An Enclosure for a Prusa 3D Printer

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Introduction: An Enclosure for a Prusa 3D Printer

About: I'm a Ph.D. in software engineering, CTO at 34BigThings, a game studio based in Turin, Italy.

After assembling my Prusa i3 MK3S 3D printer, I quickly installed a RaspberryPi Zero and a Pi camera to be able to remotely control the printer using OctoPrint.

I positioned the printer on a table in my workshop where I do woodworking. Soon I realized I needed some sort of enclosure to address some issues:

  • Protect the printer from dust
  • Light up the printer at night
  • Extract fumes produced during filament melting
  • Control ambient temperature

I took some inspiration from the popular Ikea Lack enclosure but I wanted something more compact, with the minimum size to allow the printer to operate. I also wanted an air tight box with a system to control air flow.

As you can see in the picture above, my design consists of:

  • External control panel and PSU
  • Transparent sides, top and door
  • Easy removable front door
  • Easy removable spool enclosure
  • Digital thermometer for the enclosure and hygrometer for the spool enclosure
  • 2 Air vents with filter and cap
  • A connection to the fume extraction system
  • A strip of LEDs connected to the printer PSU and controlled with a switch
  • A print bed mounted camera arm
  • Some tool holders

Supplies

Construction

  • MDF 10mm thick
  • Plexiglas 4mm thick
  • 10x ferrite magnets 15mm diameter x 2mm thickness
  • 6 bearings 19mm ext diam, 8mm hole diam, 6mm thick
  • A block of wood 13cm x 27cm x 2.7cm
  • A sheet of foam
  • Window foam insulation strip, 15mm width
  • Window seal strip, 5mm width

Electronics

  • Digital thermometer
  • Digital hygrometer
  • LED stripe 24V
    • 24V for MK3, 12V for MK2/S
    • If you want to use a 12V LED strip with the MK3, use a 24V to 12V DC-DC converter
  • Twin cable
  • A unipolar switch button to turn On/Off the LEDs

Screws and bolts

  • 4mm diam x 25mm length wood screws
  • 4 nuts and bolts M8, 20mm length
  • 8 washers, 8mm hole diameter

3D Printed parts

Step 1: Fume Extraction System

As you can see in the images above, my fume extraction system allows for air speed control and includes a knife gate air valve that I specifically designed to connect the printer enclosure to the system. You can find all the parts for the fume extraction system here: https://www.thingiverse.com/thing:4552442

Step 2: Diagrams and Dimensions

Above you can see some dimensions of the enclosure.

Step 3: Enclosure MDF Panels

Let’s start the build from the back, bottom and front MDF panels. You can see above a diagram with all the dimensions. I used 10mm thick panels. Note that for the base I used two 10 mm MDF panels to get a total thickness of 20 mm. There are two holes: one in the back for fume extraction, the other on the front panel for the cables of the printer’s control panel. To attach the panels you can use screws and/or glue.

Here is a cut list for this section:

Name | Dimensions | Qty | Material
Bottom | 54 cm x 47 cm | 2 | MDF 10 mm
Back | 48 cm x 47 cm | 1 | MDF 10 mm
Front | 47 cm x 5 cm | 1 | MDF 10 mm

Step 4: Add Feet

After gluing the two panels for the bottom, you can attach the 3D printed feet to the base using 4 x 25mm wood screws. Pre drill each hole before inserting the screws.

Step 5: Drill Holes for Control Panel

We want to attach the printer’s control panel to the front panel. It is easier to unmount it from the printer now and mark and drill the holes for the 4 attachment screws on the front panel.

Step 6: Complete the Internal Frame

Now we add the rest of the MDF pieces for the internal frame. See the dimensions above.

Note the 45 degrees bevel on the top beams which will be used later to install the LED strip.

Step 7: Printer’s Base

For the printer’s base I’ve used two 10 mm MDF panels glued together to form a 20 mm thick panel and I’ve placed it over a sheet of foam of the same size. The MDF base will provide a solid and flat ground for the printer, while the foam layer below will absorb vibrations.

