I received the Two Tress Sapphire Pro from a friend who has been using it for a while and decided to move on to something more compact. He gave me the printer mentioning that the extruder was no longer working.
Operations
The printer make a first good impression, it is a core XY system with a really robust frame. The cables are well managed and barely visible. The print volume of 220x220x220 mm is descent and a good size for a printer that price category. The printer has a MKS Nano V1.2 with Marlin installed. The small screen is really handy and allow a lot of simple operation without having the PC connected to it.
The first test parts ( Benchy and Voron cube ) were ok and I had to make some configuration for SuperSlicer. Fortunately, CNC Kitchen made an excellent review of the printer and posted the slicer configuration for it that same me a lot of time. I managed to get the parts better but still having some issue with vertical lines.
A small holder on the side of the printer allows to attached the filament spool, it is nice and handy. Loading and unloading the filament is easy but there is no automatic procedure, would have been nice to have. The rest of the printer was working as expected but there is always some issues.
Issues
The printer as every non professional and for this price tag has some issues. Here is a list of what I found bothering me and how I solved it.
The Z axis end stop is not accurate as the end stop is touching the linear bearing of the Z Axis. The top surface of the bearing is not flat making the position of the Zero point sometime not extremely accurate and requires frequent adjusting to make sure the first layer is prefect. Fortunately, there is already some model on Thingiverse to help you out. Also the cable coming out of the heated bed are kind o hanging and can be damaged in the long term. You can tie them up to the bearing with zip tied or use this more elegant solution.
The extruder delivered with the printer is unfortunately a cheap clone from the BMG extruder. After fixing the pin which jumped out, I realize that the extruder gear were not make to precision and not rotating in each other without any friction, making the movement difficult. I did not want to change the extruder directly as it is quite expensive and was looking more into the direction of a direct drive solution.
The core XY belt is not parallel, meaning that there is an error in the positioning of the head. It is not an issue if you print small parts but as the part get bigger, the positioning error make you part accuracy a problem. This can not be fixed easily and require so large changes. There is a few design you can print to try to solve this issue but I was not satisfy with them. I will have to make my own design.
The board and the firmware are fine but I do not like to have to use the SD card everytime I want to print something. Also, it is not possible to change the parameters when the printer is running, like temperature and other nice thing you missed before the start of the print. One of the option will be to install a raspberry Pi 4 on the printer and instal klipper to be able to access the printer remotly and to be able to change some important parameters during the print without having to stop the print.
Defects
As I mentioned at the beginning, my friend give me the printer as he had issue with it. Fixing the problem with the extruder was easy but the printer was showing vertical lines in the print. After investigating, one of the pulley of the CORE XY was damaged. After replacing all of them with F695 bearings, the vertical lines almost completely disappear but some were still there. After a few investigation, I realized it was coming from the cheap extruder.
Conclusion
Generally the printer make some nice parts for the price tag. If you are looking for a fairly good printer for the price, I guess this could be your choice. Keep in mind that the printer has no housing making ABS difficult to almost impossible to print and limit the printer to PLA, PLA+ or PETG. IT works great with the screen and can be use in standalone, however this is not a printer I will recommend for someone who just what to load a model and print. This printer has some issues and need some experience to set it up and use it in a reliable way.
Far-Out 