Just chiming in for future reference, I'm guessing the cap material is PBT, which is also able to be etched in a CO2 laser, which would offer greater precision than a CNC, but you wouldn't get that nice 45 deg angle. Just something to think about if anyone else has a need similar to this.
I looked at PBT and it could very well be that. I was thinking it's something derived from PET (even though i know nothing about polymers)
The difficulty when engraving these is that it will melt and form a little solid blob on the tip of the bit. If you let that happen, it will result in a larger engraving than expected and a not so sharp form.
I dealt whit that by blowing some compressed air to get rid of waste material during engraving. And stoping the CNC and going back from the start each time I saw such a blob forming.
I tried different feeds and cut depth to try and reduce that phenomenon, but nothing worked...
Here's a picture of the work in progress master section
I like your clamps. Where did you get them?
Is the waste board something you made?
These clamps are 3d printed, I found the stl on the same website as i found the design for my CNC:
RS-CNC – MakerFr
I can send you the files if you want.
I would recommend using butterfly bolts rather than these 3D printed heads. My fingers hurts when i have a lot of piece change to do.
I made the CNC and the waste board following the RScnc32 design from makefr.com. I used the electronics and motors from my previous CNC though. (smaller NEMA17 and an arduino UNO with CNC shield running Grbl)
I finished assembling this machine last july, and so far, it's proven to be a reliable design. I will probably upgrade the electronics and motors in the future. I would also like to get a better spindle with PWM.
Here's a pic of my machine: