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Dec 2016

@Enza3D, @Joerg_4, @PepCo_Parker, @Perry_1

Hey guys!

Thank you all for expressing your concerns and giving me your feedback. I really appreciate it. The reason that we have to set guidelines on dimensional accuracy is because we have to draw the line somewhere and we thought setting a 1 mm tolerance would be a reasonable first step.

I completely agree with the fact that you, as Hubs, cannot know the application of your customer if they do not communicate it. Ofcourse in some cases you will have an idea by looking at the design that it’s part of an assembly and in this case you can double check with your customer if a 1 mm tolerance is sufficient.

But in most cases this is not the case and also, not your responsibility. If you receive a model from a customer and you print it within the guidelines that we as 3D Hubs set, you will be paid out for the job no matter what.

When a customer is not happy because the print does not exactly fit, we will ask them to take a photograph of the print next to a measuring device such as a digital caliper to show the exact size of the print. Of course we do want to keep our customers happy but this is not always the responsibility of the Hubs.

Feel free to reach out to the 3D Hubs admins (such as myself) at any point if you have a situation where the customer is not happy with the result but you printed the part according to the guidelines, we’ll definitely be able to help you resolve such a situation.

Best,
Robin - 3D Hubs

Hello again Robin, So to me this means hubs will have to start watching our backs by taking photos our selves of parts with calipers next to them, it wouldn’t be hard to fake photos to make it seem like parts aren’t the right sizes when they really are. This would be the only way to insure people aren’t cheating us out of good parts, but even then now we have to charge for our time photographing and setting all that up

My costs are definitely going to go up because of this; even if the verification is for my own insurance, it’s now another step I have to do for every print and that will be reflected in my prices. Because you’re right, there’s no way to prove it is correct unless I have already verified it myself and have pictures of it.

The problem is, how do I know if a dimension is right or not? Unless I have a parametric model file, or the customer explicitly specifies the dimension of a feature, I have no way of knowing (other than guessing from the STL) if it is correct.

My issue with these guidelines is quite simply the policing of them. Are you going to ask the customer to send you the 3D print so you can verify the dimensions yourself and make a ruling on it? Not every customer will have a set of calipers and even if they do, use them correctly to get an accurate reading.

Also this requires that I record how each model has been orientated in the slicer as your tolerances are in the X,Y and Z axis however that’s not to say that I printed a model along these axis. What if it’s a curved model that was printed at 45 degrees so that while the length of the curve is beyond the 1mm tolerance, the actual readings in the X,Y and Z axis weren’t?

And lets get something else right here, these guidelines aren’t designed to make my life as a hub easier, they are designed to make 3Dhubs job easier. I am now going to have to record, document and photograph more details of a print before sending it out.