With the close marriage between SU and 3D printing, I thought it could be helpful to share with you the changes in the newest Elegoo machine; The Saturn 4 Ultra. I’m in the process of writing a book on 3D printing and design specifcally as it relates to model building, and I already have to update chapter 2.
Up until this model, all desktop resin printers worked the same way. The LCD screen (of DLP projector) would illuminate the bottom of the liquid resin in the vat through the clear teflon film on the vat bottom. The build plate would be suspended above the film one layer thickness. The pixel pattern would expose that one layer and then the plate would rise about 5mm. This rise accomplished two things: it separated the forming part from the film–where it would be held by vacuum–and provide a space for fresh resin to backfill into the space to form the next layer. Regardless of the exposure time of each layer, this separation/rise/lower motion of the build plate (Z-axis) took time and it was a constant.
Elegoo has done some lateral thinking around this. Instead of lifting the build plate via the lead screw the 5 mm, the vat itself just tips. It has its own stepper motor and bearing system. This motion is much faster than driving the lead screw. It also does something else. Instead of pulling straight up, which would like taking off a bandaid straight up, it peels the layers off the film. This greatly reduces the stresses that breaks support or pulls the forming part off the build plate.
As a result, at the same exposure time, for the exact same part, the Saturn 4 Ultra completes a job 40% faster than my Mars 3, which itself was four times faster than my 2019 Mars Classic. A job that would take 7 hours/20 minutes in my 3, took 4 hours/16 minutes in the SAT4U.
Another innovation, which at first I thought was a gimick, is the inclusion of an AI video camera that watches the print forming. I can access this camera remotely and tell very quickly if the job is forming sucesscully or failing. I don’t have to run down the shop to make this determination. These just one caveat. The job has to be at least 100mm high. That’s because the build plate must rise above the edge of the vat for the camera to see anything at all.
The camera can make time-lapse movies which are quite interesting to watch. It’s magic seeing an object forming out of a liquid. What’s interesting is while you can easily see the vat oscillating, you’re unable to see any movement of the plate. It’s only rising 50microns (my current layer thickness setting) and is therefore imperceptible. It’s basically a couple thousandths of and inch, less than the thickness of the average hair.
(https://youtu.be/S940qPHUHVs)
The kit comes with a vacuum form drip shield. This is a nice add on that should have been available for older models. You insert into the vat’s edge and it catches the inevitable drips that eventually foul the face of the machine. Today was a good test. A large blob of resin came off the plate when I was removing it and hit the shield, not the machine.
I made a cardboard cover to put over the vat when I’m removing or replacing the build plate. I’ve dropped them before and damage the film and wrecked an LCD screen in the process. The cardbaord prevents this.
I downloaded a holder from Cults3D that lets you hang the plate tilted at 45º so it can drain better.
And I drew (on SU) and printed some handles for the sides of the flip up light shield. There’s really nothing to grab onto with the shield as it comes and besides being slippery it gets resin goop all over it pretty quickly. I’m going to install these with 3M Adhesive Transfer Tape.
And if this isn’t enough, the machine has 60% more cubic capacity than my 3 which was 40% bigger than my Classic. And it cost $50 more than my 3 did in 2019. ($350 vs $399).
