Prusa Mendel

From RepRap
Revision as of 17:11, 18 November 2010 by TheOtherRob (talk | contribs)
Jump to: navigation, search

This page is a development stub. Please enhance this page by adding information, cad files, nice big images, and well structured data!

Crystal Clear action run.png
Prusa Mendel

Release status: working

Prusa Mendel is simpler remix of normal Mendel.
CAD Models
External Link

Also see SAE Prusa Mendel if being built using SAE (Imperial) Fasterers

Prusa Mendel is simpler remix of normal Mendel. I want to use bushings instead of regular bearings, right now, my prototype is using two bearings, one for X and one for Y axis. Actual State is, that I have whole machine up and running, with my DIY PLA bushings. Its pretty smooth. <videoflash>tyVM3-v84I0</videoflash>


The Prusa Mendel is on hosted github:

You can follow the changes on Changelog

You can sign up for github for free and fork the project to begin working on it.


Bill of Materials

The Prusa Mendel BOM is included in the Prusa Mendel README on GitHub here: Prusa Mendel Bill of Materials

(in works, not complete yet)

Printed Parts

6x frame-vertex       RP
2x coupling           RP
3x endstop-holder     RP
1x x-carriage         RP
1x x-end-idler        RP
1x x-end-motor        RP
1x y-motor-bracket    RP
1x y-idler            RP (available on RepRap SVN)
1x y-slider-better    RP Note: not verified, the file is four sliders as one part.
2x z-motor-mount      RP
4x belt-clamp         RP
8x bar-clamp          RP
2x rod-clamp          RP
2x pulley             RP

Printed Bushings

3x pla-bushing        RP-PLA

Guesstimate of other parts: ("vitamins")

80x M8 nut            Fastener
76x M8 washer         Fastener
3x 608 Bearing        Bearings
 6x M8x370 Stud side       Studding
 4x M8x294 Stud end        Studding
 2x M8x440 Stud top        Studding
 2x M8x210 Z-Leadscrew     Studding
 1x M8x470 Z-Stud bot.     Studding
 2x ~8x495 X-bar           Bar
 2x ~8x406 Y-bar           Bar
 2x ~8x330 Z-bar           Bar
 1x 225x225 Print bed      Thick Sheet
 1x 140x225 Print bot.     Thick Sheet
 3x ??? Optoflags          Thin Sheet
20x M3x?? for motors+pul.  Fastener
16x M3 washer "  "         Fastener
10x M3x10 for X-ends Fastener
 8x M4x15 for X&Y-belts    Fastener
16x M4 washer "  "         Fastener
 8x M4 nylock "  "         Fastener
 3x M4x?? for X&Y-bearings Fastener
 3x M4 Mudwashers "  "     Fastener
16x M4 nylock "  "         Fastener
 4x M4x?? for Z-Clamps     Fastener
 8x M4 washer "  "         Fastener
 4x M4 nylock "  "         Fastener
 4x M4x30 for Print bed    Fastener
 ?x M? washer "  "         Fastener
 ?x M? nylock "  "         Fastener
 1x standard Mendel extruder
 5x Nema 17                NEMA Stepper
 1x standard Mendel electronics or Mendel alternative electronics.

(The Prusa Mendel uses the 4 drivers in the standard Mendel electronics package to drive 5 motors by using "two steppers wired in parallel to one driver"[1]).

Printed Parts

A printed set of Prusa Mendel parts

Printing a Prusa on a Mendel

An easier option then individually printing each part if you are printing Prusa on a RepRap Mendel is the pre-assembled build file containing the Prusa parts. With this option you only need to print the Mendel plate and 3 of the PLA bushings to get a complete Prusa Mendel:

Printing a Prusa on a Makerbot

There are also pre-assembled build files available to fit your Makerbot's build area (download using right click => save as)


  • These plates use the full surface of the build platform, so remove bolts if necessary.

Plates for the MakerBot:

Printing a Prusa on anything else

Last but not least, if you have a machine that doesn't fit into any of the previous options all the .stl files necessary to print a Prusa Mendel are available on the PrusaMendel Github where you can download them and print them individually.


This page is a stub, you can help RepRap by expanding it

This needs some work by someone familiar with Prusa, for now though you can at least use the images bellow to identify each part in the design and then try every possible combination until it works.


Assembling the frame

Assembling the frame vertex triangles (2x)

This is the side of the Prusa RepRap, you will need to make 2 of these and then connect them together (see next step) to form the Prusa frame.

Parts Required (per triangle)

  • 2 footed frame vertices
  • 1 frame vertex (non-footed)
  • 1 bottom bar holder thingy (TODO: proper name)
  • 3 threaded rods (TODO: length)

(I have a pic of the assembled vertices)

Now we need to connect the 2 frame triangles to form the Prusa RepRap frame.

Assembling the top threaded rods

These connect the 2 frame triangles at their tops as well as providing mounts for the z-axis motors.

Parts Required

  • 2 assembled frame vertex triangles (see previous step)
  • 2 z motor mounts
  • 2 threaded rods (TODO: length)


  1. attach the tops of each frame triangle (that is the non-footed vertex) to the threaded rod using a nut on each side of each hole to loosely keep them in place (we will adjust the position of these later).
  2. take the z motor mounts and attach them to the outsides of each non-footed frame vertex using a nut on each outer hole.

Assembling the front threaded rods

These 2 threaded rods are used to connect the front/bottom vertex of each triangle as well as the y-stage bars and y motor mount to the frame.

Parts Required

  • 2 assembled frame vertex triangles
  • 2 universal rod clamps
  • 1 y motor mount

Assembling the rear threaded rods

These 2 threaded rods are used to connect the back/bottom vertex of the 2 triangles together as well as the y-stage bars and belt pulley.

Parts Required

  • 2 assembled frame vertex triangles
  • 2 universal rod clamps
  • 1 y motor mount


  1. Loosely attach the pulley to the center of the rod using 2 pairs of nuts and washers to keep it in place.
  2. Loosely attach the 2 universal rod clamps to either end of the rod using 4 nuts. Do not attach these using the 'U' clamping area, instead use the holes on either side of the 'U'. We will need the clamping 'U' later on to attach the y-stage bars.
  3. Loosely attach the rod to the upper hole in the 2 front frame vertices and attach the unused rod to the lower hole.

Tightening the frame

Now that the frame is fully assembled we can adjust and tighten each of it's threaded rods.


  1. Adjust each of the threaded rods according to the diagram bellow and then secure them in place by tightening their nuts with a wrench until they are strongly attached (but not so tight that you see the plastic deform).

(TODO: Diagram)

Assembling the z stage

Parts Required

  • 2 shaft couplers
  • 2 PLA bushings
  • 2 stepper motors
  • 2 threaded rods (TODO: size)
  • 2 smooth rods (TODO: size)
  • 1 prusa frame (see previous step)


Assembling the y stage

Parts Required

  • 4 PLA bushings
  • 1 belt clamp
  • 2 smooth rods (TODO: size)
  • 1 y timing belt
  • 1 stepper motor


Assembling the x stage

Parts Required

  • 4 PLA bushings
  • 2 smooth rods (TODO: size)
  • 1 x timing belt


See Also

External Links