Need help with toy design (linear + radial bearing)

[GetLastError]

Hi,

I'm building a toy and I'd like it to spin around a vertical shaft but also move freely up and down while it is rotating. Also, I'd like that the rotating body will get spinned using a gear which will be positioned in a fixed location on the shaft (at the bottom) while the rotating body should attach/detach from it.

Any idea how to achieve that?

Also, it needs to be as light and as cheap as possible.

Thanks,
Guy

 

[Nidum]

Simple solutions are keyways and prismatic shafts .

There are many other possibilities though - which is best depends on the details of the application .

Tell us a bit more about what you want to do

 

[GetLastError]

Hey, thanks for the fast reply.

One correction - the shaft isn't rotating (it's just a cylindrical rail).

I attached a quick sketch of what I need,

I don't know what bearing to use to for the rotating disc and also, the disc should build momentum somehow at the base and then be able to leave the base upwards.

Thanks,
Guy

 

[Nidum]

So the rotating part of the toy gets spun up to speed when at the bottom of the axle and then detaches from the drive and rises freely up the axle .

Easiest solution is friction drive - loose component just sits on a powered wheel or pulley faced with something like soft rubber .

 

[Nidum]

Almost as easy is the face gear drive - one powered face gear engages another one on the loose component .

http://www.voith.com/en/m_vt_Voith-Hirth-Coupling_Features.png

 

[GetLastError]

Many thanks!

So the rotating part of the toy gets spun up to speed when at the bottom of the axle and then detaches from the drive and rises freely up the axle .

Exactly.

Easiest solution is friction drive - loose component just sits on a powered wheel or pulley faced with something like soft rubber .

Can you give me a direction on where to purchase the relevant parts?
How can it get detached in the easiest way?
What good bearings can I use for the linear+radial motion?

 

[berkeman]

Hi,

I'm building a toy and I'd like it to spin around a vertical shaft but also move freely up and down while it is rotating. Also, I'd like that the rotating body will get spinned using a gear which will be positioned in a fixed location on the shaft (at the bottom) while the rotating body should attach/detach from it.

Any idea how to achieve that?

Also, it needs to be as light and as cheap as possible.

Thanks,
Guy

Welcome to the PF.

Can you just use a ball bearing race where the inner surface is the shaft itself? You may need a wider diameter shaft to capture the ball bearings reliably...

https://upload.wikimedia.org/wikipe...int-contact-bearing_din628_type-qj_180-ex.png

 

[Nidum]

How big is toy ?

Any significant levels of power involved ?

 

[GetLastError]

Thanks berkeman, yes I thought about it. The problem is that I'm very new to mechanical engineering. I learned how to design in solidworks and I think that I can make such part that fit a 8mm rod but I'm not sure what are the limitations of part making in general and who to order the parts from...

How big is it ?

The axle is 8mm in diameter, the disc is about 20cm and it weighs 250 grams in total.

Any significant levels of power involved ?

Not sure I understood the question, I'm going to boost it with a simple DC motor.

BTW the face gear looks like an excellent option, but it needs to fit the axle as well... will I have to design/make the part myself? or do you think there's a stock one.

 

[Nidum]

I suggest that you draw up your design to be exactly how you want it to be without initially worrying too much about using standard components .

 

[Nidum]

You should explore the subjects of rapid prototyping and 3d printing .

Have a look here

 

[GetLastError]

Looks great, thanks!