Name | Dimensions | Qty | Material
MDF Base | 46 cm x 39 cm | 2 | MDF 10 mm
Foam Base | 46 cm x 39 cm | 1 | Foam 30 mm

Step 8: Plexiglas Panels

The plexiglas panels for the sides and top are designed to be air tight and removable. I used 4 mm thick plexi. Before attaching the panels to the frame, you need to apply a strip of window foam insulation 15 mm width to the MDF frame to guarantee air tightness.

Then the panels are attached with 4mm diam x 25mm length wood screws. The screws allows for an easy panel removal when you need to access the internal of the enclosure. Pre drill some holes on the plexi panels and add a countersink, then clamp the panels to the frame, pre drill holes on the MDF, finally insert the screws.

Here is the cut list for the plexi panels:

Name | Dimensions | Qty | Material
Sides | 55 cm x 48 cm | 2 | Plexi 4 mm
Top | 55 cm x 47 cm | 1 | Plexi 4 mm

You need to make some holes on the left side panel: one small hole for the PSU wires and a series of holes and cuts for the air vents.

Here are two PDF documents you can print on A4 sheet (print them with actual size without any rescaling) with the shape of the holes to make on the plexi panel. Attach the printed paper on the panel and follow the lines to make the cuts and the holes.

Step 9: Front Door

The front door is attached to the enclosure with two 3D printed hinges and is kept closed against a strip of windows seal by some magnets. This will ensure air tightness and allow to easily remove the door by just pulling it out of its hinges. The ability to remove the door is very important to control temperature during warm days when the air vents may fail to cool down the enclosure.

For the front door you need to cut a plexi panel of 48 cm x 41 cm and some 3D printed parts: 2 hinges, the handle and 5 magnet holders. You will need also a strip of windows seal, 5 mm wide, like the one in the image above. Use only one of the couple of strips by splitting the twos in the middle.

Apply the seal strip on the door frame, insert the magnets into the holders, install the holders to the frame with some small wood screws, then glue the hinges and the handle on the plexi panels. To glue the 3D printed parts to plexiglas you can use glue for plastic, two component epoxy glue or super glue. Remember to sand the surfaces before gluing them to ensure a strong join.

At this point you can close the door and mark where to attach the magnets that will match the ones already installed on the door frame. Once you attach the magnets to the door, tune the magnet holders distance from the door to allow the door to close completely and stick to the seal.

Step 10: Spool Enclosure

The spool is located on top of the enclosure, on a 3D printed spool holder. I wanted to protect the spool from dust and humidity as well as the printer itself, so I designed this little plexi box to be simply placed over the spool. I sealed the walls with silicone and attached a strip of 5 mm wide window seal to the bottom edges. I added a little pocket on the back to hold some silica gel bags to absorb humidity. I also added a 3D printed holder for a digital hygrometer attached on the top front of the box.

Here is the cut list for the spool enclosure:

Name | Dimensions | Qty | Material
Sides | 23.2 cm x 23.6 cm | 2 | Plexi 4 mm
Top | 14 cm x 24 cm | 1 | Plexi 4 mm
Front/Back | 14 cm x 23.6 cm | 2 | Plexi 4 mm
Pocket sides | 28 mm x 28 mm | 2 | Plexi 2 mm
Pocket bottom | 50 mm x 28 mm | 1 | Plexi 2 mm
Pocket front | 46 mm x 28 mm | 1 | Plexi 2 mm

Step 11: Installing the Printer Inside the Enclosure

At this point we are ready to install the printer inside the enclosure. But before starting it is better to remove all the plexi panels and the front door to have enough room to work. You need also to unmount the PSU and the control panel, because these parts will be moved outside the enclosure.

Step 12: External PSU

The PSU doesn’t like high temperatures, so it is better to move it outside the enclosure. Also, with the PSU outside, it will be easier to reach the power button.

To avoid adding extra wires to the PSU connections, I moved it from the right side to the left side. In this way I had enough cable to put the PSU outside of the enclosure. I routed the wires outside using the little hole in the corner of the left plexi panel drilled previously.

To attach the PSU to the left panel of the enclosure I didn’t use any 3D printed bracket. Instead I used a simple block of wood of 13.5 cm x 23 cm x 2.7 cm dimensions. You can easily find a PSU holder on thingiverse, but if you want to use my method, here is a trick I used to transfer the hole locations of the PSU attachment screws onto the block of wood.

