Not Cleanable; Model Breaks

Hi,
Is there a way to quantify what 'Not Cleanable; Model Breaks' means?

The parts that I had this error message returned on are a thin box-like structure with one thin face mostly open. There are undercuts inside the structure. The part is the side tank from a steam tank engine (like Thomas the Tank Engine)
If I thicken the walls, the gap between the walls may become less than the wall thickness, and make cleaning just as difficult. I could potentially fill in the undercuts, I expect this would assist in cleaning.
I would prefer a quantified answer rather than experientation, I have already missed the high resolution detail material printing run because of this problem.
Thanks,
Mark

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Even a photo of the equipment used for cleaning might be useful?

There are videos available in the support section I think

Big table vacuum cleaners

Can you attach the file on the forum?
or send it to our customer service department.
It would be easier to say what it is in your case.

Thanks.

G'day Artur,
File is attached.
Madox, I don't think it is a vacuum cleaner used for cleaning detail materials as the support material is a gel, not a powder, and does not fall away easily. Indeed it takes a fair bit of effort scraping it out by hand. I would expect a dentist-style water or air jet would be used.
Before asking, I did search the forum, FAQ and tutorials though.

Here's the overview of the process:
http://www.youtube.com/watch?v=IM8WU8JfyI8&feature=playe r_embedded#!

I suspect the model was unable to be cleaned due to the semi-circles causing undercuts on the inside. There's no good way for the waterjet /manual tools to reach behind those walls.

My suggestions:
Split the part in 2. to make the inside easier to clean (either remove the rear wall (the one with a round hole). and make it into a separate part.
or the wall with the semi-circular indents on it.
Glue the pieces when they arrive.
Option2. make the top wall (the one with the semi-circular features thicker on the inside to make the inside wall flat.
No gluing but the part will be a bit more expensive.

Thanks Artur,
I guess the simplified answer here is don't have a void with an opening smaller than the face it is in :confused

Unfortunately making it in two parts and fitting/gluing together later removes half of the reason why I get parts rapid prototyped. Making it without undercuts is my preferred method of your two.
Thanks for clarifying,
Mark

Mark,

Just out of curiosity, did you boolean all the rivets to the plate surface?.
Nice bit of modelling!.

Cheers

Stu.

Hi Stu,
I use CAD for my drawings, so to make rivets I protruded the rivets as cylinders then rounded the edge to form the dome. The rivets on curved surfaces weren't so easy, I protruded the rivet width as a recangle from a nearby perpendicular surface to the furthest point of the rivet, then cut out most from the same perpendicular surface to leave a square projection, followed by rounding off the edges perpendicular to the curved surface to make cylinders then rounding the edge to make a dome. These rivets aren't perfectly formed but you can't tell on the model.
Hope that makes sense!

Thanks for the explanation Mark, it's sounds like you have more patience than I do.
I should try out a CAD at some point, I just use Blender at moment, it has it's good and
bad points. I think CAD would be more suitable for the kind of modeling I like doing,
but it's just a hobby for me.

Cheers,

Stu.

Hi Stu,
What sort of modelling do you do? I find CAD is great for mechanical items or models of mechanical items. Its only when you get to compound curves and organic shapes that I feel the 3D modelling programs come into their own...I am also fluent with Rhino. CAD creates virtually no errors when doing solid parts, unlike surface modelling
But there will be as many opinions as there are modellers here :laughing:

Hey Mark,

My modelling style leans more towards mechanical stuff (I don't really have
the artistic flair for organic modelling). So, I think CAD would be worth looking at,
but as it's only a hobby for me, paying out £££ is not an option. So Blender it is!.

Rhino does look great, but what made you decide on that app?. Someone on this
forum mentioned a CAD package called Alibre Design, they do a personal version
that is only $99, I may look into getting that when I have a bit of spare cash (oh, and
a new computer) :blush: .

Cheers

Stu.

Stu, Blender's far from being the only free 3D modelling app available. Check out FreeCAD - it's a directory of downloadable CAD-based programs, most, if not all of which you can get for nothing. Even if it's just a stopgap till you have the cash, there's nothing stopping you exploring some options.
While I haven't tried it myself yet, I've heard trueSpace is supposed to be really good.

Andy

Andy,

Thanks for the info, I'll check it out!.

Cheers

Stu.

Im trying to figure this one out as it is very vague.
I have a model that traps several cc's of support material inside in a detail materiel. I want it there as it helps strengthen the model.

It has a mounting hole on the bottom and a couple holes on the sides. Area of holes are roughly 2-4 square mm and wall thickness is generally 1-1.4mm shaped like a big egg.

Shapeways is saying it is not cleanable and would break in the cleaning process. However Ive had a similar model that trapped a few cc's of material inside with just a single mounting hole on the bottom of diameter ~2mm and this printed and was delivered without and problem. What exactly makes such a model more likely to break in the cleaning.

Does anyone know what kind of criteria SW is using to deem something uncleanable? Other than splitting the model in half what is the most reasonable way to fix this. Larger holes or only one hole, since that seemed to work before.

Thanks for any help.