Re: CADing a baseplate
 

Getting the pattern to line up with the ends of the plate just takes some trial and error (or math, if you're clever about it ;)). I create a test version of the pattern in a sketch to check this because it's faster for me.

I've found a way using patterns, mirrors, etc. to do it fairly efficiently. The part's rebuild times are bad (up to 40s on my computer), but full rebuilds are rare, it is otherwise fast, and produces exactly what I want, not some representation.
Here's how I do it:

1. Create a sketch of one corner of the baseplate - two triangles and two square/rhombi
2. Extrude/Cut each shape and add fillet features individually
3. Make a pattern for each shape: one triangle along x axis, the other triangle along the y axis, the rhombi along the x and y axes. The rhombi must be patterned separately, as the number of them along the x and y axes is different for each one.
4. Mirror the triangle patterns across appropriate planes
5. Add extra material and holes for gearbox cutouts, electronics, etc.

This process is illustrated in the attached images. Feel free to ask if you have any additional questions!

Re: CADing a baseplate
 

Try using the fill pattern feature in Solidworks 2012. Google for YouTube tutorials.


Should take less than 5 minutes to generate the pattern

Create the base plate
draw a line for direction of fill
select full preview
enter boundry margin
create a seed cut, select diamond at 45 deg
select a seed pattern
select spacing