Prusa Mendel
Release status: working
Description | Prusa Mendel is a simpler remix of normal Mendel.
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Prusa Mendel does less. But what it does it does better. It's a pure 3D printer.
- If you want to pay more for a cool brand and worse quality, buy a Makerbot.
- If you want a printer that will last forever, buy a Shapercube.
- If you want to use linear bearings, go ahead and modify it.
- (I've been corrected that Prusa and Sells are both crappy for milling.)
If you want to do milling, its probably not as good as Sells Mendel in case of milling more then PCBs.
Prusa's main goal is to be the purest and simplest 3D printer you can build.
- It's much simpler to build it.
- It's much simpler to modify it.
- It's much simpler to print it for your friends.
- It's much simpler to repair it.
- Because of small complexity, it can be living thing. I update it all the time. It's unique feature but it should be standard. We are living in feature, we don't care if it's a bit different every time; our printer will print it in same time ;-)
Prusa Mendel is the Ford Model T of 3D printers.
The Prusa Mendel is a simpler remix of the original Mendel. It uses bushings instead of regular bearings. The current version uses three 608 bearings in total, one for the X axis and two for the Y axis. The 624 bearings are gone altogether. I have the entire machine up and running, with printed PLA bushings. It's pretty smooth.
Contents
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Development
The development of the Prusa Mendel is hosted on github: http://github.com/prusajr/PrusaMendel.
You can follow the changes on Changelog.
You can sign up for github for free and fork the project to begin working on it.
History
Bill of Materials
Printed Parts
Non-Printed Parts ("vitamins")
Note that additional parts are required for the extruder, although some extruder parts are included in the table below.
Quantity | Description | Type | Comments |
---|---|---|---|
83 | M8 nut | Fastener | Buy a 100-pack to be on the safe side. |
93 | M8 washer | Fastener | Buy a 100-pack to be on the safe side. |
6 | M8×30 mudguard / fender washer | Fastener | |
2 | M4×20 bolt | Fastener | |
2 | M4 nut | Fastener | |
2 | M4 washer | Fastener | |
22 | M3×10 bolt | Fastener | |
16 | M3×25 bolt | Fastener | Or eight M3×25 bolt plus eight M3x20 bolts. The M3x25 bolts are too long for the recent Prusa z-motor-holder and rod-clamp, and also for the Z motor couplings. See Section 8, steps 4 and 13 for details. |
4 | M3×40 bolt | Fastener | |
70 | M3 washer | Fastener | |
40 | M3 nut | Fastener | 8 optionally locknut / stop nut / nyloc |
2 | M3 grub screw / set screw | Fastener | |
3 | 608 roller skate / inline skate / skateboard bearing | Bearings | |
4 | ballpoint pen springs | Spring | To fit over M3 bolts. Ballpoint pens are a common, cheap source of suitable springs. |
6 | M8×370mm | Threaded rod | 3 per side |
4 | M8×294mm | Threaded rod | front / rear |
3 | M8×440mm | Threaded rod | top / bottom |
2 | M8×210mm | Threaded rod | Z-leadscrew |
1 | M8×50mm | Threaded rod | or bolt for X idler |
2 | 8mm×495mm | Smooth rod | X-bar (consensus seems to be that this is too long, and 420mm might be a better length, but this still requires confirmation from a finished builder. [As a "finished builder" I can confirm 420mm would be better.]) |
2 | 8mm×406mm | Smooth rod | Y-bar |
2 | 8mm×350mm | Smooth rod | Z-bar |
1 | 225mm×225mm print top plate | Thick Sheet | |
1 | 140mm×225mm print bottom plate | Thick Sheet | |
1 | 840mm×5mm T5 pitch timing belt | Belt | |
1 | 1380mm×5mm T5 pitch timing belt | Belt | |
5 | NEMA 17 bipolar stepper motor | Stepper | Be sure to get ones with ~20mm of shaft length. Shorter shafts require modifications to the X pulley assembly and Z motor couplers. One of the five motors, for use with the extruder, should be capable of creating a holding torque of at least 40Ncm. |
50 | small cable binder / ziptie | Misc | |
1 | Wade's Geared Extruder | for 1.75mm filament RepRap Universal Mini Extruder; or any other compatible extruder for either | |
1 | Electronics + endstops | this can be RAMPS, Pololu Electronics, Gen6, Gen3, or anything else compatible |
Quantity | Description | Type | Comments |
---|---|---|---|
3 | 30mm×10mm Optoflags | Thin Sheet | if using opto endstops |
2 | 8mm ID spring | Spring | if using opto endstops |
1 | object with precisely 290mm length | for frame alignment | |
1 | object with precisely 234mm length | for frame alignment |
You can combine the latter two by having a piece of thick sheet with dimensions 290mm×234mm. Make sure to mark which side is which.
