Knowing the differences between top-down and bottom-up resin 3D printers can be advantageous if you are in the market for a resin 3D printer. This blog will help you learn what to look for, what to expect, their advantages and disadvantages. Let's start with the DIFFERENCES BETWEEN BOTTOM-UP RESIN 3D PRINTERS AND TOP-DOWN RESIN 3D PRINTERS.
Two key differences distinguish bottom-up resin 3D printers from top-down resin 3D printers:
1. How the finished print is positioned on the build plate of the machine
As the graphic above shows, the finished print of a bottom-up resin 3D usually hangs
upside down on the build plate.
The finished print of a top-down resin 3D printer sits on top of the build plate and the light source is generally situated at the top of the machine.
2. Where the light source of the resin 3D printer is situated
As the graphic shows, the light source of a bottom-up resin 3D printer is generally located at the bottom of the machine.
The light source of a top-down resin 3D printer is usually located at the top of the machine.
ADVANTAGES OF BOTTOM-UP RESIN 3D PRINTERS AND PRINTING
1. The machines are usually small in size and compact
A small and compact resin 3D printer is ideal if you have limited workspace or would appreciate being able to move your printer around comfortably.
2. The vat is usually smaller and requires less resin to fill
Needing less resin to fill the vat makes the startup cost of getting a bottom-up resin 3D printer less than a top-down resin 3D printer, which requires more resin to fill.
3. There's a wider variety of affordable bottom-up resin 3D printers in the market
If you're on a tight budget, you can easily pick up a decent bottom-up resin 3D printer for USD 500. As with anything however, you get what you pay for and some of the very cheap resin 3D printers can be high maintenance and unreliable. Examples of Bottom-up Resin 3D Printers with these benefits include: Any resin 3D printer from Formlabs, Anycubic, Peopoly DISADVANTAGES OF BOTTOM-UP RESIN 3D PRINTERS AND PRINTING
1. The build-volume of the compact bottom-up printers can be limiting
If you're looking to print sizeable objects, a bottom-up resin 3D printer might not be the right solution.
2. The printer can run out of resin while printing
As the small vats don't hold much resin, you can sometimes run out of resin during the printing process. It's usually not a problem if you are around the printer to fill it up with resin again as needed but not great if you like printing through the night.
3. Prints can easily detach from the build plate while printing
Because the print is built upside down, it has to combat gravity to stay attached to the build plate. For this reason, some prints need more supports than they would if they are printed on a top-down resin 3D printer. Having more supports on a print requires more resin and more time to remove the supports or sand off the print in the finishing stage. Printing larger objects is also more challenging as their weight can cause them to detach from the build plate, fall onto and scratch the film or silicone layer. It doesn't help that parts printed on a bottom-up printer are exposed to stresses while being printed. During the printing process, the part needs to detach or peel off of the bottom surface of the vat whenever a new layer is printed. The suction force that is applied to the print to detach it can cause deformations in the print or completely detach it from the build plate in which case it can break or scratch the film or silicone layer.
4. Bottom-up machines have more consumables, which makes them higher maintenance machines.
Every bottom-up machine design includes a film or silicone layer that needs to be replaced regularly. It's a consumable that affects the quality of your print as it deteriorates over time.
Prepare to spend more time and money maintaining your resin 3D printer if you decide to buy a bottom-up resin 3D printer.
As mentioned before, the fact that a bottom-up resin 3D printer requires less resin to fill the vat means it has a lower upfront cost than a top -down 3D printer, but studies show the long term costs of a bottom up 3D printer can be significantly more than that of a top-down resin 3D print. Click here for more information on how to calculate the true cost of a resin 3D printer.
5. It takes longer to prepare the printer before printing or between prints.
When printing on a bottom-up resin 3D printer, you have to clean the vat regularly to remove hardened resin bits that sink to the bottom of the vat during printing.
