Cooling with compressed air

Just a short post on the current state of compressed air cooling.

I am currently testing the Merlin extruder, i decided to name it in the same way as the hotend since the two belong together, which uses compressed air from an aquarium membrane pump (bubble pump). A medium size pump is sufficient for one hotend and one part cooler.

I made the mistake of ordering a larger pump than needed, which makes the printer unnecessarily loud due to to much air hissing out of the small gaps. On the up side, i might be able to push the Merlin hotend beyond 260¬įC with this. ūüôā


Compressed air part cooler

Merlin Extruder with compressed air hotend and part cooling

Merlin Extruder with compressed air hotend and part cooling

Merlin extruder with compressed air cooling



Dual material file heft

This is something i wanted to do for a while. A handle, in this case a file heft, that is a mix of soft but tough material on the outside and hard plastic on the inside.

Like the bottle cap it’s ABS with TPU, but this time the ABS is the bulk of the piece. There are 2 perimeter shells of TPU around a 50% ABS hexagonal infill.

The heft weighs just 24 g, but is very stable with a smooth and grip friendly surface.

You can see the ABS infill structure through the transparent TPU perimeter

Assembled file

Dual material bottle caps

After some terrible experience with TPE i tried TPU. What a difference!

TPU prints super easy and gives you high quality surfaces and it is super tough.

Today my wife needed a new cap for an expensive cleaner, so i took 10 minutes to model one in C4D and printed it in TPU. The first print worked immediately, but i wanted to try something new. I set the TPU up together with ABS and printed the cap with ABS for the infill and TPU for the perimeter.

The result is very much ¬†worth the extra effort. The TPU gives a nice finishe and due to it’s elasticity it seals the bottle very nicely. The ABS gives the extra bit of stiffness so the cap does not deform so easily.

Next up is a file heft made up in the same way.

Printed bottlecaps as replacement











SainSmart TPU on Amazon

Old file repository

It was brought to my attention that there are still people trying to access my old TP, Xpresso presets and other example files.
If you are looking for any of those please check here
Google Drive
Many of the files will not load correctly in current Cinema 4D versions since they are partly over ten years old and to much has changed since then.

Vacation on a beautiful island

Our vacation in 2016 brought us to the Acores, more specifically to Terceira. Different to the largest island Sao Miguel Terceira has only very limited tourism. What we experienced is a lifely island with beautiful landscapes, coasts and buildings, as well as a lot of friendly people. Surprisingly many of whom spoke english, which easily made up for our total lack of portugese.

The Hotel

Terceira Mar Hotel was our first choice and it was a good choice. The room was clean, the view spectacular, the employees friendly and competent and the food good.

The huge salt water pool was a welcome refreshment after a day of touring.


Squirrel watching us failing at pool

Squirrel watching us failing at pool

Terceira Mar Hotel

Terceira Mar Hotel

Terceira Mar Hotel garden and pool

Terceira Mar Hotel garden and pool

Squirrel and the sea

Squirrel and the sea













Angra do Heroismo

Angra is the capital of the island and the largest city. The city center is in walking distance from the hotel, which made it easy to discover restaurants and shops before falling tired into our beds

Angra do Heroismo as seen from Monte Brasil

Angra do Heroismo as seen from Monte Brasil

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Angra do Heroismo Port

Angra do Heroismo Port

Park in Angra do Heroismo

Park in Angra do Heroismo













Angra do Heroismo Port

Angra do Heroismo Port







The Coast

Since Terceira is a volcanic island there is little what you would call a sandy beach. There are a few smaller patches that are inviting for a swim though. The locals mostly make do with what is prepared for swimming by adding ramps, handrails or steps.

Praia da Vitória beach

Praia da Vitória beach

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On the Island

I let the images speak for themselves, this is one of the places I really want to visit again.


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Monte Brasil

Monte Brasil

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Since agriculture is¬†a primary part of the islands economy¬†a lot of land is used for cattle and crop, however the efforts to conserve the islands beauty are paying off, you don’t see any massive scale fields or herds, on the contrary, what is there adds to the experience.


