Why I'am hesitating to become a cocreator.

First I begin with a thing you've been told a lot by now but maybe in greater detail:

## The price has to be of the biggest model possible =>

# Theres the extra work to calculate the Volume.
This would be acceptable if there's a nifty *.stl to Volume-value coverter for MACs in existence? (haven't searched yet)

# This would mean furthermore a wrong price view up to a factor eight for me (worst case).
A (bad) solution for me would be to upload one model (independend from the cocreator model) as a lower price border demonstration.
(the ring with the smallest allowed diameter)
This is an ugly hack, and I think you won't be happy about it either.


Secondly:
Does the personalized models keep stored?
And can the customer choose from the stored ones?
I suppose no, because that may fill up youer servers memory too quickly.

If yes thats halfway ok, so I could upload a bunch of sizes incrementally over time, and the thing is running by itself later on.
If no I'am very unhappy with the solution because I'am in the opinion that recurring manual work is not necessary for such simple tasks.

I would like a optimal tradeoff method like saving much manual labour for the community by just sacfificing a little of your server memory.
It would be a half automated solution like this:
Upload models of say three to four basic sizes (so that the in case of rings the wallthickness keeps roughly the same in spite of scaling)
Intermadiate sizes will be seamlessly scaled up by shapeways.
(automatically scaling stl files can't be a too daunting task.)

It would be also in your intrest because with less manual tasks
your community modellers will increase in productivity.

For your Largest volume issue, the model I upload for customization is Maxed out (at maximum volume) then when you turn it into a co-creator, it tells you what the current volume is. My software also has a volume calculator, but that changes slightly when converted to stl. From other posts, a solution is in the works, but it's a tricky widget right now.

As far as I know, personalized items are not stored, other than by you. I keep a base file, modify it upon request, export, and keep the new rendition and the old in the same file. Right now I have 238 ckd's (my softwares cad files including automatic backups) 234 stl's, 20 dxf's and 69 wrls (837 total shapeways related files) in my Shapeways work folder. So it's a lot to look after, but organization is key. Many, including myself, would agree with the having size selectable, and either auto generated or already have the item loaded for sale. More interactive cocreators wouldn't be able to be done so easily, but could be done similarly.

I've seen all your issues brought up before, and I know they are being worked on and considered. We just have to be patient and remember shapeways is still in beta and only 2 years old.

NetFabb basic (which I believe can be downloaded for free, but maybe not for the Mac) shows the volume of an object in its summary, and there is also a script available for Blender (somewhere in the Shapeways forum) that computes volumes.

Link to the forum entry with the script: https://www.shapeways.com/forum/index.php?t=msg&goto=8790 #msg_8790

It appears that people with Macs were having some problems with the script, but I don't see any complaints after his last version. You may also want to look for an earlier version that doesn't do wall-thickness checks, but does do the volume calculation.

YouKnowWho - Thats a lot..but they do add up quick.

Would the method with the lower price bound demo model that I described above be a practicable method for some of you too?
yes/no? why?

@Youknowwho4eva
Considering your 114 models that would be 7.3 files per model in average,
but only 28 of them seems to be cocreator, so thats not really a representative number (files per cocreator file).

@GHP
NetFabb seems interesting but as you believed its only aviable for Linux and Windows.
The Blender-script enforces the usage of blender version 2.49
and the many additional features are unnecessary for me, they mean only a greater deal of alpha status.
Im sure the work of writing this skript was worth it and is of immense value for some, so don't get me wrong. Currently I have blender 2.49b installed so I will most likely try the script before upgrading.

best would be a commandline-tool like:
>> stl2volume testfile.stl
>> 1.61 ccm

I agree with Youknowwho4eva, decide on your max volume by making the biggest/simplest version you'd be happy to offer through co-creator and upload that and see what shapeways reports as the volume. They have the final say on the volume of a model anyway.

Or make your "biggest" limit by cost rather than by size. Like if I make a ring that I think won't sell for any more than $50, then the biggest size I'll allow in the cocreator would be the one that costs $50 (even if it's quite a small ring). Put a note in to say "larger sizes available by arrangement" or something. This will deter people with big fingers from buying, but will make the deal sweeter for those with small fingers. Might be better than deterring everyone off because of the cost.

just a thought
SN

>>make your "biggest" limit by cost rather than by size<<
Then Shapeways shoud give us an input field of maximum cost rather than maximum volume.
With startup cost & sandstone volume discount (>20ccm >10% dense)
and with maybe upcoming other pricing models the reverse calculating of volume becomes increasingly tedious.


>> biggest size I'll allow in the cocreator would be the one that costs $50 (even if it's quite a small ring)<<
I wouldn't be happy with that.
I would rather make say three cocreator models
for following priceranges. (think I like this idea most)
#1 minimal size to average female ringsize (ring finger)
#2 average female ringsize to average male ringsize
#3 average male ringsize to maximal size

To be fair only one of the three models would be categorized & tagged so only one instance shows up in the gallery.
And in the desciption of this one I could include links to the cocreator models for the other two sizeranges.

