I have concluded the best low cost FDM 3D printer for small and very high-quality prints is the Tiertime Cetus series printers. They are made with the quality linear bearings and other quality parts required for accurate FDM printing.

Not perfect in every sense, but excellent quality and design when low hardware cost and highest print quality is desired.

Print Size

Very high resolution in the .15 to .05 MM layer resolution requires very long print times. For this reason, such resolution creates a practical print time limitation, generally limiting printing to small volume models. Print a 250 x 250 x 250 MM model with 0.05 MM layers requires 5,000 layers! At a mere 1,5 minutes per layer that’s 125 hours or over five full days. (5.208 days to be exact!)

For this reason, there is no driving need to acquire a large volume printer when the desire is to print very high-quality small items. The Cetus envelope is 180 x 180 x 180 MM. A very reasonable size for small, high resolution FDM printing. 

Other Options

I own a resin DLP resin type printer that can easily exceed the resolution of FDM printers, but that print material comparison is not the point here. FDM is a much easier process for desktop and in-office production.

The Plan

I am thinking 0.1 MM FDM is a good choice for master model making for lost wax casting.   Using the available Cetus 0.20MM amd 0.40MM diameter nozzles and using layer heights down to 0.05 MM, very detailed and high-quality parts can be produced. Tiny layer lines will be present but can be reduced in post processing.

I haven’t explored the 0.20MM nozzle for some time. I used it once when I was very inexperienced with little knowledge of printing with this small size. I wasn’t interested in printing very slowly or producing very small models. I believe I was pushing the speed and I remember suffering some printing issues.

But for producing small silver and other metal casting models, I now realize the value of the smaller nozzle. I certainly will be testing this size nozzle again, soon. I don’t intend to make this my only nozzle choice as I have been producing excellent models with 0.40MM orifice and 0.10 layer heights. Some 0.20MM layers turn out very well too. 

Let’s Do It!

Putting my money where my thoughts take me, I have ordered an upgraded Cetus MK III printer. I have included the heated bed and all other newer options. The heated bed is the reason for the upgrade. The FDM filaments for casting required a heated bed and my original (Mama) Cetus bed is not heated. I would have tossed out almost all the original components to upgrade the old MamaCetus. Better to have a perfectly working Cetus printer I can use, sell or give away rather than create a box of useless spare parts. (This email address is being protected from spambots. You need JavaScript enabled to view it..)

A Return to ABS

ABS ThimblesPerhaps I should title this as a question, as it isn’t anything permanent. Nothing in 3D printing seems permanent for me. Always trying new and revisiting the old. This case I am returning to ABS after a good while away from using the material. 

I had a partial spool of yellow ABS on the shelf for a couple of years. Just in the box with its bag of desiccant. The moisture issue in my opinion is far overblown (as most things these days). Here in North Texas, I don’t live in a humid tropical jungle with constant high-level saturated air moisture.

What is critical is the grains of moisture per cubic meter of ambient air. The true amount of moisture exposure, not the percentage air can hold. Enough about my view of the science but safe to say the two-year storage was not determent at ail to my old ABS filament.

I had a small project for outdoor use so I wanted to see how it would print in ABS. What is new to my printing is I now use a glass plate with hair spray for adhering the print. The small parts printed perfectly and loved the new stick down process. Not one sign of an edge warp. 

Since It was loaded in my delta printer, ready to print some more, I finished off the spool with some larger prints. One was a cell phone case with a large flat (but thin) surface on the print bed. It was a perfect print. I realized what I have been missing with this material.

The last couple of meters of material went to printing ABS sewing thimbles for my wife. Again, absolutely perfect prints. I am now somewhat amazed.

I bought a new spool od ABS (red) and have continued re-discovering ABS printing. I am not experiencing the warping off the bed that made me shy away from this material.  I am certain the warping issue is just lurking somewhere, but the glass and hairspray is far better than other print adhesion I have used with ABS.

No, I am not going to quote temps, speeds, etc. There is no one magic number. Use the manufacturers recommendations and work out your own numbers from there. It is not critical to a one-degree accuracy or magic mm/s. None of the hobbyist printers in existence on this planet are calibrated to the same (or any) absolute reference. 