The main reason for the existence of the island is volcanism and it shows. Not only at the coast where the lava met the see, but also inland where most of the walls that seperate the fields are made of volcanic rocks.

The last erruptions happened only a few thousand years ago so there is still some activity left.

One of the volcanos can be visited and differently to most volcanos on the world you can visit this on the inside!

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The highest point of the island is Serra de Santa Bárbara. On a clear day the view is phantastic and you can see some of the other islands of the acores

Serra de Santa B√°rbara

Serra de Santa B√°rbara

On not so clear days you get moistureized ūüėČ

Serra de Santa B√°rbara

Serra de Santa B√°rbara

Serra de Santa B√°rbara

Serra de Santa B√°rbara








The Whale Dolphin watching tour was a failure success, we saw at least 20 dolphins.




Last but certainly not least, the portugese like their food and¬†here on Terceira that means either sweet, meat, cheese or fish. All are excellent and even the smallest food joint can cook up a mean burger. Don’t forget to try the icecream and don’t bother with Strawberry or Vanilla, go full hog ūüôā


First clean up

What friends, coworkers and charity did not want.

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I am a bit sorry, but there weren’t many options left.

Books, books and more books

Regale01 Regale02

I have decided to get rid of a good portion of my printed books. An estimated 3000 books are up for graps, mostly german Science Fiction and Fantasy. I am still sorting out many english books where i haven’t decided yet what to keep and what not.

I just want to give them to a good home so they are not up for sale but i will simply give them away to anyone who is interested in reading them ūüôā

If you are interested mail me at

All books have to be collected here in Friedrichsdorf.

New GreenTec Filament from Extrudr

GreenTec 02 GreenTec 01 Greentec 03





On the left printed @0.15mm Layer height with an 0.5mm nozzle on my DuoCore @210¬įC. On the right printed @0.2mm Layer height with an unknown nozzle @200¬įC on a friends i3. What is interesting are the differences in slicing, the left was sliced using S3D, the right one with Slic3r.

I was very positively surprised by the new GreenTec filament from Extrudr, that i ordered on a whim alongside a couple of kilos of my usual ABS.

Not only does it produce a nice matte finish, it prints without any hint of warp, the stability is excellent and it is a dream to postprocess with any kind of tool.

The only two drawbacks i found so far are that it¬†sticks so strongly to the printplate (aluminum with 3Dlac @60¬įC) that damage to the part or printplate are a very real threat and the current price of ‚ā¨56 / Kg

I hope the price goes down over time, but even at the premium it might be worth it, especially considered that i don’t have to feel so bad about producing garbage prints since GreenTec decomposes neatly, different to PLA.

biodegradable plastics

Thermal Runaway – Silicone cover to the rescue

Silicone Cover after Thermal Runaway

Silicone Cover after Thermal Runaway

As it turned out, it was a lot earlier than expected that the silicone sleaves from this posting

Silicone Sleave for Merlin¬†made the trouble worthwhile. Some peculiar behavior of Marlin lead to a thermal runaway for a couple of¬†seconds at full power. The silicone, that is rated for 450¬įC deteriorated, but the extruder remains unharmed and even the hotend survived thanks to the new cooling.

For those interested, what happened was that while homing Z Marlin stopped working completely. Everything was frozen including menu and the PID for the hotend, which got stuck with the heater switched on. I haven’t found the reason for the behavior yet, but i’ll do the homing before the heating in¬†the foreseeable future.

Interesting differences in print quality

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These two extruder bodies were printed in clone mode. The white one shows serious stribes that resemble Z wobble, but the blue one doesn’t. Since only X movement was¬†different between the two it is either that, which i don’t believe due to the error¬†existing on all sides, or it derives from the difference in the material. Interestingly the original setting was for the white material. If anything the blue one should show small signs of underextrusion since the filament diameter for that was smaller than for the white.



This is the difference in stepping distance when doing 0.1mm steps. This is not simple z wobble but something different again since it occurs along the z axis, not perpendicular to it.

This is the difference in stepping distance when doing 0.1mm steps. This is not simple z wobble but something different again since it occurs along the z axis, not perpendicular to it.

Interestingly the problem is uneven movement along z, not perpendicular to it.

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