Quality Assurance Agreement with SD3D

Before completing your order with SD3D, please make sure you agree with the following quality assurances regarding FDM 3D Printing.

Quality Settings

Quality at SD3D refers to the height of each layer that is laid down. The smaller the layer, the finer the quality, and the longer the print will take to complete.

Slide Left & Right

Draft Resolution (0.4mm layer heights, 0.6mm Nozzle)

We generally recommend to individuals printing large parts looking to save some money to print in draft resolution.  For parts that do not have a lot of detail in the Z-direction will not require a higher resolution.

If you were printing a block letter where only the top surface matters to you, then there will be zero difference in quality from Fine to Draft, and you can save some money.

While that is true, smaller parts that have z-direction detail may require a standard or fine quality print.  We do not gurantee any detail will print that is smaller than this 0.4mm tolerance.  These prints are also done on a 0.6mm diameter nozzle, meaning the tolerance in the X-Y direction is 0.3mm.

Standard Resolution (0.25mm layer heights, 0.6mm Nozzle)

Without knowing every detail about your project, we generally say that our standard resolution of 0.25mm layer heights should work to your liking.  These prints have 60% more layers than our draft resolution, so you can see how this will take longer to print, which results in a higher cost.

These features are very noticeable on big curves.  As you can tell from the photo to the right – the top looks a lot cleaner the more layers there are.  This is because the angle the part is required to jump on a curve each layer is reduced the smaller the layer heights.

We also reserve the ability to print your part on a finer 0.4mm diameter nozzle if required.

Fine Resolution (0.1mm Layer Heights, 0.4mm Nozzle)

Our fine resolution prints are at 0.1mm layer heights, and we use a smaller 0.4mm diameter nozzle.  This smaller nozzle also allows for a bit tighter 0.2mm tolerance in the z-direction.

We have to stress that fine resolution is only going to be noticeably better quality in the Z-direction (and minorly in the X/Y), but will have the same issues with overhangs and support settings as a draft resolution print (as discussed below).  This scarring will not be reduced because of the increased quality.

Continuing from standard resolution – you can see that this top is even cleaner because the angles have more layers.

Ultra HD Resolution (0.08mm Layer Heights, 0.25mm Nozzle)

Finally, specific projects may require our Ultra HD Resolution.  These prints take much longer to print, but are very tight on tolerances.  The nozzle diameter on these prints is 0.25mm, the smallest easily available nozzle on the market for FDM printing.

The layer heights on these prints are 80 microns, or 0.08mm.  This means that the tolerances are 0.08mm in the Z direction, and 0.125mm in the XY.  This allows for details such as fine lettering to show that would not be clear on any other quality option.

These prints take much longer to get started (due to how thin the initial layer is) and are much more sensitive to clogging.  Because of this we have a much larger startup fee involved.

Infill Properties

Infill refers to the amount of material that is printed inside of the part. 0% would print a hollow part and 100% would result in a print that is solid with material.

As you can tell from the photo above, the higher the infill the more densely filled the print is with material.  Anything below 20% is considered to be low infill by our standards, with 25% seeming to be perfect for most jobs.

A 0% infill print will likely lead to a very weak part with a very ugly top surface quality.  For large flat surfaces, we recommend a minimum of 20% infill to achieve a high quality top surface

People will often request parts in 100% infill when it is not needed.  100% vs 50% will result in a much more expensive part without much strength added. For most applications there is no need to go above 60%.

Overhangs

Overhangs refer to angles on parts that will require support material. The less overhangs, the better the surface quality of your print.

overhangs 3d printing

Overhang angles are extremely important to take into consideration when designing a part to be 3D printed.  Without understanding how support structures work, it is easy to think that any structure can be easily printed with a clean surface quality.

As mentioned above, a fine quality print will not result in any better surface quality over a draft quality print when in reference to the scarring resulting in support for extreme overhangs.

This scarring is just about impossible to get rid of 100%, even on our specialty printer.  This scarring is worse on some unique materials, especially on the flexible options.  That is why complex flexible models are very difficult to print, and you should be warned of such before moving forward printing with a unique material.

If you have a part with angles roughly 45° or more, then you will require support.  This support will leave scarring such as you can see from the image on the right.  The more extreme the angle and the closer to the build plate that angle is, the more difficult this support material gets to remove cleanly.

A sphere is one of the most difficult things to print perfectly because the part sits on a single point and requires support material for the entire bottom half.

Tolerances

There is a bit of clearance that should be accounted for if you want parts to snap into eachother

3D printers generally have a positive tolerance due to the nature of the additive manufacturing process. This means that the machine will err on the side of depositing slightly more material than is represented in your design. Therefore when designing parts to snap or fit together, a clearance between the mating parts is required.  This clearance is going to be the tolerance of the X/Y direction, so at least a gap of 0.3mm will be needed. If designed without this clearance, the parts will only mate under a forced compression fit or may be impossible to mate without sanding.

This clearance can be tighter if being printed in Fine or Ultra HD Resolution, but we do not recommend ever having a clearance lower than 0.15mm for parts mating together.

This is very crucial to understand before moving forward with your print.  The SD3D staff will not be able to tell if you added this clearance for your parts until after the print is completed.

Thin Walls and Build Limitations

Very thin walls or parts that were not designed with 3D printing in mind may not be printable

When designing a part, a wall must at least be as thick as the nozzle being used in order to be recognized by the printer.  For most prints here at SD3D, that means any part with walls smaller than 0.6mm will not be printable.

For structural integrity we recommend parts be at least 1.2mm thick, or two shell walls.  Lower than this and the part may be easily broken.

Sometimes parts are just not designed for 3D printing.  As mentioned above about the requirement for support on overhangs, extreme angles require removable support material.

If you design your part as the model pictured to the right, support will be printed without the ability to remove it.  This hollow cube has an entrance at the top.  That hole will be the only exit to remove the support material (light blue on far right), which is not large enough.  This part would not be printable.

Further Printing Concerns?

If you have concerns about the quality of your future print, don't hesitate to ask!

Before submitting your payment for printing, please make sure you are aware of and OK with the above assurances.  If you have further questions or concerns, we can be reached from 10:30 – 6:00 PST Monday – Friday at (800)530-9140, or via email at Info@SD3D.com

You can also submit a contact form via our contact page:

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