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tetrahedron

  • Thread starter Thread starter Israr
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Israr

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What will be the best method to create a tetrahedron model in part mode?


I have createdit by joining the centers of the the four spheres.


The challenge is you don't have to use approximate dimensions.


It should be a perfect tetrahedron.


Israr






Edited by: Israr
 
Call me a dummy, but what is a "tetrahedron". If I knew, maybe I can help you.
 
its a triangular pyramid, right?
 
With "spheres"?
 
Yeah, I gotta plead stupid here myself. This is the first time I have ever heard this term. When I do a search for it the only results for images I get are triangles. Is this just another word for a hollow triangle?
 
it appears that it is a pyramid with 4 equal sides both in edge length and surface area


you can achieve this by doing a blend


in sketch mode


step 1 draw base triangle


step 2 end it with a point


then it will ask for the heighth give it anything


next you will go to tools relations click model then switch dims


do the trig and use the base length as part of your equation d2="formula here"*d3


http://mathworld.wolfram.com/Tetrahedron.html


thats how i would do it
 
I did it by creating 4 datum points with all 4 dimensions equal, (using relations). Then create a prutrusion, a triangle using the 3 base points, and extruding it upto the 4th point. I then made 3 extruded cuts, "sketch plane" is "make datum" through 3 points and the "cross reference plane" is "make datum" through center axis and through the opposite point. Sketch rectangle aligning the bottom vertexes of the rectangle to the lower 2 points and the top of the rectangle to the top point. Extrude "upto" and select the top edge of the original protrusion. The whole part only has4 dimensions. By modifying the first dimension, you can create any size "tetrahedron" that you want


View attachment 1521
 
Can be done with a single sweep feature using the add-inner-faces option. THe trajectory will be an equilateral triangle. The section will be a line from the trajectory to the apex of the tetrahedron.


... same works for a square pyramid


View attachment 1522
 
Hi, friends,


I did it using the blend command in Pro_E-2001


View attachment 1524
 
Here it is in a nutshell. Create the 3 default datum planes, then an axis through 2 of the planes, thenadd a sweep with "in faces". The trajectory of the sweep looks like:


View attachment 1531


And the X section looks like this with the top end of the line aligned to the axis:


View attachment 1532


Set relations so that the 2 dimensions are equal and this is what you get:


View attachment 1533


You now have a real tetrahedron with all edges of equal length. You can modify the first dimension to get whatever size you want.
 
tetrahedron













tet
 
dougr,


May be your reply is having good info but sorry I can't see it.


The solid version of tetrahedron I created is:


2005-12-31_220345_tetrahed.prt.zip


Israr
 
Another solution similar to yours Israr:


After creation of second sketched curve make pattern of this curve, Axis pattern, number of pattern members: 3, angel 120.


But I'm curious why is important to be right way to create tetrahedron?
 
Isair,


I put the question just for discussion and academic purpose. By right way to create tetrahedron I mean the best option out the the many available options.


hrj0,


I will check it if there is some error.


Israr
 
hi everyone!


by now most of you must have arrived at numerous solutions. i have been posing this question and the icecube model problem to my friends and students since my autocad days.
In case of regular geometrical solids always the solid of lower order is the subset of solid of higher order. Therefore the best way of creating a solid regular therahedron (ie a tetrahedron with all edges equal to 'a' and all faces obviously equilateral triangles is to slice a cube approprriately.This way we dont have to calculate the approxc height. you could work on this hint Israr. but your method of using four spheres (one sphere on three) is mathematically more interesting. also using relations is right but,causes problem when exporting model toanother platform.but my proe2001 could not open any of the part models provided. but i would like to know if any one has better solutions.
suraj.
 
surajcad,


The files are created in Wildfire 2.0 so you can't open these in Proe2001.


Israr
 
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