Category3D Printing

A few Hotends


Here are a few hotends i have lying around,. While i obviously use the Merlin most, i also employ the Hexagon sometimes.

I haven’t come around to actually using the E3D yet, though i did some extruder designs for it. The Prusa hotend will very likely remain unused till the end of time 🙂

Esun ePC and the Duo Cube

ePC Benchy01 ePC Benchy02

For testing purposes i bought a spool of the new Esun ePC polycarbonate from RepRapWorld. While not cheap it isn’t actually very expensive with €20 for 1/2 Kg. Given that the Merlin Hotend uses a PTFE inliner i was a bit sceptic if it would withstand the 255°C, but no problems turned up at all.

As can be seen in the images bridging does not seem to be optimal, there are even some holes in the top surfaces, something that did not happen with a simpler testprint before. Maybe a bit slower print speed (this one was done with 130 mm/s default in S3D) or maybe lower temperature will help. The stability is good, i destroyed an earlier print using a pair of pliers and i had to use quite a bit of force. Also noteable, the layer adherence was excellent, the part did not brake along layers at all.

Given the very good heat resitance (even better than ABS) i think i will find a lot of uses for machine parts, especially extruder parts since according to Esun the ePC material is not inflamable.

One thing to note, the ePC did not stick to glass when i used 3DLac, i had to print it with an ABS raft, easy enough with the DuoCube 🙂

Testing the Duo Cube – 50% Benchy

Duo Cube printing a 50% scale Benchy @ 0.02mm layer height

Duo Cube printing a 50% scale Benchy @ 0.02mm layer height and 0.2mm nozzle

Trying to print a 50% scale Benchy with a layer height of 0.02mm. A first test to print a M4 screw did work, the screw was functional and stable, showed that there might be a problem with bridges and steep overhangs at this scale. Als Top Layer don’t close easily.

This time i try it with a maxium speed of 40mm/s instead of 20.


Edit: As it turned out, overhangs and bridging don’t work at all. I have to invest a lot more time in determining a working setup for this,

Duo Cube is alive


Thing 92556 printed @ 50%



The Duo Cube works just fine, dual printing now as well

DuoCube dual color testprint

Z Axis setup for the Duo Cube

At the top the M8 threaded rod is mounted using an axial ball bearing, so it just hangs down from it.
At the lower end it goes through a radial bearing that is mounted from the bottom. The pulley is mounted in a way that the whole screw is tightened slightly, that way it never bends but will always be straight.
I use an axial bearing at the top since the load is the weight of the X assembly plus the tension on the screw, while at the bottom i only use a radial bearing since it mostly has to cope with the pull of the belt and in axial direction only with the tension force.

Z-Axis-01 Z-Axis-05 Z-Axis-04 Z-Axis-03 Z-Axis-02

Using Sinterbronce bearings

This popped up a couple of times on the reprap forum.

Often people ask what bearings to use and i am surprised how often the recommendation is LM8UU for linear bearings.

While LM8UU are cheap (at least the low quality ones) and easy to source, they come with some drawbacks. Ballbearings like LM8UU are designed to withstand rather high loads, much higher loads than are usually encountered when building 3D printer. They are also comparably loud and bulky.

For me sinterbronce bearings are a much preferable alternative for most cases.

They are cheap, even the quality stuff, they are silent, small and very easy to use.

Here are a few images on how i use them for linear motion.


x carriage

DSCN1033_small DSCN1032_small DSCN1029_small DSCN1028_small DSCN1024_small DSCN1022_small














As you can see i only use the rather thick walled variation, they don’t deform easily, which makes it much easier to use them.

The images show the use for the X carriage of my Duo Cube printer as well as the use for Z. Depending on load and available space i either use zip ties or counter plates to mount the bearings.

The rendering shows the shape of the mount. It only holds the bearing in the middle and stops it from leaving the mount. Other than that it can rotate rather easily, which makes it super easy to align the bearings.

I have been using this type of mount in various prototypes over the last year and never had any problems, on the contrary, the precision fit is first class, even the small X carriage has no noticable give at all, but runs smooth and easy.


LM8UU to Sleave bearing adaptor





If you want to replace a LM8UU linear ball bearing with it’s more silent, cheaper and less weighty sleave counter part 8x12x12 you canuse this adaptor.

I basically only use sleave bearing for all linear bearings nowadays and for quite a few radial bearing uses as well. The smaller formfactor alone is a huge argument for me.

LM8UU Adaptor


On Thingiverse

Silicone cover for E3D v6


Since i use an E3D v6 alongside my Merlins for comparison reasons i decided to put a silicone cover over the heater as well. It served me very well on the Merlin.

The design is simpler and has only two parts.

Just fill the silicone in the outer mold and gently press the inner part into the outer until it sits firmly. Silicone will ooze out at the rim.

Even if you use separation agents, chances are high that you need to destroy the outer mold part to extract the cover.

You will need 7-8 grams of heat resistent silicone.
E3D Mold 2 E3D Mold 1





STL and C4D files

On Thingiverse

Handle for Airbrush Gun

I don’t have much (or more exactly any) experience with Airbrushing, but the first thing i noticed with my new tool was the bad fit for my rather large hands.
A bit of modelling in Cinema 4D and a couple of prototypes remedied the problem quite nicely.
The handle is easy to remove for cleaning.

On Thingiverse

AirBrush Handle STL and C4D

Airbrushgun02 Airbrushgun01 Airbrushgun06

Airbrushgun05 Airbrushgun04 Airbrushgun03



Silicone Sleave for Merlin

After i did the cover that you can mold around the Merlin heater block, i wanted to make a sleave that can be put over the heater.

The mold comes in three parts, just drill up the holes to 3mm and assemble the parts with M3 screws to hold them tight. It is strongly recommended to use PTFE spray or other any other separating agent. The resulting sleave has a thickness of 1mm and can be easily ripped.

I recommend printing the mold in high quality to get a smooth surface, the silicone will show every small fault of the print.

MerlinSleave03 MerlinSleave05 MerlinSleave04Heatblock Sleave 03

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