Selecting Correct Process and Material for Outsourcing 3D Printing

Among different material we can find while trying to outsource 3D printing from a shop like PCBWay, selecting the right process and material for our project is important.

I have ordered some of the material for different project of mine for 2 years now, so I wanted to document these knowledge and the outcome. I will update this post in future if I have ordered parts with new material or process.

I am using PCBWay manufacture for my parts. I collected this parts over the course and I will only mention the materials that I ordered and used for my current and upcoming projects.

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Stereolithography / SLS - It's a 2.5D process, it uses photopolymer resin and builds each layer of a part by exposed light and it solidifies the layer.

Selective Laser Sintering / SLA - It's simlar to the SLS and uses laser and power.

Fused Deposition Modeling - This is also 2.5D process, It laysout each layer by metling plastic in a path that defined by the section of the layer.

After ordering parts in different process I realized if you -

1. Complex parts and can't use support -> SLS
2. Need Detailed or Precision parts than -> SLA
3. Parts need withstand high heat and shock -> SLS
4. Need to print something without worrying about support -> SLS
5. Need to do in cheap -> FDM
6. Need to print Engineering exotic material -> FDM

You learn more from excellent article from PCBWay - Overview: How 3D Printing works?

Nylon PA12 does have better impact resistant as a result better high strength. This are powders and melted to make shape as a result the surface is course like pavement. But this can be avoided by painting on top surface. One down side is printed parts with this can be bent easily, to avoid that design the parts with features that is perpendicular to the bent direction.

Huge advantage of this process is printing without support. This gives the possibility to design and print complex support without worrying support might ruin the part as well as it's surface. Small downside that I noticed parts are not that precise but the discrepancy is negligible, so chose SLA process instead for precision.

If this is printed with FDM or SLS, it requires support, which will ruine the thin line which holds the keycaps. With SLS I don't have to worry about support and get better parts.

This is called MJF(Muilti Jet Fusion) smilar to SLS but uses a agent like glue to bond the powder togather. But this provides same benifities as the normal SLS but with better surface.

Because the powder is bonded using an agent, so this feels the gaps in between the powder hance less pores. PCBWay will paint on top of the surface, so that will further reduce the graininess of the surface.

On the other hand, the same part that is printed using MJF is twice as expensive than normal SLS, so it is suggested to use normal SLS as this will give same benefits with less price.

One major issue with SLS is because of its powder-based it doesn't have good mechanical properties, as a result it bends easily. With the glass fiver with nylon gives the part more rigidity, so if you want to use a part mechanically this is better choice for that. The parts have course surface but this can be mitigated with pros-processing.

This material also gives printed part more heat resistance capability, so if your part is used outside and in the harsh environment, use this material. This also cost more than the normal SLS nylon material, close to twice the price, but that's because the post-processing takes more effort.

I used this for my mutatnC project. This part is the back of the device, also in contact with the battery which will get hot when they are getting charged. So this material is perfect for that application.

Smooth surface is the main highlight for this matarial. This would be a good choice for wearable as they will touch skin and avoid skin irritation.

I used it for my mutantW watch project. It smoth to touch so the printed watch didn't got rash in the skin if i wear it long time. The dimensional accuracy was really good as the watch band fits perfectly with the printed part which was off the shelf cheap watch band.

It's main properties is High precision. It's also pretty ridged. So if you want a small part with precision, ridged then use this material.

Wanted to see if I can have a pick and place nozzle with out buying them from the original manufacturer. It came great but the nozzle hole was too small around 0.2mm so didn't go printed. I will later try to increase the hole size and order the print again.

mutantW watch top LCD cover use this material with SLA process. This material is transprent and was a geart alternative for glass that I used before. YOu do have worry about scratching the surface and lossing the transparency, but good care and adding a off the shelf screen protector will solve it if it fits the size.

I used it in my mutantC v5 keycaps. This is also SLA process and i selected is because it provides high details. My keycap has a logo embossed on it and the part 5x7mm and the logo has some details that are less than 0.5mm and this print came out great.

According to PCBWay this material has High strength, toughness and heat resistant. So I selected it to print a linear rod metal bearing alternative. The part is tough but wasn't dimentional accurate, the whole supposed to be 8mm but it's smaller than that and the part didn't went through the 8mm rod. I would recomend this if you have a part that will be on hit often and need to have detaile writtings on it.

This normal SLA print material, I wanted to try this out because it was cheaper than all other metarial in SLA process with good precision. Also it has good properties which makes it more easy to spray paint it but i han't tried it as I am happy with UTR Imagine Black material.

I need some parts for my Prusa printer's hot end. Those parts needed to be heat resistant as they will be close to the printer's hot-end. This print produces gas that is not good for your health and closed area which my Prusa MK3. the parts were good and using them for a month now and no issues at all. It's a good choice to outsource print of this exotic materiel from print house like PCBWay without worrying.

Don't order parts while the part is not finalized this will save a lot of money. First finish the design and print it in your personal FDM printer even you need SLA or SLS capabilities. Finish the part design by doing trial and error than place an order as ordering and getting the part in your hand takes time.

Want to use something that is wearable or will contact your skin select SLA as part printed with this process will have smooth edges which will be conformable in your skin and will have less harsh surfaces.