Place a sheet of paper on the back of the PSU and scrape a pencil over the holes. You will see a marking for each hole appearing on the paper.

Now glue the sheet of paper to the block of wood and drill the holes. Since the block of wood is too tick for the length of the screws, I drilled first a larger hole, 3/4 of the thickness deep, to let the head of the screw sit in the bottom. Then I drilled the final hole with the diameter of the screws at the center of the hole.

After attaching the PSU to the wood with its screws, I attached the block of wood to the plexi panel: I made some holes on the panel, transferred the holes to the wood, pre drilled the wood and attached it to the panel with some 4 x 25 mm screws.

Step 13: External Display and Thermometer

We want to control the printer while it is closed inside the box, so we need to move the control panel outside. If you followed the steps above, you have already unmounted the control panel and drilled the holes for the attachment screws on the enclosure's MDF front panel.

Now unplug the two ribbon cables from the control panel, insert them inside the hole in the front panel and reattach them. Finally mount the control panel to the enclosure with its screws.

At this point you can install the digital thermometer. You need to 3D print some parts: the thermometer holder with its lid and the probe bracket.

Insert the digital thermometer inside its holder. Attach the holder to the front panel with some tiny wood screws, then insert the probe cable inside the front panel central hole. Insert the cable under the printer’s base foam, then insert the probe in its bracket which you have attached to the bottom wall with some tiny wood screws.

At this point you can seal the hole on the front panel with some silicone to ensure air tightness for the enclosure.

Step 14: Air Vents

The air flow system is based on air being extracted from the pipe on the back wall, attached to the fume extraction system. New air is let in from two air vents on the left wall. The propellers on the air vents are used as air flow indicators. There are two air vents with different designs because I first designed the bottom one, then realized I wanted the air to flow above the plate and made the upper vent experimenting with a different design.

If you followed the previous steps, you have already made some cuts for the air vents on the left plexi panel. Now you need to 3D print the air vent caps which are made of three parts: a base, a filter holder ring and a cap. Glue the base to the external side of the plexi panel.

When ventilating the enclosure, we don’t want any dust to come inside. So we need to install some filter sheets on the air vents. I made mine using a bag from my shop VAC (a Kärcher WD).

This bag is made of a three layered filter. I removed the central layer to allow less resistance and a better air flow.

Now it is time to install the propellers on the inside. You need to 3D print the axis and the propeller. You also need a bearing 19 x 8 x 6 mm for each propeller.

I suggest to put some oil on the bearings before installing them, they need to have very low friction for the propellers to rotate even with a small air flow.

Step 15: LED Strip

I used a strip of LEDs with 12V input but the PSU of the Prusa i3 mk3s has an output of 24V. So I installed a little DC-DC 24V to 12V converter to power the LEDs with the correct voltage. I routed the output wire from the converter into a unipolar switch button. I attached the converter on the back of the wooden block and the button on top of it for an easy reach. In the pictures above you can see the final installation and a schematic of the electric connections.

I inserted the wires for the LED strip in the hole for the PSU, attached the wires to the LED strip and the strip cable to the bottom wall with a little 3D printed bracket. Then I attached the LED strip to the left, front and right edges of the ceiling with its own adhesive.

Now that all the wires have been routed through the hole near the PSU, we can close it with silicone for air tightness.

Step 16: Spool Holder

For the spool holder you need to print some 3D parts, then for each rail you need:

  • 2 bearings 19mm ext diam, 8mm hole diam, 6mm thick
  • 2 nuts and bolts M8, 20mm length
  • 4 washers, 8mm hole diameter

Install everything following the image above.

At this point, to complete the spool section, you can drill a hole in the top panel to insert the 3D printed filament hole plug. You need to drill a 16 mm diameter hole. See the drawing above for its positioning.

Step 17: Camera Arm

I wanted a camera mount attached to the printer plate to get better printing time-lapses. With this type of attachment the camera moves with the bed, so the printed object is not moving relative to the camera.

The camera I’m using is a RaspberriPi v2.0 camera, connected with a ribbon cable to a RaspberriPi zero installed inside to printer’s board box.

I modified a design found on thingiverse adjusting some sizes to make it fit in my enclosure and leave enough space for the hand when removing the steel sheet from the print bed.

