Hello fellow Hubs,

I need your expertise.

I’m working on a comparison sheet for designers for several SLA and Multi-jetting materials (machines). I’m especially interested in how they differ in terms of specs and what that means for their application. From that I then try to understand which materials are actually competing with each other and how they should be grouped.

I’ve found this to be harder then it sounds as the internet is flooded with promotional material and very few actual comparison data.

For this example, let’s assume we take Desktop SLA (say Formlabs Standard Resin, let’s go for white), industrial SLA (say 3D Systems Accura Xtreme White), Multi-jetting (3D Systems Visijet RW), and Polyjet (Stratasys Vero White).

I’d love to know how a designer would go about differentiating these solutions. Is this even the right grouping or is it already off?

One (highly simplified) way of looking at it is as this:

screen_shot_2017-01-11_at_18.30.04.png

Not sure if this data is very accurate but I’m mainly interested if this is actually a comparison one can make. Would love to get some expert feedback / input on this.

Thanks!

Filemon

If you are trying to compare, you might want to consider other categories that people may judge by:

post processing—for example, Formlabs requires removable supports, others may use soluble supports. More labor involved in removable supports.

cosmetic results–removable supports leave tiny marks that need to be removed for best appearance, may not be issue with others.

build size- machines have different build envelopes that need to be considered.

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Hi Filemon, you should specify that you are specifcally refering to the Form2 since the Form1 and Form1+ are not for precision printing at all…more for “fun”. Further, I would not compare the Form 2 with industrial SLA. All the professional engineering customers I have printed for are not satisfied with the Form 2 materials and accuracy. Specially if you want to perform a final dimensional check before ordering expensive molds. The dimensional accuracy varies based on geometry, orientation and number of support structure. Its very inconsistent. There are also several versions of each type of Form2 resins which perform very differently. I have been using the FormLabs printers for over 2.5 years. Thank you, Ara

Can you be more specific ?

What dimensionally accuracy where expecting your “professional engineering customers” ?
What resins / layer thickness did you use ?

If you print with Formlabs Surgical Guide Resin, Grey v3 or High Temp you have parts with ± 50µm dimensional accuracy, measured by 3 different scanners (3Shape, Solutionix and another I don’t remember).


Also, customers are able to improve the dimensional accuracy by changing the X/Y Scale on the printer directly.

I would group resins by applications. If you want to print product mockups, high temperature might not be needed but you want the best cost per part, enough, a good strength and elongation ratio (stress/strain) or a good tensile modulus for robust prototypes and of course the surface finish possible so it looks like the end products…

Accuracy doesn’t mean a lot. Could be layer thickness, the dimensional accuracy, the size of the pixel or the average size of the laser beam…
So I suggest the following

-Minimum feature size (not XY resolution which is dumb) based on a measurement of the 1951 USAF resolution test chart

-Print the same 3d model at the same layer thickness and scan it with the same scanner (solutionix or equivalent) and compare it with the original

-Measure surface quality (surface roughness) with a Profilometer of this model.


- give the parts to a random person in the street and ask it which part he prefers (most scientifical test yes)

2 Likes

Ok, good points. Thanks

Thx @cyprien

The object properties are so intrinsically linked to the machine as well as the starting material. I think it would be easier if you instead tried to map the object properties you can achieve with each material/machine combination, for example tensile strength, toughness, hardness, elongation to break etc. This all depend on geometry and build orientation, but you can give an average/maximum/minimum as you choose. Previous posters have already pointed out there is ambiguity in the term “accuracy”. You might also want to include some non-numerical categories, such as what post-processing is necessary.