Update

While I have been waiting for the end-mills, drill bits, 6mm acrylic sheets and acrylic glue to arrive, I have been working on other projects. The orders have arrived and I have finished the other projects.

Where was I?

Here is may last plan for 6 mm thick acrylic:

My last Section:

May last layout for my CNC mill:

The layout shows two slew bearings while the section has three bearings. The prototype bearing was quite good so I don't think I need the second bearing on the tower.

I also have not really considered the tower and the base board.

CNC Mill Parameters

• Restarts: Add origin and maximum extent realignment holes.
• Job Size: One piece at a time.
• Feed Speed: 1200 mm/min (up from 600 mm/min).
• Depth Speed: 150 mm/min.
• Drilling: Peck.
• Over Depth: 0.5 mm (down from 1 mm)
• Spindle RPM: As low at I feel comfortable with, about 3/4 on the dial.
• End Mill: Flat two flute 2mm diameter (better if single flute).
• Cut Depth: 0.25 mm (if all works well this can be increased to 0.5 mm).
• Compensation: 1.8 mm cut width for nominal 2 mm bit diameter (may need to be reduced).
• Use conventional and climb cutting directions where appropriate. 

Base Board

The working envelop needs to be 2:1, the key assumptions are:

• Arm 1 length: 200 mm
• Arm 2 length: 150 mm
• Arm 2 rotation limits 10 to 140 degrees

I calculated the following:

Here is the base board layout including the tower location:

It fits on a 400 mm x 400 mm board. This layout has a effectively wider feet spacing.

The normal layout is still 400 mm x 400 mm:

Tower Design

TBC ...

Limit Switches

TBC ...

AlanX