CAD Selection Task: Standard Instructions

The TASK provided here is the selection criteria for joining the A.T.O.M society. Those who sucessfully finish the task within the given time frame will be eligible to give an interview and eventually become a member of the A.T.O.M society.

  • The tasks are not only to test your problem solving skills but also to see your diligence to learn new stuff the ablity to get the work done.

  • You will be required to finish Two tasks in the alloted time frame. Both of them are supposed to be done in any 3d modeling software preferably Fusion360.

  • If there are any 3D Designs or any other previous works (even 2d sketches are fine) related to the stuff you have worked on, you are welcome to share those as well with your submissions. It is optional, but this would help us further see your creativity and skills.

Hints / Reference


Task 1 : 5pts

Problem statement

  • The objective of the task is to make a 3D model of a part using the given engineering drawing.

  • To achieve this task you may use any method but the end result should be as close as possible to the original drawing.

  • You will be judged on the basis of your way of designing, so keep that in mind and make sure to follow proper practices(Like using constraints appropriately).

Note

You may use any software that you are familiar with but you are recommended to use Fusion360.

Expected Output

../../_images/cad.jpeg
../../_images/cad2.jpeg

Task 2: 5pts

Problem statement

  • The objective of the task is to create or draw an eg/cad drawing for the following displayed below.

  • To acheive this task you are supposed to create a project in autocad and and make the desired output.

Description

  • The Elliptical Crank with simple joints is a versatile mechanical system featuring three degrees of freedom, allowing for a wide range of motion. This design focuses on fundamental movement capabilities, simplifying control and design while offering flexibility for various introductory robotic applications.

  • You will be judged on the basis of the following criteria:

Expected Output

video link


../../_images/cad89.jpeg

Note

Advancement to the Personal Interview round requires completion of both mandatory tasks. To enhance your selection prospects and distinguish yourself from other candidates, we strongly recommend completing the optional Task 3 as well.

Task 3: (Optional)

Problem statement

  • The objective of the task is to design and model in Fusion 360 a single-stage spur gear reduction gearbox that increases the torque by 3 times and reduces the speed by 3 times, based on the given DC motor specifications.

  • The gearbox must be designed for a motor delivering 14 kg·cm torque at 100 rpm, using a gear ratio of 3:1.

  • The design should clearly present:

    • Pinion and gear tooth counts for achieving the ratio.

    • Gear module, pressure angle, pitch diameters, and center distance.

    • The expected output torque and speed.

  • The design is based on the following assumptions:

    • Module (m): 1 mm.

    • Pressure angle (φ): 20°.

Expected Output

../../_images/gearbox.jpeg

The judging criteria for CAD selection tasks will include an evaluation of the design history of CAD during the interview.

  • Manufacturability of the links and mounts (Preferebly 3d Printable)

  • Adhering to the giving details and guidelines.

  • Reusability and esay to modify in future if required.

  • You may use any methods and tools to achieve the task buy make sure to follow proper 3d modeling practices like constraints, joints etc.

Caution

THE DRAWING SHOULD BE DONE ACCURATELY AND AS EXPECTED .

Warning

The Deadline for completing the task: 26th September, 2025

Head over to Submissions to submit your work