I’m rambling and mini-ranting. My point is supposed to be that I re-discovered ABS as a nice useable raw printing material. Technique was my issue, more than the material itself. The real issue as in every creative craft is the user knowing how to work with the material at hand.

Looking back on my purchase history, I determined I have purchased and used over 10 spools of ABS. But that is only 8% of my total purchases. I have experience with ABS but it has not been my material for everyday use.

A heated bed is necessary. An enclosed print area is good but not absolutely necessary. I don’t own an enclosed printer so that is one reason I stayed away from using a lot of ABS. That may still prove to be a reason. But I am seeing good prints without an enclosure. I am printing in a small office, not a large drafty open space or cold shop environment. 

There is a small added benefit of ABS over PLA filament. The specific gravity (weight) is less per volume. Printing filament is sold by weight rather than volume or length. So, there is about 17% more length on a spool of ABS. The prints weight less, but more prints can be made. 

The following pictures are some of the items I have just printed with ABS. Yellow is the old ABS and the red is the freshly opened new spool.  

Three Color Printing

Geeetech A20TI have previously posted I ordered a Geeetech A20T three color single nozzle printer. It is a first cousin to the Geeetech A20M. Only real difference is the addition of the third color extruder feeder and three color nozzle assembly.

I striped-out the nozzle threads on the A20M which is non-repairable. The new “replacement” extruder requires several months delivery from China. One has been ordered. So, I decided to move up to the A20T while I am waiting for repair parts. From what I can determine, the A20M has changed styles on the two-color extruder so the old style I have is becoming pure unobtainium. Except by direct order to China.

I am posting some of the pictures of the packing and general appearance of the new A20T. Like I say, it is very much the same as the A20M. It is amazing build quality for a $400.00 three color printer.

Some fine tuning is required and expected during assembly. It is not RTR (Ready To Run) as it is shipped semi disassembled. The Z axis nut was very loose in its bracket (tighten two screws). The same condition existed on the A20M when assembled.

The A29T also required some free play removed from the Y travel. Simple turn of the eccentric adjuster under the bed and all is well.

I did not install the broken or loss-of-filament detectors. They are a PITA when loading filament and I have never had an issue needing such auto detection. It’s a marketing gimmick for inexperienced users who fear filament run-out.

After full assembly, the first task is manual leveling. I added a borate glass bed on top of the aluminum bed. I raised the Z axis limit switch 3MM to accommodate the added height. Simple two screw adjustment on the easily assessable switch. 

Then on to the manufacturers recommended leveling procedure. No issues at all.

I ordered the auto leveling “3D Touch” sensor for the A20T. It is exactly the same as the one I installed on the A20M. However, at this writing Geeetech is having issues with the Marlin software mods to operate the sensor. The operational system with the proper mods for the 3D Touch must be loaded to the printer controller to initialize the 3D Touch. 

Geetech supplies hex code for this printer rather than Arduino source. So, I can’t modify the software myself. I hope to eventually get the source like I have for the A20M and tweak the system the way I want.

Geeetech may be updating to the newer Marlin 2 code. Or moving from the installed Marlin 1.1.8 to the 1.1.9.  No idea or word from Geeetech at this time. Marlin 2 is not required but is the new version for 32 bit controllers.

I printed the two, factory supplied gcode print files and have included pictures of the results. Both are examples of the color blending possible with a single nozzle multi-color printer. The I printed some standard multicolored prints I designed.

The Texas coaster is unique as it is programmed for four nozzles and colors. The three filament colors (red, white, blue) and a fourth color which is a blend 50/50 of red and blue (purple). The purple is used for the background. Yes, Single nozzle multi-color printers can make new colors.

The A20T can also operate just fine as a single-color printer. The requirement is there must always be three filaments feeding into the nozzle.

In the future as I experiment with this printer, I will demonstrate many of the ways color can be combined and created with this machine. Far more options than three solid colors.

Shipped direct from China... or maybe just the west coast USA???	The 3D Touch was ordered with the printer. Black package on top.
Next layer down, the superstructure.	Last layer base components
Assembled printer in its new home.	4 color Texas coaster I designed.
Test block for color printing I also designed	Handy way to feed the 3 colors of filament. Spools holders included with printer.
First print, color mix gcode supplied by Geeeteck	Interesting color shift, mixed color gcode also by Geeetech.