Monday 28 May 2018

HangPrinter Workshop with Torbjørn Ludvigsen and RepRap 10th Birthday party at E3D in Oxford

RepRap Hangprinter Workshop @ E3D with Torbjørn

In this blog post and video I'm going over how we got on at the recent HangPrinter workshop at E3D in Oxford (UK).

The HangPrinter workshop video can be seen below, or over on YouTube in Full HD on my channel here - 

I'm lucky to be only around 90 minutes away from E3D, they now have a new and dedicated unit in the breathtaking Oxford countryside. 

This is a typical view on the drive over to visit E3D - if you ever get the chance - take them up on the offer!

Their previous setup consisted of five separate workshops. A company motorised golf cart shuttled various components and completed assemblies from one to the other most days. (no joke).

Now with everything under one roof, E3D is an even more well oiled machine of innovation, development, manufacturing and thousands of orders being shipped all over the world.

I arrived at E3D a few days early before the workshop started. Torbjørn already had his Hangprinter attached to the roof of the E3D workshop. It's around 7 meters up and was a stunning sight.

I was utterly taken back with this 3D Printer, now the size of E3D's workshop and printing out a wonderful HangPrinter chair... 

Hollow chair form and HangPrinter chair (at the back) - was printing well until I 'tested' the disaster recovery feature ;)

That was until I stepped on and tripped over the lines and stopped it printing - all about 10 minutes after I first arrived! - I made a significant entrance :)

The printer tried to compensate for my unintentional 'test' but it did not manage to keep the lines from getting tangled around the spool - it was my fault, but it also highlighted a bug that Torbjørn had seen a few times before. It was the first time that day we got out the BIG ladder to sort out the spool line. It would not be the last, but we did have less crashes of people into lines as the weekend progressed.

A day later Torbjørn discovered the Mechaduino firmware had a nasty rounding error, so that bug would be tracked down and removed before the workshop even started. The V3 design is now significantly more robust at disaster recovery with that very nasty bug now gone.

The magic sensor - *Mechaduino*

The Open Source Mechaduino by Tropical Labs is a very neat little magnetic encoder board.

It's perfect for a project like Hangprinter as it has no endstops, bed probe or way to know if the print head has become knocked out of alignment.

We assembled up these onto the backs of NEMA17 motors for the Hangprinters being built in the workshop weekend. They are a far better, neater and lower cost solution to most other encoder systems available.

The Mechaduino uses a simple round magnet on the end of the NEMA17 motor shaft. That magnet (you should superglue it to the shaft) will then rotate each micro-step of the motor's movement. A multi-pole magnetic encoder will detect the exact orientation and know if a motor has skipped steps or if force is being applied (torque mode).

Once the mechaduino is assembled, the internal firmware (running on a 32bit ARM cpu) calibrates the rotation of each motor individually. This is required as the magnet may be aligned slightly differently, or the distance from the sensor may be variable. After calibration, you can mark up each motor with an Axis and also give them a unique address. This is so the modified Hangprinter Marlin firmware can communicate to each one connected to the bus.

Preparation for the workshop - 

We had plenty to do before the workshop participants arrived the next day, Torbjørn and I set about with as much pre-assembly as possible to make it a more straightforward build schedule.

Basic assembly done, we left all the interesting build assembly steps to the participants.

That included, firmware, software and application setup on their laptops.

Measuring and wrapping lines around the HangPrinter pully gears.

Assembly, soldering and wiring up.

Wiring was the most time consuming, we could have saved around four hours if a pre-made wiring loom was available for the Hangprinter system - that's one for next time or anyone else that's thinking about running a 3D Printer workshop.

After some final assembly and a pre-flight check that everything worked. It was on to the calibration of the Hangprinter.

Auto-calibration of the build space is one of the most impressive aspects of HangPrinter - and only possible by the Mechaduino drivers and encoders.

You basically turn on 'Torque mode' and walk the print effector around the build volume - a script takes data points and maps out a calibration of the build volume. 

You can check the calibration - shown above it was millimetre perfect!

You finally then just set the print nozzle onto the build platform and register a zero Z position, switch out of torque mode and can shortly start a print. Above Sanjay from E3D is checking out the test print from the SuperVolcano hot-end and 1.2 mm nozzle.

The lines were tightened and print quality significantly improved. This turned out to be a very nice print.

During the workshop, I setup the HangPrinter portable frame - still a very large print area, but tiny when compared to the ceiling mounted V3.

The 'portable' uses a slightly smaller configuration for the motor plate, and three arms to form the frame.

These are all still 3D Printed parts for the frame sections to join. The top mounts are hinged for even more portability. (it all fitted into my car as an example).

The extruder mount fits onto the effector, I have made various mounting plates, above for the Bondtech extruder, and another for the E3D Titan Aero.

