Classroom Test Divider and Supply Holder

Summary Continued

This model is designed for school classroom desk groups, and it can fit:

• Four test dividers

• Four TI-30X calculators

• Four rectangular erasers

• Four metal or plastic 12-inch rulers

• Ten wooden pencils

• Two scissors in varying sizes

• Six Expo dry-erase markers

• Two whiteboard erasers

Goal

There was already a version that my teacher @MCdeltaT_264915 created to hold test dividers and calculators, but there were a lot of other things students needed at their desks. There is no model posted online, so I have to upload this as an original model, but note this is actually a remix. My goal was to utilize the existing space to make materials easier to access, ensuring that time in the classroom is spent more efficiently on learning.

Design Process

v1

I started off with a paper sketch based on a traced outline of the test divider. I added the initial measurements I thought could work for various features.

I already had the base that could hold four calculators and test dividers, as well as a separate eraser holder attachment.

I split the initial eraser holder design in half so I could fit it in the gaps better, decking to put two parts for two erasers each in different wedges.

I extruded the sketch up and made cuts to grab the eraser better, but because of its position, the cut also affected the main structure.

I fixed this by moving the holder away to make all of the cuts and adjustments.

After that, I used two move/copy bodies features to get the eraser holder in the right position. The first one was to translate the body, and the second one was to rotate it.

After combining all of the features into a body, I mirrored the body over the top plane and then the right plane, so I could get another eraser holder directly across from the original. To get rid of the extra eraser holder I made, I used the delete/keep feature.

I made a small extrude so there is no weird gap in between the main structure and the eraser holder. By unchecking the merge result to have it be its own body, and moving it up the feature tree to combine with the other parts, it showed up on the other side as well.

I moved on to the pencil holder by creating an arc for the wall and using offset entities with a 0.3 cm offset and lines to cap the ends.

I extruded the sketch 4 cm up and used the same method as the eraser holder to create another pencil holder.

After creating an area to hold scissors in a similar way as the pencils, I filleted the edge that stuck out due to the nature of the initial design curving in.

I made a ruler/compass holder using the same methods as before.

I made a sketch for the stapler that was similar to the sketch I made on paper, but I added a border because the inside would be a hole to put it in.

After extruding it, I filleted all of the edges so it looked nicer.

To ensure the rulers, compasses, pencils, and scissors wouldn’t fall out, I made a sketch on the bottom plane and extruded it 0.2 cm up.

v2

I needed to align everything so it didn’t look uneven. I started by changing the fillets for the rulers and the compass back to normal.

I went back up to before the fillet for the corners so I could align things.

It was difficult to bring the eraser design back after creating a new version, so I had to recreate it. I made a boss extrude for the pockets and didn’t merge, made another extrude for the bottom and didn’t merge, then I made the cut extrude on the sides that only affected the Boss-Extrude23 body. After that, I filleted the edges of the cut and the entire top and side. I combined the two extrudes to create one body, mirrored it over the top and right plane at the same time, and used Body-Delete/Keep to remove the two extra bodies. Finally, I combined the two eraser holders I had left with the main structure, creating one body.

I dropped the stapler because it wasn’t very practical, and I decided to replace it with another space for scissors.

I made a sketch for the pencil holder, but tried to align it using a construction line and making the center of the arc coincident with it. Before I used unspecific measurements that I thought would be the right size, but not focusing on the angle.

I extruded the wall and a base from the bottom 0.2 cm up, along with adding some fillets.

Next, I went to making a better ruler section. I made construction boxes to represent the rulers and triangles as wedges to split them up. I also put a closed arc at the end to act as a wall and keep the rulers in.

After that, I made a base and filleted the edges.

I made a sketch with boxes cut out to make slots for the scissors, resulting in a better fit.

I extruded the sketch and filleted it.

I unmerged all of the extrudes so I could mirror the features over both the top and right plane.

After deleting all of the extra bodies, I got perfectly mirrored versions of my additions.

I rolled down the feature tree to put back some of the original modifications that were lost when I started from before the fillets, while also removing some other fillets. I used convert entities to make a new sketch for the cut extrude on the bottom of the calculator section because the original did not work.

Because of this new cut extrude, I had to add the fillet present in the original model.

To minimize the filament used, I made triangular cuts in the unused eraser and scissor parts.

After getting feedback, I went way back up the feature tree to make the eraser fillet larger so it would be well-connected to the main structure.

