Beste practices for 3d Clay printing.

How to properly operate your 3D Clay printer

In general the information provided in this section is applicable for all VormVrij® branded 3D Clay printers. If there is a very different approach for a specific model, it will be highlighted in the provided answers.

Is it difficult to 3d print with Clay?

No, and yes.
It’s as difficult as you make it.
Printing with clay is different compared to 3d plastic printing. In most cases you have to mix your own print medium and prepare your own clay cartridges to feed the printer.

On the other hand, once you have the clay, printing is quite straight forward. Simple designs, like basic tube shaped objects, are super simple to create.
With every new printer you receive one filled clay tube and an SD card with example G-codes. You can make your first prints right after installing your LUTUM® 3d Clay printer.

Can I use grogged clay, and what is best practice?

The new stainless steel augers [1] allow to print with grogged paste (0.2mm grogg at 25% mix).

However wrong usage can wear these augers realy fast. We offer specialty

Augers from hardened Maragin steel on request, they are over twice the cost of our standard Stainless steel Augers but the material is about 3 times as hard compared to our standard variant.

There are some advantages to print with chamotte.

  • You need less water to get the correct clay viscosity
  • The prints are stronger
  • The final objects shrink less in the kiln

But there is a catch, use this clay improperly and the auger screw will wear to the point it needs replacement. [2] This is an expensive part so best follow the guidelines below.

With grogged clay you need to make sure there are no blockages in the clay flow. If there are, you need to solve the blockage, do not increase pressure or flow.

If there is a blockage at the tip, for example a build up of firmer clay than what’s in the cartridge;

this happens when the rotation speed of the auger is higher than the actual displacement/extrusion speed of the clay.

It will start to separate particles and water, water goes up, clay goes down and becomes more difficult to extrude.

To fix this you can increase the flow for more pressure. This is not the correct way, the auger will start to wear[3] as it grinds along the chamotte particles in the clay. Especially in the upper part where new clay is fed.

Eventually the soft slurry will move down and more of the screw can rotate while chamotte just hangs around.[4]

Over time it becomes worse as the only way to print is rotating the auger faster to debind the clay and push it out.

To solve this properly, as soon as you see that the extrusion speeds start to change during a print while the speed and flow of the machine remains the same:

  1. increase the pressure.
  2. clean the nozzle assembly up until the screw.
  3. before re-attaching the nozzle assembly extrude clay to refill the extruder with new homogenous clay.
  4. the rotation speed of the auger at moderate speed of 50mm/s with a 3mm nozzle should be around once every second.

You can print chamotte without wearing the auger significantly. Make sure the auger is not mixing, just pushing your clay down.

I Purchased a LUTUM printer, are there example files to test?

fter assembly and setting your machine up according to the assembly manual you are ready to print some files.

With the printer came a disk, there are two folders with test files on the disk, in general these are easy files to print.

some first tips:

  • start with the simple cilinder 70×400, if you find the printer not laying a circle without stuttering, decrease the print speed until it has a nice even movement. (practice file) this is normaly around 80% printspeed, Play with flow and pressure to see the immediate changes in deposition.
  • If you see pulling in corners, increase flow or presure and/or decrease printspeed.
  • Make the plaster wet before you print on it, (but no water should be present on surface when printing) this is better for fisrst layer adhesionand prorecte the print from drying too quickly (water evaporated from plaster goes around print).
  • use the small brush to keep the start and end of print lines in place for the first (and or second) layer and/or increase flow a little for good adhesion.

folder: ‘examples 4M’

These files are all 1×3 (layer height 1 – nozzle 3mm)
you can use the light green nozzle. or cut the dark green nozzle down to exact 3mm.

The light green is actually a little bigger (4mm outer radius) and might give some issue with the basket and cube file.

folder ‘gcode testfiles …june’

test-1 , the cylinder is standard 3mm nozzle but it’s a single walled structure and can be tried with every nozzle (adjust pressure+flow to accomodate for the nozzle size)

test-2 , are 7 pieces and need the gray nozzle (fine clay) and has a 0.8mm layer height (Difficult print on a 4M)

test-3 , water drain is big and needs the 3mm nozzle and has a 1mm layer height