Fab Lab Ciudad de México

Mexico City

Group Assignment – Mechanical and Machine Design- Querétaro

For this assignment we designed a motorized rail for time lapse recording.

In Querétaro we did the mechanical design of the rail, the chassis and the holder for either a camera or a phone. We sent the files and the final prototype to the Mexico City team to program it

Luis-Mechanical design, fabrication

Jorge-Acrylic enclosure, documentation

Jonathan- Smartphone stand, fabrication.

The first step was to make conceptual sketches to land the ideas that seemed most efficient to us and then establish the first dimensions according to our needs and the available material (the length of the lead screw rods, for example).

Once we agreed on the functions that the machine would have and the mechanisms that it would require, made a draft in Solidworks.

This first draft was modified, integrating new ideas and discarding others that made the design unnecessarily complex or made the manufacturing process difficult.

The Mexico City team proposed making the chassis out of corrugated cardboard, that way the cost of a larger piece was considerably less than the cost of making it out of plywood or acrylic.

Unfortunately the cardboard was not strong enough so we had to modify the measurements to be able to make it in acrylic using assemblies and screws, avoiding structural problems when moving the motors.

One of the last changes to the mechanism was the rotating base because we were considering that the rotation would be carried out by a motor and a timing belt, which we improved by using only a motor and a kind of 3D printed bearings taking as inspiration this design of the FabLab León of 2019.

 

http://fabacademy.org/2019/labs/leon/machine/

 

To place the camera we made a threaded base that worked as a cap for the bearings and was fixed to the engine from the bottom and to the camera from the top. We also included a threaded rod bracket at the end of the chassis.

The final model of the chassis with the motors looks like this

The machine looks like this:

To use the rail with a phone instead of a camera we also designed a universal base that holds the device using a pair of rubber bands.

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Ciudad de México 2021