Category Archives: Materials

3D Modelling Materials

Custom Parts for Ikea Lillabo Train Set

The wood composite seems well suited for printing some custom parts I designed to supplement the Lillabo Train Set from Ikea.

The parts printed out well on the first go, with only minimal clean-up required due to the oozing. The circle part of the buffer still had a hole in it even though I set the solid layers to three (infill=20%), but adding a red sticker easily solves that.

It makes me think that a useful feature for a slicer would be to gradually increase the infill for the last few layers, i.e. 20% on layer n-3, 40% on n-2, 80 on n-1 and then 100% on the top.

Materials

More Wood Composite Observations

A quick post with a couple more observations on the wood composite together with some photos.

Sam’s Gears

Whilst printing a tray of the excellent Sam’s Gears by pleppik I wanted to reduce ooze so I increased the speed and also the temperature to 230°C, and midway the extruder jammed due to a blocked nozzle. At higher temperatures the composite turns darker and becomes harder, and it may have been this that caused the jam, or possibly some other detritus. It could also of course been caused by something other than the material, however this is the first time this nozzle has jammed. Generally going slower and cooler seems to be the best tactic.

The Venetian Lion by tbuser I printed scaled down 50% and 25%, and with support. The support came away quite easily, but I can’t compare this to other materials as this was the first print I have done with support. The temperature was set to 220°C and layer height was 0.24, this produced a finish more akin to brown PLA rather than a “wood” finish.

A couple of Simplified Gekko’s by CodeCreations were next to test the hypothesis that visible layers look better with the wood finish. Whilst not terribly beautiful prints, the colour and texture detail, particularly of the heads, are quite pleasing.

Dizingof’s Dragon Bowl came out quite nicely, but highlighted a problem which crops up frequently: the latest version of Slic3r seems to jump around a bit, particularly when infilling, and because of the ooze problem this results in imperfect finishes.

Dragon Bowl

I printed out 2 copies of the bowl, one at 220°C and another at 185°C. The latter is lighter in colour, this is also clearly visible in the Sam’s Gears print, where the crank handle was printed cool, but the gears hot. Another property I am seeing: prints at lower temperature are much more compressible (spongy) and flexible. The pins I printed for Sam’s Gears were so flexible they were not really usable (hence the bolts instead). The texture at lower temperature is also more “wooly” and woodlike. Several of the prints, such as the pin board, have quite a look of MDF about them.

Sam’s Gears, Crank Detail

Whilst testing how paint applies to the material I realised that I hadn’t yet tried painting regular PLA. Surprisingly, at least to me, the PLA also took the water-based acrylic paint I tried well too – so long as the surface was sanded beforehand. The wood composite took the paint well without sanding, apart from the bottom plane, which is quite glassy. This would need to be sanded before applying a coat, otherwise the paint peels off quite easily.

Materials

More Wood Composite Printing

A short post to give some more feedback about working with the wood composite. I decided to print out “Working Micro Gear Heart Keychain” by CrazyJaw.

Heart Gears – Under a Fluorescent Lamp

The stuff really sticks nicely to the bed without it having to be heated with no curling. The gear heart trays are quite small so I will try and print something larger to see how well it copes.

It acts largely like PLA, but oozes much more. I had to up my retract settings a little, and it still blobbed quite a bit. I was printing at 195°C and so it may be that a cooler hot-end might reduce the ooze. I chose 195°C because I got the impression at 185°C it came out a little rough. Now I have a couple of prints done I will be more daring and print at 180°C for longer.

An interesting observation is that the visibility of the layers, which is usually something we try and minimise, becomes a feature aesthetically. It gives the print more of a wood grain look. The photos were taken in a range of lighting conditions to try and convey how it looks.

Heart Gear – Daylight

The parts still feel, and act, like a polymer, which is to be expected, but it has a much rougher finish – at least at the temperatures I have been using so far.  Directly after printing it has a rather spongy feel and after a while it hardens somewhat, but it is generally a bit more rubbery and compressible than PLA.  Sanding, drilling and cutting is more similar to working with PLA than with wood, unsurprisingly. Sanding makes the surface much lighter and detracts from the overall appearance. I used various grades of paper, including wet&dry, to some success, but bringing out the Dremel makes it much lighter work, remembering to keep the revs nice and low.

I also drilled and tapped a small test piece for a 3mm bolt. It holds well though I would be wary of putting it under any serious load – as with PLA.

I also applied some water-based acrylic paint to a piece (not shown) and it appears to go one well. Once it’s dry I will report how it looks and holds.

 

So far it’s a fun material to work with, and the aesthetic quality will definitely add something new to 3D printing. From my very limited testing I would be wary about using it for precise or complicated engineering parts and would probably lean towards structural components. However, my machine doesn’t produce very high quality prints, plus I’ve only just begun playing with it, so there may be much more to this material than I have discovered so far.

I should state, the gears don’t actually turn, but this is due to my being unable to print out the pins to a sufficient quality. A tighter calibrated machine could well produce a working copy with this material.

 

Materials

Printing with Wood Composite

The recent articles (3ders, Thingiverse) about printing with “wood” piqued my interest, and I was excited to see the GRRF sells 0.5kg rolls. It seems I submitted my order in time because they are now out of stock – but taking pre-orders. The filament arrived today and I got a chance to make a test print – the trusty, if now unoriginal, minimug.

The GRRF page and the original Thingiverse entry by Kaipa state that it’s warp-free and requires no heated bed, so I gave this a try and true enough it printed out perfectly. The hot-end was set to 190°C at the start, and I manually increased the temperature in 10° increments to 220°C back and forth to produce the colour gradient.

The bottom of the print is smooth, similar to the finish from PLA, whereas the sides and top are rougher. So far I haven’t attempted working with it (drilling, cutting, etc), which I will try tomorrow. I did try a little sanding which required a bit more effort than real wood and again was similar to working with PLA. I’ll be interested to see how well it takes paints and lacquers.

I find this development pretty exciting as it opens up another material that works immediately with a reprap FDM printer. Kaipa isn’t revealing what is in the composite, nor his process, but Viktor from the forums pointed out  a material from Tecnaro called Arboform. This thermoplastic composite is based on Lignin, a natural polymer, which is a by-product of the pulp industry.

“Mixing lignin with natural fibres (flax, hemp or other fibre plants) and some natural additive produces a fibre composite that can be processed at raised temperatures and, just like a synthetic thermoplastic material, can be made into mouldings, plates or slabs on conventional plastics processing machines.”

What’s also really interesting is seeing the other products from Tecnaro: Arbofill and Arboblend. The latter having comparable properties to ABS, apparently.

I believe Tecnaro only sells granules, and cater for manufacturers, as their minimum order quantity is 25kg (1 bag) but considering the recent arrival of filament extruders (Lyman, Filabot) it seems it would be a perfect match for the 3D printing community. Anyone in Germany (Baden-Württemberg) want to split a 25kg bag with me?

 

… and of course the minimug was watertight!

Wood Minimug - watertight

Watertight!