Wednesday, December 23, 2015

The Time Transparency Clock


Since the last post I have worked hard in the design and build of the Wood/Plastic clock. I have made a lot of changes in the original design, and I think that the final result is really a very nice clock!

It even has a name thanks to my sister! The time Transparency Clock:



Acrylic is difficult to work in the CNC with small diameter end mill bits. I used a 1/16” 2 Flute carbide end mill for the wheel teeth. After damaging several plastic stock and 2 end mill I learned:
  • Use new and sharp bit or a sharp bit that has been used only in plastic. If you used a bit to cut wood, forget to use it later in plastic.
  • You need to remove very little material each pass :.
  • 24,000 RPM spindle speed and 10 inches/minute feed rate.
  • Keep the bit cool with compressed air.
For the internal cuts I used a 1/8” 1 Flute end mill. You also need a new and sharp bit or a sharp bit that has been used only in plastic but feed and RPM are different: 15,125 RPM, 16.1 Inches/minute feed rate and .004” maximum step down per pass.

With the above settings, and with lots of patient it is possible to get a very nice and clean cut. Below a video showing the internal cut with 1/8” end mill:



The other complicated thing is to bond brass and acrylic. After several test I ended using 2 part transparent epoxy.

Here is a video showing several details of the clock.


I love the action of this clock!


Happy holidays to all!

No comments:

Post a Comment

Please be aware that any comment with commercial links will be immediately deleted and declared as SPAM.

If you want to advertise in my blog please contact me to agree in a fee and i will be happy to add your link in the side bar.