I have a small CNC that I built awhile back.  Its a larger version of my KReduCNC. Some of the parts were lasercut and machined plastic parts.  If a particular component worked out, I would convert it to steel or aluminum as needed.

Today I am going to replace the Z motor and bearing mounts. The parts will be machined from 3/8" 6061 Aluminum.

The bit

I have been playing with the Whiteside RU2100 spiral router bit, and felt that making these parts would let me test the bit further.


Making the Parts


Problems Encountered

Originally  I wanted to machine the .26" diameter mounting holes with the bit, but this did not work.  The bit does not cut all the way to the center so cutting a hole that small was impossible.  Luckily I was able to stop the job before breaking the bit ruining the part. (See Working with Aluminum #11)

In addition, I was getting some chatter marks on the finish cuts.  I have had much better results with other bits cutting this deep.  



I drilled out the divots with a 1/4" drill bit on my drill press.  This was easy with the divots acting as a guide.  In addition to the mounting holes, I added two small holes in the sides and tapped them for a #6-32 machine screw.  This would allow me to secure the plates to the steel shafts on the machine. 



I was very happy with the parts, but will be looking at some other spiral bits that will allow me to machine small through holes.

I discovered a few other things with this little project.

  1. The large amount of chips created were not contained very well with my Swarf Shield. I had to clamp some extra pieces to the sides to keep the chips from getting into my electronics.  This was a temporary fix at best.  I will have to revisit the shield for use with larger bits.
  2. I do not like the KoolMist misting system.  It is not very consistent, unless its on full blast, and that is just not how I use it.  I will be looking into my own drip system a little later.