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Dec 2016
93 / 116
Jan 2017
Jan 2017
Sean_Houlihane
Jan '17

One reason that ther may have been a delay in feedback is that people might have read the guidelines, and felt they had an interpretation which made sense - then later came here to read the detail (or made a print for a specific purpose) and realise that the context can have a big impact on exactly how the guidelines are interpreted.

Sure, use these guidelines as a benchmark, and require a hub to agree to deviate. Under the guidelines, this part Dial Gauge holder for Anet A8 by tsh2 - Thingiverse is impossible for me to make. See the surface where support was removed on the square at the bottom, all untidy, but quite functional. It didn’t occur to me on first reading of the guidelines that you intended to block me from offering parts like this.

Vienna3DPrint
Jan '17

Hi Robin

Do not reduce it to the accuracy. The mandatory removal of the support is another unsolved issue.

Until now I charged either nothing for it, because the object was small and easy to remove, or for support material as it was like 50% of the print, or both: support and removal. Sometimes the customer wanted to remove the support himself.

What now, if the customer wants to remove the support himself ? (To safe money)

It´s quite unfair to raise the overall price, because that affects support free prints also.

Should the hubs, regardless from the wishes of the customer, charge the removal of support (and remove the support anyway) ?

I also just removed the support. I did not tweak the print. Some objects are just crazy ! On big objects it really took several hours just to basically remove the support. With sanding and what so ever finishing this process may take days.

Which customer is willing to pay for it mandatory ?! Well, some want the support removed, but others not.

And as mentioned before: This guideline will make it very hard for single head printer hubs to continue to print with support.

3D hubs may improve the overall quality, but also raises the overall price for 3D prints.

bye, Tibor

PepCo_Parker
Jan '17

No offense Robin, but you’ve spat in our faces with this one. Basically what you have stated here, is that you took selected people’s criticism and acknowledged it, then based on those few views which you guys selected, you already had enough mindset to implement it, but them put up a forum post to again only portray the illusion that we had a say. And you may try to argue against that, but pushing the update through right before the holiday season, despite the discussion on here, only proves that. I dislike that a handful sampling made the decision for all of us hubs. It affects all of us, why shouldn’t we all have had a say?

keebie81
Jan '17

Maybe its me but I dont understand the big issue with a 1% or 1mm accuracy whichever is greater. Thats a quite large tolerance. If you cant print within that you need to work on your printing skills. I typically get under 0.2mm tolerance on parts I print. Looking at a part I did a while ago its off by .08 to .1mm

PepCo_Parker
Jan '17

No offense but if you don’t understand it, you haven’t read this thread. There have been numerous points as to why it’s not feasible, and I have even stated that hitting the targets isn’t even my personal concern, it’s people manipulating those rules to get free prints. I suggest you start at the top and read your way down to get a full understanding of the points raised.

keebie81
Jan '17

Well the same customer that is going to manipulate these rules to get free prints would most likely still complain and get a free print without these rules. This is also why you should price your prints to accommodate for the once in a while customer that causes issues. Same with any business you need to weigh the risks and prepare for them or close up and find something else to do

PepCo_Parker
Jan '17

This is true, but tolerances as you’ve stated, have never been an issue for me. These rules seem to only be giving the customer more power over the hubs, when it’s unnecessary. If the hub communicates properly with the customer prior to the order being accepted then there should never be an issue in the first place. These guidelines make it easy for someone to improperly set up a pair of calipers, take a few photos and bam, there’s a 200$ order down the drain when the hub did nothing wrong. There have been other issues raised by the community on this forum, but I would be a broken record if I repeated them again. Also please don’t feel I’m attacking you. You’re raising different opinions and challenging what we thing which is good, and encouraging! So long as both sides of this argument are open and understanding to one another.

