DIY 3D Printing

[BCR751]

@BCR751 Is the other side of that car just as bad?

Yes, John, the other side of the shell looks just as bad as the side shown in the photo.  I heard back from the designer and he's going to show those two photos to Shapeways and see what they have to say about it.  I'll report back.

Doug

[peteski]

Good point @Mark W , but that does not PREVENT them from doing it, so it's not really a myth.  Doesn't economy depend on how many machines they have running and how busy things are?  Plus there is the evidence above, SOMETHING messed up the sides of that car and we already know the the first car could only have been printed vertically in FUD but not FXD (50mm vertical limit).  Only other thing I can think of is they printed that car on ond sideand the initial support layer messed it up.

@BCR751 Is the other side of that car just as bad?

Here is an image of one of my models that I send in- I don't think they can move or separate the parts at all, note that the seats are directly below the roof:



Here is how they looked after printing:

John,
I'm not sure where you are going with this.  Printer prints from the bottom up.  Are those parts designed to be printed as shown in the rendering (with truck frames to be printed over a bed of wax)?  With the interior and roof being stacked over the car body, there will be a solid block of a wax support inside the car body and another solid wax block over the interior up to the roof. Since the roof has no wax supports over the top of the surface, it will have the smoothest finish.

[Lemosteam]

Not going anywhere with it @peteski per se just showing that parts can be stacked and printed within the 50mm limit, and still come out OK.  My assumption is that SW can place whatever they want in the open areas. When it's ordered.

[peteski]

Not going anywhere with it @peteski per se just showing that parts can be stacked and printed within the 50mm limit, and still come out OK.  My assumption is that SW can place whatever they want in the open areas. When it's ordered.

Oh, ok.  But if you don't have any material physically interconnecting those individual parts, can't Shapeways rearrange them for printing?  You should be able to tell if they did or not by examining the parts looking where the fuzzy surfaces are.

[Mark W]

..
Here is an image of one of my models that I send in- I don't think they can move or separate the parts at all, note that the seats are directly below the roof:

...

As long as the parts aren't connected via spruce, the machine techs would definitely rearrange your parts to optimize print time and material use.  Let's make up a rate of 4 hours per inch to print FUD.  Roughing for N scale, your arraignment is about 2.5 inches tall, so that's 10 hours of print time, plus all the support wax in between. 

But if you rearrange your parts so that each free part is 'sitting on the ground', you're done printing in 4 hours and barely used any support wax. 



This is how I've been arraigning my designs since the beginning, and has afforded me the secret benefit of user-defined orientation this whole time!  If the parts are well organized and the tech can "drag and drop" into the print tray, I've found nearly every time, they'll print in the exact orientation uploaded.  I only know of one instance out of several hundred prints where the tech rotated the dry-bulk trailers 90 and it resulted in a mess.  I showed a comparison between the rotated and non-rotated orientation, and they sent it for re-print with no questions asked.   



But aside from all that, the more I look at Doug's 3rd print result, the more I'm convinced that it wasn't orientation or arraignment at all.  If it were, you'd expect at least some patch of good somewhere.  But the way it is so consistently... stripey...makes me wonder if it wasn't more of a machine calibration issue.  At this point, if you're up for a 4th attempt, I show Shapeways your two comparison photos and try again.  Otherwise, get a refund and call it good.  (then wait until their next sale and open a fresh order, if it's an item you really really want)

[Lemosteam]

Oh, ok.  But if you don't have any material physically interconnecting those individual parts, can't Shapeways rearrange them for printing?  You should be able to tell if they did or not by examining the parts looking where the fuzzy surfaces are.

If they are, they are spending much time splitting up a single stl file into separate models.

[peteski]

If they are, they are spending much time splitting up a single stl file into separate models.

I don't know - it it speeds up the printing process and saves on wax . . .

Can you verify (by examining the surfaces of your printed parts) if the in fact split them up to flatten the printing process, or if they printed them as they were in the STL file?  You should be able to easily tell how they were printed.

While I dont' have proof either way. Mark W's explanation makes sense to me.

[Lemosteam]

I don't know - it it speeds up the printing process and saves on wax . . .

Can you verify (by examining the surfaces of your printed parts) if the in fact split them up to flatten the printing process, or if they printed them as they were in the STL file?  You should be able to easily tell how they were printed.

While I dont' have proof either way. Mark W's explanation makes sense to me.

That's a question for Shapeways that none of us can answer, unless Mark or someone else has physically seen the technician do it.  I posted my response because even though you SEE separate parts in the image, the .stl mode fileis a SINGLE entity, not an assembly of parts.  I know of no CAD way to break it up, unless the machine's software has the ability to do it.

[Mark W]

Yep, Shapeways' software does it.  Separate parts are automatically identified upon upload as part of the automatic checks.  Then once ordered, a technician will manually check each file and arrange the tray. 

When you upload a model and it runs the software checks, you can view the results under the "3D Tools" section.  Their software can even attempt to automatically fix certain issues it identifies. 

[BCR751]

Yep, Shapeways' software does it.  Separate parts are automatically identified upon upload as part of the automatic checks.  Then once ordered, a technician will manually check each file and arrange the tray. 

When you upload a model and it runs the software checks, you can view the results under the "3D Tools" section.  Their software can even attempt to automatically fix certain issues it identifies. 

Well then, if this is the case, and knowing the issues with how something like the fluted sides on the RDC prints, why can't/won't the technician insure the item is oriented correctly?  Without know diddly about 3D printing, this sounds like an easy fix.

Doug

[Mark W]

..why can't/won't the technician insure the item is oriented correctly?...

Well that's the golden question.  What is the 'correct' orientation?  A designer's intended orientation, or the way one person thinks may optimize print quality may be different than the technicians.  Until recently, the technician's job had one goal; minimize waste.  First, disqualify anything that may break too easily to avoid having to re-print or refund, then play Tetris with the tray arraignment and fill as much space as you can (on the ground plane, but not vertically as previously explained).  In this practice, correct orientation is based on space available.   Print quality is not a factor here, so long as the result meets the general standard (which I believe your 3rd print does not meet). 

Now Shapeways has finally introduced user-defined orientation preference, so that removes any guesswork a tech would have to do and can finally consider print quality.  BUT, this doesn't mean designers can just click "this end up" and be done with it.  As I hinted before, designers should be conscious about the way the parts are arranged within their models.  Print quality depends on quality designs as much as it does quality machines and practices. 

[Lemosteam]

I think those separate entities are identified by the fact they are non-contiguous, and the software looks for that.  I am still not convinced that the system or the tech can break apart a model file.  I will talk to my contact there to find out for sure or start a new forum entry there.

[peteski]

I think those separate entities are identified by the fact they are non-contiguous, and the software looks for that.  I am still not convinced that the system or the tech can break apart a model file.  I will talk to my contact there to find out for sure or start a new forum entry there.

I would still be interested in your analysis of that stacked print of the car you are showing us. Can you tell (looking at the surface finish) if it was printed stacked like in your STL file, or were the individual parts rearranged for printing.  If you understand how the wax supports are utilized, you should be able to easily tell how it was printed.

[BCR751]

I heard back from the RDC designer.  Shapeways told him they would only discuss issues related to the actual CAD design and anything involving the structural integrity of the model.  Any requests for special orientation during printing, reprints or refunds need to come from the purchaser of the product.  And, again, the orientation is basically up to Shapeways. 

I'll ask to have the RDC re-printed but I'm not holding my breath.

Doug

[Lemosteam]

I am still waiting for a complete response to all of my questions on their forum. Hopefully tomorrow.