Laboratory rocker mechanism: motor radius and pin location ratio

[JohnSa]

Hi all

I have a question about this device in https://www.thingiverse.com/thing:2948680/files. Where can I find more information/reading material about this type of mechanical movement (for example, what is the ratio between the motor circle radius, pin location and the table bearings).

I wish to print a smaller one but I do not know where to start.

Thanks

 

[Lnewqban]

Welcome, @JohnSa !

Do you need an specific output for the sample to be rocked?
Example: frequency, maximum angle, weight of sample, way to fix sample to platform, etc.
The one shown in your link has an electronic panel controlling the motor.
It seems that because of that, the frequency and duration of the oscillation can be programed.

 

[Baluncore]

Welcome to PF.

Start reading here; https://en.wikipedia.org/wiki/Linkage_(mechanical)

If you can post your required dimensions and the rocking angle limits, we can compute the length between the pins, and so the pin positions on the components.

 

[hsi100]

I have a question about this laboratory rocker, mainly about the part in the image attached red ellipse. Is there a technical scheme and mathematical equations set that allows me to simulate it using Matlab/Python? By this set it will allow me to calculate a rocker in different sizes.

BTW: I am a programmer and keen 3D hobbyist and not an engineer so any help will be appreciated.

 

[Tom.G]

Try looking for formulas or design procedures for 'cam design'. They should be "close enough" at least for a first approximation -- and likely sufficient for such a non-critical application as agitating a liquid.

Or to really dig in, try a copy of "Machinery's Handbook". A PDF of the 3915 page 29th edition is available on-line at:
Machinery's Handbook 29th Ed.

(above found with:
https://www.google.com/search?hl=en&source=hp&biw=&bih=&q=machinery's+handbook+pdf)

Cheers,
Tom

 

[Juanda]

I have a question about this laboratory rocker, mainly about the part in the image attached red ellipse. Is there a technical scheme and mathematical equations set that allows me to simulate it using Matlab/Python? By this set it will allow me to calculate a rocker in different sizes.

View attachment 333991

BTW: I am a programmer and keen 3D hobbyist and not an engineer so any help will be appreciated.

If you have no experience I'd first check the link posted by @Baluncore at #3.

Welcome to PF.

Start reading here; https://en.wikipedia.org/wiki/Linkage_(mechanical)

If you can post your required dimensions and the rocking angle limits, we can compute the length between the pins, and so the pin positions on the components.

The section "Planar one degree-of-freedom linkages" should be especially relevant.