The "Ponoko" RepRap
This is a laser-cut RepRap (technically a RepStrap) very similar to the BitsFromBytes design but modified to be cut without any routing. It is designed to minimize the number of speciality and expensive components needed to construct a RepStrap. It uses exactly the same motors and electronics as a Darwin RepRap, and is capable of accepting alternative stepper motors and DC gear motors (all available from http://rrrf.org). The extruders are of an exchangeable design, and are directly compatible with a Darwin exchangeable extruder. This extruder is available from Diamond Age Solutions Ltd. (VikOlliver's company) or can be cut from the source files by a service such as Ponoko, who have kindly given Vik a discounted account for supplying reprappers. Additional lasercut extruder kits are available.
Note that the RepRap and this RepStrap are part of a research project. This means it can be a bit of an adventure assembling one. This may put you off, or it may improve on the thrill you get from achieving a working machine.
The lasercut kit from Ponoko does not include anything other than the structural plastic parts. You will need the electronics kit and motors in addition to the lasercut bits. You can find the source files here]. We now have a Bill of Materials.
You will need a number of components to complete the building of the lasercut kit: a laser-cut kit (really), fastenings, basic tools and probably some way of repairing or re-fabricating broken parts. You will need about two square metres of bench space, decent illumination, and possibly aids for close-up work. We recommend a smoke detector in your workshop if one is not already fitted.
It helps to have already installed the the RepRap host software on your PC and the firmware on your electronics before you begin construction.
Do not force acrylic - it cracks. Do not tighten fastenings in acrylic more than is absolutely necessary - it cracks. Be very careful when moving your RepRap under construction, as an acrylic structure is fragile before it is fully braced - it cracks. You may spot a pattern emerging.
Do not throw anything away until the RepRap is assembled and working. You may need to fabricate replacement parts from them. Some of the parts come from the holes in other parts.
Do not separate parts until you need them. Do not take the paper off until you're ready to assemble them. Some parts need the paper. For ease of handling, you can split the large sheet in two. Locate a cut which threads its way through other parts approximately in the middle of the sheet. You can cut the top and bottom rails to extend the cut from edge to edge. Carefully cut the paper backing and you can separate them.
Do not allow small children to put the little bits of plastic that fall out in any bodily orifice. Or cats.
If you cut the rod and studding with a hacksaw, they will have razor-sharp ends. You should dress them with a file or grinder. Go around the diameter of the cut, filing at 22 degrees, 45 degrees, and again at 67 degrees to round off the corners. Test them (gently!) with your finger and if you feel any sharp edges, keep filing. After this process, the studding will probably have its threads clogged. Find the end of the thread, and file the end of it down to the depth of the thread cut. You will find that 6 one-meter lengths of 8mm rod and 5 two-meter lengths of studding are enough. Unfortunately, if you're using 5/16th inch as a substitute, you'll need 12 three-feet lengths of 5/16" rod and 5 six-feet lengths of 5/16" all-thread.
Do share your tips and improvements with everyone.
The following pages deal with the assembly of the mechanics. If you start with the first one, it will link you on to the next and so forth; a pictorial summary is shown below. Once construction is complete, the process of fitting the electronics is very similar to fitting them to the standard Darwin - additional clamps are provided with the lasercut kit to allow the fastening of circuit boards to the RepRap frame and X Carriage.
- Installing the X Axis - in progress:
-- Main.VikOlliver - 29 Nov 2008