Mug Telescoping Fidget (PIP)

Summary:

A telescoping fidget that looks like a mug and has no assembly required!

Summary (expanded):

This fun fidget is designed to look like a mug, but is much smaller, measuring at just 8cm by 8cm, perfect for anybody’s desk. It was designed to be “print-in-place,” so it requires zero assembly once printed. 

Problem Statement:

By using a series of offsets in tandem with drafted extrusions and cuts, you will make a telescoping fidget that can be printed in place. You will have a partner, your “accountabillibuddy,” who will help provide feedback with initial designs and instructions. You will also help each other solve problems and fix errors as they happen. Having identical designs is a must.

Constraints:

• The sketch must begin with a constraint box (center-rectangle created from the origin)
• Your outermost outline must fit within an 8cm x 8cm box or equivalent area (64cm2)
• Dimensions/Relations should be efficient. 
• It is not required to fully define your entire sketch, but it will help.
• The sketch must contain zero error messages.
• Demonstrate efficient use of “Offset Entities”

Design Process:

1. Initial Inspiration

• We chose a mug because it has a simple yet recognizable silhouette.
• When searching, we couldn’t find a perfect design, so we combined two with features that we liked:

1. Tracing

• Imported the image into Solidworks. We made sure that it fits within an 8x8cm square so as to fit the design constraints.
• Ensure that the gap that forms the interior of the handle and the total outline are two distinct shapes.
• Fully define your sketch.

1. Offsets

• We chose to manually select the entire outline of the mug, excluding the handle. The following is what it should roughly look like (ignore that the mug is accidentally inverted in the attached photo):

• We then had to manually connect the excluded areas in the offset using the line tool to create a full shape. It should look like this:

• We continued creating the offsets until we reached the center of the mug.

1. Extruding

• Our initial design had the handle and the body as two different shapes, accidentally creating a gap between the two when extruding with a draft angle. If following the previous steps this gap should not exist.

• We then used the extruded cut feature on the next innermost ring to create a hollow shape. It should look like this:

• Extrude the next ring, making sure that it is up to the surface with the previous extrusion in case of further modifications. Cut the next ring from this extrusion. We repeated these steps until we had extruded and cut all offsets.

1. Mirroring

• Finally, mirror the cup along the front plane. The cross-section should look like this:

Design Choices:

1. Handle Shape

• We opted to make our handle a lot rounder than our reference image. We both preferred the shape, and it helped us achieve our goal of wanting the handle’s shape to blend in with the shape of the mug. Our goal was to make the handle tangent with the mug, but we were only able to achieve that on the top of the handle. The bottom of the handle have to extend much farther for it to be tangent, but we avoided this because it looked awkward.

• Our very first sketch had the handle appearing attached to the shape of the mug, but because of how we drew it afterward and never actually combined the shapes, we encountered a strange gap between the mug shape and the handle that proved very difficult to fix.

• Most of the solutions that we could come up with either did not work or were inadequate. One idea that I had was to actually draft the handle in the opposite direction so that the draft was parallel and to somehow move the handle over to the left so it would become attached to the mug's body. We couldn’t figure out a way to bring that to fruition. The handle would look very strange anyway, with the cross-section looking more like an hourglass rather than like a diamond.
• Here’s a solution that Mr. T came up with for us on the top of the handle. I honestly forget exactly how he did it since we ended up not using it in the end. This solution was very quick (from what I remember), but it really disrupted the flow of the handle into the body that we desperately wanted to achieve.

• Our final solution that yielded the best results was, surprisingly, the simplest. All we had to do was combine the outline of the handle with the mug body to create a filled-in shape and then recreate the interior of the handle as another filled-in shape. Initially, we could just make the offsets with the required settings To achieve the gap, though, we had to cut the interior shape from the extrusion of the entire outline. To make the drafts match, this cut had to draft outwards.

• This design was not flawless. The first time I tried it, I discovered that that incredibly sharp point created at the bottom of the interior hand shape would mess up the cut extrude. It gave it a really weird interaction between the handle and the body, where it looked like the handle got skinnier, straying away from our vision of a consistent width with the handle. It’s hard to see in the following image, but it is there.

• The solution to this problem wound up being to go back and edit the sketch to give that point a tiny chamfer. Initially, I tried a large chamfer, but when trying the cut again, it changed the inside silhouette of the handle too much. A microscopic chamfer on this point was enough to solve the problem when cutting. Here’s what it looks like with this chamfer.