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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Fri Feb 05, 2010 10:46 am 
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flambore wrote:
So is this a discussion about football/soccer/rugby, or C4U puzzles? I'm confused. :?



It is about the World Cup Organizers in South Africa. They are not sure which Petaminx
(mf8 or c4u) to use for the official match ball!

:lol:


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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Fri Feb 05, 2010 12:53 pm 
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Kelvin Stott wrote:
Jason wrote:
Football is called football precisely because you use your feet, you don't run around with the ball in your hands! That should be called something completely different

Yes, it's called rugby - a real men's game with no sissy padding or helmets (apart from a vital nut protector!) :P

Rugby players wear shoulder pads and aren't as giant as American Football players.

I'm looking forward to seeing how the 3x3x6 and 3x3x7 look, and if I like them I'll consider getting the 3x3x6.

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Fri Feb 05, 2010 6:44 pm 
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Focus gentlemen.

I've let the KO discussion wander a bit because there is some tie to the original post (and it is an issue about which people have some things to say that are actually new) but the football stuff is really off topic.
stardust4ever wrote:
Dave, what exactly is it about Drew's Petaminx design that would make it excessively difficult to produce via the injection-mold proccess? It is based directly off of the V-Cube Technology, which seems to take to injection molding relatively well. I believe all that would be nessesary would be to trim away the minute amounts of overhang to permit the pieces to "pop" out easily when the mold releases, say for example trim away the slight concave overhang on the interior of the face centers. The slight amounts of material that get cut away could be added back to the underlying parts to make them flush. This would give the areas directly underneath the face centers a flat cylindrical arch rather than spherical, and with proper edge beveling, which the Petaminx STLs already have, and by precisely fine-tuning the spring tensions, everything should in theory hold together just fine. Not only that, but because ABS plastic is non-porous and has a lower friction coefficient than 3D-Printed Laser-Stinted-Powder, and has higher precision and slickness than hand casted Epoxy resin can achieve, it very well might rotate very well, especially after a little bit of lubing and TLC is put into it
What are are describing is not minor work, and there is a bunch of work thereafter. See this for some ideas on what is involved, it opened my eyes quite a bit.

You have to consider injection cooling issues as well. When you make hollow pieces it is important to allow for shrinkage and distortion. I honestly don't know much about it myself, just enough to know it isn't simple. When you look at the design of the mass production Gigaminx and Teraminx compared to the designs of cast versions, ask yourself why they are different: The Gigaminx isn't just arbitrarily way more complex and weaker. There are reasons they chose to make the pieces hollow, and reasons they chose to make the corner stalks thin (I wish they could have found a way to design them thicker).

If you took Drewseph's design and just made two part steel molds of it it just wouldn't work (drafting being the first reason, as you noted).
Ever look at the corners of the PVC minx compared to the Mefferts? These are essentially the same design (almost identical) yet the PVC has almost all of its pieces with dimples in the corners. When you cast large solid pieces like this you get differential shrinkage it seems, and I suspect this applies to parts in general. I don't know what goes into Meffert's having fewer dimples (there are some) but this is an issue no one bothers with on cast puzzles. So how that issue might affect Drewseph's design is something they have to think about but you probably haven't considered (and piece distortion on a Petaminx vs. a Megaminx is far more important to avoid).

Again, I'm not trying to say Drewseph's isn't beautiful design work or that it was in any way easy, what I am saying is that his expression of V-Cubes technology meets a Dodecahedron wasn't anything a production Petaminx designer would need if they had built a Gigaminx and Teraminx. There is no special trick to extending these designs to a level higher. His constraints are 4mm leg parts. Their constraints are far more complex, and that 4mm constraint doesn't apply to them (injection parts of ABS can go thinner: Your V-7 has 2mm thicknesses in places).

Starting from a bunch of .stl files (a bunch of triangles in the shapes of Drewseph's pieces, not the actual design that generated them) just doesn't help that much given all the other work needed. They would basically have to redo all of his design work to generate those same pieces, and then apply their changes for injection constraints. I'm not saying it isn't helpful to someone who had never considered the problem before, but if you've built a Gigaminx and Teraminx I don't think they would be the place to start.

I wish these companies would work with designers of this forum instead of just grabbing what they wish from the forum without attribution or compensation, but I think if people are making a big deal about the Petaminx they are missing the real issue because they are blinded by the magnitude of this particular puzzle and the achievement it represented in design and hand building.

