BMC, Big MamaCetus now lives up to her promise and expectations.
After being abandoned by Tiertime (Cetus) support, I have been on my own to trouble shoot and fix the problems with the Cetus MK III printer.
What I think led to the issues was my lack of knowledge of how the multiconductor ribbon cable termination sockets mechanically function. Absolutely no instruction was provided by Tiertime on the process to open/close or unlock/lock the connectors.
Looking at these very small connectors, I assumed (incorrectly) they were simply friction fit terminations. This was false. There exists a very tiny lock/unlock bar to clamp and unclamp the termination to properly insert and remove the cable from the connection.
I was able to force fit (with rather moderate effort) the ribbon cable into these sockets without releasing the clamp bar. But something went astray from the high current 20 conductor ribbon cable to the heated build surface. One conductor in the center of the cable vaporized when I first enabled the power. The trace is supposed to be non-connected as an empty buffer between the plus and minus high current leads on both sides of this unused trace.
Somehow it conducted a high amount of current, which made it glowing hot. This short circuit COULD and likely DID lead to all the other failures.
The issue was that the printer could still print but had no temperature control over the build surface. The build plate would power full on and become extremely HOT. Even melting PLA rafts to the build plate. The CPU could not read the temperature sensor attached on-to the build plate.
Having no schematic or description of operation, I had to use my experience of how I thought it SHOULD work. Again, NO HELP was available form Tiertime after the very first contact. That’s another story.
I discovered the micro SD memory card failed on the main board, and the CPU board never, ever produced a WiFi signal. The Build Plate cable was the only visible damage and was obviously bad. The cable is not available as a repair part. Tiertime did send me a new build plate with a new cable. I also bought a second replacement just to have another good spare cable on hand. It is an obvious weak point in the bed heating system.
The new build plate cable didn’t fix the issue of not reading the build plate temperature. There is a signal problem between the build plate and the CPU.
At this point Tiertime stopped responding to my subsequent attempts to communicate. At least six more attempts through website and Facebook.
I bought (paid for) a new intermediate control board and a new CPU unit. Both came with necessary cabling, so all in the signal path was changed. The order department in China is very responsive to paid orders. I received the new parts 3 full days ahead of promised delivery.
After installing all the new parts, Big Mama Cetus was powered up again. Glory Hallelujah! Everything is working as it should. She is in perfect health.
I have now made a half dozen parts and all are perfect, top notch quality and all function of the printer are correct. Cetus MK III is a great tool when wired correctly and all components are in working condition.
I have been constructing electronic components since I was 10 years old. I am presently 73. Sixty three years of experience and a ham radio builder and licensed for over fifty years. I know my way around electronics. I am a career expert in electronic and all other types of environmental and machine control systems. The average Joe is going to have no idea how to solve these types of issues.
Can I recommend Tiertime and Cetus? I think the product is not perfect, but the two I own demonstrate I do like how they work. Currently, I think the support group is in a mess and un-supportive. Published support information is disjointed and randomly arranged. Scattered. Look long and hard, there is good information. But a vast amount of conjecture and guessing from “user forum” type comments.
In my honest opinion, User Forums is NOT a good way to provide customer support. Too much “chaff” for the few grains of valid information.
Tiertime Cetus Mk3 3D printer has been a real test of my trouble solving skills and patience with a non-communitive Cetus support team.The new
The basic printer is as good as my original Cetus. The problem is the addition of a heated build plate. That requires a secondary control board mounted on the Z axis column. It’s fed with a 24-volt power system. The bed is 160 watts.
A very thin, flexible 20 conductor ribbon cable is the connection between the 160-watt heated build plate and the secondary control board. The 24-volt power brick feeds into the Auxiliary board first before feeding the main system board through another power cable.
Two parallel 8 conductor (trace) groups in the very thin ribbon cable carry the 6.7 AMPS of current to and from the heated build plate. Two more conductors (traces) together on one side carry the signal voltage for the temperature sensor on the heated build plate.
No instructions other than to “connect the ribbon cable” face up or face down are provided. There exists a microscopically small clamp-bar that needs to be open/closed to install and remove the ribbon cable from the termination block. It’s a secret I had to learn the hard way.
I fried the first cable when the unused “safety” conductor trace between the 24V, 6.7A plus and minus groups MELTED as it shorted between them. Not sure of the exact cause mechanics. But that single trace had to be carrying a very high current.
I re-fit the cable after discovering the clamp/unclamp feature. The printer seemed undamaged. The melted cable still operated! I did some PLA prints and some new wax filament prints. But I noticed the bed temperature was very erratic and out of control. The build surface was getting far too hot.
The fact is there is NO temperature control of the heated build surface. It simply runs full-bore.
First contact with Cetus/Tiertime support got me a replacement build plate. I also bought (paid) for a second replacement build plate. Apparently the 20-conductor ribbon cable is not available separately. (That’s extremely ignorant!)
The build plate is not the problem, the melted cable is. That’s why I wanted a spare AT ANY COST.
The new bed/cable did not solve the problem. Temperature reading were very unstable and jumping back and forth. I discovered a tiny slice in the edge of the new cable that partially cut the trace carrying the temperature sensor. The flexing of the cable with the print surface movement was like bending a paperclip until it breaks. An ohm/continuity test of that trace shows it finally failed full open.
The third cable was tested, and all 20 leads are fine. However, there is still no reading of the print surface temperature.
At this point Cetus/Tiertime is totally ignoring my in-depth investigation and reporting and my many requests for further assistance. Total lack of customer respect and communication.
I have ordered a replacement intermediate controller board as the signal for the temperature reading seems to be processed on this board. It’s a multi-layer PC board so circuit tracing is mostly a guess.
There are no circuit schematics available of which I am aware.
Two other problems also manifested on the control system. The 8GB micro SD card became unreadable. I replaced it with one I had. This “fixed” the 50C degree low (but tracking) temp readings. Now I only see a fixed 19+C read. Also, the Wi-Fi has never operated from day one. Both of those involve the main processor, so I have ordered (at my own expense) a new CPU board.
I now have an additional $200 invested into the Cetus Mk3. Not acceptable by anyone’s standards. I just want an operational Cetus Mk3 so I can run wax printing. Some (low) controlled heating of the build surface is a requirement.
In my experience, all forms of 3D printing hardware require extreme user trouble shooting fix and repair abilities. Properly operating hardware still requires extreme effect/cause diagnostic skills because of the very high number of inter-reactive variables of hardware and software and also printable design requirements.
There are a great number of fails before success and a huge supply of bogus internet advice. The internet never deletes outdated or erroneous information. Dealing with difference in language and non-standard terms just adds to the confusion.
However, that is no excuse for Tiertime/Cetus ignoring a paid-in-full customer in need.
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.
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.
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.
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!
A Return to ABS
Perhaps 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
I 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.
Using wax base filament for FDM printing models for Lost Wax Casting (LWC) master models.
3D Printing operation details will be published here. The casting and finished art will be presented elsewhere with links provided.