Folks,
I'm embarking on a project to build a modified copy of a DIY 3D printer. See http://reprap.org/wiki/WebHome to get a rough idea. In my case, I have my own lathe and milling machine, so I can fabricate more substantial components, e.g., by machining aluminum. I also have larger stepper motors, some 3/8" precision rod and linear bearings that I can use.
The goal is to design a 3D gantry that will sweep roughly an 8" cube and mount alternate tool heads, e.g., a lightweight plastic extruder, as well as heavier and higher vibration machining heads (~Dremel motor). I would like to design the gantry to minimize static and vibrational deflection, while minimizing weight.
Any suggestions on the best way to proceed with a FEA for this (lumped?) configuration? BTW, I have a background in computational physics (but finite difference methods, not FEM, and awhile ago :-) And I have an older version of Mathematica (4?) as well as a copy of Oleg Vino's book. "Fundamentals of kinematics and dynamics of machines and mechanisms" on the way via interlibrary loan.
Oh, yes, a cheap way to proceed is desired :-) I'm not interested in buying a FEA app.
Mike
Palo Alto, CA