Pendulum Clocks
Last updated on Friday, April 05, 2019 05:45:03 AM Mountain US Time Zone


AutoCAD, Plastic Mill Table Cover, Path Tracing Tool,

This page documents my CNC parts fabrication of Brian Law's Clock #19. The plans includes .dxf  files.
The workflow uses: AutoCAD to isolate the single part to be made (from the .dxf page of parts), mirror
the part if needed to get climb vs. conventional cuts, offset the cutter radius on the correct sides, remove original
outlines, run AutoCAD to GCode (AC2GC) VBA macro with the correct parameters to generate the gcode,
test run by tracing on paper, then plastic or metal cutting for the final part. There are over 70 fabricated parts
plus additional parts including, one-way bearings, bearings, shafts, threaded rod, SS cable, screws, & nuts. 

[in progress]


AutoCAD .dxf polylines having joined segments (pedit).

0.5mm mill radius offsets drawn.

Original traces erased then mirrored to yield offset tool path & climb cutting. 

AutoCAD to GCode (AC2GC) VBA macro screen. G21 commands Mach3 run in metric.

Mach3 tool paths offset 0.5 mm radius.

Plastic Mill Table Cover

For tracing tool paths on larger (A4) pieces of paper I made a clear, 1/8" thick acrylic top for the mill table. 




Click on linked thumbnails

Path Tracing Tool

Ink path tracing tool. I wanted the pen tip to remain rigid as it moved through a 4mm range
so I made a second ink tracer using 5/16" OD & 1/4" ID brass tubing. The steel end plugs
are 1/4" OD with 2.5mm holes. The plugs are pressed in. The hole in the top plug is to aid
 its removal. The pen cartridge tip was selected for its uniform diameter instead of a taper.
A finer point & an improved design. See original path tracing tool.

The steel plug's length is less than 2mm.

An AutoCAD .dxf file having end mill radius offset paths & mirrored.
Back-plate layout. Paper tracing helps me check the gcode & fixtures.

CNC milling of part using a 1mm, 2-flute, carbide end mill at 5665 RPM.
Here, climb cutting has the end mill traveling clockwise.

Part cut completely through but the double-sided tape is still intact.

Finished 10T gear & its blank.

A few assorted parts for the clock. Left to right: one-way & standard 4mm ID bearings, 1mm
SS cable, M6-1 threaded rod, 4mm steel rod, 4 & 8mm reamers, & some CNC-cut gears.
The one-way bearings act in place of a ratchet for winding the weight.

One-way bearing.

Click on linked thumbnails

















Click on linked thumbnails

AutoCAD, Plastic Mill Table Cover, Path Tracing Tool,