1. What is the current status of the project ?

Last update – 02/2024

Finally, the hardware and software issues that had a direct impact on the print quality were finalized. I am happy to say that the printer now prints at the quality I imagined it would.

We have been working hard for the last six months plus to fine tune countless individual details, so I am really glad to have this often very frustrating episode behind us.

This also marks the end of the first phase of my project, the initial development. The word ending is a bit of an exaggeration, of course, but I wanted to say that we’ve got the essentials behind us. I mean, the printer is printing 🙂 I have plenty of ideas for HW and SW improvements in my head, but these are such “nice to have” things.

As for materials I started with the nylon PA12 where I found the right values of the print profile parametres (galvo speeds, temps, etc.) ensuring the repetetive and reliable printing. In coming weeks I plan to start do the same for the TPU.

We’ll also concentrate on finishing the documentation and preparing everything else related to the publication of this project. Printer documentation like STLs, STEPs, assembly manual, source code comments, etc. is now under the focus. I’m also working on the kit for those without the possibility to make Inova printer completely by themselves.

We’re doing everything we can to make this project opensource by about May 2024. We’re already looking forward to seeing where SLS4All project goes with the support of the community.

2. What is SLS?

Selective Laser Sintering is one of the 3D printing methods, which was explored and patented in early 80’s. It utilizes laser beam to sinter powder materials layer by layer together. As compared to FDM/FFF technology it is suitable mainly for the functional parts, like prototypes or small series end products. It is mainly given by the exceptional mechanical, chemical resistant and temp resistant features of the SLS printed parts.

3. Is the printer intended to print metals?

No, it is quite different discipline. This printer is about to print plastic polymers.

4. What are the estimated material costs of the build?

Cost of the material is somewhere around 3.000USD w/o VAT.

5. Which type of laser is used in SLS4All?

It is the laser diode source emitting the laser beam within the blue spectrum (wavelength 445nm). We have tested two laser modules – with optical power of 5W and 10W.

6. What is the spot size and max. scanning speed?

It is approx. 250 microns for 5W laser with max. scanning speed around 1,650 mm/s. For 10W laser is approx. 350 microns with max. scanning speed around 3,300 mm/s.

7. Does it use f-theta lens?

No, it doesn’t. It uses simple optic lenses. At this moment Keplerian telescope optical arrangement is in place.

8. What is the desired effective print volume?

At this stage it is 150x150x180mm. Total print chamber volume is 177x177x200mm.

9. What material is being used for printing?

It is the Nylon PA12 at this moment. Flex TPU is planned as the next one.

10. What is the common layer height?

100 microns

11. Is the powder toxic?

No, it is not. There are no health-risks but safety glasses, gloves and respirator are recommended.

12. How much does the powder material costs?

Branded powders start at 100USD per Kg. Unbranded quality powders directly from manufactures at Alibaba start at about 55 USD per Kg (excl. shipping).

13. What kind of recoating mechanism is in place?

I started with counter rotating roller but moved to flat-bottom blade later.

14. Does printer use active heating?

Yes, it has 14 thermo regulation loops in total. Five for powder chamber, the same for print chamber and four for surface heating control.

15. What firmware does the printer use?

Highly modified version of the Klipper Firmware running on BigTreeTech board SKR 1.4 Turbo and Raspberry Pi 4B (2GB RAM at this moment). Due to problems with the Raspberry Pi availability we have moved to the Radxa Rock Pi 4B, 4GB RAM, 32GB eMMC.

16. What control SW does the printer use?

It is our own proprietary SW implemented as the web-based app.

17. Which 3D file formats are supported?

At this moment the STL, 3MF and OBJ formats are supported.

18. What is the connectivity of the printer?

It can be connected via ethernet or wifi. USB is also ready to use.