Kijenzi Printer

Kijenzi 1.0

The Kijenzi printer is a modified version of the Athena Reprap printer that is designed for usage in rural/rugged areas. "Kijenzi" loosely translates to "little maker" in Swahili, and this page details the design and development as the Kijenzi printer as it is prepared for usage in western Kenya.

This printer line is being designed with help from users in Kisumu, Kenya. This user group represents a small group of technical professionals who are responsible for the maintenance and repair of both medical and non-medical equipment in the the county's many health facilities.

The Kijenzi printer is being developed iteratively, with new features constantly being added in between field trials in East Africa. Some of the desired features,their reasons for inclusion, and their current development status can be seen below.

Feature Description Reasoning Status
Collapsible Frame Frame that separates the printer in to 5 modular components Useful for quick deployment, convenient packing, and modular repairs in the field Prototype construction underway
Climate-controlled build space Build envelope that allows for indirect control of temperature, dust, and humidity Useful for being able to attain quality prints in a range of environments Prototype completed
Heated Bed Printer build plate with controlled heating allows for a wider range of build materials Prototype construction underway
Dual fan Extruder Head Improved cooling for parts and hotend allows for a wider range of build materials Prototype construction underway
Autocalibration/Autoleveling Allows for printer to be calibrated without user Necessary for collapsible frame Researching options
Bluetooth connectivity via phone Printer controlled via bluetooth Majority of users in the developing world have access to smartphones, but not laptops Prototype construction underway
Back up power supply Allows for printer to continue operation after power outages and insulation against surges Power connectivity is often inconsistent in developing nations Prototype construction underway
Android App for accessing key stl files/gcode Printer app that connects to vetted database of parts Allows for easier access to the useful parts for developing world consumers Ideation

Climate controlled build space

The purpose of this modification is to create a base for controlling the climate of the build-space. The primary focus of this modification thus far is to create a positive pressure within the build-space by closing off the printer and including a large, constantly running fan on the top of the printer. This design is also fairly insulated so that with the future addition of a heated bed, the temperature in the build space can be kept uniform for better quality prints.

Tools and BOM

Tools needed

  1. MOST Delta Reprap
  2. Power drill
  3. Circular Saw
  4. Drill bits (1/2", 1/4", 1/8")
  5. Level
  6. Jig Saw
  7. Superglue
  8. Plastic bonding agent (must be appropriate for polypropylene)
  9. Ethernet cable crimper
  10. Phillips head screwdrives

BOM

Hardware

Item Quantity
#8 Machine Screws, 1/2" 20
#8 Machine Screws, 3/4" 20
#8 Machine Screws, 1" 4
#8 washers, 3/4" 16
#8 Self-drilling machine screws, 3/4" 12
3" utility hinges (may optionally be printed) 2
Magnetic drawer latches/plates 2

Electronics

Item Quantity
200mm x 200mm, 12V Computer fan 1
Female CAT-5 Ethernet Connectors _
Male CAT-5 Ethernet Connectors _

Other

Item Quantity
PLA Filament Roll <1kg
12" x 24" x 1/8" polypropylene Sheets (may be improvised as done below) 3
4" x 24" x 1/8" basswood Sheets 3
6 cm x 30 cm x 13 cm plywood 2
hexagon plywood base from Athena kit 1
Rubber Foam Weather seal 10'
Nail-on EPDM Rubber Door Seal 16'
Computer fan filter cloth 1
Rubber Band 1

Building Procedure

  1. Using your MOST Delta Printer, print the following components:

Corner Brackets (x6)

Hinge bottom (x2)

Hinge top (x2)

Magnet Brackets (x2)

Ethernet housing (x1)

Recommended Print settings for all components:

