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• Release Candidate: Build Status

  Tomas Starek • 03/09/2023 at 12:27 • 0 comments

  Work on the upgraded version of the printer has progressed on all fronts, including firmware and software.

  I dare to call it a Release Candidate, and I firmly believe it will be.

  After thorough testing, I will fine-tune the documentation, which will then be available as open source.

• Design of updated version is finished - fabrication stage started!

  Tomas Starek • 12/13/2022 at 17:42 • 0 comments

  I have finished designing an updated version of my SLS 3D printer. I have now started to produce individual parts and components. I have begun fabricating the printer cover panels and will continue with the construction of the frame from the extruded aluminum profiles.

• This Will Be An Open Source - Updated Version Of Inova Printer

  Tomas Starek • 09/17/2022 at 13:07 • 0 comments

  Based on the recent print tests I realized I am much too close to the physical limits of the current printer prototype to get the best print quality I can. Therefore, I decided to focus my efforts on the development of the updated version which addresses these limits. From my perspective it is more time effective than to upgrade first prototype.

  I have already finished the design of the bottom printer's part. The top printer’s part is finished from say 80%, so I think I will start building it in about a month. If it works well, I plan to gradually release this version as an open source.
  

• Printer testing video is here!

  Tomas Starek • 08/14/2022 at 10:19 • 0 comments

  It's been a struggle with time, but finally the video is out showing the testing of the printer :-)

• Q: Will be kits sometime available? A: YES!

  Tomas Starek • 06/26/2022 at 11:03 • 1 comment

  I had some time to think about "the kit" and I have, I hope, a good news because your interest persuaded me to do it.

  My short-plan is as follows: 

  1) I need to tune the printer to make nice, repeatable prints. I believe it should not take too long. It could be done in a couple of weeks. Simultaneously, I plan to start some preparatory activities for kit. These will mostly relate to organizational and logistical aspects.

  2) Make design changes I am calling v2 and do the documentation - drawings, assembly manual, source codes, etc.

  3) Build and test v2. Here will be also a good space to fine-tune assembly manual, etc.

  4) Finalize all the manufacturing and logistical aspects, announce prices, delivery dates, etc.

  5) Open pre-orders, start making kits and publish the Inova documentation (DXFs, STLs, manuals, FW, SW, ...)

  6) Support you in building your own Inova (kit or your own build from scratch) :-)

  When it will be?

  It is not a small bite but I will do my best to be able to deliver first kits to you by the end of autumn. Let's fingers crossed. I will keep you informed about the progress of the steps above on a regular basis.

• Print bed surface heat consistency

  Tomas Starek • 05/20/2022 at 15:25 • 0 comments

  As a result of the last print test I spent many hours by finding the right way how to ensure the best possible heat distribution/consistency across the print bed surface. Problem was, some areas of bed surface were under or over heated.

  I ended up with new halogen shielding and quite simple procedure how to tune it. Unfortunately, current design of the topFrame limits me in making heat distribution good enough for the whole print bed area. As a result of that I must use smaller print space in the Y axis for further testing. It will be around 130mm instead of 150mm. But good is, that it should not be problem to fixed that. So, the final working area will be still 150x150mm 😉

  Here is the pict of what I am talking about. The orange rectangle is the 150x150mm effective print area - it is rectangle because of camera view perspective. I need to have the temps diffs max about 2.5°C. Therefore, the top and bottom row inside the rectangle is a bit problematic. The test was done for 100°C.

  
  When I checked video from the last print, there was a diffs range up to 5+°C :-o

  I will make the next print test in coming days.

• Initial test prints: the PA12 print profile experiments

  Tomas Starek • 05/11/2022 at 20:02 • 0 comments

  I did 3 tests past two weeks and here are the results. If you are intersted in more details please join Discord - https://discord.com/invite/qDFNFASM57

   Test nr. 1 - first few sintered layers on my printer ever!

  Test nr. 2 - moving forward, now it starts to be really 3D :-)

  Test nr. 3 - last time numbers were not printed. Now they are! Few more print tests like this one and then Benchy is waiting :-)
  
  

• Recoater rebuild: Part 2

  Tomas Starek • 05/03/2022 at 20:40 • 0 comments

  Recoater rebuild is done. I did a few tests today and it looks very promisingly. It is smooth, silent and rigid enough. I will heavily test it in next days.

  -

• Recoater rebuild: Part 1

  Tomas Starek • 04/27/2022 at 18:15 • 0 comments

  I moved on a bit with the recoater remake. I have printed out and fine-tuned all parts I will need - the blade holders and pulley holders. I made it from the ASA so hopefully it will be able to withstand the high temperatures (if not then it will be CNC machined). ASA is more temp resistant (temps just below 100°C are OK) than ABS and more rigid. Good thing is that it also prints easier than ABS.

  Blade itself is ready as well - CNC machined from aluminum, as planned. Linear rails are just perfect.

  I will mount everything into the printer in coming days.
  

• Recoater Redesign: Blade Insted of Roller

  Tomas Starek • 04/21/2022 at 12:55 • 0 comments

  As written on my blog and meant here before have been still facing some troubles with the recoater. Therefore, I decided, even I really didn't want to, to change its design.

  Main problems are with the roller part. Unfortunately, I have made its diameter of 38mm, which implies high rotating speeds and causes layer shifts. I spent some time to come up with the solution how to incorporate roller with smaller diameter into the current printer design. But due to space constrains it's not easily possible.

  Another issue is that once the roller, being from PTFE, starts to warm up, it starts to deform a bit due to nonsymmetrical heating of it. I eliminated this by "grilling" the roller during the printer heat up, but I cannot be sure that it is perfectly circular and concentric with the axels. As we are speaking about the hundredths of millimeter which plays a role, it is a problem.

  It is not all. Last problem is related to smooth rods which are approx. 550mm long. I thought it will be OK without support, but it is not. And again, you cannot ensure layer thickness precision which is needed.

  Here are intended changes:

  1) Replace smooth rods with the linear guides

  2) Change the recoater from roller to blade. I will come back to the roller in v2.

  3) Change the drive train, to be able to worh not only with the steel rope but also to test special heat resistant GT2 belts.

  4) Change the cover of linear technics parts to be comfortably accessible for maintenance.

  I have proposed this design:

  It consists of MGN9R rails with the MGN9H trolleys. Aluminum wiper will have precisely flat bottom (will be CNC machined). I read research papers related to the blade shape and I was really surprised that flat bottom is better than symmetric, asymmetric or rounded. But it has some logic.

  You can see the design in deep detail here: https://sls4all.com/fusion360-model/

  I would like to rebuild printer in this way in two weeks or so. Hopefully, it will work as intended. There is one thing which makes me worried - I can't pull the trolley exactly on the axis direction of the rail... will see.

  I expect from this change to be able to focus on the sintering parameters and be sure that there is one layer like each other.

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