I don't think we should complain if these companies are investing their own effort and money into making "open" designs available to the mass market. There are pleny of non-open designs (Void cube, Superfloppy, Cubic 3x3x5, the KO of Daqing Bao's 2x3x3, etc.) that are being exploited that deserve attention. I'd rather they focus their efforts in areas that do not infringe.

When we make a bunch of noise about puzzles where no one really has a substantial claim, it just diminishes the voice of those who have a real claim. To any KO producer reading our forum it will be that much easier to just write off anything said here as uninformed predjudice.

Dave

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Sun Feb 07, 2010 2:01 am 
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Holy cow, that article you sighted is nearly 13 yeas old, though it answer some basic questions I've had, such as what happens to the air inside the mold, among other things. Another thing that crossed my mind was that V-Cube parts with squarish geometries and 90 degree angles may very well be much easier to pop out of a two part mold than the 36, 72, 108, 144 -based geometries of pentagonal symmetries, as well as all the other occasionally irrational angles that can be found inside dodecahedral objects. There's also a lot more empty space surrounding the cores in dodecahedral puzzles compared to cubes. But I'm pretty sure that the V-Cube face centers display a lot of the same concave design issues that the petaminx parts do (the core is a spherical shape with conical slice cuts), but Verdes got them molded anyway. And most of the non-edge parts are solid plastic, which explains why the V-6 and the V-7 weigh in about the same. I've seen pictures of the internals of both the C4U and MF8 teraminxes, and the C4Y parts looked extremely thin and brittle compared to the MF8, which appeared thicker and more solid. If they continue the same fabrication with the petaminx, then I'd love to see Tony Fisher don some steel-toe combat boots, drop-kick the petaminx, and watch it explode :twisted: (or simply use it as a soccer ball :mrgreen: )

I did download the petaminx files a long ago while they were still up, and converted the STL files (which are useless for raytracing) into 3DS format. The parts basically looked very similar to the pieces from my V-Cube 7s did once upon a time when I had all the parts disassembled and loose :scrambled:

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Wed Mar 17, 2010 6:57 am 
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http://forum.cube4you.com/thread-2711-1-1.html

I just saw James have posted picures of his new cubic 3x3x7.

It looks really cool but I think 95% will agree that cuboid puzzle would be so much nicer!

I am still gonna get this one sooner or later tho :roll:

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Wed Mar 17, 2010 8:26 am 
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it looks not good, if he had made it in the size of a 3x3x5 it would be ok.....

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Wed Mar 17, 2010 9:10 am 
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how did you see the size of it? Its looks like the 3x3x5 size to me?

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Wed Mar 17, 2010 2:54 pm 
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Dang, those "plates" are too skinny. Seriously, they look like stacks of square black plates!!! With a really, really thick plate in the center. I hate to think of what the 3x3x9, or x11 will look like...

Part of the fun of owning a 3x3x5 (whether falsely extended or real) is the shape-shifting aspect of it. :roll:

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Wed Mar 17, 2010 8:36 pm 
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*sigh* that's depressing

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Wed Mar 17, 2010 8:52 pm 
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This is why I made a FF 3x3x5 that shapeshifts

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Thu Mar 18, 2010 12:05 pm 
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Just my two cents here, but I really like the new 3x3x5 and think it's very fun to play with. It's really a different puzzle than a "full sized" one, but still very fun in a different way. I'm looking forward to the new one too...

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Thu Mar 18, 2010 12:23 pm 
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cant help but thinking about before c4u released their cubic 3x3x5, people were THRILLED about the puzzle. now you just hate it. come on! get over it and build you own proportional cubes then :)

most of you are asking for Not making popular mods available to everybody anyway (massproduction).. hmm

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Thu Mar 18, 2010 12:46 pm 
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I think it looks very cool, but I think that James should sell both the cubic AND proportional ones. I'll bet a good third of us would purchase both.

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Thu Mar 18, 2010 3:17 pm 
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I would prefer proportional ones because it would be much easier to apply popular sticker mods to them.


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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Fri Mar 19, 2010 9:15 pm 
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I'm with volitar.

But these at least give you a base to start building a FF, proportional puzzle onto.

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 Post subject: Re: C4U 3x3x6,3x3x7 and petaminx
PostPosted: Sat Mar 20, 2010 6:14 am 
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theVDude wrote:
I'm with volitar.

But these at least give you a base to start building a FF, proportional puzzle onto.


Yes, but people like I would much rather just buy a correctly proportioned one, rather than having to build it from that.

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