Pencil Holder - Setting Up and Printing - Idiot's Guides: 3D Printing (2015)

Idiot's Guides: 3D Printing (2015)


Setting Up and Printing


Pencil Holder

Project Time: 4 hours

In this project, you’ll be stepping up the difficulty a bit. Printing a pencil holder requires a couple of tricks to accomplish. As you’ll notice once you open the file, the model is solid and doesn’t open like a cup. In order to use it as a pencil holder, the Slic3r settings must be modified to remove the top and make the inside hollow. This should give you an idea of how powerful the slicing software is and how it can be used to customize the model.

Load the .STL File and Resize the Model, If Necessary

In Repetier, click Load and select the pencil_holder.stl file, which is included in the model pack at the Idiot’s Guides website ( Next, check its size on the Object Placement tab, which should already be up. This model is a lot larger than the last one, so you should make sure it fits on your 3D printer.

If it doesn’t fit, you can try resizing the model. On the Object Placement tab, you should be able to select the loaded model. You have the option to do basic modification, like repositioning, rotating, and resizing the model.

You can resize the model, if necessary, in the Object Placement tab.


While you can resize to fit on your printer, keep in mind that it can’t be too small. Otherwise, it won’t be very useful as a pencil holder.

Preheat the Extruder and Heated Bed, and Load the Filament

Make sure Repetier is connected to your 3D printer. Just like in project 1, you may want to start by getting the extruder and heated bed warmed up. If you recall, ABS requires settings of 230°C for the extruder and between 80°C to 100°C for the heated bed, while PLA requires settings of 200°C for the extruder and between 50°C to 70°C for the heated bed (if you have one). Both ABS and PLA work well for this model, so you should be fine using whichever you have on hand or prefer.

Once the extruder is up to temperature, load the filament into the hot end, if you haven’t already. The steps for doing this are exactly the same as in project 1, so check that out if you need a refresher.

Modify the Slicer Settings to Make the Model a Cup

For this model, you have to make a couple of changes to the Slic3r settings in order to remove the top of the model and make it hollow; otherwise, it won’t function very well as a pencil holder.

In Repetier, go to the Slicer tab and click the Configuration button. (See project 1 if you need a refresher.) Once the configuration window opens, under the Print Settings tab, locate and click on Layers and Perimeters. Here, you want to change the number of horizontal and bottom perimeters to 4. Then change the number of top perimeters to 0. This gives the bottom and sides of the model a solid thickness of 4 layers and removes the top of the model entirely.

Turn off the top perimeters.

Next, click on Infill, which is located below Layers and Perimeters, and change the fill density to 0%. This makes the inside of the model hollow.

Set the fill density to 0%.

Slice the Model

With your Slic3r settings modified to make the model cuplike, you can go ahead and slice the model. Go to the Slicer tab and click Slice with Slic3r. This print should take 2 to 4 hours at the standard size, depending mostly on how fast your printer moves.


The actual slicing process might take a few minutes, so be patient here, especially if your computer is a bit older.

Start the Print

After the slicing has been completed, click on the Preview tab. You should see that the projected extrusion paths make a pencil holder instead of just a solid model. This is because the preview window shows you what is supposed to be printed, not the original model.

Check the preview to verify if the print looks right.

If you’re happy with preview and the extruder and heated bed are up to temperature, you can start printing by clicking Start Print.

Watch the First Layer

As you should do with every print, stick around to watch the first layer. The first layer is the most important, so make sure it turns out right. You want good adhesion, but you don’t want the hot end so close to the bed that it squishes the plastic.

Printing the first layer. Always check the first layer to make sure it looks correct.

Remove the Part

Once the print has finished, give it at least five minutes to cool off, so it can completely harden. Letting the heated bed cool down to room temperature makes it more likely that the part will just pop right off. But if you’re eager to start storing your pencils in style, you can use a tool to remove the pencil holder. Just be sure to do this gently to avoid damaging the bed or the part.

You can use a tool to carefully remove the part from the bed.

With the part removed, you can admire your handiwork. To test it and make sure it works, place some pencils (or even pens) in it. If they don’t fall out, then congratulations, you have a pencil holder!

It holds pencils!