CWCrawlers
Jan '17

If you have a dispute you can call 3D hubs in and they can act as moderator… thing is at the end of the day you gotta play the role of a customer… if you get a part in that you specified as needing to be precise and someone send you a WILDLY out of tolerance part… you would not be very happy would you?

I feel like if you have a potential issue with an order its your job to communicate that with the client BEFORE you guys go agree on a print… That said I do understand your concerns but having a guideline you AND client can refer to would be a good thing in the long run.

PepCo_Parker
Jan '17

One of my points though is that until now I’ve just done this personally, why is there suddenly a need for 3D hubs to intervene? And a customer doesn’t need to give ‘wildly’ out of tolerance parts, only 1% off. As some have brought up, unless we as hubs are to now measure every part we make and document it, there is no way to prove otherwise.

CWCrawlers
Jan '17

Quoting the list above: “FDM parts need to be produced within an accuracy of +/- 1mm or 1% depending on which is greater.” +/- 1MM is BIG… That means that your 20MM calibration cube could be 19 - 21 MM and STILL be a-ok. That is a huge tolerance. Their not asking you to hold .0005" tolerance on a 3" deep hole…

MadBuggyofDoom
Jan '17

That’s a tiny tolerance, make a 200mm part and it’s got to be within 2mm?
It’s not about how it comes off your machine, it’s about how it measures when you get it there. Many materials can grow and shrink more than that just from differing moisture levels. Never mind the rest of the stuff I mentioned earlier.

It comes off your machine and measures perfect, gets to the customer and it’s out of tolerance. Now, who is footing the bill and who has to prove it was in spec (and how, since the guidelines are so vague with obviously no proper QA process in place) - guess what, it’s the hub.

Georgei
Jan '17

Dimensional accuracy: +/- 1mm or 1% depending on which is greater

So

20mm object = +/- 1mm tolerance

200mm object = +/- 2mm tolerance

cobnut
Jan '17

@Vienna3DPrint the guidelines say “whichever is greater”, so for a 20mm cube, 1% is 0.2mm, yes, but 1mm is greater so you could print anywhere between a 19.01mm and a 20.99mm cube and still be (just) within the 1mm tolerance for a print that should be 20mm.

Vienna3DPrint
Jan '17

The whole sentence says: “FDM parts need to be produced within an accuracy of +/- 1mm or 1% depending on which is greater.”

greater=accuracy

Maybe a native English speaker could formulate a less contradictory sentence.

bye, Tibor

Vienna3DPrint
Jan '17

As I mentioned before: greater is misleading, as I don´t think the dimension is meant, but the accuracy.

Robin must reformulate the sentence, as it leaves room for interpretation.

bye, Tibor

Georgei
Jan '17

The greater refers to the dimension (i.e. +/- 1mm or 1%) and not the accuracy. It is common statement in engineering at least.

The below text is from the original quidelines draft text from 3DHUBS

FDM parts need to be produced within an accuracy of +/- 1mm or 1% depending on which is greater.

For example, in the case of a 40mm cube, a 1% accuracy requirement would result in a max of 0.4mm deviation. As this is below 1mm, the 1mm is leading and determines the maximum. A printed part of 40.6 x 39.4 x 39.3mm would be acceptable as the deviations are within this 1mm. Printing a cube that is 38.8 x 39.4 x 39.4mm would not pass the dimensional accuracy requirements as the width deviates more than 1 mm.

cobnut
Jan '17

@Vienna3DPrint hmm, good point, I’m now wondering if I’ve read it the right way (as a native English speaker!). A better (but not necessarily ideal) sentence would be either of:

“FDM parts need to be produced within an accuracy of +/- 1mm or +/- 1%, whichever is the lesser inaccuracy.”

(so the 20mm cube should be produced to within 0.2mm, because 1% is less inaccurate)

or

“FDM parts need to be produced within an accuracy of +/- 1mm or +/- 1%, whichever is the greater inaccuracy.”

