Adrians Prusa Notes

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Revision as of 17:11, 26 June 2011 by Adrianbowyer (talk | contribs) (Altered reprapped parts)
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Adrian's Prusa Notes

Release status: experimental

Ab-prusa-all.jpg
Description
How Adrian builds a Prusa Mendel.
License
GPL
Author
Contributors
Based-on
Categories
Prusa Development
CAD Models
External Link


Introduction

This is my page of notes on how I put together a Prusa Mendel. These are not so much improvements, but more modifications and options done for both personal convenience and the convenience of RepRap Ltd, as this is the one we sell. I have documented them here as others may find them helpful.

This page is intended to be read in conjunction with the main RepRap page on Prusa Mendel Assembly here

The files needed for what's here are in my fork of the Prusa Mendel Git repository here: https://github.com/AdrianBowyer/PrusaMendel in the directory AdriansPrusaModifications.

Configuration

The main components I use in my version of Prusa Mendel are:

  1. Sanguinololu electronics,
  2. Aluminium heated bed,
  3. My Universal mini extruder, and
  4. XBox 360 203 watt power supply.

I also use some modified printed parts and a few extra ones. All this is described and linked to in the sections below.

Mechanics

Ab-prusa-all.jpg

The most significant difference between my version of Prusa Mendel and the standard one is that I reverse the X axis. Looking at the front of the machine with the Y motor at the back, the X motor is on the left, not the right. This allows easier wire layouts, and - in particular - allows neat connection of the wiring to both the X axis and the heated bed by cable-tying it along lengths of 3mm filament for support.

I have also made a number of minor mechanical alterations that are listed in the next section.



Altered reprapped parts

endstop-holder.scad

Endstop.png

The endstop holder is the left hand image. It holds a microswitch with 9.5mm mounting centres and M2.5x12 mounting screws. Get a microswitch with just a button, not the lever as well - it's more accurate.

If you set the variable pcb_mount=true; in the OpenSCAD file it also generates a PCB holder (right image) to allow you to mount the RepRap control electronics on the machine using M3 screws. See below.


pla-bushings-4.scad

Pla-bushings-4.png

If you have all 12 PLA bushings in an array as a single STL file it makes arranging them in a build less versatile as you can't cram them into small spaces. Arranging them one at a time gives a lot of versatility, but they are so delicate that they can detach, even from a well-heated bed.

My compromise it to have four on their own raft. This prints reliably, and is easy to slide about between other parts to print wherever you want. Print three of these to get 12, obviously. The raft is thin enough to cut from the finished parts easily with a scalpel. Mind your fingers...



x-end-idler.scad

X-end-idler.png

I have replaced the unsupported bridges with thin webs (left picture), which both print more cleanly and are stronger. The M8 nut cavity now has a hole through for the M8 threaded rod, and a 45o conical base to the barrier that rests on the nut (right picture). This again prints more cleanly.




x-end-motor.scad

X-end-motor.png

This has the same webs and cone as above. In addition there are two small holes (A A) that allow a 3mm diameter length of filament to be attached using a cable tie to run the X-axis wiring.

X-wire-support.jpg

The picture on the right shows the idea, though that was taken with the old design. Also, the wires are shown taped here, before they are cable-tied. This is generally a good idea: attach all wires with sticky tape first, then, only when everyting is in place and you're happy with the layout, go round putting the cable ties on and cutting off the tape.



Heated Bed

Extruder

Electronics

Power Supply

Ab-prusa-y-belt-clamp.jpg

Ab-prusa-y-belt-and-motor.jpg

Ab-prusa-heated-bed-1.jpg

Ab-prusa-heated-bed-2.jpg

Ab-prusa-heated-bed-3.jpg

Ab-prusa-sanguinololu-jumper.jpg