CAD Visuals

Iteration 2

April 6th, 2017

*Corresponds to Concept Iteration 4

The main features of this iteration are a comprehensive CAD Design for our desk and development of Fits & Tolerances.

Cad Design

The CAD model incorporates multiple brainstorming ideas with material selection, mechanical operation, and manufacturing needs in mind. Some of the most notable changes include a more stable, rotatable L-desk that can extend the workable surface of the desk while not compromising on comfort. The inclining surface is adjusted using a bar and hooks to incline surface at 4 different angles. The benefit of this compared to hydraulic systems is that it is easier to manufacture, offers a variety of angles, and reduces cost. The two stationary parts of the desk are made of particle board coated with acrylic to provide a cost-effective writing surface, while light weight but sturdy aluminum serves the legs, L-table, frame and the inclining mechanism.

Fits and Tolerances

Considering fits and tolerance for our prototype is essential for weighing out cost and helps to narrow down which machine process is most suitable. Reducing cost will help make the product more affordable for our target market. Using the most optimal tooling/machine process for specific tolerances will reduce time and possibly material.

We have indicated here the fits and tolerances for features that should be considered highly for maximum functionality of our desk prototype:

1. An attachable secondary surface which is rotating about a leg (which will be a cylindrical shape) from the base table will have a fit that allows the secondary surface to spin freely about the leg. The values within tolerance zone of the leg will be less than the values within the hole tolerance of the secondary surface. This is a clearance fit.

2. A metal frame which outlines and surrounds the glass and particleboard components is used for support of the angle-adjustable surface. It is critical that the frame is flat and leveled with the glass and particleboard tabletop to ensure user-friendly application. Some variation of an interference fit is necessary for a snug and smooth surface.

3. The bar which will be the source of angle adjustability will be attached to the glass frame, and must be allowed freedom of rotation without position of its pivot being affected. The pivot piece must be within minimum clearance or minimum interference, therefore a transition fit is ideal.

4. Pivot between glass and particleboard surface. A more snug fit is appropriate and therefore tolerance range should not be too wide. This is to ensure the pivot and axis of rotation does not affect the smoothness and flatness of the tabletop surface.

The main changes in our CAD model were changing the style of the frame from a single I-Beam style frame, to a more rectangular, picture-style frame. This allows the diffused LED strips from the interior side of the frame to evenly light up the inclining surface. Also, the notch locations and design were changed to accompany the upper frame redesign. The other addition is the two mating sleeves underneath the swivel desk which was added due to concerns that the swivel desk would fall without extra support. Minor changes include shortening the width for the left particle board portion and removing a cupholder, and widening the right particle board portion for added writing space.

Please find our CAD files here: AutoDesk Fusion 360 Project page bCourses Group folder

CAD Renderings