How to draw triangles

Max3…yes…yes…yes…
I just got it to work…I had to type the command in the command line to get it off mesh and into surface…

Thank you…thank you…thank you…I owe you a lunch…

Fred…thank you so much…just got it working…it is different in version 6, than it was in version 5.

I really appreciate all your help…

Richard…

I know that, but the boy is struggling to build a triangle

You’re welcome, Richard
Have fun and good luck.

Lol. This is not a big thing at all.

There’s probably already a Grasshopper script out there that can take any of these polyhedra and explode it into 3d parts with controllable sheet thickness, label all the parts and dimension them.

not a how-to because I don’t explain anything ;)…

but maybe some ideas in there for others:

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11 posts were split to a new topic: Rhino for Mac GUI

Hi @Rocket2004,

Why do you need to unroll it? [Edit, I see you have, so the question may be moot] You have just two triangle patterns: a triangle from the pentagons and a triangle from the hexagons: within each category the triangles are all the same.

I guess that this is roughly what you intend to have after turning (not to your dimensions):


FWIW this was produced by modelling one of each type of triangular ply segment solids in-situ and Boolean Intersection-ing them with the desired hemisphere to get the outer surfaces. Each was then polar arrayed around a line from the model centre to the peak of its stellation to complete the pentagon/hexagon. The completed stellations were then mirrored (using the 3-pt mirror plane option, with the model centre as the third point) around the surface to complete the model. Positioning and original triangle shapes came from the great Rhino Polyhedra plugin, using the Geodesic Icosahedron Pattern 4 option (i.e a stellated truncated icosahedron). The model would look better if I had had time to orient the materials onto the veneers correctly.

Regards
Jeremy

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Thank you…this is more like what I am trying to make.
image

RR

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Yeah, mine is a smaller diameter than yours, but the “ply” is made from 3mm layers so I get less contours than birch ply would give. But I’m wondering if you have to increase the height of the stellations to get that many?

The stellation on mine is 15 degrees. I make all my cuts on the table saw with a variety of jigs that I made just to build this ball…it is tons of work…and has to be perfect to work out properly…hopefully I will not die before I figure it out…

Photo credit: https://www.oddballgallery.com/

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2+k USD for a wooden ball?
That’s crazy
:crazy_face:

That is art!

Jeremy,

Thank you…

I admire your courage - I would not want to attempt anything like that without a decent 3 axis CNC at the least… A good “manual” tool to have though in addition to your saws would be a decent sized disc sander - great for finishing those compound angles.

i haven’t really looked at this but…

…sometimes, if working with multiple angles, it’s better to build the jigs to hold the pieces at the various miter/bevels and keep your blade & fence at 90°…

doing that allows you to switch between cuts etc without messing with the saw and/or needing to keep dialing it in to very precise angles.

idk, i’ll look at it a little later to see if this is even possible on these cuts… but at first glance, it seems to be an option … (the main problem will be the hold downs interfering with the blade if the pieces are small)

3 axis would be real tedious. You’d have to carve all those bevels with ballnose bits.

This kind of plywood origami is one of the few applications that would really justify a 5 axis cutterhead.

It’s not tedious, if the parts are laid out flat on the table (bevel up), it’s one operation like waterline (Z-Level) machining. For a sufficiently fine surface, it would take a long time to machine though, but unless you’re in production, often the actual machine time doesn’t matter that much.

Certainly a 5 axis would be nicer with swarf cutting, but 5 axis is mostly out of the reach of hobbyists/artists plus the investment in the machine, CAM software and learning time is does not have much ROI for non-production applications (IMHO).

Some parts I cut on table saw with my homemade jig.
Pentagons that will go into finished truncated icosahedron.
Each triangle has a stellation of 15 degrees.

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