ToyREP is a tiny and inexpensive FFD 3D printer designed mostly as a technology demonstrator or child's toy.
The print volume is 100x100x100mm (125x125x100mm with some upgrades) with a cold bed made of polyacrylate.
Hot end is a E3D clone for 1.75 PLA or ABS filament with 0.4mm noozle.
Using very cheap 28BYJ-48 stepper motors (with Bi-polar hack) in all axis and geared extruder, Arduino Mega 2560 with Ramps 1.4, DRV8825 and modular RepRap construction based on Mendel, Printerbot, Cherry, Prusa i3 and CARP Box ideas.
It is designed to use 12V 40W PSU for LED lights that should fit under bed. Power consumption is currently ca 40W when heating hotend and 15W-20W when printing (Eventually 40W 100x100mm heat bed would rise PSU requirements up to 80W.)
 |
| Using a scalpel blade to remove excess wax |
This is the result of my master thesis at the University of Oslo, at department for robotics.
The printer is a modified RepRap Ormerod, with two added axis (A and C).
This master thesis have been a proof of concept, but since it was working I decided to try two hypotheses, is it possible to print without support (what you see in this video) and is it possible to make a smooth finish on a surface which are in another plane than the xy-plane (what you see in the two other videos).
All the g-code for these parts are basically hand written (with the help of java). I have been using spherical coordinate system to compute the paths and therefore all the parts are round.
With the exception of the 5-axis system that moves along the y-axis almost all the parts are from the RepRap Pro Ormerod 1.Hopefully he will open source the build plans soon.
The videos are at 40X speed.
The project brief was about designing a product for play. While I was trying to explore the world of play, I was fascinated by Little Shining Man (Heather & Ivan Morrison, 2011), a huge cubic kite which consists of hundreds of tetrahedral cells, and I decided to explore this intriguing architectural structure.
During the process, I designed 3D printable components for easier and faster kite building and I also found out a way to make the structure collapsible, so that it can be flatten when not in use. Little Shining Man is basically a flying sculpture, so it can be transported on a truck and displayed or stored at a gallery.
Whereas when people build large kites with open kite components, it is collapsible for easier transport and storage. Consequently, this tetrahedral kite becomes a more accessible 'product'. I am also planing to publicise the kite component data for 3d printing as an open source project so that people freely download and make their own tetrahedral structures.
The base of the printer is a 3030 aluminium extrusion, everything is mounted on this extrusion, wich means everything is tight and compact, making it easy to carry or put away.
The Z axis is made out off 2 12mm rods with a carriage attached to it using 4 LM12UU bearings. In this carriage, there are 2 8mm rods mounted, wich are for the X axis.
The carriage for the X axis is mounted using 3 LM8UU bearings, two on the bottom and one on the top. For the Y axis, I also use 2 8mm rods. The wooden plate for the heatbed is attached to the rods using 3 LM8UU bearings. Both X and Y axis are driven by NEMA17 motors using GT2 belts.
The Z axis is driven by a M8 threaded rod. The Dbot is controlled by a Ramps 1.4 motherboard, and powered by a 360W LED PSU, wich are both also mounted onto the 3030 aluminium extrusion.
The extruder is a fully self designed extruder, wich is also printable. This is done to keep the costs low. Both the extruder motor and the motor that powers the X axis are located on the opposite site and used as a counterweight for the X axis rods and carriage. The ramps board is located in a casing with a fan, for proper cooling.
The bed itself is a MK3 heatbed. The printers volume is 200(X)x190(Y)x185(Z), wich is almost the whole heatbed capacity. I invented my own heatbed nut mounts, so you only have to turn the screw to level the bed and don't think about the nuts.
Auto Bed Leveling using piezo electric discs for very high sensitivity.
Mounted between the bed springs and the z-stage, any force down on the bed can be registered and used as a probe signal. Hence one can measure when the hot-end touches the bed surface. No modification to the hot-end or carriage is therefore needed, and the probe is insensitive to temperature.
This is still a work in progress, so although it is working for me in it's current form, it needs constant tuning as the circuit is not yet perfected, and the mechanical mounts have some known issues. A new circuit and new mounts have been designed but not yet tested.
So far, I've tried to only use parts available from sparkfun. I'm guessing a total cost for all parts of less than $20 USD.
Kamaq is a 3D-printer (FDM) controller software running on an embedded Linux system. It is capable of controlling a RepRap-style 3D printer, but with different electronics. Stepper motor control is done using a 8-channel (7.1) USB audio device and some class-D audio amplifiers. Endstop switches are monitored via GPIO inputs (interrupt-capable) and temperature control for extruder and heated bed via standard hwmon-compatible ADC's and GPIO-outputs for heater control. The software has a web interface for machine control and monitoring.
