Thin Walls Problem

https://www.shapeways.com/model/printability/2386287/0/26?ke y=2635ec097f1d0a53054b9a23e3ba7618
Hi! I'm new here and trying to make my first print. I'd like to use colored sand stone, since it is cheap and fully colorable. I've provided the link above so hopefully you guys can give me tips on how to fix the problems (mainly the thin hands). Will this be a definite problem when printing or do you think it will just be delicate? I noticed that sometimes there is a "Fix" button in this window. Maybe it's my internet being slow, because it never does anything to fix the thin walls. My model is a DAE made in Maya. Thanks!

Hi.

These claws can't be printed in sandstone.

Take a look on the info about minimum unsupported wires for this material

https://www.shapeways.com/materials/full-color-sandstone

Fix thickness button works, but it takes its time. And you won't like the results. you gonna have fatty fingers were have to had claws, cause it increased the thickness in all directions.

It's better you increases the thickness in your design manually.

Good luck with your awesome robot!

Regards

Luis

PS: you have to increase the waist too. Take a look into the rule "Hanging structures break easily" and "Sandcastle Rule: If this structure was made of wet sand, would it break?" in

https://www.shapeways.com/materials/full-color-sandstone

Thanks for the help! And good point about the waist too. Perhaps I'll need to make it out of a stronger material and I can color it myself.

That would certainly work - print in "strong&flexible" nylon (not much more expensive, lighter, less fragile and with somewhat finer details) and paint with acrylics. The problem with the "sandstone" material is that it is actually very fragile right out of the printer and needs to be treated with a cyanoacrylate "superglue" solution to achieve the final sandstone-like hardness. This step is where thin attachment points between the rather heavy - gypsum-based - parts of a model tend to give way - I (or rather they) have this problem with my models all the time. Plastics-based successors to the process are just entering the market, so there is hope for improvement at least sometime in the near future.

You can print it in strong flexible, but with some improvements could be printed in full color sandstone too.

There are many models previously printed in sandstone with stiff arms or legs.

https://www.shapeways.com/model/784191/dog-d0g-half-life-110 mm.html?materialId=26

@holden8702: I had intended to write something along the same lines originally, but then found that the very model I wanted to use as my example (YeaglemanBrothers' tiny blue Dendrobates treefrog with its spindly forelegs), is currently unavailable due to misprints, despite my having received a perfect print about a year ago (and definitely after shapeways started doing FCS inhouse). So thin parts in FCS appear to suffer from reproducibilty problems - whether this is due to the process itself or to shapeways' timing constraints is at least debatable. (I do notice that the example you linked is flagged with the new "first to try" label, so does not appear to have a successful printing history yet)

I have some more questions about sandstone. Do you think printing the model on it's side (instead of standing) would improve the durability of the waist when printing it in sandstone? Also, would modeling the object into two pieces or multiple parts improve the printing process? Then I could glue parts together (such as at the waist)

You can't choose the position of printing.

Only the shapeways printing team do it, and may be not for a printability purpose, may be to put as much models as possible in one printing machine.

And yes, you can make it in two parts and glue it together.

Mkroeker: I had watched this model is flagged as "first to fail" too.

But this is a good example of the border between design and printability. This design of Vidal is a masterpiece. And all we are here to find this "edge" too, isn't it? ;D

Much will depend on whether the model is for one's own pleasure, or intended for sale. For own purposes, selecting "print it anyway" on checkout
might be all that is needed - if the model then arrives in pieces, they can usually be put together with superglue. (What is the thickness of these "fingers" ? Worst case they would crumble completely, so nothing to glue back - though then it might be easier to just replace them with a piece of copper wire, might even look more realistic.)

@hannahnew That fingers will really crack in sandstone at the transportation. The object it is passed in like 6x2 hands aka 12 hands till arrive to you or more , people can hit the package by mistake or other accidents and boom that hand will crumble.

Your design fits better WSF or the new Full Color Plastic *the one in testing with dim colors.

Best bet it is -> WSF , treat it with sealant and paint manually.

Sandstone has "sand castle" rule , it means it is like a lump of beach sand you use to make a castle with water ... very prone to crack. That it is the reason I don`t use sandstone and I`m not really into using it in future.

I`d rather go straight to new material in testing even with dim colors.

Thank you for the advice, numarul7!
For now, I have held off printing the model until the new full color plastic material is available.
I signed up to be a tester, but I don't know how likely it is that I'll be chosen... ??
I fixed the thin wall problem and I'm eagerly waiting on the new material

Next wave it is next week.

Hi Hannahnew! Welcome to Shapeways!

Hey! How did you get that URL? I can't figure out how you did that! HAHA!

As for your dilemma, I'd pretty much say what the others are saying. Are you wanting to sale this design on Shapeways or were you just making this for yourself. If making for yourself you could make the parts so they have mortise and tenon joints so they're easier to glue together. You could sell it that way too, if you think your customers wouldn't mind doing the assembly.

Your fingers on your design, (end effectors in robot talk ) are what we refer to in 3D printing as wires, and in this case they fall under the category of unsupported wires. For Full Color Sandstone they need to be 3 mm thick. Also, as mentioned, Shapeways has a new material that they just came out with a few days ago that they are testing called Full Color Plastic, which has a guideline for unsupported wires of 1.6 mm. Both of those are pretty thick if you want your design to be small scale, but not too bad if you want it in a larger size.

Yeah I agree that's a cool robot! Let us know how this comes along!

Hi there!
I got the link from a pop up window. When I uploaded my model and went into the edit page of the model, it shows all the materials and prices. If a material doesn't pass the thin wall check, then you can click the Thin Wall link and that opens the pop up window. From there, you can see the problem areas and at the bottom shape ways provides the URL for sharing. The screenshot shows it under "share this view" Hope that helps!
And yes, I plan to use the color plastic instead. I'm in luck that it was being announced as soon as I signed up here!

OH!!! I see now!

I knew about the pop up window, but I didn't see the sharing link, because I never read anything, because I hate reading! hehe

Thanks for explaining that me, I love learning about new things.