Because the light source sits at the bottom of the machine, these hardened resin bits can unfortunately build up and block the light from shining through the PDMS or silicone layer - thereby directly affecting the quality of your print. The print will be weaker in the areas where the light couldn't get through. 6. More time spent on troubleshooting There's a lot more that can go wrong during the bottom-up resin 3D printing process that does not apply to top-down resin 3D printing - the print might detach from the build plate due to gravity forces, fall and break. The larger the print, the more likely this could happen unless you print on a top-down resin 3D printer where the print can't fall off. The film or silicone layer (which is non-existent in a top-down resin 3D printer) might become cloudy, tear or get scratched easily. When it does, the print quality gets affected. You'll then need to spend time and money to replace the film or silicone layer. You may not have cleaned your vat properly before you started printing in which case some hardened, free-flowing resin bits might sink to the bottom and build up until they block some of the light from reaching the resin to cure your prints. That could cause weaknesses in your print. As the light source of a top-down resin 3D printer sits at the top, there's no chance of that happening when top-down resin 3D printing.
DISADVANTAGES OF TOP-DOWN RESIN 3D PRINTERS AND PRINTING 1. Most machines are larger in size
This can make them difficult to move around or less suitable for you if your workspace is small. Gizmo 3D Printers have just launched a brand new range of desktop size top-down DLP 3D printers however so this is changing!
2. The vat is usually larger and requires more resin to fill
This can make the startup cost of getting a top-down resin 3D printer more than a bottom-up resin 3D printer as you have to take the cost of the resin you need into consideration too when buying a resin 3D printer. Check if the supplier has different vat sizes in stock as you only have to fill a vat that is the size of the object you want to print. You don't have to pay to fill a 1 meter tall vat with resin only to print a 5cm tall object for example.
3. There aren't many affordable top-down resin 3D printers in the market
If you're on a tight budget, there aren't many options available at the moment for affordable top-down resin 3D printers. Prices start from USD 3795.
How much are the following, many ADVANTAGES OF TOP-DOWN RESIN 3D PRINTERS AND PRINTING worth to you?
1. The printers are available in larger sizes, allowing you to enjoy the freedom of printing bigger if you need to
If you're looking to print bigger objects, top-down resin 3D printers might be the right solution for you.
2. The printer can't run out of resin while printing
As the vats hold a lot of resin, you won't have a situation where you run out of resin which you could if you use a bottom-up resin 3D printer. You can leave the printer to print over night.
3. Prints are not working against gravity to stay attached to the build plate
When adding supports to a 3D model you want to print on a top-down resin 3D printer, you don't have to add more supports to keep the print from falling off of the build plate as you do with bottom-up prints - because the print is built sitting upright on top of the build plate. Having less supports on a print means less resin used and time is required to remove supports or sand prints in the finishing stage. Larger objects are also easier to print on a top-down resin 3D Printer than it is on a bottom up as there is no chance of the print detaching from the build plate or falling and breaking for example. There's also no peeling step in the printing process. As mentioned before, the suction forces required to detach a print from the bottom surface of the vat every time a new layer is printed on a bottom-up machine can cause the print to fall off of the build plate or deform.
4. Top-down machines have less consumables which makes them lower maintenance machines. Low maintenance is a major factor when it comes to saving time and money during a printing production.
Unlike bottom-up machines, top-down resin 3D printers have no film or silicone layer that is a consumable which affects the quality of your print as it deteriorates over time.
If you decide to buy a top-down resin 3D printer, you can look forward to saving time and money maintaining your resin 3D printer. There's no doubt you will be spending less time and money on consumables if choosing to print on a top-down resin 3D printer.
5. It's faster to remove a print and start printing again - no further preparation needed.
When printing on a top-down resin 3D printer, you don't have to clean the vat as you have to do regularly with a bottom-up machine. You can start printing right away! This is because the light source of a top-down resin 3D printer is located at the top where it can't be blocked by hardened resin bits that sink to the bottom of the vat.
6. Less time spent on trouble-shooting
There's a lot less that can go wrong during the top-down resin 3D printing process that could go wrong on a bottom-up 3D printer. There's no chance of the print falling off of the build plate while it's being built, no deteriorating film or silicone layer to replace at any time and you don't have to clean the vat after every print as any hardened resin bits won't affect the printing at all.
Examples of Top-down Resin 3D Printers with these benefits include:
Any resin 3D printer from Gizmo 3D Printers, Milkshake
Which printer sounds like the best option for you and why? Let me know in the comments below :)
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