You might not own a 3D printer, but you may want or need something printed. There are a number of commercial printing services that allow you to upload a model and have them print it in a number of different materials. Despite either having or sourcing massive printer farms these services are often the most expensive option for your one-off print.
Print farms are designed to print a large number of models usually at a single quality. Anything custom is going to cost more like changing layer height, infill, material, or print speed.
You might want to consider finding a hobby or semi-professional printer instead of a print farm. Before you do that you should know the limitations of FDM/FFF printers. These are printers that lay each plastic layer one at a time building up from the bed of the printer.
Some models are simply not printable
This is especially true for 3D models that were not designed for 3D printing to begin with. Some models can visually look fine but have thousands of errors for a 3D printer. The best models are solid or water tight (but does not have to hold water). This means there are no gaps between inner and outer walls of the model. It also means there are no 3D elements of the model that either are separated by an air gap, or improperly merged so the model contains crossed over geometry.
Extremely small models could lose detail or simply fail to print. Very large models may not fit on the printer without cutting it into multiple pieces.
Very complex models may result in repeatedly failed prints or just be too complex for software to figure out how to print it in layers.
You cannot print clear on FDM/FFF
There are clear or semi translucent filaments available, but a printer will never be able to print glass clear. The nature of melting plastic layers together reduces transparency. There are some post print techniques that can get more transparency but it will never be clear.
Some materials cannot be used outside
PLA will eventually breakdown or crack in direct sunlight. This is the most common, easiest to print, and one of the cheapest print materials so a lot of people use it as their go-to material. Other plastics may hold up better but almost all of them will fade, change color, or completely lose their color.
Printed parts should never be used when safety is needed
This means you should never use a 3D printed plastic part where someone’s health and safety is reliant on that part not failing. Some obvious examples would be rock climbing gear or functional car parts.
This extends to food safety as well. Because printers put each layer down prints have many microscopic holes that bacteria could get into. It is almost impossible to clean these parts fully. You might, however, be able to apply a post print coating that could make printed parts food safe.
Some materials and colors show layer lines more than others
Typically white or shiny colors will show printed layer lines giving you the impression that the print is worse than the same model printed in another color. Semi translucent materials hide pint layers well, and some colors just naturally hide these lines better. Some of this can be mitigated with smaller print layers (significantly adding more time to the print), but the reality is, even on the absolute best print, you will see print lines if you look close enough. Post sanding and finish work can all but eliminate these layer lines.
Most hobby printers do not have multi-color capability
And even if they do expect these prints to cost significantly more due to increased print time, more prone to failure, and increased material for color changes. Most 3D models you find online will not be multi-color ready.
- Find a local printer. This means faster turn around and minimal or no shipping costs. It also allows you to establish a relationship with someone local if you find yourself needing another print in the future.
- Ask for well lit high resolution pictures of the printer’s other prints. If possible, be specific and ask for images of the same material, color, and print settings. This gives you a better idea of what to expect.
- Some prints (like figurines) will require a huge amount of support material. Detailed models will need significant clean up time which can add to the cost.
- You should expect your hobby printer to give you an accurate quote. All print software can estimate time and material use.
- Be understanding of delays. 3D printing is not at the paper printer point. They are more likely to run into problems than most other appliances. Failed prints can be the printer owner’s fault, but a lot of the time it can also be poorly manufactured materials, errors from the software creating the print, and other issues outside of a printer’s control.
- Do not accept clearly awful prints. Use the example pictures, suggested above, as a benchmark.
- If you want a model modified expect to pay a lot more. 3D modeling is not easy and takes a lot of time to learn. Not all hobby printers can make changes, but those that can will charge a high rate by the hour (expect between $40 and $150 an hour).
- If you want a model designed from the ground up to your specifications expect not only to pay for that modeling time noted above, but also expect to go through at least 3 iterations before you get a final model. Even more iterations may be needed for a functional part. You should expect to pay for every iteration. No one will be able to design and print the prefect model the first time.
- Consider offering a barter for 3D prints. Some people are good at modeling and printing but might lack the painting and finishing skills. This is a great opportunity to help a fellow maker and limit both your costs.