I made the cuts up to the surface of the calculator holder so it wouldn’t be too hard to grab, and I filleted everything to match the past versions.

I printed out my model. Overall, it came out well, with everything functioning. However, there were some things that could be improved.

The erasers fit, but only the smaller, narrower ones. When looking at the previously created eraser holder designs, I didn’t realize there were two different ones to accommodate different eraser sizes. I wanted the next version to also fit the larger erasers.

The pencils did fit, but they sometimes stuck out because there was too much free space.

There was a similar problem for the rulers, but more pronounced.

The scissors looked good, which makes sense because I tested the holder out before by just printing that section.

v3

I created a list of changes to make, along with a sketch for individual pencil slots.

I went back to the beginning, even though some parts only needed minimal changes. It was not difficult to recreate those parts, but it made creating new things much easier.

I copied the design from the past version because the scissors fit very well.

I started recreating the ruler section with smaller dimensions so it wouldn’t fit wooden rulers, because adding them as well made the metal rulers way too loose. I also realized putting the wedges a bit away from the construction line rulers meant I was putting too much space, so I made the lines for the wedges on top of the ruler sketch lines.

I extruded the final sketch 5 cm up and filleted it.

I created a sketch to fit one pencil in each slot, with the original idea of fitting 5 pencils.

After extruding the sketch 5 cm up, I used convert entities to make a new sketch for the inner circles and extruded that 2 cm up.

I made a reference plane across the diameter of the circle by first making a plane using the inner cylinder as a feature and the top plane for reference. Next, I made another plane that was offset 0.4 cm from the first plane.

On the new plane, I made a constraint box based on the diameter of the cut extrude circle.

Using that sketch, I made a cut revolve and repeated the steps for the other areas.

To have space for the whiteboard markers and the whiteboard erasers, I decided to put all four erasers in one area. However, it looked quite large when I recreated it.

While I thought the eraser stuck out too much on SolidWorks, seeing the individual parts next to each other in real life made me realize it wouldn’t actually be that bad, so I decided to keep the design.

Since the other pencil shape looked odd, I changed it to a neat pyramid with 6 spaces.

I made marker holders with the same idea as the pencils, but larger to fit their width, resulting in 3 for each space.

I made a sketch for the whiteboard eraser holder with a plan to mirror it over the right plane, just like I would for the marker holder.

After extruding both 5 cm up, I mirrored them over the right plane.

I tried different configurations to make the eraser holder fit as best as possible, and I ended up going with the first option because it used up the space the best.

I wanted to make a single base for everything at the end, so I moved the cut revolve sketches down where the bottom intersected the bottom of the boss extrude, and I lowered the boss extrude to 1.75 cm in height.

I moved the whiteboard eraser holder closer to the main structure, so it stuck out less, and mirrored the new version.

I put cuts in the eraser holder so it would be easier to grab the erasers if they got shorter from usage.

I added fillets to support the whiteboard eraser holder better, making sure it is properly connected to the main structure.

I made a sketch using convert entities that covered the entire bottom and extruded it 0.2 cm down to create a base.

I added back all of the fillets and other features from the original calculator holder, and cut the top 7.6 cm to reduce the filament used.

I made cuts for some unnecessary parts, cleaning up the base.

Since I had space, I added a fourth row to the pencils, resulting in a total of 10 pencils held.

After that adjustment, I decided to print my design for the second time.

After checking the second printed version, I had a list of changes I wanted to make, all regarding loosening spaces up.

• The pencil slot’s width

• The rulers, specifically for the plastic rulers

• The whiteboard eraser holder (it fits, but very tightly)

However, some things went very well!

• The scissor holder was good, just like last time

• The eraser holder didn’t look as awkward or large in real life as it did on SolidWorks, and it worked

• The pencils fit lengthwise almost completely

• The marker holders are just the right size to be neat but also easy to grab

I remade the ruler section with smaller 0.3 cm spaces to create a tighter fit.

While the original dimensions of the rectangle were 5.4 cm x 1.8 cm, I increased both measurements by 0.15 cm.

I wanted to test out different possibilities for the pencil holder dimensions, so I created a model with 0.85 cm diameter circles and another one with 0.9 cm as the diameter.

Based on the printed test, I decided the 0.85 cm version would be better.

I made an assembly with the 0.85 cm part and printed the final version.