Dimensional Print Studio

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 have a heated bed on Cetus with a glass surface placed on top. Hair spray is my adhesive. It generally works very well. But there are some “tricks” in getting a good print without using a raft.

The big issue with Cetus is there is no manual leveling of the print surface. A thick raft is used to build a level surface before starting the intended print. 

This takes considerable time and some wasted material. The material consumption is no big issue unless one is close to the end of the spool.

PETG is particularly sensitive to everything being “right” with initial layers.

I use G-code produced with Simplify3D. It has much better control of variables than offered with the stock UPStudio slicer/print software. There is a new Beta for UPStudio which shows promise but stopped working on my WIN10 PC.

UPStudio is still required - to load 3rd party G-code to Cetus. Simplify3D cannot communicate directly with Cetus.

PETG extrusion temperature is 150C. with a 90C bed. I am presently using 0.25 layer height with +200% for the first layer (0.50 height) This is required to help compensate for the un-level bed. I am using 100% extrusion flow with a 0.4 diameter nozzle. non-solid infill is set at 150%

These figures don’t seem extreme, and what I have found as necessary to get good non-raft PETG prints on Cetus.

Sone factors when set too high tend to push the Cetus extruder close to its flow limits. Missed steps (clunking) can be heard if pushed harder. This is the feeder gear slipping on the filament and cutting a notch. This will usually stop filament feed.

Travel (print) speed is also quite low with PETG, 2100 mm/m with under-speeds of 60%. Rather slow but PETG is also speed fussy.

Note Well:  These are setting that work for me. Your results will certainly vary. Use these settings as an example of where you may have to go to get satisfactory PETG prints on a heated bed Cetus.

Here are a couple (or more) of big item prints I have designed.

The tissue box I designed for my own office. The olive green one. Then I noticed a new but bare tissue box out in the music room where my wife provides piano lessons. Thus the white-ish box was born. When she noticed the new boxes, she immediately wanted several more made. Number 5 is on the Mamacetus printer as I write this. Print time per box is over 12 hours.

Next project is what I call a K-cup stackable pod rack. There are three here holding 27 pod cups. Less space by about 1/3 of the rotating wire rack I have been using and holding 3 more pods Another rack on top of these would equal the height of the wire rack. So 12 more pods in the same space. It's also a good excuse to design/print something.

Ordered a TinyFab ESP32 CPU to convert one of my Tiertime Cetus printers to Marlin gcode CNC operation. It is still in BETA so I am jumping in early on this.

The Tiertime folks have control software called UP studio ( V2 & V3) but it has always been a bit awkward to use if one wants total printer control. Their software is intended to out-think the user. I have made great prints using it but I have to compromise to using their quirks.

Just recently UP Studio (both versions) are refusing to display properly on my WIN10 computer, so time to try alternative control methods. Oh yes, on older hardware the the new UP Studio causes random print pauses where everything freezes and the nozzle drops a big blob. No fix in sight. Tiertime says to revert to older software... That's not a fix.

I believe the ESP32 indicates it is a 32 bit processor and that should make it pretty much state of the art as small CNC controllers go. Info says it is compatible with Simplify3D control software, which I fully understand how to use.

Apparently the ribbon cable shown attached (in the picture) is a connection for a LCD display and manual controller. I am learning as I progress on this project. I simply want to have standard gcode control for a starter.

From the TinyFab website I see they have a complete electronics swap out if I ever desire to go that far.

Cetus printers have one very significant issue and that is bed leveling. There is NO MANUAL leveling with stock Cetus. Heated bed is available (I have one) but the cable and cable sockets are a weak point as they are unable to carry the high current. For that reason I have my heated bed disabled to prevent fires. Yes fire. I have had one.

I am not going to spend a lot of T&E (Time and Effort) and money fixing everything with Cetus. It does work as-is and it does a good job for the original cost.

Will certainly report how the new CPU runs with Simplify 3D.