My old interest was stimulated by a fellow 3D enthusiast to go do some MSLA (Masked Sterolithography) 3D resin prints. I have all the necessary equipment but have not been actively printing using the process for many months.
There is no question that almost every type of SLA printing produces the finest resolution and details in 3D prints for a hobbyist printer. The low cost of MSLA brings it into reach of the average hobbyist budget.
This post is not about the pros and cons of the process. I like MSLA because of the superior details it can reproduce without the layering lines of FDM (Fused Deposition Modeling) filament printing.
I can endure the efforts and materials required for MSLA printing because I truly enjoy the results. Usually very high quality.
That does not imply that every print is perfect without effort. Also not every design is a good candidate for MSLA printing.
Shown in this post is a very small razor blade storage box and a small vase. Both of which are my designs and have previously been printed using FDM and now using MSLA.
The red vase is extruded PLA+ and the green is photo-resin. The green was also scaled 95% so it wold fit on the Anycubic Photon Mono SE printer shown in other pictures. Stand way back and they both look good, but look close, there is a big difference.
I am now stimulated to do a few more MSLA prints. I have plenty of resin and I have the time. There is no excuse. I don’t need one. I just love the high quality results.
Printer size limits the range of prints I can do. Not yet in the market for a larger printer. If I get bitten harder by MSLA and need to create larger or higher quantity of items, then that will justify a larger system. The reality is the larger printers are not a good choice for small “onesies” prints. Printer size should be chosen for the item print size or number of multiple prints desired.
Printing ten items on one build plate takes the same amount of time as printing one item. Not less material but huge time advantage. The full build plate area is exposed (printed) at one time in a few seconds.
This may be the start for me doing more resin prints. I’ll go where the results take me. It depends on what I can design and if other folks like what they see with resin based printed items.
Many options to explore and enjoy.
I love the prints my Geeetech A20 printers make. I don’t exactly love the printers. I have an A20M (2 color) and an A20T (3 color). Owning both indicates I don’t actually hate them. They are just hard to live with…
The A20M was first. The original mixing extruder hot end had a design flaw. There were two very tiny multi orifice plates in the melted plastic flow path. One for each filament. I assume they were an attempt to mix colors when extruding. What they actually did was constantly plug up.
I ordered a new hot end from China when I discover a new improved A20M hot end was available without the tiny multi orifice plates. But delivery was going to be over a month.
So I purchased the A20T which uses a totally different hot end. Duh! Of course it is different, it has three feeds. But the overall extruder design is totally different and no orifice plates.
Both printers use the same design filament stepper drive. Geeetech calls it the Titian. Borden tubes and remote drives are unavoidable in most single nozzle extruders. No room on the hot end for multiple motor drives.
The Titian has a geared-down drive system to improve feed torque. Don’t know how really necessary that might be, but they like to brag about it.
All five of my drives have worked well for several years and hundreds of prints.
But I have now discovered a design weakness. The tiny idler wheel that presses the filament (under spring pressure) against the toothed drive wheel has a very tiny ball bearing. The wheel itself is mounted almost totally enclosed in its mount (see first picture)
In two of my Titian drives, one on each printer, this bearing has seized and the pressure wheel is frozen solid with no rotation. When it fails, weird squeaking and clicking sounds emanate from the drives when trying to feed and the gear quickly grinds a notch in the filament and flow stops.
The first drive (A20M), I got the axel screw out but the bearing and its microscopic balls just fell apart all over my work space (picture 2). With the A20T drive arm, the axel screw will not come out and the wheel is totally locked into the arm and doesn’t rotate. The A20T arm is the one on the box in picture 1.
There has been a small design change in the pressure arm. The Titian drive taken off the A20M has a clearance slot in the arm to let filament “dust” escape. The arm from the A20T Titian does not have the slot. It was packed with debris. No idea which is the “current” design until my new parts are received. I have five Titan repair kits on order @ $20 ea.
The drives have operated for more than a year with no issues. I do think the tiny ball bearing is inadequate for the task. Certainly not designed and rated to take the spring pressure loads. The bearings are sealed and inaccessible, so no way to lubricate. Certainly a design flaw in bearing choice. Yearly bearing changeout should not be necessary.
I have had no such problem with my five other FDM printer filament drives.