(so the 20mm cube should be produced to within 1mm, because that is the greater inaccuracy)

depending upon which meaning 3DHubs are actually looking for, and the 1% should be +/- as well. @Robin3D ?

edit (just noticed the doc does include examples)

Vienna3DPrint
Jan '17

Also with example it makes no sense.

40mm=2,5% (1mm), 400mm=1% (4mm) Why should the tolerance be bigger at smaller objects ?

40mm=1% (0.4mm), 400mm=0,25% (1mm) would be more accurate.

Maybe more understandable would be: Accuracy can be expected within 1mm deviation in any direction for objects below 100mm expansion and 1% deviation in any direction for objects above 100mm expansion.

But ok. Shall it be. I´ll pass on any questions to 3DHubs. It´s their guidelines, it´s their explanation.

bye, Tibor

MadBuggyofDoom
Jan '17

Anybody can get a part off the machine in that tolerance, even the inept, the issue is keeping it in tolerance. I could take nylon parts off my machine accurate to 0.01mm and I still wouldn’t guarantee a general 1% accuracy in nylon to a client unless it was to very specific measurement/temperature/moisture levels.

I’ve just taken a part off my cheap home machine which is supposed to be 130 x 50 x 25mm - it measures 130.05 x 50.02 x 24.95mm. You couldn’t really want any better, it’s full of 13mm holes which are 12.94-13.00mm in diameter, there’s 6 x 3mm holes in there which are all 3.00mm. The ovality and coning are all way within 1% of true too.

The issue? They won’t be tommorow when it’s absorbed some moisture and the temperature changes. Or next week when the stresses have relieved after spending some time at working temperature.

Filemon3D Hubs Employees
Jan '17

Hi all,

Allow me to check-in on this thread as well with an attempt to summarize and hopefully shed some light on the most asked questions (forgive me if it’s a bit lengthy).

Why these guidelines?

As mentioned in the original thread, the goal of the FDM quality guidelines is to improve FDM printing standards globally.

One of the top customer complaints is about print quality being below expectations. Phrased differently, there’s a huge opportunity for both Hubs and 3D Hubs to grow their business if a cross platform standard is set. This can be used to set the right expectations up front, as well as setting a minimum requirement for FDM printing, which enables us to cater to more professional audiences.

To be clear, the main message is to manage the customer’s expectation. These guidelines serve as a standard reference (e.g. backup) whenever there’s a dispute between customer and Hub. If a Hub and customer agree to deviate from the guidelines, that’s completely fine.

I hope this also explains that this is not about “policing” Hubs, but rather a tool to help set clear expectations.

Implementation of Guidelines

As many of you highlighted, after we’ve asked for feedback over the holidays (and you delivered) we failed to respond. This was a mistake on our side and I understand the negative impression it has left. I do want to stress that we’ve discussed all feedback elaborately and made changes accordingly. Below, more information on the main topics.

On dimensional accuracy

After checking with a significant sample of top Hubs as well as 3D printing experts from the industry, the current suggestion is considered to be reasonable.

To illustrate the variety of opinions, while the feedback here has been that the requirement might be too harsh, the opinion on Reddit has been that the requirements are too loose. My personal opinion is that with a well calibrated printer these requirements should be met without difficulty in most cases.

Clearly, there are scenarios in which an accuracy of 1mm might be tough to achieve - say, a FDM printed sphere. In those cases, be sure to set expectations with your customer before accepting the order. Again, the guidelines will be the point of reference whenever there’s a dispute between customer and Hub. If you both agree, then all is good.

On support removal

The majority of the customers expect to receive a finished product when ordering a print and we think that’s reasonable. Delivering a print with the support still on is considered below the minimum required level of service. Another indicator is that a large part of Hubs already delivers support removal in their service.

That being said, if a Hub and customer both agree that support can stay on the part - for faster delivery for example - then that’s their decision and 3D Hubs will not get involved.

