Homemade CNC Router / Mill

I was off to a good start with the frame scrounging. Calling into a local aluminium fabricators I was eventually led by the manager to a couple of large skips out the back, loaded with large profile offcuts and scrap. Not having a clear picture of the design I just grabbed the largest, most likely looking profiles I could carry.

After much scribbling and CAD twiddling I came up with a design. The largest profiles were cut lengthwise on my table saw, to form a pair of sturdy L profiles. These form either end of the router and sit atop 4 steel box sections that were the product of a previous scrounging sortie. Getting the frame square and true was fairly easy. Placing the thing on the largest, flattest precision surface I could find (my kitchen laminate floor), I just used an engineer's square to line it all up as I tightned the bolts.

Note: Using dissilimar metals in the design will introduce errors due to the different thermal expansion and contraction charactersitics, but If I ever get down to a precision where this matters I will be a happy bodger indeed.

The gantry was made using another pair of the same L profiles bolted between two of the other extrusions.