Chopper Design Documents

& Design Changes/Issues.

This page is a list of the design documents that I've found and used in creating the CNC version of Chopper presented here. There are a small number of design issues that I'm also posting here. First, to make others who may not have stumbled across them aware of potential problems. Second in an attempt to get a concensus if what an acceptable solution might be. Third to draw attention to design changes I've made to make building Chopper easier.

This page is a work in progress and is very incomplete as of 04/09/19.

Design Documents

Cleofett's AutoCad Drawings

My Primary source for Chopper's design has been an AutoCAD drawing file created by Cleofett. A portion is shown to the left.
See her Astromech forum blog entry here.
You can download the drawing from:
01/14/20 - Or you used to be able to. I can no longer find it in the dropbox. If anyone knows where it is currently located let me know.

AutoCAD, by AUTODESK, is a relatively easy to use 3D drawing format. It is easy to apply dimensions to Design components. That's necessary when you are converting to a different CAD format.

Dassult Systems offers a free download of it's Draftsight software an AutoCAD "work-alike" [it's a free trial which continues to work after you decline to purchase it. Some of Dassult's extensions to basic AutoCAD are disabled but you don't need them.]
You can download it from the Dassult website.

Joymonkey's Skin Drawings

Design Issues

Battery Box Crash
Chopper's Battery Box was derived from Cleofett's .dwg drawing files. However, as noted by TinyP the original 6.625 in tall battery box hits the body in 3-leg mode.

See TinyP's build log, page 8, scroll down to post #74
to quote him: "One compromise that I already anticipated was the battery box hitting the body when in 3-leg mode so I had to adjust the height of the box closer to 6" instead of 6.5".

Picture Left & text above from TinyP's Build log

Outer Edge of Leg Crash
After I posted my preliminary CNC design for the legs, Matthew Zwarts warned me that there was a problem with the Leg design crashing into the foot shell. The pictures below illustrate the problem and the fix that I'm proposing.

The image below links to a .dwg file if you need more detail. The left drawing is the Cleofett original. My first thought was to simply shorten the offending section keeping the angle the same (shown in the center drawing). That however would leave the detail part hanging over the edge. My second choice, illustrated in the 3d model above, and in the right hand drawing, is to change the angle of the leg part so the outside edge matches the inside edge.
This is a 3d model of the revised leg profile shown at the same angle as the image above.

Design Changes
Space inside the Foot Shell

This design
is copyright Media-Conversions LLC and is made available for non-commercial use only.

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