We are aware that at this point there’s no automated system in place for calculating (and thus pricing) support. These tools are planned for Q2 / Q3 2017. Currently, we communicate to customers that possibly cost will be added for models that need a lot of support. For example, in the checkout; “Models with overhangs steeper than 45 degrees, needs support material possibly resulting in additional costs”.

Ok, hope that explains a bit. Please let me know if any questions remain.

Best,

Filemon

Enza3D
Jan '17

@Filemon

What about policing the dimensional accuracy? I really do not feel comfortable with only pictures, and what happens if I measure the parts before I send them, and so does the customer, but we have different measurements? This is really my main point of concern, so if this could be clarified, that would help quite a bit.

PepCo_Parker
Jan '17

Agreed. No offense @filemon but you’re just saying the same argument that has been countered time and time again on here. Our concerns weren’t hitting the targets, as a few of us have stashed several times, it’s enforcing them. It’s starting to feel a bit like beating a dead horse here, plenty of people have come onto this forum saying that these tolerances are easy to hit, which in my opinion they are, excluding post processing expansion or manipulation. Our concern was people manipulating the system to their advantage, or at least a fair few of us had this concern and I do feel it must be addressed.

Filemon3D Hubs Employees
Jan '17

Ok, got it @Enza3D @PepCo_Parker.

The guidelines only serve as reference for when there’s a dispute. Platform wide this is a very low number. The situation in which the Hub claims to deliver according to specs but the customer claims the part was not is expected to be even lower.

Having said that, if this does happen we’ll take a case by case approach. If your Hub has a good reputation you’ll obviously get the benefit of the doubt and in some cases the refund to customer will be on us. I’m curious to hear if you guys have any other suggestions on how you feel guidelines should be applied in situations?

Joerg_4
Jan '17

Hi all & @Filemon

I don’t see a big issue with the guidelines as it helps both sides to adjust expectations vs. possibilities.
But may be some fine tuning is inevitable:

1. Dimensional accuracy: May be it makes sense to add specific tolerances for specific materials, like:

PLA: +/- 1mm or 1%

Nylon: +/- 1.5mm or 1.5% (or whatever makes sense)
ABS: +/- 2mm or 2% (or whatever makes sense)

2. Dimensional accuracy: Contrary to popular belief it is still my opinion that it would make sense if 3D Hubs would provide a file to approve the dimensional accuracy (and may be other parameters).
All existing Hubs shall print this file to approve their print settings.

Instead of printing Marvin new Hubs will have to approve that they are able to print according to the guidelines.

Sure, there are plenty of models on Thingiverse, etc. for testing the printers accuracy, but if there were an official file all hubs will do the same test.

What do you think?

Cheers,

Joerg

Georgei
Jan '17

“All existing Hubs shall print this file to approve their print settings.
Instead of printing Marvin new Hubs will have to approve that they are able to print according to the guidelines.
Sure, there are plenty of models on Thingiverse, etc. for testing the printers accuracy, but if there were an official file all hubs will do the same test.
What do you think?”

And the question still remain: How do you check if it was printed accurate? I can say that it has been printed OK. How 3DHUBS check that it has? From the photos? I do not think so. Only if you physically you sent the part there and they measure it. I do not think they want their office filled with test prints. Lets be pragmatic and realistic.

cobnut
Jan '17

Sorry @Georgei but your comment has made me think of this episode of Doctor Who: I can just see all the staff at 3DHubs fighting their way past mounds of 30mm cubes (to within 1% accuracy, of course).
make_your_own_doctor_who_the_power_of_three_cube.jpg

CWCrawlers
Jan '17

Maybe to help quell the “uprising” support can pick top performing hubs, have them try the new rules out on a few orders and see how it goes… I feel like hub reputation is something people are forgetting plays a role here! If you consistently do garbage prints then that weighs different than if you do good work consistently. In the end I feel like we can sit and bicker but till we TRY the new rules we can worry ourselves bald over them… but till we begin to use them we can’t really say much.