload them directly here. First upload on a site like Flickr.com your photos, then share the link here and it will show what you're trying to make if you use the correct link, give it a try.

[Legoman021]

Im planning on making something like a transport-unit. I will probably just use a geared down normal motor for each of the wheels now, and use turntables (as u guys suggested). I tested some linkages, and as Jurss said, if u rotate 1 end 90 degrees, it rotates the other end not fully with it. Thanks for all the replying.