3D Prints Explained
Below are some specific details concerning the 3D prints offered on the website. Some prints are fully finished and will appear both on our 3D prints page as well as in other areas of the site. Other parts are basically removed from the printer and offered without any finishing work done. This is still a fairly new process so we are figuring it out together in a way. I am confident it will make reenacting better in the long run but it will take some time and experimentation to get there.
- Print Types
- Layer Heights
- FDM Materials
- DLP Materials
- Bumps, Blobs, Zits, Strings
- Reducing Cost Over Time
FDM - This is a less detailed style of printing with parts made from thin strands of melted plastic which offers some advantages in material properties. This is the typical type of printing most people think of when they hear 3D printing. it is weakest along the layer lines. There are also surface anomalies such as slight bulging at corners or around surface details and generally a seam where a layer starts and finishes.
DLP - This is a very detailed form of printing with very small layers made from liquid resin hardened by UV light. Some prints polish up to a near perfect surface or will only have slightly noticeable layer lines. These are generally more fragile than FDM parts although this may change in time. And this doesn't mean that these parts are weak; I have been fairly surprised by the strength of parts although casting resins are still much stronger.
As these prints improve over time the version number will increase. So a new design might start with 1.0 the go to 2.0 and so on. Large changes will generally be given whole number leaps such as 1.0 to 2.0. Smaller improvements that are less noticeable will increase the version number below the decimal so an item might go from version 1.0 to 1.1 and so on. This has nothing to to with historical versions or variations its a way to track other improvements to the usability. Generally new items will have already gone through many small improvements from testing before I start offering them for sale.
Simply put, thinner layers produce better looking parts and are slightly stronger. I work with layers as thin as 0.02mm (much thinner than average printer paper) and typically do not go any larger than 0.2mm (about the thickness of 80lb stock paper).
This normally only applies to FDM prints since I print most resins solid. To save material and time, otherwise solid objects are hollowed out leaving an outer wall and an infill pattern. The walls are generally 1 to 2mm thick and the infill could be any number of patterns and the amount of infill is done as a percentage. For example 15% infill means that 85% of the inside is empty space. I generally only use 2 types of infill just to help standardize things and I have selected infills based on strength and print time savings.The lower the percentage infill, the larger the infill pattern and the larger the percentage infill the smaller and more dense the pattern becomes.You often see a shadow of the infill pattern on the outside of a print (yes, you can eliminate this shadow by printing cooler or making walls thicker but then you either weaken the layer adhesion or add significant time and material cost).
- Cubic - This is a sort of repeating hollow square shape which provides reinforcement in all directions. It produces closed cells inside the model. If you were to drill a hole into the model and pour water in, it would only fill the cube(s) that the drill bit punctured and not fill the entire model.
- Gyroid - This is a spiral wavy pattern which provides Reinforcement in all directions. It is make a sort of open cell structure, if you were to drill a hole into the model and pour liquid in, you could fill the entire empty space
All FDM materials take paint pretty well and most are considered food safe.
- PLA - Is a fairly strong and inexpensive material. It is often talked down on by most makers but actually produces very durable parts as long as there is support across the layers or if the layers adhere together properly. It is very hard and doesn't bend hardly at all before it breaks. It starts to soften around 250 degrees Fahrenheit. This softening is not much of an issue if parts are printed with a fairly thick outer wall. This is the most common material used for FDM prints. It is technically biodegradable, but it requires very specific conditions to degrade so there is basically no chance of it decaying any time in the next few centuries. Can be sanded smooth.
- PLA + - Same as above but slightly stronger.
- ABS - Not technically as strong as PLA but still it does flex before breaking which does make it durable. Can be sanded smooth
- TPU - This is a rubber like material that is flexible, somewhat hard. parts made from TPU will bend, stretch and return to shape. It is more expensive than PLA and it is very difficult to print. It generally has a very rough surface finish. This can not be sanded to smooth the surface.
- Nylon - similar to nylon parts that you might find in the hardware section at home depot.
- PC - Poly carbonate is extremely strong, particularly when it is reinforced. Similar to the material that water cooler jugs are made from.
- CF - Carbon fiber is a reinforcement fiber that is often added to the above materials. It increases the strength of the parts considerably but adds expense. Few parts actually require this much strength. This often doesn't effect the strength between layers.
No Resins are currently considered food safe although there are supposedly some coming to market soon. All take paint pretty well. These materials can be sanded and polished very nicely.
- Resin - This just refers to our standard resin which is hard and fairly strong. If you drop a part on cement it might break or chip. You would be able to crush most thin parts in you hand but it would likely hurt a lot as it produces sharp edges when it breaks. We typically only print this is black, gray, and white.
- Color Resin - This resin is softer and a bit weaker than our standard resin but it can be used to print vibrant colors. When scratched it produces a white chalky powder.
- ABS Resin - This resin is stronger than the others but is much more expensive and it still does not seem quite as strong as the FDM version of ABS. We typically only print this in gray.
More materials will be added in the future once we have had a chance to put new ones to the test. I am paying very close attention to new resins as they seem to be making a lot of progress and I hope soon that they will have an extremely strong food safe resin.
Bumps, Blobs, Zits, Strings
There is basically no such thing as a perfect print. There are always some small errors. Many prints could be made perfect if you put enough time into them or sanded and painted them but all of that would add expense as well. On resin prints this might be where the support structures have been removed or slight misalignments between layers or on FDM prints this might means seams, blobs, strings, or a shadow of the inside pattern. Generally I feel like 3D prints are not perfect, but they are at least the bare minimum to be acceptable. Some prints do turn out better than others but I do not differentiate unless a print truly turns out bad enough that I deem it to be defective, in which case I will sell it accordingly.
Reducing cost over time
It takes a long time to print things and there is a lot of waste but as long as I can continue ironing out the process and continually perfect each part we can bring costs down. Based on other online printing service quotes I can say with certainty that the parts I am selling here are already undercutting most 3D printing services by a lot. I want to make these things usable and not just decorative. As long as parts continue to sell I will keep reinvesting in additional printers which will help bring the prices down even further. So if a part seem a little too expensive now, it might still be worth buying as an investment in future development.