Calibrating the second nozzle offset

Anyone who ever built a dual x printer knows the problem, how to get the difference between the two nozzles down exactly. I tried many things myself, including printed interference patterns, and conduction. All work to some degree, but never reliably.

Then one day i saw one of those cheap USB microscopes and it was pretty clear what will work.

€12 spent on ebay later i was the proud owner of a super cheap USB microscope with the fantastic resolution of 0.3 megapixel.

USB Microscope looking at merlin hotend tip







I printed a small helper, a crosshair for the microscope

Nozzle in the crosshair








With the help of the microscope and the crosshair it was suddenly very easy to calculate the precise offset between nozzle 1 and 2. I just placed nozzle 1 in an easily recognizable place, noted down the coordinates, then switched to nozzle 2 and drove it by hand to the same visual position, et voila, the two coordinates that represent the same exact spot in X/Y. With a bit of work you can do better than 1/10mm, though that should suffice for most uses.

Another advantage of this is that it is now easy to check the repeatability of positioning in X and Y. In the past i had to flexible endstops, the microscope exposes stuff like this easily.

Another advantage is that you can now easily see if a nozzle is worn down.

Thanks to Thomas Kramm, we got this idea while presenting at the  Maxon Supermeet 2018

New Merlin design available from Protoworx

Angelo Malaguarnera made the effort to create a new version of the Merlin, that not only looks very good but comes in two variations. One with a horizontal heating cartridge and one with a vertical.

The longer heating area allows for higher printing speed.


























The new hotend will soon be available from Protoworx 

As usual it comes under Cern OHL 1.2 license.

Merlin 2018 PDF

Merlin 2018 STEP


Merlin Set available from Protoworx

Protoworx now offers a complete Merlin Set

Merlin Hotend Sets jetzt im Shop verfügbar

Some practical stuff

A friend of mine made me these super nice countersinks with a knurled aluminum shaft. To turn them into useful tools for manual work i designed and printed some hefts for them. For fun i did one in TPU, the other in ABS. Both work fine, but the TPU heft is much smoother and it’s slight flexibility gives a nice grip. The print quality of the TPU one is seriously much better, it was printed on the DuoCube, while the white one shows the Z wobble that my old machine acquired a few months back. I have to address that at some point in time, but hey, the machine is about 7 years old now and still pretty good for that.

Black: Hard TPU, White: ABS

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°C with this. 🙂


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 Bárbara

Serra de Santa Bárbara

On not so clear days you get moistureized 😉

Serra de Santa Bárbara

Serra de Santa Bárbara

Serra de Santa Bárbara

Serra de Santa Bárbara








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 🙂


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.

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