I may get another year or two from the A20’s. Then it’s EOL* for them.
*End Of Life
The everyday nozzle hole size for FDM filament printing is 0.040mm. It is the default standard. Not every printer follows the crowd. MakerGear uses 0.35mm as their standard size nozzle.
Nozzle hole size is one factor that determines possible extruded line width, height and extrusion amount. Those are variables that are altered depending on size and strength of the item to be printed.
Bigger hole size is of course more plastic flow and smaller is less. But there are other adjustable variables that affect the actual flow amount. It’s all a game of balance and tuning to get the exact extrusion flow desired or required for a good print.
The smaller the hole size the more critical all the adjustable setting factors become and lowers the flow rate considerable amount. Also greatly increasing the print time.
Standard range for nozzle hole size is between 0.20mm up to 1.0mm on hobbyist machine with 0.20mm to 0.60mm (0.40mm standard) as the most common.
I have used the 0.20mm size nozzle on occasion. Used mostly for very small prints of very high detail. Also requires very long print times.
Today I have been using the 0.60mm nozzle on a small project. I see that I have been missing some of the benefits of using the wider nozzle. A wider extrusion is laid down so fill-in and wall pass counts can be reduced and extruding run at higher print speeds. Ninety plus percent of my prints really don’t require printing with a 0.40mm nozzle.
I now realize there is nothing sacred about the “standard” 0.40mm nozzle. It’s pretty much all purpose, but that doesn’t mean it’s the best choice for every print.
I think I will be using the 0.60 size nozzle much more often. Especially where I don’t need super-fine layers and fine details.
The photo is a small box printed with 0.30mm layer height and a 0.60mm nozzle using PETG. The results are great! Looks like an old pair of blue jeans. The filament is Overture brand called Stary Night (blue). I can see the stars!
I made a series of container boxes for a ham radio buddy. He needed them for his “go-kit”. A rapid deployment case containing a portable radio and everything needed to put a short wave station on the air from remote locations.
He enjoys operating radio from federal and state parks. I assume almost any established park qualifies for POTA (Parks On The Air) Its a good reason to pack up ones radio gear and go operate from a remote location.
Everything needed packed into one case makes certain nothing is missing or forgotten. It’s why the case is called the “go-kit”.
What I designed and 3D printed are organizer boxes and special brackets to hold radio gear for travel and help position gear when operating.
Black was the color of choice and I had several spools of that color PLA (PolyLactic Acid) on hand.
I created three container boxes with removable lids and several mounting brackets and adapters for holding radios and video screens in operating position.
It all worked well for a couple of weeks but then I received a report that the plastic boxes were all warping out of shape. The Go-Kit is stored in the trunk of the car and evidently the Texas heat has encouraged the container boxes to take on strange new shapes.
The boxes are fairly large and I originally designed them with 3mm thick bottoms, tops and side walls to save space and weight. I didn’t consider storage in a hot automobile trunk.
Walls that thin should have been designed with ribs and gussets to resist warping. But that would have greatly reduced internal space. The equipment brackets are designed much heavier and ARE well ribbed and braced. No problems at all with the supports warping. Just the warping with the thin walled boxes.
I experimented with ASA and ABS plastic for the replacement boxes. Both materials warp excessively during test printing. I discovered I can not print the size boxes needed with either ASA or ABS.
I made another test print with PLA+ which is a new higher temperature PLA with much less tendency to warp. 225C print on a 70C build plate. I am now reprinting all the boxes with 5mm walls and double print +45/-45 degree infill pattern. Twice the previous infill and very high rigidity. A real strong and true honey-comb infill. More than double the amount of PLA+ for the same size boxes. They are also twice the weight. Can’t escape that when warp-free results are required.
Print time is also nearly doubled as well. But that is not an issue. It is what it is.
There is a very small loss of useable storage space with the thicker walls and that too is of little concern. I had to be very careful in the re-design where I could “steal space” for the added wall thickness. The packing case did not get any bigger, so the container boxes had to lose some internal volume.
Only one container box had a critical inside dimension. The one labeled "KEY" that holds the paddle key for morse-code sending. There was space to expand that case on the exterior dimension.
Lesson learned here. Sometimes one cannot think of all the factors when creating a new design. It was a learning experience that will not be lost in future designs and revisions.
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