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.
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
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.
- 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.
- 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.