Toying around with 3D printer

Welcome to 3D printing

That is what I call a printer... and if you ask my wife that would be another toy that we could live without :-)

Nothing new under the sun...

I evaluated 3D printers already at 1998... and even bought one for my employer at that time. The printer was SPI/SolidScape MM2 (Model Maker II) 3D wax printer / 3D rapid prototype machine with two nozzles. The print quality was outstanding and the printing speed was good enough for small prototypes.

I still think that the printer rocked and that it was one of the best investments the company ever did. The printer cost whopping ~100 000€ so it was not meant for us mere mortals.
I studied DeskArtes, Vertex, SurfCam and AutoCAD plus few other software just because it was a lot of fun to design and do rapid prototyping.


As it turns out I still yearn to play with 3D printers since I bought Velleman Vertex k8400 3D printer ( few weeks ago. Not did I just bought the basic one (k8400) but also bought the second extruder (K8402) and a box load of goodies to go with it... I guess it was time to spent the annual company bonuses :-)

The delivery

The package arrived and what a nice packing

The actual printer package is tight and neat

Best disclaimer ever! :-)

All parts are packed on well marked bags

Some filaments (Velleman ABS & PLA)


The building instructions are nothing short of brilliant.
There are few things that could be added and maybe more emphasized - more about this later on in the text.

How long time does it take to built this?
Some estimates (as per the chapters in the guide, for k8400+second extruder (k8402)):
1-3. Move along, nothing to see here. Skip :-)
4. 1 hour
5. 1 hour
6. 30 minutes
7. 15 minutes
8. 20 minutes
9. 10 minutes
10. 20 minutes
11. 30 minutes (including the second extruder stuff)
12. 20 minutes (took more time as the EXT1-THERM and some other connectors on the motherboard were pretty busted... didn't want to return the darn thing and just fixed it by myself). (My father was a professor in electronics so I am at home with fixing electrical appliances too)

13. 1 hour (cables are PITA... something for the kids to help you with)
14. 15 minutes
15. 80 minutes
16. 80 minutes
17. 45 minutes (I had to re-adjust these later though!)
18. 20 minutes (for a single extruder)
19. 60 minutes (took more time as I had to re-arrange the cabling few times)
20. 30 minutes
Add-on's (second extruder tube and some hassle) - took like 10 minutes.

(Please take into account that I am a machine engineer by training so building IKEA furniture is fun in my playbook and I had all the best tools available for building this printer)

So all in all that would be ~10 hour marathon! ... but wait! There is a downside to building things fast - I connected the end X- and Y-end stops in wrong order, forget eight M3 bolts from printhead ends and had to re-adjust the pulleys so please add few hours to this marathon.

Then there is an issue of 298mm and 289mm rod lengths: as the brilliant time lapse Youtube clip shows the rods are about 0,5-1mm too tall! I solved this the easy way and just left few bolts loose in the end but by no means is that an ideal solution - it may cause xy shifting later on!
Also attaching and adjusting the belts with not-ideal rods complicates things so some fearless tweaking is expected of you.

Summa Summarum: prepare to use about 15 hours to build, test, re-adjust, test, load, etc to achieve the goal.

Few additional notes

  • Buildtak sheet - it works well with PLA but ABS will ruin it. A new sheet will cost a fortune and I don't think you need one... read below for more information
  • The Velleman site only has Repertier Host package for Windows. Linux user anyone?
  • Temperature sensors (extruder). As the manual states please take care to position them correctly - I need to emphasize this and warn you that there maybe two thick bumps on the wire and if you choose the wrong one you will destroy the extruder. I kind of did it but as I was monitoring the first heating closely and noticed that the extruder started to melt I was lucky enough to pull the power plug and force the nozzle back up and salvage the molten part(!)
  • The driver boards on motherboard definitely _need_ extra cooling - you can do eggs and bacon on them after short (30min) printing. Please get five of these (for 2 extruder model, otherwise you need four) at the same time when ordering the printer plus adhesive

Now I have few principles...:

  1. Never mock things without solid reasoning
  2. Always suggest workarounds if available... and there always is! (=take the initiative! always find a better solution. World is not built yet :-)
I will be coming back to Buildtak issues (cheap alternatives and test results) and Repertier on Linux config later on once I have fully tested them.
I will also add few tips and trick later on to this original article.