RUG/Pennsylvania/State College/Solidworks OHM
The Open Hybrid Mendel (or OHM) is a project of the State College Reprap Users Group. It is a Mendel design, which uses both standard Sells Mendel parts, a Prusa Z drive, various redesigns from the community at large, and a number of small design improvements developed in our PSU Reprap class. It is so named due to this hybridization of designs, and obtains the 'Open' designation from the OpenX and OpenY axes it uses. The prototype for the OHM design was Etherdais_Unit_One. On this page there are the sub-assemblies and full assembly of the most up to date OHM design done on SolidWorks. Under each sub-assembly and the final assembly there are screen pictures and zip-files for all the parts. So be prepared because you now have the power to create your very own OHM!
This is the full assembly in SolidWorks. Each subassembly is represented by a different color of printed pieces.
Above are SolidWorks pictures of the full assembly. Below is the zip file containing all parts and hardware:
Though all parts work together to make a 3D model somewhat like a human body; we broke the assembly down to five sub-assemblies.
The OHM uses Camiel's thin shelled Vertex design, maintaining vertices similar to the Sells design, but using less filament. The frame has one motor that powers a belt to move the bed in the y-axis. It uses threaded rods to connect the vertices and is the same as the original Mendel design.
Above are SolidWorks pictures of the frame assembly. Below is the zip file for this assembly:
Z Axis Assembly
The OHM uses a Prusa double motor design for driving the Z axis, avoiding the large prints and continuous belt of the Sells Z-drive design. We still use Sells bar clamps to clamp the smooth rod to the Z-motor mounts, as they are compatible, and look sharp together.
Above are SolidWorks pictures of the z-axis assembly. Below is the zip file for this assembly:
X-Z Axis Assembly
Currently, the OHM build uses something like a standard Sells X-Z assembly, as described here in Mendel_X-axis. An important change in the design of the assembly is to be noted. The x vert drive side plate 360 end is no longer being used for future RepRap parts. A modified version of the 360 end is being used. This piece is longer and doesn’t require a spacer piece. This allows for adjustment as well as a better belt configuration that reduces stress.
Above are SolidWorks two pictures of the x-z axis assembly. Below is the zip file for this assembly:
Y Bed Carriage
Our bed subassembly is modified from the Mendel bed assembly. We are currently experimenting with heated beds on our printers, but many of our older printers do not have printed beds as of yet.
Above are SolidWorks pictures of the y bed carriage assembly. Below is the zip file for this assembly:
Extruder and Carriage
We are in the process of finding a design which is more compatable with the TechZone steel hot tips we've been using recently, though the current design is a hack of [http:/ /www.thingiverse.com/thing:5111 herringbone extruder gears], and [http://www.thingiverse.com/ thing:8252 GregFrost's hinged wades extruder.]. As of last 12/10/12 a new design was made by
Above are SolidWorks pictures of the extruder and carriage assembly. Below is the zip file for this assembly: