Already printed model being rejected

I too am suffering from successfully printed models getting rejected...

I personally have 18 successful prints, and there are another 12 outside, yet it fails on a curved area...

I think each time they check different areas, even with successful prints before.

If they knew it had successful prints then this knowledge would mean less time spent checking, and could improve order turnarounds..

Yep, been getting a lot of rejections for models that have previously printed. To save on printing costs my designs use minimal material and wall thickness where possible. It seems recently new processes have been introduced which have increased rejections. I also see inconsistency in the error reports a model rejected one day is accepted another.

To avoid rejections for future designs, I suggest updating the material design rules and increase minimum wall thickness which seems to be the biggest issue.

Not that it contributes much to this discussion but it's happening to me too.

Successful prints, often within the guidelines are being rejected now. The problem seems to be interpretation of the design rules.

I'm getting a bit fed up with having to contact the service department each time (next e-mail on it's way soon)

Yes, this is certainly what it feels like is happening. Perhaps the result of different people scanning the file on different days, months or something. I've also wondered if there were two different teams and depending on the load an upload may go to a team that isn't used to a specific designers quirks.

I follow the approach that it sounds like most of you use. Once the model is uploaded and passed, I order one or more myself to make sure it is right before placing it in the store. There is usually an issue or two and once those are resolved, the models print and are shipped to me. If they pass my own little quality test (I don't swing them around, but for some models I do drop them on the carpet!) , if they are good to go, I then put the item for sale in the shop.

Until recently that has been working pretty steadily.

A month or two ago, I chose to improve some of the models. Geometry that had passed previously was suddenly a problem when the updated model was uploaded. The changes that were made, like adding tread to a previously smooth tire, were not an issue. It was previously accepted and repeatedly printed geometry that suddenly had problems. The majority of the issues were the old supported / unsupported wire and details versus supporting geometry interpretations that I thought I were in the past or at least already resolved on printed models.

The other issue was the use of a sprue to connect parts together. In the latest batch of prints the sprue was being interpreted now as an unsupported wire. That sprue, which based on printing successfully in the past, had been considered necessary due to loose shells issues. It is apparently now optional. No sprue is good as it does save some material volume, but now that has to be deleted for 20+ models that have an average of 5 parts each. Yikes!

Again, I'm ok with that but am concerned the interpretations will change again and the sprues will have to be added back. In this case tags wouldn't have helped as any change to the model, afik, results in a brand new interpretation check.

All that said... this process and Shapeways in general is leaps and bounds from where it was two to three years ago. Consistency in service is the hardest thing to maintain when a company grows. I'm not making an excuse for them as this is impacting me significantly, but it's my hope that posts like these and ideas like the tagging get attention sooner than later.

A few days ago, I have (again) been hit by the rejection of a model that was succesfully printed earlier.

There have been hints that Shapeways is thinking about marking successfully printed items so that they will not be rejected later. Would be nice if that was implemented at last.

Greetigns
Dragoman

I am still awaiting the wonderful news of already printed models being tagged, so that they are able to be printed again and again without worry. I'm working on a model at the moment that is really going to push the limits, and I may have to make some sacrifices on the design. I'd feel a lot better if I knew that after my initial print, it would print again and again without worry.

Several months ago Shapeways (in another forum posting) described their process where they looked at the revision # of the file and whether there had been any sales for that file. It turns out they don't need a new flag to tell them that it's been previously printed. I still wish that they'd bring it out where the customers can see it, but that's a different subject.

The process IS in place now. What I'm not sure of is whether all operators are following the process or not.

Please note: I have ZERO interest in starting a flame war here. Please keep any comments polite. I just wanted to point out that the current process should be handling the situation. I am every bit as frustrated with the rejections as anyone else.. they happen to me also.

I would imagine that as the New York facility gets built out, we'll have less of this happening, but it will take time.

===
Please be aware that there are two situations here. One is where a model DOES fit the design rules and is rejected erroneously. The other situation however is when you have a model that is particularly troublesome. This model https://shpws.me/lmd5 had very very thin railings that kept breaking during cleaning. It would print just fine, but then break during cleaning or shipping. The production team asked me to beef up the railings.. which I was happy to do. I don't expect for Shapeways to have to print my models 2-3 times for every order just to get one sucessful print.

BattlegroundToys: you should not have to remove those sprues, but at the same time, what you may need to do is beef up the sprue to the point where it can actually support the parts connected to it. You need to try to put together assemblies that can be picked up by human fingers and not break apart.

I think there are at least two other loopholes in the procedure:
a) a model does not fit the design rules everywhere, but the flaw is either overlooked or deemed harmless during checking
and the printing, cleaning and shipping proceeds without problems. Then a minor design change in another part of the model
leads to re-evaluation and this time the flaw happens to be found.
b) the model "has been printed successfully" from the point of view of the customer, but not on the first attempt, and repeats would be
too expensive for shapeways. (cf the recent "stag head")
perhaps even
c) the model "has been printed successfully", but at a time when the work volume was much lower and the cleaner could afford
to spend more time with more delicate tools.
(And no, I do not have a solution)

Maybe there should be an advanced option to have the products delivered for home cleaning?

I received some very greasy white detail products which took me a couple of hours to clean myself, but I had time to take care over them. Perhaps if this were an option at a reduced price then perhaps more borderline fragile products could be printed? Just a thought.

As most designers here, I always test print my models before making them available for sale in my shop. So, whenever I received a successfully printed model, I always assumed that the model was ok and immediately made them available in the store.
I think that if the operators need more than one attempt to get the model printed, they should warn the designer, so we can modify it BEFORE we make them available in the store, thus avoiding that someone order it just to have it rejected later.
Usually I only receive this feedback after a model from a customer is rejected, which is really annoying.
Just my 2 cents.

Regards
Luis

Add me to the list of people getting these errors more often again.
This issue appears to move in cycles: Everything generally prints OK for a while, then everybody starts having every print rejected for a few weeks, then eventually things return to normal.

I've noticed that when these rejections begin re-appearing, it is predictably near-100% of the time issues with points and similar details. For example, picture a cone shaped model. You print it OK a few hundred times, and then suddenly get a rejection because the point becomes too narrow to print.
As a designer, you lop off the point and re-submit, but then it is rejected because the base becomes too narrow at the edge... and so on.
The solution is either the designer accepts that cones are an unacceptable geometry and never uses them again, or they redesign everything that they had printed before to suit the newly undocumented aesthetic, or they send the models elsewhere and give up on Shapeways, or they just ignore the problem and wait for whoever is sending those bogus rejections to figure out what they were doing wrong.
My assumption here is there are humans tasked with analysis that are mistaking detail with support structure, and ignoring numerous "already printed" flags that have supposedly gone up at Shapeways (we really should get these PRINTED IN X flags on the actual model page). I've always figured they are new hires still learning how things work, and/or regular staff over-reacting to a meeting to watch out for Stag models and similar.

It's incredibly frustrating, but seems to sort itself out over a month or two... so if you're a designer and keep getting these errors, take your store down for a while and wait for the problem to be solved.

***edit*** Also, advice for new designers: Now may not be the time to try to upload your 1st print. When these issues flare up, it can make the process seem a lot more difficult than it really is, and might frustrate you to the point of giving up.

From one designer....

Hi guys,

To provide an update:

This weeks release included a Printed Before tool into InShape (our internal system).

We now have Printed Before visibility in our rejection tool. This is not to say that all models which have been printed before should always be printable again--there are exceptions, like by material, or if it was printed several times unsuccessfully (as described belo), but we will be diligent about checking them, and we should no longer have any issues with mistakes in rejections of Printed Before.

What this means is things like your 84-times printed before model won't be incorrectly rejected again! I know it is a small step, but we are improving our tools as fast as we can.

The cycle of "everything is ok and then there are a lot of rejections" does indeed correlate with us growing, hiring new people, and getting more machines. To give you an idea, our New York Factory of the Future got another two machines last week and we're hiring another engineer. As we grow, we are streamlining the process, and improving so hopefully the cycle of disruption can be minimized.