When cutting the threaded rods from 1m lengths, you will need 6x1m pieces (or 5x1m pieces and 1x50cm piece). Cut them as follows:
Rod 1: 370mm, 370mm, 210mm, ~50mm (The last piece will end up somewhat shorter than 50mm. Use it for your idler.) Rod 2: 370mm, 370mm, 210mm, ~50mm Rod 3: 370mm, 294mm, 294mm, ~42mm Rod 4: 370mm, 294mm, 294mm, ~42mm Rod 5: 440mm, 440mm, ~120mm Rod 6: 440mm
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].
Where To Purchase
See the Mendel Buyers Guide for information on where to purchase all of the parts needed.
Printing the 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 the PLA bushings to get a complete Prusa Mendel:
- Mendel Plate (contains all printed parts except the PLA Bushings)
- PLA Bushing
SAE versions:
- SAE Mendel Plate (contains all printed parts except the PLA Bushings)
- SAE PLA Bushing
Printing a Prusa on a CupCake CNC
There are also pre-assembled build files available to fit your CupCake CNC's build area (download using right click => save as)
Note:
- These plates are 85x95mm in size.
Plates for the MakerBot (the plates have changed, these print times are no longer accurate):
- Makerbot Plate 1=> 6 hrs 30 min
- Makerbot Plate 2=> ~2 hrs 30 min (needs retesting)
- Makerbot Plate 3=> 5 hrs 40 min
- Makerbot Plate 4=> 2 hrs 30 min
- Makerbot Plate 5 => 1 hr 50 min
SAE versions (the plates have changed, these print times are no longer accurate):
- SAE Makerbot Plate 1=> 6 hrs 30 min
- SAE Makerbot Plate 2=> ~2 hrs 30 min (needs retesting)
- SAE Makerbot Plate 3=> 5 hrs 40 min
- SAE Makerbot Plate 4=> 2 hrs 30 min
- SAE Makerbot Plate 5 => 1 hr 50 min
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.
Buy the printed parts
Mendel_Buyers_Guide#RepRapped_Parts_Kits
Assembly
Assembly instructions >> Prusa Mendel Assembly.
Also see SAE Prusa Mendel if you are building this machine using SAE (imperial) fasteners.
Media
- Two printers simultaneously - Prusa and shaper cube working side by side.
- Prusa homing using endstops
- Prusa development overview
- Prusa Y axis stress test
- Prusa Z axis stress test
- Early preview of the Prusa Mendel redesign
- Fumon's Prusa build session 1 - D1plo1d building Fumon's Prusa Mendel at Hacklab.to. Should give a hint as to how the Prusa Mendel parts go together.
Prusa Improvements/Hacks
- Rob's Auto-centering shaft coupler - designed to reduce shaft/motor vibrations (print 2/replaces 2x coupler). May require widening the openings on the z motor mounts to allow the rotation of the zip tie. Use a zip tie gun to get maximum compression on the coupling.
See Also
External Links
- Prusa's Blog
- Prusa Builder Blog Feed
- Assembly photo gallery
- Prusa Mendel Visual Instructions - A nicely formatted version of the assembly process in PDF.
- Paperback version the Prusa Mendel Visual Instructions, also available in color.