A short while later, I manages to string the machine and get it all set up for it's first 3D print.

I did not calibrate the portable Hangprinter. All the calculations for the firmware setup were made from the cad drawing of the built machine. This proved to be good enough for a first print, but some real-world calibration was

Amazingly it all worked the very first print. It was over-extruding, and the lines were a little loose, Z height calibration was not correct (my fault in the cad file - not allowing for a lower build platform).

But not a bad first print.

The lines you can see on the build platform were used to get a centre point (by hanging the effector on the D lines) and also to align up the A, B and C lines to the A frame mounting points.

We all then stopped for a special RepRap Birthday celebration - 10 years of Replication!

Special guests.

Lots of 3D Printing talk and ideas :)

And you can't have a party without a cake !

Happy Birthday RepRap !

Adrian Bowyer checking out the test Octopus print on the Hangprinter V3 installed at E3D - Image by Sally Bowyer of RepRap Ltd. CC BY-SA 4.0 Original image on Instagram here

The workshop was a wrap, we had a lot of fun and now even more HangPrinters are ready for printing.

Thanks Torbjørn - we had a great and successful 3D Printing workshop. I hope more people run them and the HangPrinter becomes even more popular.

Torbjørn continues with the Hangprinter project, and I'll be also setting up my machine for further experimentation and development. Stay tuned for future updates.

Almost all the parts (including many spares) for the Hangprinters were printed on my newly built Prusa i3 MK3 - A few were also printed on the MK2 as a comparison of quality, speed and accuracy.

A build video (with my daughter) and thoughts on the MK3 machine will be coming up in a future video and blog post.

HangPrinter Portable - 
If you have an interest in the 'HangPrinter Portable' I made for the workshop, leave me a message of ask me about it over on Twitter. I'm planning to make a few changes to the top mounts to be more solid, but then I would be very happy to post the design files, firmware configurations and 3D Printed components for this version if anyone is interested?

Thank you ! -

I had a great time working with Torbjørn, we were also very lucky to have access to the brand new E3D workshop - tools, components and lots of help from everyone! - Our thanks to everyone involved and the entire team at E3D for helping to make the workshop weekend a really great success.

If you want to find out more about the amazing HangPrinter project, please visit -

Version 3 HangPrinter Forum thread is here -,792937

GitHub Source for HangPrinter is here -

Thanks for reading, see you next time.


Please join me on Twitter @RichRap3D

My profile and posts over on Google+

Files and designs shared on YouMagine

Files and designs shared on Thingiverse

Files and designs shared on GitHub

Files and designs shared on Repables 

My Youtube channel is here, all 3D Printing in Hi-Def video content.

Thursday 29 March 2018

Valentines 2018 Mixed Materials 3D Printing experiments

Mixed Materials 3D Printing experiments

For Valentines 2018 I wanted to try making things with the family. Not just 3D printing, but a combination of 'mixed materials'. In this blog post and video I'll show you what we did for together for Valentines day gifts using a number of different materials and techniques.

It's true that you can get some really interesting 3D printing materials, including wood, rubber, metal and even cork. But the objective of this project was to help get you thinking about using more than just different 3D printing filaments, colours or thermoplastic materials in your projects.

ColorFabb Bronze filament - can look very nice when buffed, but what about using 'real' materials...

The video below goes over some of the experiments our family did over Valentines 2018 - 

Or you can watch it in HD over on YouTube here 

I have wanted to combine fabric materials that my wife often uses into a 3D model for some time. I'm also really interested in doing more work with real wood. Lets see how we got on and what my kids also wanted to experiment with.

The first task was to select a 3D model we could experiment with, after a brief look I decided to design my own heart shaped gift box, with a lid that could be complemented in different types of materials. 

A simple heart box for experimenting - the lid can be decorated in various ways - see below

After printing the prototype in 3D4M C8 and a few more in Polymaker Polysmooth (PVB) materials, I smoothed one in the Polysher to check the fit and finish.

Printing in C8 Material for the prototype - 

Many more printed in Polymaker PolySmooth PVB

Before and after smoothing in the Polysher

The first was smoothed for my oldest daughter, a simple box that she wanted to decorate.

The second was glitter covered. This uses the Polysmooth trick of adding glitter straight after being smoothed in the Polysher. The glitter sticks and produces a smooth sparkling finish that will not rub off when dry.

Next was an experimentation with paper. 

I have used paper before, I custom covered an entire E3D BigBox with paper a few years back, it was a really fun project to do over Christmas whilst assembling the and wooden version of this rather big 3D printer.

For this I made a 3D printed guide for drawing around different types of materials.

This proved to be really useful in getting patterns to be inline across the three separate sections of the heart box.

