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What’s Considered a Good File Size for 3D Printing?

There's a lot of different information online about what makes a reasonable file size. However, there are ways you can lower the size of your file to make the machine run smoothly.

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Large file sizes can cause your computer and 3D printer to slow down, resulting in lower-quality prints. There’s a lot of different information online about what makes a reasonable file size. However, there are ways you can lower the size of your file to make the machine run smoothly. 

Anything under 50MB is generally considered a good file size for 3D printing. Smaller files are easier to upload and download, which is best when using a 3D printing service. Most 3D printers work best with files smaller than 50MB, although any size less than 20MB speeds up the process. 

Your file size does matter when you send it off for printing or upload it to the internet. The good thing is large files usually contain more detail than what a printer can replicate, so you won’t lose anything by shrinking the file. Read on to learn everything you need to know about the ideal file size for 3D printing, how to reduce the size, and what happens when you can’t. 

How Big Your 3D File Size Should Be

Many people new to 3D printing believe that only larger files get you a better print. However, that’s not true. You can still achieve a high-quality print with a smaller file size. Plus, smaller prints don’t need as much detail to be successful. 

As previously mentioned, a good file size for 3D printing would be less than 50MB. Larger files can contain too much detail for the printer to replicate. You don’t need it there to get a great looking object. Your goal should be to have a small file with enough information to get a high-quality print. 

Still, everyone’s printer is a bit different. A newer, more expensive printer might handle a larger file than an old printer. You may want to check your printer’s user manual if you’re not sure what yours is capable of. 

Many printing places also require different file sizes and have their own limits in place. For example, an online 3D printing service may require a file less than 100MB, while a local place requires a file less than 50MB. Since it can vary, always check the requirements before sending out your files. 

How To Reduce the File Size

You can reduce the file size from your 3D modeling program. STL and OBJ, two common file types for 3D printing, can be extremely dense. When booting up your software, you might receive a prompt for a tolerance. Choosing the proper tolerance will help keep the file small. 

Tolerance in 3D printing is how accurate the print turns out compared to your 3D model. Setting it too low will force the printer to make an exact print, which requires a lot of file space. 

Printers can only handle a tolerance of 0.01 millimeters (0.0004 in) or higher. Going smaller than that does nothing with most printers since they can’t recreate that level of detail. However, printing too high above that can make your polygons visible in your print. You can alter the settings or sand your print if that happens. 

Additionally, you can lower the number of polygons (triangular surfaces) on your 3D model. Having more than one million isn’t necessary for a quality print. Plus, having more than that can greatly slow down the printing process and uploads. Lowering it a bit won’t impact the final results either. 

Overall, you’ll want to check the settings on your 3D print to determine where you can reduce the file size. You’ll need to meet all of these conditions to lower your file size significantly: 

  • The file is at 50MB or lower. 
  • The tolerance level is at 0.01 mm (0.0004 in) or slightly higher. 
  • The 3D model has less than one million polygons. 

What To Do When You Can’t Reduce the 3D File Size

moving computer files

There are 3D modeling programs that won’t let you adjust the 3D file size. It might not let you change the tolerance or reduce the number of polygons already in the model. In those cases, you’ll want to export the file to another piece of software that has those options. 

While it’s inconvenient, doing so will help your print turn out without having such a large file size. In many programs, you can find these options in the “Edit” menu, usually located around the top left of the screen. 

You can also reduce the model’s size in the program before exporting it. You want the 3D model to be the same size as your final print. This method works when you design the model large but need the print to be significantly smaller in size. Shrinking it should also lower the exported file’s size. 

What Happens When the File Is Too Large

When the file becomes too large, you’ll run into several problems. The heavy files are harder for computers and 3D printers to manage. They might not even be able to print them, or parts turn out wrong. 

Plus, you’ll struggle to share your 3D models with people online. Not sending a file can be a massive problem if you’re trying to share the model with a coworker! You’ll want to make sure you always lower the file size before trying to send it. 

When reducing the resolution, make sure you don’t drop it too much. Having a low-resolution model means you’ll get a different set of problems. The print won’t turn out smooth, but you can easily sand and shape it once it’s out of the printer. 

Overall, finding a reasonable file size will give you the best results without overloading your technology. 

Final Thoughts

Files smaller than 50MB tend to print the smoothest. You also won’t have any issues sending it to others online or having a professional print it for you. Some places recommend having files smaller than 20MB, but that’s not as common. 

Having less than one million polygons on the design also helps drastically reduce the amount of data the file takes up. You won’t need that many for a quality print! Plus, you can sand down the print and make it smoother after it comes off the bed.

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.