Online since 2002. Over 3300 puzzles, 2600 worldwide members, and 270,000 messages.

TwistyPuzzles.com Forum
 It is currently Mon Mar 10, 2014 8:13 pm

 All times are UTC - 5 hours

 Page 1 of 1 [ 2 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: How to design heptagonal prism?Posted: Fri Jun 29, 2012 9:02 pm

Joined: Fri Nov 05, 2010 2:20 am
Location: Wherever
Hi,

I recently downloaded FreeCAD, and played around with the controls and stuff, but now I want to design a puzzle.

So, I was thinking heptagonal (7-sided) prism, but then I have no idea how to even create the basic solid, let alone the pieces and cuts.

Help?

_________________
A budding puzzle designer!

Check out my Shapeways shop!

Top

 Post subject: Re: How to design heptagonal prism?Posted: Sat Jun 30, 2012 5:51 pm

Joined: Sun Nov 23, 2008 2:18 am
When I want to make a regular polygonal prism in FreeCAD, I do the following:

Step 1: Make a polygon using the Draft Toolbar's Wire tool.
This is easiest if you make the polygon centered around one of the axes(for example, the Z-axis) and parallel to one of the coordinate grids(for example, the xy-plane).
Under these citeria, the corners of a regular n-gon are defined by the polar cooridinates r, 360m/n degrees where r is the n-gon's out radius and m is any integer between one and n.
Here is the polar to rectangular calculator I use to convert the polar coordinates into the rectangular coordinates the wire tool requires.
For a heptagonal prism centered at the origin with its axis of sysmetry coinciding with the z-axis, you would use:
r, 360m/7 degrees converted to rectangular for the x and y values.
a constant h/2 for the z values, where h is the desired height of the prism.

Step 2: Use the Upgrade option from the Draft menu to turn the polygonal wire into a polygonal face.
Pretty self-explanatory.

Step 3: Use the extrude tool on the polygonal face to produce the prism.
Continueing from the above example, you would chose to extrude in the negative z-direction for h units.

Creating a prism aligned with the x or y-axis would be as simple as switching around the numbers, and centering it somewhere other than the origin could be done simply by adding the offsets to the number entered into the wire tool.

Creating a prism with a skewed axis is beyond my knowledge however.

Cutting up the solid can somewhat difficult, especially since FreeCAD does not, as far as I know, have a split solid tool. However, I have found that creating wires, revolving them to form surfaces, and extruding surfaces to produce solids that engulf large segments of puzzle's base solid goes a long way in creating things that can be cut from or intersected with the base solid to form individual puzzle pieces. The Edit menu's duplicate and placement options are also useful for quickly making extras of a complicated part and preparing the puzzle for stl export, and the Drafting toolbar's mirror tool is useful for making chiral copies.

Also, FreeCAD's Forum on SourceForge is filled with people willing to help out others on how to do different things in FreeCAD.

_________________
Just so you know, I am blind.

I pledge allegiance to the whole of humanity, and to the world in which we live: one people under the heavens, indivisible, with Liberty and Equality for all.

My Shapeways Shop

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 2 posts ]

 All times are UTC - 5 hours

#### Who is online

Users browsing this forum: Google [Bot] and 2 guests

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ Announcements General Puzzle Topics New Puzzles Puzzle Building and Modding Puzzle Collecting Solving Puzzles Marketplace Non-Twisty Puzzles Site Comments, Suggestions & Questions Content Moderators Off Topic