Project help requested - Gearbox in clear display


I am looking for someone to build a display case that I need for a upcoming show. It will look vaguely like this:

but simplified with just a few gears in a square, clear box. Size would be about 1 foot square. It would be motorized from an source just outside the box. I’ll work with anyone on the specifics if interested. My company does fluid simulation and I will be running a simulation model next to this model. We will need it completed by about mid-January.

If you are interested in this project, of course I will pay you to build it (extra Christmas money anyone?). contact me directly at chris at



And other meaningless words as required…


Do you have the gears themselves or are you looking for someone to supply them


I will be buying the gears separately but happy to have input on them. The gears we buy will need to have an associated stl file because we will be doing a computer simulation next to a physical demonstration.


The easiest thing to do for this would be to get a used differential from a car probably


Like this


that would be great if the CAD geometry exists somewhere. We have to have an exact match between the two so the fluid flow can can predicted and the physical test can verify the simulation.


I’d see if there are any cheap differential for sale on Facebook or Craigslist then check grab cad to see if anyone has made a model of them


We tried that to no success. We can, however, purchase a few new gears that come with the stl files. so it is easier to do that and build a box around them.

Again, if anyone wants to help build such a box, we will pay for your work.


What other requirements?

  • does it need to be strong enough for regular transport? (i.e. demos?)
  • does the fluid need to be replaceable or just whatever for demos?
  • All clear cube or a partial?
  • required operating speed for the gears or just anything? (vibration concerns)
  • Do you have the sealed bearing flanges or able to obtain them?

I can probably make something depending on the other considerations above.



Hi Jim,
I’m pretty open to design and can change as may be best. To your questions:
It will need to be transportable to shows but we can pack it well.
Would be best if fluid could be removed
I’m thinking clear on 4 faces of box with back and bottom being metal for mounting purposes for shafts
A bit of a vibration concern but lower RPM is OK. We need to turn fast enough to get liquid splattering because that is what we are visualizing.
We will get the sealed components and an external motor.

Let’s talk if you think it makes sense. I’ll PM my number.


could you get a diff cover and make a vacuum form of it?