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Showing vector angles

Posted: Thu Mar 16, 2017 2:38 pm
by jweather
My particular addiction is building models of polyhedra using a kids' building toy called Knex. To do so, I 3D-print vertex connectors with the appropriate angles. I had some difficulty obtaining the correct angles until I found Great Stella, and Robert helpfully pointed out the Display/Show Vertex Angles option, which is exactly what I was looking for:

Image

Here are two models produced this way:

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And plenty more on the way, including a truncated icosahedron. Thanks!

Re: Showing vector angles

Posted: Wed Sep 26, 2018 2:13 am
by robint
Thats real neat JW but I dont like the price tag on the Knex product bits of plastic more expensive than great stella.

I tried to use drinking straws once but found they were made of a plastic with no known adhesives (short of hot melting)

I like the idea of wooden satay sticks and a hot glue gun, then perhaps covering with rice paper or papier mache

I have fiddled with paper models but doesnt suit my fat fingers and the magnet modeller is neat but expensive. Even simple models can quickly escalate to 100+ vertices

I want a method that results in a precision machined look - hmmm :?

Re: Showing vector angles

Posted: Thu Sep 27, 2018 6:22 pm
by Peter Kane
I just tried gluing two plastic straws together using UHU Por and it worked very well - a nice strong bond without any melting. I didn't try anything clever, I just glued them side by side with a patch of adhesive about 1 cm long. I think Por is great. I bought it originally to stick together expanded foam - the sort of stuff you use for upholstery - but it works well with quite a lot of materials. Fingers too.

Alternatively, you might consider pencils.

Cheers,

Pete K

Re: Showing vector angles

Posted: Thu Sep 27, 2018 7:04 pm
by robint
Thanx PK

I'll give it a try, my range of glues was limited at the time. Drinking straw are polypropylene which is (along with Polyethylene notoriously difficult to glue)
but I came across this on AZ https://www.amazon.co.uk/CLEAR-ADHESIVE ... B006U49M3G

it has a base primer and uses superglu cyanoacrilate stuff to join- so not suitable for fingers - if you get stuck then immersion in warm water for 1/2hr ish softens the bond (as I found with OH's mouth)

FYI i found that evo stick is in fact AFAIK basically liquid nitrile rubber solution

Anyone tried sate sticks and a hot glue gun?