114 that you can see. 202 total. Not everything I draw I decide to put up here. Not everything I put up here I decide to make public, some I haven't tested, and I'd like to before making public. Besides I'm only seeing about 300 files that can be uploaded to KC (stl, and vrml) leaving me at 1.5 files per model.

My ring finger is a size 7 US. My middle finger is about a 7.5. I've found that that's actually on the small end of the spectrum. The smallest ring i've made was a double-- 5 and 6.5. The largest was 8 and 10. I usually make a size 13 as the max size and upload that to figure out the volume. I don't know what software you're using but Solidworks does have a built in "mass calculator" which can be used to figure out the volume of your model. it doesn't come out exactly as the shapeways calculation but it's pretty close.

You could also offer multiple co-creators with size ranges (ladies small 4-7, ladies large 7-10, mens 10-13) or something like that. That way a small-handed lady isn't paying for a ring made for a giant man. Another thing to keep in mind is that (at least for most of my ring designs) the change in size actually causes a very minimal change in price. That depends on the design, though, of course.

I order rings to sell IRL so I have uploaded many sizes of the same design that are available only to me in addition to having a co-creator model on here. It makes it a little hard to look through my designs but easier to place my orders.

You mean you order them and sell them from your place, and it gets quite confusing in your personal my designs area? I only want to sell online for now, so hiding doesn't work for me. But the size ranges are a good idea.


By now I used OpenSCAD exclusively.
It's actually a CSG programming language with a instant preview, and it has no means for volume calculation.


>>the change in size actually causes a very minimal change in price.<<

Yes for many rings the cost scales only linear due to a constant ring thickness t and ring width w:
V ~ 2*r*PI*w*t
Your "Infinite Loop Ring" probably behaves this way.

Your "Moonball Rings" shoud scale quadratic.
V ~ 4*PI*R^2*t

But in case of rings where the with AND (parts of the) thickness has to grow with the ringsize like my haskell ring ( https://www.shapeways.com/model/136891/haskell_promo_ring_20m m.html)
the price starts to scales cubically!
V ~ 2*r *PI*w(r)*t(r)
Then these are no minimal pricechanges anymore. :confused

yes, i mean i buy them and either ship them from here to online customers or sell them at a brick & mortar store. and yes, my personal design list is long.

Your math is over my head-- haven't taken a math class since 1999. I let the computer do my math for me. But the size of the balls on my ring is constant, all that changes is diameter of band and the space between the balls. It scales the same way as the infinite loop ring except the infinite loop ring has a little more than twice the amount of band. It all depends on how you choose to adapt your ring to the size.

For instance, with your ring, you could change the size of the band and the space between the logos and thereby avoid having to scale the height of the band for each size. In that case you'd probably want a mens version and a women's version since a man's ring is usually taller than a woman's ring.

Ok I try to explain it without any math:

#0 (CONSTANT)
Rings which have endorsements of unchanging size grater than its carrying body nearly keep their price no matter how big their ringdiameter get.
Your Moonball rings are of this class, this explains why you expierienced almost no price variations.
I initially thought they would be of class #2 (see there).

#1 (LINEAR)
Rings which doesn't change thickness and width doubles their price when they double their diameter.

#2 (QUADRATIC)
Rings with doesn't change thickness but do change width
quadruples their price when they double in diameter.

[The volume of a spherical hull with constant thickness does it too, it quadruples when ball diameter doubles. So if your Moonballs would grow with ringsize (this is what I initially thought) but keep their wall thickness, your rings would be of this class too.]

#3 (CUBIC)
Rings which do change thickness and their width octuplicates (!!) their price when they double in size.
Thats the case for my Haskell ring, in the form I have it now.
And the resaon why Shapeway's maximum volume/price requirement is a problem for me.

As it is now the logo is exactly as wide as the outer ring diameter.
It's important for me that the ring should look the same (same proportions) no matter of the finger diameter. I could do different scalings for logosize but that woud screw proportions and bring me at best from #3 to #2.

The symbols run into the ring main body tangentially in the center.
(This turned out accidentaly but I'am especially happy with that)
Keeping this poses additional constrain to scaling.

Sidenote: Different scaling of different parts in my models does reqire changing only a few numbers in my code. It's very straightforward in most cases.


I would use the cocreator-size-ranges solely for previewing an average / most-probable price for women & men but I doesn't want to prevent a women from buying a wide or a man from buying a slim ring, so I guess I have to split each of woman & man size ranges into two ranges making effectively four cocreator models for one kind of ring.
[Sadly the (haskell) programming community consists almost entirely out of men.]
But you do have a point, making the hight parameterizable as a second cocreator option is a must
because it's already a single number is in my code.