Using any sort of paper (or other materials), you can draw around and then cut out each part to fit into the 3D printed inlay areas.

The template was made fractionally smaller to allow for drawing and then cutting, so it should fit perfectly.

The next idea from my wife was to try out an embossing machine she uses on fabric.

I designed up a test 'die' with the letters A and S.

They needed to be mirrored before 3D printing, so the end pattern appeared correctly after being embossed onto a material.

We then tested out leather, vinyl, suede, and some faux materials to see what sort of pressure was needed to get a good level of embossing.

The 3D4M C8 material was a little too soft for very fine features, it got a little squished and sharp edges were slightly crushed after a few operations in the 'BigShot' press.

We later discovered that almost any normal PLA (with some impact modifiers) was one of the best materials to use for printing embossing patterns. It's a hard plastic that's stiff enough to work many times, even on very dense materials and fabric's.

This is an area we are still experimenting with, now moving on to 3D printing both positive and negative embossing sides to get even better results - an update on that in a future post.

I'm really pleased how even a simple embossing pattern turned out, this really has a lot of maker potential for interesting projects.

We experimented with many other types of materials, not all shown in their completed forms. 

One was with sand and sea shells - bonded into the lid using clear resin. 

A Polysmooth 'sticky' lid being covered in real bronze powder - allow to dry and tumble finish.

Another had real bronze powder poured over when 'sticky from the polysher'. Another mixed different colour PolySmooth materials - self bonding when smoothed.

To finish off some of the boxes I also did end up using some ColorFabb Bronzefill filament for inlay sections - tumbled and buffed to a shine.

Finally I really wanted to experiment with a real wood veneer. I was lucky enough to have some leaves of walnut burr to try out.

Using the 3D printed pattern it was easy to trace out onto the thin wood. 

I used some 3M blue tape to help keep the delicate burr grain from splitting - a tip here is to use sharp scissors rather than a knife blade. 

If you do decide to cut it out with a blade, consider rounding off the tip. A sharp blade-end can actually rip wood like this, you are better off going very gently around the line a number of times rather than try to cut out the wood in one pass.

You can leave on the masking tape after cutting, or remove if you feel the wood will stay together.

Then it's a matter of bonding the wood inlay into the 3D printed part.

I used white 3M waterproof PVA, just a thin film of glue over both sides.

I also printed out matching blocks to help compress the wooden inlay into the heart box lid.

These were really useful as it made the job of clamping up the part easy. Just let it dry for 24 hours and remove from clamps.

I'm really quite happy with the first result.

I finished the lid with two coats of polyurethane varnish spray, to seal the wood and the bronzefill.

As a proof of concept, this turned out well enough to make me want to experiment more.  I'm no expert in using wood vineere, so if you have any other tips, do leave them in the comments. I'm really keen to do much more with real wood and 3D printing, I think I will be designing more objects like this for future projects.

The modular jewelry tree - 

I also designed a secret side-project for my wife as a gift. Along with the heart gift boxes, the modular jewelry tree project files are now up on Thingiverse and Youmagine if you wish to use the model for yourself.

My secret project was inspired by something that my wife had mentioned at Christmas. The comment was that her small jewelry stand for necklaces was not big enough and didn't have enough hangers.

Designing this, printing and then polishing and finishing was quite tricky to keep secret, but I managed to get it all done before Valentines day.

This colour of PolySmooth filament produces a really nice 'glazed ceramic' look when smoothed.

It's also a modular design, so you can select different sections in whatever order you require to get the height and length of arms for your jewelry.

The little holes in the stacking pin are for added strength, the force extra material using perimeters so you get a strong connection even with a low level of model infill (15%) - that said for the best end results you should still glue/bond the sections together.

You don't need to glue the arms, they should slide and clip in, holding in the main pillar.

The sections have a slight twist, the purpose is to allow earrings or bangles to hang down, and not overlap any hanging below.

The files are up on Thingiverse and Youmagine - 

Modular Jewelry Tree - 
Will be uploaded shortly

Proto-Pasta Surprise - 

I had a very nice surprise filament giftbox from the masters of materials at Proto-Pasta.

If you watch the video, I'm genuinely stunned with the multi-colour transition roll of filament. I had hoped to be able to get hold of a roll at some point. 

I now know this was the experimental reel made just before Joel (the 3D Printing nerd) visited the Proto-Pasta team for some custom experimentation of transition filaments.

You can see Joel's recent visit video to Proto-Pasta, on his channel here

Thanks for reading, see you next time.


Please join me on Twitter @RichRap3D

My profile and posts over on Google+

Files and designs shared on YouMagine

Files and designs shared on Thingiverse

Files and designs shared on GitHub

Files and designs shared on Repables 

My Youtube channel is here, all 3D Printing and Hi-Def video content.