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* Adding cheap IMU unit like the MPU-6050 | * Adding cheap IMU unit like the MPU-6050 | ||
* Building a smaller version of Clerck | * Building a smaller version of Clerck using Nema14 motors for lower mass and cost | ||
== References == | == References == |
Revision as of 11:55, 26 November 2015
Sources files and external documentation
Source code: | Guthub repo | [1] quicklink to firmware |
Licences: | The repo has GPLv2, the blog uses Gnu Free Documentation Licence, the Vimeo videos are CC-BY licenced | Follows FSF's recommendations |
Build process: | Blog posts [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16] | videos and images, very detailed |
Development thread: | at forums.reprap.org | some activity, not very detailed |
Wiki page: | at reprap.org | outdated |
All videos: | Vimeo user 23166500 |
Background
The RepRap project first showed the world cheap small scale 3D printing in 2006. Their design was intentionally not very well thought out. The idea was that a 3D printer that could print its own parts would be improved through evolution like iterations, no matter the quality of the first design. This turned out to be quite correct, as a large community quickly grew around the first few RepRap designs. RepRap users started to experiment and remix all parts of the printer, including its Cartesian coordinate system.
Understanding the market
Early non-Cartesian 3D printer designs were the Tripod-Repstrap[1](2007) and its geometrically similar successors Rostock (2012)[2] and Lisa Simpson (2013)[3][4]. Other non-carthesian RepRap designs include GUS Simpson (2013)[5], Morgan (2013)[6], Wally (2013)[7] and Feather (2013)[8].
All these printers tries to trade heavier geometrical computations for getting rid of hardware requirements or time consuming build steps. They all have frames, and there's still spare clock cycles left in their Arduino CPUs. The idea of Clerck is to skip the hard custom frame altogether and instead rely on wire-connections to already-built rigid structures, like insides of houses.
Making this work would lead to potentially enormous print volumes for prices down to ca $300. Competitors prices are:
Name | Price | Print volume |
---|---|---|
Big Rep | ca $40,000[9] | 1 m3 |
Gigabot XL | ca $13,000[10] | 0.27 m3 |
X1000 | ca $16,000[11] | 0.48 m3 |
Other large scale experimental printers include the Wasp's Big Delta Printer[12] and the KamerMaker, a scaled up Cartesian design[13].
The presented competitors are very expensive and not very self reproducing, many of them are not even free design hardware. They don't satisfy the needs of for example the Open Source Ecology project, who wants to print structural plastic components like car body panels and redworm towers with OSHW tools.
Project goals
- Low part count
- Easy to print, assemble, install and distribute
- Huge build volume
- Cheap
- Able to print many of its own parts
Design
- Put all the hardware (except AC/DC-converter) in one single unit.
- Only one force vector upwards, compensated with counter weight.
- Over-constraining allows flexible compensation of slack lines.
- When printer is idle, one could retract all the strings. Enables elegant storage solutions. Could make it popular in big cities, where indoor area is scarce.
- Parallel lines attached to common spools to prevent rotation.
Video showing the design in action
Costs
! Item | ! Qty | ! Total price |
---|---|---|
E3D V6 Valcano hot end | 1 | $150 |
Nema17 stepper motor | 5 | $60 |
Arduino Mega | 1 | $10 |
RAMPS | 1 | $5 |
drv8825 stepper driver | 5 | $10 |
623 bearing | 10 | $2 |
623 bearing v-groove | 5 | $5 |
608 bearing | 4 | $2 |
JY-MCU Bluetooth Transceiver RF Module | 1 | $6 |
220V AC to 12V converter (power supply) | 1 | $16 |
2.7mm Eyes Inside Dia Fishing Rod Part | 9 | $9 |
Hobbed drive gear | 1 | $2 |
Set of M3 screws, nuts and nyloc nuts | 1 | $5 |
Meters of Non-elastic fishing line (dynema) | 15 | $1 |
PLA and electricity for 3D printing parts | 1 | $10 |
Total Cost | $293 |
Difficulties
- Keeping rotations small, despite forces from
- Power cable
- Filament
- Accelerating motors
- Keeping filament and power cable from gears, print and (outside of) hot end.
- Accurate enough firmware configuration to keep lines tight throughout print volume
- Finding home position reliably and repeatably
Home position
If an IMU unit (accelerometer + gyro) was added, this might be the only needed sensor. Homing could be done like this:
- If printer is not horizontal, tighten D-lines until it is
- Lower printer (extend D-lines) until hot en crash into print surface
- Set D-length. D-axis is now calibrated
- Extend D-lines an additional 2 mm
- While not horizontal:
- Calculate direction of inclination
- Tighten A, B or C to counteract inclination
- Tighten D-lines 2 mm
- We are now at home position, all axes calibrated
Next steps
- Adding cheap IMU unit like the MPU-6050
- Building a smaller version of Clerck using Nema14 motors for lower mass and cost
References
- ↑ http://builders.reprap.org/search/label/tripod
- ↑ http://reprap.org/wiki/Rostock
- ↑ http://reprap.org/wiki/LISA_Simpson
- ↑ http://forums.reprap.org/read.php?178,267835
- ↑ http://reprap.org/wiki/GUS_Simpson
- ↑ http://reprap.org/wiki/RepRap_Morgan
- ↑ http://reprap.org/wiki/Wally
- ↑ http://forums.reprap.org/read.php?1,214837,214859
- ↑ http://www.fabbaloo.com/blog/2014/2/15/big-rep-one-is-one-big-rep
- ↑ http://shop.re3d.org/collections/gigabot-3d/products/gigabot-xl
- ↑ http://www.3ders.org/articles/20140608-introducing-large-format-x1000-3d-printer.html
- ↑ http://www.3ders.org/articles/20150914-wasp-big-delta-3d-printer-has-potential-to-build-insect-repelling-houses.html
- ↑ http://3dprintcanalhouse.com/
Contact details
tobben at fastmail.fm
http://www.appropedia.org/User:Tobben