This blog covers key differences between filament printers (FDM 3D printers) and the resin Gizmo 3D Printers (SLA DLP 3D printers) that I’ve discovered working with both.
The 3D model I’m using to demonstrate these differences is a Christmas Wire Ball I found on Thingiverse that was designed by creator luckyx182. I selected this object as It has large cavities and overhangs - which one always needs to consider when setting up a print.
Christmas Wire Ball by luckyx182 Published on November 10, 2018. www.thingiverse.com/thing:3207977
FILAMENT 3D PRINTING How does filament 3D printing work?
Filament 3D printer in action
FDM 3D printers feed a thread of plastic from a spool to a print head. The plastic heats inside the print head which then deposits melted plastic as it draws and builds the layers of a 3D printed object section by section.
FDM 3D printer print head in action.
Where there are overhangs and cavities, the model may need to be rotated to allow for easier printing or rely on scaffolding to support the model while it prints. Scaffolding often requires almost as much material as the actual object and needs to be cleaned off once the print is complete.
Most of what you see 3D printed here is scaffolding.
As you can see, this object required a lot of scaffolding to support the structure we are after. I first tried to print the ball whole, but halfway through it became clear that It would be impossible to clean the scaffolding out of the center of the object without breaking it and so I stopped the print. It was much more sensible to print the ball in two halves and glue them together afterward. Although cleaning up the scaffolding will still be a delicate job.
I split the ball into two halves to print instead.
The two halves printing on an FDM 3D printer.
RESIN 3D PRINTING
How does resin 3D printing work?
Top down SLA DLP 3D printer Gizmo 3D shining UV light from a projector onto a bath of resin.
Most of the resin printers I have looked into, draw the print up from the vat of resin as each layer prints. Meaning gravity can pull the print off the build plate and limit the size you can print. Gizmo 3D Printers are top down, which means that as each layer prints, the model moves down into the resin to allow the next layer to print. Once complete, the whole model is raised out of the resin to reveal the completed print.
When done printing on a Gizmo 3D printer, the model lifts out of the resin.
As whole layers are solidified at a time, it is much faster than an FDM printer which lays sections of plastic at a time to complete a layer before moving onto the next. It also means that there is no time difference between printing one object or filling the build plate with multiple copies. I was able to print one Christmas ball in one hour and 12 minutes - the same time as I was able to print 6. For comparison, the FDM printer took two and a half hours to print a single Christmas ball.
I really wanted to print the ball in one piece so I spent some time making sure the auto-generated supports would do the job but added only a few extra supports before I was confident it would print. I set up the supports to hold up the overhangs and stick the model to the build plate. The print came out much better than I had expected, and I found I could cut the total supports down to just five upon my next attempt.
Only a few supports were needed to print these objects on a Gizmo 3D printer.
You can see the supports don’t take up much space but still provide enough support to the model. Depending on the size of the model, the supports can be so fine that upon removing the print from the resin, they brake away on their own. The Gizmo 3D printers also use comparatively less material on support structures than FDM 3D printers, which means you throw away less material per print. On larger prints, I have found that thicker supports are required. This is so that the model doesn’t break away from its supports when it’s being raised out of the resin or break under its own weight.
A resin print requires curing after the print. You can see this print is still very soft, but the supports come away quickly, and I’m not too worried about damaging it in the cleanup.
When I use the cheaper resins, I wash my prints with a special cleaning liquid being developed by Gizmo 3D Printers to take away the excess resin that hasn’t run off the print but when I use the sturdier resins alcohol cleans them up nicely.
Washing the prints with a special cleaning liquid by Gizmo 3D Printers
Without a wash, they cure tacky to the touch. I have a UV light box for curing, but you can just use the sun.
Only a few supports were needed to print these objects on a Gizmo 3D printer.
One hour in the box and it’s ready to hang on the Christmas tree.
3D printer resin or filament summary:
If I printed this object on an FDM printer again, I would add more scaffolding to avoid it breaking off the build plate. More scaffolding would also help avoid any deformities forming in some of the wires, but I would still need to glue the two halves together at the end and wait the extra time for it to print. FDM is great for simple objects with few cavities or overhangs, and when detail isn’t a concern. The Gizmo 3d printer was able to print this complex object in one piece with a smooth finish much faster than FDM is currently capable. The cleanup and curing carry much less risk of breaking the part and even considering curing I still saved time (68 minutes) using this printer.
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About the author: Ryan Madden is a 3D printing enthusiast based in Brisbane, Australia. He has been printing on various FDM 3D printers for years as a hobby. He started printing on resin 3D printers for the first time in February 2019 when he was hired as 3D printing technician at Gizmo 3D Printers Pty Ltd. Have any questions about the Gizmo 3D Printers? Feel free to book a call or email info@gizmo3Dprinters.com.au