Sunday, December 13, 2015

From Digital to Reality

For the last few weeks I have been building a CNC plasma table for someone and a router both based on the same design.

The CNC plasma table is built much more robust however and uses all aluminum parts some of which I had cut on water jet and started assembly today.

I soon discovered during assembly that the machined brass eccentric spacers used to adjust the guide rollers were not made properly.  Most were not the same size, some holes were too much in the center, all sorts of issues.

The lathe operator is brand new so he is not yet up to speed on exactly the quality is needed.

So I grabbed the CAD file I made and printed out for the machinist, and instead saved it as a .stl file in very high resolution and printed it from plastic.

Every part came out darn near perfect fit in the 9.8mm holes I had drilled (I wore out my 10mm bit and stores are closed today) 

I assembled everything and works better than the machined brass. 

I worked out the costs of this little part.

Time averaged 5 min per piece.
Cost averaged 5 cents of plastic per piece.

Now can you afford not to look at this manufacturing method?


Here is another




2 comments:

SiGraybeard said...

In the last photo - are those ball bearings pressed-set into printed wheels?

Good point about the utility of the 3D printer, too.

admin said...

yes, although i probably would print a little oversize, then make a jig to put on a drill and smooth with a little sand paper next time.