Layer Height: 0.20 mm

Shell Thickness: 1mm

Bottom and Top Thickness: 2mm

Fill Density: 20%

Print Speed: 50mm/s

Print Temperature: 185C

  1. Attach the brackets to corner brackets to each of the the plywood sides using 2 #8 3/4" self drilling screws. Make sure the holes on the bracket are centered. Also ensure that the top bracket is flush with the underside of the top PLA corner piece of the Athena printer and that the bottom bracket is placed approximately 2.5" from the ground.
    Kijenzi10.jpg
  2. Prepare the polypropylene sheets by ensuring that they are the correct size to be placed over the brackets. If you cannot find polypropylene sheets, you can cut a bin into pieces as seen in the picture.
    Kijenzi2.jpg
    Kijenzi3.jpg
  3. After aligning the polypropylene (PP) sheets to the corner brackets, using a power drill and a 1/8" bit, drill holes through two of the PP sheets in the locations of the holes seen in the brackets.
    Kijenzi15.jpg
    Kijenzi5.jpg
  4. Attach these two pp sheets to the brackets using the #8 1/2" machine screws and accompanying washers. Make sure that the PP sheets are attached on the OUTSIDE of the corner brackets. Only use two 1/2" inch machine screws per corner, only using the inner holes.
    Kijenzi13.jpg
  5. On the remaining side with no polypropylene sheet, attached the two 6 cm x 30 cm x 13 cm board to the corner brackets by pre-dilling holes and using the #8 1 inch Machine screws. Ensure that these are flush with the top and bottom brackets
    Kijenzi16.jpg
  6. Attach the hinge bottoms to the wooden support to the left of the open side of the printer. In the distance between the top and bottom bracket (approx 40cm) you should center the hinge at about 13 cm (1/3 of the way) and the other at approximately 27cm (2/3rd). Do this with the 1/2" flathead screws
    Kijenzi21.jpg
  7. Do the same with the magnet brackets on the opposite side.
    Kijenzi23.jpg
  8. Place the top hinges onto the bottom hinges and attach the magnet latched to their brackets with 3/4" self-drilling screws. If the hinges do not go on easily, sand them down first
    Kijenzi24.jpg
  9. Cut the 24" basswood pieces to a length of 40mm, and on one side, line the perimeter with the rubber-foam weatherseal.
  10. Attach the basswood pieces over the hinge brackets, the magnet brackets, and the empty third side with two 1/2" wood screws.
    Kijenzi26.jpg
  11. Cut the Nail-on EPDM rubber into 2 foot strips
  12. Using a 3/4" inch self-drilling machine screw for the open side and the 3/5" machine screws on the closed sides, attach the EPDM strips vertically along the corners. For the closed sides, place the machine screws through the outermost remaining bracket hole.
    Kijenzi27.jpg
    Kijenzi28.jpg
  13. Glue the length of the strips onto the wood and PLA brackets with super glue and onto the polyproprylene with the plastic bonding agent.
    Kijenzi29.jpg
    Kijenzi30.jpg
  14. Cut what remains of the strip into 1.5" sections and use superglue to attach it to the gaps between the top of the platform and the rest of the assembly.
    Kijenzi33.jpg
  15. Cut the last sheet of PP into a 40cm x 25cm section and place it into the space made available for it in the hinges.
  16. Drill holes into the PP using the hinge brackets as a template. Use 1/2" machine screws to hold it into place.
    Kijenzi31.jpg
  17. Do the same with the handles. Placing them roughly over the magnets.
    File:Kijenzi50.jpg
  18. If extra seal remains, you may use it to seal the bottom by wedging it into the space between the printer base and the bottom of the polypropylene sheet
    Kijenzi34.jpg
  19. Take the hexagon plywood piece and trace the outline of the fan onto it.
    Kijenzi17.jpg
  20. Using a jigsaw cut out the outline of the fan, and use the half and quarter inch drill bits to make holes for the wiring and tubing to pass through.
    Kijenzi19.jpg
  21. Thread the filament feed and wires though the appropriate holes.
    Kijenzi20.jpg
  22. Using the female cat5 connectors sort out all of the wiring (other than the hot-end and U, V, and W stepper motors) including the wiring for the fan, into the ethernet ports. BE SURE TO REMEMBER AND NOTE WHICH WIRE GOES INTO WHICH PORT!
    Kijenzi37.jpg
  23. Use 1/2" screws to secure the fan, 2 hinges, and the ethernet ports to the top of the platform
    Kijenzi38.jpg
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