17. Machine design¶

This week I worked on Solving the cad design errors in the initial prototype of Automatic Car Washing Machine which is the group project of machine design. As in Week15 I Have designed the first prototype.

Problems Faced: Design Errors¶

Mechanism Errors:¶

Due to the weight was not distributed equally and one axis had no support to make it stable and allow it to move smoothly, we figured out the strucrtual design and the motor couldnt move the following box as we wanted:

after a discussion with the team members we all agreed to add one more motor on the other side so the load will be distributed equally and will more stability to the design.

So as a designer, adding more motor will decreas the working, I had to think on ways of adding one more motor and increasing the working area as much as possible:

so I went to the structural memebers and sketched the following:

Then I made fillet for all of the sharp edges and created holes for the extra motor box.

Then I changed the assembly based on the new structural members:

Holes distans Errors:¶

Fortunately, there were no major problems faced while assembling the model. Some minor changes were made such as the distances of the bolt holes since they were not overlapping and therefore we were not able to screw some parts with the other. The changes that were made were very minor which only required change in distances by +/- 1 to 2 mm.

Motor Holes distance were changed from 5mm to 5.5 mm and it did helepd as the screws after the edit fitted properly

Stability Errors¶

After the design was fabricated we found out the design was not stable enough there are still much of vibrations and it need something to make it rigid and stable

so I thoughd about adding more press-fits to the design to improve its stability:

To get the right dimension I made a sketch on the top side of the assembly: