Parts below minimal clearance when I don't care if they fuse or not

I had a rejection of a model recently for parts closer than the minimal clearance (in WSF, so 0.5mm). For this model I don't care if the parts fuse or not (it's one solid sculpture, no moving parts and it doesn't matter to the look of it if things are fused or not). It seems to me that in this kind of case, when the issue of fusing or not is irrelevant to the design and if they fuse it won't endanger the rest of the print run, it would make sense to just print the thing as is rather than require a redesign.

The justification I got from customer service was that it can be difficult to clean the unused dust out from small gaps. Well, I get plenty of orders as it is with dust still on them, in crevices etc., so this doesn't seem like a real problem in general. Is there any other justification for requiring a redesign?

With your models too?

I'm talking about it here

https://www.shapeways.com/forum/index.php?t=msg&th=18631 &start=0&

Something has changed in shapeways checking rules, and not for best ....

I can understand the frustration since in your case it doesn't matter if it fuses or not.
But I can also understand why shapeways would cancel such items.
In some cases it may be more difficult to guess how important it is for customers to retain the separartion. For instance on some patterned surface that hase some very fine details. In some cases the designer knows it probably wont print all the detail, but is fine with that.

In other cases, the designer doesn't realise he left too little clearance and expects the details to print just fine. If shapeways would decide to print it and send it, the designer would/could be mad since shapeways decided to print the model, instead of noticing the designer that his model did not meet the criteria, and send out a model which can be claimed faulty. Even worse if someone bought it from your shop, expecting to have the detail as shown in the model, but ending up with a not so detailed model.

So for shapeways, it's a logical decision to stay on the safe side and reject models that don't adhere to the guidelines.

But Shapeways doesn't need to guess at the designer's intentions, I'm right here saying it's ok! It makes sense to reject once, before there is a chance to communicate about it. But it doesn't make sense to reject after I have said that it's fine if parts fuse.

You're right, if you as the designer have said that it's okay if they fuse, they should just print it for you.

Maybe if it is for sale in your shop, they can get issues with customers that see the 3d model and expect it to not be fused, then complain about it being fused. Even though to the original designer it doesn't matter.

On the other hand. If it doesn't really matter if it fuses, how much work is it to alter the model to make it fused, instead of having a the clearance problem.

If it's for yourself, you can use Print It Anyway.

The issue with a customer ordering, is the customer receiving what they're expecting? If a customer orders a part, expecting the part to have clearance, and they receive a fused part. Shapeways is liable for that. So we'd issue a refund. It seems like it would be simple enough if you included the possibility for fusing in the description, but then the checker would have to read through your item page to make sure that you do warn of fusing. And even then, you'd be surprised how few people read the description.

Ok, I can understand the issue if the design were some intricate latticework or similar, with holes that could be filled solid or not. For some context, I've attached the image shapeways service sent to me.

The two parts are indeed 0.36mm apart from each other. But note that immediately to the right are two overlapping parts, and even further to the right the parts overlap even more. To the left the parts have a larger gap between them. So there is a progression from clearly not being fused to clearly being fused (in fact overlapping) as we move from left to right.

Here, surely it should be clear that at some point we move from non-fused to fused, and it doesn't matter to anybody where.

It is of course possible to "fix" this problem - by adding small blobs of material to bridge between the parts that are too close and connect them. The problem is that these blobs will likely be visible, in a small way making the aesthetics of the design worse. I'm fairly sure that this fix will affect the aesthetics of this design more than variation in the printing process fusing parts that are nominally separate in the model.