To provide more insight into the process of why rejections happen in the first place, here is the process of ordering a model:

You upload a model.
We do an automatic check on upload.
When it gets ordered, it gets sent to the production facility, where they manually check it.
A person checks for printability within 1-2 days (which for the most part actually happens within 24 hours)
Sometimes we can see immediately that it should be rejected and sometimes we can't. If it gets rejected this usually happens right away (and we notify you with time to change your model)
If it gets approved, they print it and here is where delays can happen: they may try to print it once (which will take a few days) and it may break in post production, or crash the tray, or even break in shipping - so they will try to print it again (another few days) and the same thing may happen. At this point they reject it and tell Customer Service to tell you, but it is now officially late. (this is the worst case scenario)
The percentage of orders that this happens to is low (it hovers around 10% and is decreasing)

We do it this way to allow as many models to get printed as possible. To make it stricter means making design rules stricter and rejections higher. So yes you would get faster rejections, but you would also get more rejections - and possibly models like the planes would become unprintable outright. We are pushing the boundaries of what is possible with this technology and any advances we make, we want to pass on to you to let everyone design things. So we let you push the boundaries, so we can learn together.

I hope this provides some insight!
Best,
Natalia

SO glad to hear that you're growing! Which materials can those printers print?

<joke> Send that new guy to Texas for a week and we'll teach him not to reject OUR models. </joke>

Natalia; that news is amazingly welcome, thank you to the entire team for it. I really do appreciate everything that happens during the process; and really try hard to make sure my designs are as optimised for printing as possible. My latest order may prove a bit difficult, but if it does print, I'd wonder if it would actually print again...

To that extent, would you recommend that shop owners contact Service, to see if an already printed (but possibly fragile or difficult) model could be printed multiple times?

Also, wonderful news about the growth of Shapeways! Thank you again.

If a model prints but is impractical - too many attempts needed, breaks during handling etc - the designers should be notified of the exact problem.

[QUOTE]"Your model XYZ123 printed but will be rejected because...
[X] Multiple prints required
[X] Breaks in handling
[.] Other

Description:
Parts too fragile, Need 4 prints to get 3 successes.
Breakage at this point on model (include diagram - may be hand drawn)"
[/QUOTE]

That degree of detail would be enough for the designer to fix the problem, but hopefully not put too much burden on the production team.
If need be, omit the description, just have check boxes.

Thanks for the feedback here, and congrats to Customer Service - you do very well indeed.

Even for folks like me without a shop (yet?), such information would be useful to help
prevent under-designing future models. (Or to avoid nasty surprises when one wants to
replace a worn/broken model later - be it game pieces or scientific models handed out in
lectures)
I can imagine that the full-blown feedback system as suggested by ZoeBrain might
impede your workflow, but how about a single status flag for a start, something
that operators can set when they schedule a reprint (or that gets set automatically *by*
scheduling a reprint) and which would add ***MARGINAL DESIGN*** to the model entry
on the packing slip ?

@calistotash, yes definitely contact service to ask about a model you want to print multiple times

@stony the new printers are FUD and WSF printers in the NY factory

@Zoebrain, this is a really good suggestion, I've passed it onto the service team, will keep you posted about what we can do to implement this!

thanks everyone!

+1 Zoe's suggestion.

Part of the issue, I think, is that the printers want to be awesome techno-cowboys. When they see a marginal model that's going to take a few tries, their natural impulse is to think OK, let's run a couple of extra parts and pull this off, the customer will be wowed and we'll have printed this difficult thing, let's gamble that they'll only want one of them and we'll get away with it. Sometime that's what happens and hey, you're surfing the edge and everybody smells like a rose. Other times you come back the next week and want 25 of them and then the printers are all, oh shit we can't print 100 parts to make this happen.

I think it's pretty much human nature to take those gambles in the hope of looking good; anyway after 15 years working with 3DP, I'm still dealing with it. So I think making it easy and guilt-free for the printers to report this situation before it escalates would be great.

I think you've hit the nail on the head Bathsheba.

After many successful prints of my Small Twin Rail Mobius in Silver without any reported problems, it has now been decided that the model is too fragile. Whilst I must accept this, the timing sucks for those who've ordered the model as a Christmas present as it is now too late to adjust the model for it to be re-ordered. Appologies to those effected by this late decision and my ability to change the model for you.

Paul
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