Created a nearly accurate drawing of the mounting plate of a Turnigy Park300 1080kv brushless motor.
Edited the metadata of the file
Designed a boom mount for the arms

Created a boom mounting plate using the previously designed motor
mounting plate and two tube clamps for 16mm tubes. The design is not
(yet?) a valid 2D model for laser cutting, only for printing.
Created the center plates

Created a top and bottom center plate. Each copter arm will be held by 3
tube clamps, two on the bottom plate, another on the top plate. In
future versions, mounting holes for the controller board will be added
as well as slots for attaching the battery with velcro tape and the ESCs
with cable binders.
Modified the document metadata
Created a new version of the center plate

This version was designed from scratch making extensive use of
construction help. No guessing and estimating was used during the creation
process, everything relies on symmetry.
Created new top & bottom plates using the template

The newly created template was used to create a new set of center plates.
For now, only the drill holes for mounting the boom clamps were created,
assuming 14.2x23mm clamps for 16mm tubes. The drill holes are 4.1mm in
diameter and suitable for M4 bolts.
Further holes to mount the PCB and slots to attach the battery and the ESC
are supposed to follow.
Converted all drawings to AutoCAD R14 format

The files were originally created using a demo version of TurboCAD 2D/3D
Deluxe 19, which turned out to be too expensive to buy so I acquired a
copy of TurboCAD 2D 16 at a much cheaper price. But Version 16 can't open
version 19s files and version 19 can only export down to version 17 (which
in turn again can't be opened by version 16), so I chose to export all
files to an older AutoCAD format that can be read by version 16 so I would
be able to continue using my files.
Converted from v19 files to v16 ones using the DWG files
Reorganised the files
Created a new center plate template for the diy model from scratch
Deleted the DWG files as they will be out of date soon
Created a new version of the bottom center plate using the new template
Added drill holes for the cable binders holding the ESCs
Created a new version of the top center plate

This version was created using the newly created template. Bottom and top
plate are now precisely chamfered at the edges.
Fixed a misplaced hole

One of the hole used to attach the ESC to the plate was misplaced by a few
millimeters. This has been fixed.
Added holes for the battery mount

The battery will be mounted on a separate plate that will be attached to
the bottom plate via M3 screws with a spacing between the screws large
enough to accommodate batteries with a width up to 65mm.

Also added a lot of measurement labels on a separate layer for information
purposes.
Created a battery mounting plate

THe plate measures 9x9cm and is supposed to be attached to the bottom face
side of the bottom center plate, using some spacers to provide room for
sliding a piece of velcro tape through it. The plate is deisgned as a
frame in order so save weight.
Moved the holes for the battery mount

In order for the holes on the battery mount to be centered, the holes in
the bottom plate needed to be moved slightly.
Enlarged the holes for the battery mount

The battery mount will now be attached to the bottom center plate using M6
plastic screws with 50mm length that will also double as a landing support
for the center part of the copter. Thus the mounting holes on both plated
were enlarged to 6mm.