Note that the printer plate attachment can be mounted without removing the printer plate, just push it in place. Its pressure fit is strong enough to hold it in place but, if you want, there is a hole to insert a cable zip tie to secure it in place.

Step 18: Tool Holders

Finally I added some 3D printed tool holders on the right side of the enclosure: an holder for a window cleaner spray bottle which I use to clean the printer bed and a multi tool holder for the tools I use most often: some pliers, a glue stick, an allen key and a wire brush to clean the nozzle.

Step 19: Attaching the Enclosure to the Fume Extractor

In the picture above, you can see how I attached the enclosure to the knife gate air valve of the fume extraction system.

The connecting pipe is press fitted on the enclosure and on the valve, to allow an easy removal when moving the enclosure.

Step 20: Resources

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    15 Comments

    0
    FUSUY
    FUSUY

    9 months ago

    nice.

    0
    kb7gpDave
    kb7gpDave

    Question 9 months ago on Step 20

    Doesn't the cross-ventilation affect the printing process? especially when printing ABS? I understand an enclosure is almost necessary for ABS and this one would fill the need.

    0
    Giuseppe Portelli
    Giuseppe Portelli

    Answer 9 months ago

    You can choose to open the upper air vent hole, in this way the air will flow well above the print bed. The purpose of the ventilation is to maintain an optimal temperature. For ABS you can pre-heat the bed and wait for the enclosure to reach the desired temperature before starting the print. During printing you can ventilate if the temperature becomes too high.

    0
    kb7gpDave
    kb7gpDave

    Reply 9 months ago

    Got it... I haven't had much luck with ABS and I don't have an enclosure...Yet... what have you found best for amb temperature in your experience?

    Great instructable by the way.

    0
    Giuseppe Portelli
    Giuseppe Portelli

    Reply 9 months ago

    Currently I'm using 25 degrees celsius for PLA and 30 for PET-G.

    0
    mwitherspoon
    mwitherspoon

    Tip 9 months ago

    Nice set up!

    I'd add a dryer vent flapper to that exhaust vent to prevent back drafts bringing in dust when not in use, and keep tiny critters out.

    And as another person mentioned, there is an optimal cabinet temperature to getting the best print quality. Or at least there was back when I ran an FDM unit at work. The unit wouldn't even start the print until the interior cabinet temp was reached.

    0
    Giuseppe Portelli
    Giuseppe Portelli

    Reply 9 months ago

    There is a knife gate air valve that I close when I'm not using the printer. As for the external vent, there is only a 3D printed protection grille, a vent flapper would be better, I agree.

    The air flow system purpose is to keep the optimal temperature for printing. You can do it manually by tuning the air extraction power. An automatic temperature control system would be a nice to have.

    0
    MarekP29
    MarekP29

    9 months ago on Step 15

    Why not put 2 pieces of 12v strip in series instead of dc-dc converter?

    0
    Giuseppe Portelli
    Giuseppe Portelli

    Reply 9 months ago

    It should work, just make sure to have two strips of equal length (equal number of LEDs) otherwise the voltage division won't be equal for both sides.

    0
    Inspectorj
    Inspectorj

    9 months ago

    Nicely done. I don't have a 3D printer but appreciated the precise drawings and attention to details.

    0
    ElectroFrank
    ElectroFrank

    9 months ago

    This the sort of thing I am intending to build for when I get a Prusa.

    Air vents - why are there two ? Why are they different ?

    As they are not propelling anything, are the "propellers" intended as airflow indicators ?

    You might consider some kind of thermostatic control for the interior air temperature, as I understand it affects the print quality.

    You may find this interesting on the subject of printer table stability:

    0
    Giuseppe Portelli
    Giuseppe Portelli

    Reply 9 months ago

    Automatic control of the inner temperature would be nice to have. It would work better during winter because when the external temperature is high, it is very difficult to keep the internal below a threshold, at least with the current power of my air extraction system.

    0
    Giuseppe Portelli
    Giuseppe Portelli

    Reply 9 months ago

    Yes, propellers are used as air flow indicators.
    I designed the first air vent on the bottom, then I realized I wanted the air to flow above the plate, and added the secondary upper air vent where I experimented a different design. Now I can choose to open one or both if I want more air.

    0
    kopmanol000
    kopmanol000

    9 months ago

    Wow great job on the project i love all the features