Exhibition in Designmuseum, Copenhagen Denmark

Skrevet af Michael Holm / Kulitorum.


I am currently exhibiting one of my 3D printers, my Mendel Sells at DesignMuseum Denmark in the exhibition ARKITEKTONISK STUEGANG.

The Danish artist Kaspar Bonnen asked me to borrow one of my 3D printers for the exhibition, and of cause I agreed. The printer at the exhibition is a RepRap Mendel. The Reprap project was started in 2005 by Dr Adrian Bowyer, a Senior Lecturer in mechanical engineering at the University of Bath in the United Kingdom. The idea was to create a 3D printer that was able to copy itself.

This means that the printer can print all the parts that it is made from and with some added "vitamines" - nuts and bolts, electronics, motors etc. The printed copy can also copy itself. This leads to the naming of the original RepRap printers, which are named each after famous biologists, e.g. Gregor Mendel (1822-84), as "the point of RepRap is replication and evolution".

The RepRap project is probably the first real open-source hardware project in the world, and may very well have founded the open-source hardware trend that's still flourishing in the world.

Basically, the idea is that the printers can self-replicate, and with any luck each new copy or generation, if you will, will improve.

And this has indeed been the reality of the RepRap project. These printers are just some of the derivative printers that the RepRap project have spawned:

RepRap Prusa i2, Rostock, Mendel90 and Huxley.

And plenty more

How 3D printers work

The kind of 3D printers we are looking at here are all of the "Fused deposition modeling" type. This means that they melt a string of plastic wire and "draws" a 3D object layer by layer with molten plastic to create a object. So it starts out by drawing the first slice of the object on the "bed" and fill it with some form of cross-hatch pattern. It then moves up in 3D space, typically 0.2mm and draws the next slice of the object on top of what it just drew. Continuing in this fashion, it will print layer upon layer to create a 3D printed object.

There are thousands of homemade 3D printers out there, and most of the people that have a 3D printer at some point finds something that they can improve. Someone finds a faster way to heat the filament, a more stable or faster way to move one of the axis or something else, and when they do, they will typically share the new discovery with the community. There are a huge amount of blogs and build logs and other information that you can find online, some of the more interesting are http://richrap.blogspot.dk/ - http://hydraraptor.blogspot.dk/ - http://sdreprap.blogspot.dk/ and many more.

Thingiverse

Having a 3D printer is not enough, if you don't have something to print. Myself, I have been working with 3D Computer Graphics for more then 20 years, so I can build most anything in 3D that I could possible wish to print, but most of the times I go to Thingiverse to check if someone made the thing before. Thingiverse is a website where people share 3D models of stuff that the users of Thingiverse can download and make them selves. A warehouse of virtual objects to download and make youself. Many of the designs are made for 3D printing, some for laser cutting and a few are made to be produced by other means. At Thingiverse you can find objects in the categories 3D Printing, Art, Fashion, Gadgets, Hobby, Household, Learning, Models, Tools, Toys & Games.

How to make a 3D printer

When I build my first 3D printer in 2009, there were nothing to buy anywhere. You had to make everything yourself. This forced me to learn to use a lathe, to engage in electronics production, to read up on plastic materials, to consider some mechanical problems, to source materials from all kinds of sources and to build it all my self. This was a great project that forced me to use almost all my skills and was great fun. I build a RepStrap, which is a machine that you hack together to allow you to print all the parts needed to build a proper 3D printer. When I made my repstrap, I believe I was one of the first 3 people in the world to build a RepRap 3D printer outside of Bath University where the idea and realisation of the project was born.

Building a RepStrap is still a possibility, and a challenging one, but there are easier ways to get 3D printing today.

The easy way. Buy one :) - You can find home-level 3D printers from 3.000 DKK to around 25.000 DKK (USD 400-6.000), and they differ greatly in quality and amount of work you have to put into it. The most popular "ready to print" printers are probably the MakerBot line of printers. MakerBot have had great succes with their printers - maybe too much. While I do not have any personal experience with their machines, I hear that their service is getting worse and worse these days. But there's plenty of other suppliers.  In Denmark I like Thy3D but I don't really have any hands on experience. 

The better way, if you ask me is to find a local hackerspace/makerspace. A hackerspace is a community-operated physical place, where people can meet and work on their projects. Most hackerspaces today have some form of 3D printer available where you can print the parts for your own 3D printer. Here's a list of Danish hackerspaces - I'm sure each one of them will be able to help you make a 3D printer. The great thing about making your own printer is that you can better fix it when something breaks or you want to improve something.

I hang out at Labitat, a great hackerspace in Copenhagen. The first thing I ever printed on my RepRap Sells (the one at the exhibition) was another RepRap Sells that I donated to Labitat. It has been printing at Labitat for 4 years now, and have printed between 30 and 40 printers for Labitats other members. In RepRap terms, the printer at the exhibition have 30+ grandchildren :)

Go make a printer

Making a 3D printer have been a very gratifying experience for me, one that have challenged my technical skills more then any other project I have ever made. And watching a 3D printer performs its magic is still as mesmerizing as it ever was. With my 3D printer and a CAD system, I am able to go from idea to product in a matter of hours and printing small objects and gizmos for almost any purpose - something you have made yourself is just too cool.

If you have any questions about my 3D printing endeavors, feel free to send me a email at 3dprinter/@\kulitorum.com (remove the / and \)

 

 

J-head 3mm to 1.75mm conversion

Skrevet af Kulitorum.

 I have always been printing 3mm filament, but heard that people were getting better results with 1.75mm, so I thought I'd give it a try.

 

My J-head is "convertible" so it's supposed to workk with both 1.75 and 3mm filament. The instructions says to split the conversion tube (a PTFE tube, ID 1.75, OD 3mm) into 4 and put the pieces under the set-screw used to hold the inner workings of the hotend together.

I stole these images from reprap.me, so you can see what I mean:

 

This method didn't work for me, the tube would be pushed up through the hole in the set-screw. It worked (it only came up a few mm) but it was very hard to get the filament to hit the small hole, without the setscrew guiding it.

So I had to come up with another idea. This is my solution:

 

Screw a m2 nut onto the PTFE conversion tube (it's a bit hard, but possible)

Trim the tube to be flush with the nut.

Put the set-screw on top to hold everything in place.

Volia, problem solved. This has worked perfectly for me, and loading filament is very easy, as the set-screw is tapered in the end, so it guides the filament into the PTFE tube.

Gentlemen, sharpen your j-heads

Skrevet af Kulitorum.

I had problems getting my material to stick reliably to the printbed. I have tried all sorts of methods, some with more succes, some with less.

I have been printing directly on mirror for a while with my old printer, and that have worked well with PLA but for some reason it don't work quite as well with my new printer, the mendel90. So I tested and tested to make it work, and noticed that the filament had a tendency to curl up and get in contact with the head-block of the j-head. Looking at the j-head tip (China copy, but I think "original" versions too), it was clearly a relatively large surface just out of the nozzle.

 

So I thought that if I sharpen it, to make the bottom surface outside nozzle smaller, it'd be more likely to connect to the bed, and less to the nozzle. With a small round file, I filed away some of the nozzle, and made it smaller.

And it seems to work. Both PLA and ABS is now a lot easier to get to stick.

Next time, I guess I should turn it on a lathe.