TheodorK

If you check the ultimaker github repository you can find the designs of the printer and you can figure out the technical specifications

It migh be a good idea to upload the ultimaker firmware (from github), through the arduino IDE so you know you have a working FW version. It could also be a bug of a fault in the Gcode generated by the slicer. In general the stepper motors and drivers do not need cooling, they stil perform very wel at for example 90 gedrees, and are most of the times spect to still operate at 120 degrees in the case of the stepper motors, so air cooling is a bit overkill.

I also have a old prusa i3 (from 2014) which I recently upgraded with an UM2+ feeder and an e3d v6 hotend. I also use a z hop when traveling from one side of the print to another. The only reason I can think of that a z hop could reduce stringing is that the nozzle is not moving over already printed parts, these printed parts then could stick a little to the remaining plastic inside the nozzle end could sort of "pull the plasic out" and with a z hop this is not the case. This same effect is visible when printing a flas square with some holes for example, when the nozzle travles it oozes a little when moving, leaving spots of filament on the surface. When moving over an object, instead of a surface these become strings, resulting in stringing.

Older versions can indeed be downloaded through github https://github.com/Ultimaker/Cura/tags download the right 'asset' at the bottom of the page Hopefully this helps and works

If the text won't show on the bottom layer it might help to flip the model upside down (only if the other side is flat). Most of the times the top layer comes out much better than the bottom layer, because this layer is squeezed onto the build plate, as you can see in your first picture @SirUlrich, the left lide is squished more than the right side. When the print is flipped around the text sits on the top side and this will probably yield much better result, tekst wise. Because of this I always try to print all the details on the top side. Also make sure that the text you want to print does not have smaller lines than the 'line width' set in cura, otherwise the lines will dissapear because they become to small to print.

It looks like the first layer is not sticking well enough to the print bed, this might be an auto leveling issue or your bed is 'to' clean/smooth, which causes the plastic to seperate from the build plate when the nozzle is moving away from the lines being printed. I've experienced this same issue with my old 3D printer (glass bed instead of PEI), nowadays I use a coating of hair spray or dima fix/3D lac to prevent this and to make sure that the top surface of the bed is sticky enough for the filament to adhere to the surface.

Well this is a very interesting topic, but while reading this I lost track of the development progress for the UM3 version of the sensor, does anybody have an update? Maybe now that the S3 is released (and the UM3, S5 and S3 run on the same code base) it would be a bit easier to implement the sensor for the UM3 since there is already a woring implementation for the S line printers.

Hello @SandervG, The UMS3 was the printer I've been waiting for, but came a bit late as I purchased an UM3 a few months ago. The one feature missing on the UM3 is the filament flow sensor, and this has cost me already quite some filament on long (2 day +) prints, with the filament jamming and as a result of that being ground away without the printer knowing it has stopped feeding plastic. After some research on the forums I found that there was a project for the UM2+ with a filament flow sensor working quite nice. I also read that the initial intend was to include a filament flow sensor in the UM3 but is was scrapped during development because the results were not reliable enough. Now, a few years later both the S5 and S3 have a working filament flow sensor and I figure that the code and reliability are now up to Ultimaker’s standards So this got me wondering, since the intent was to include the sensor in the UM3, there is space for the sensor wheel, the PCB and the wiring. So does the UM3 firmware and main board have the possibility for the implementation of a filament flow sensor, and what would be necessary to do so, or is it possible to pause the print externally with a third party sensor, or just a rotary encoder (for example via an I/O input). Also now that the sensors are implemented in both the S5 and S3, the firmware for this sensor should be pretty optimized by now, but the firmware for the S5 is not yet open source (I might be wrong? couldn't find it on github), so implementing this in the UM3 firmware shouldn’t be that difficult. The only issue would be the signing of the firmware before uploading. Since I have a background in electrical engineering and writing firmware/software, implementing a filament flow sensor in the UM3 looks like a fun thing to do and I guess that there are plenty of people who would love to tinker with a flow sensor in their Ultimaker. So when/where can I find the firmware for the filament flow sensor and would it be possible to (co-)develop this into a product? With kind regards, Theodor