Building a 3d printer


Pictures from the building process

We had been talking back and forth about building our own 3D printer for most of a year. Finally, this winter we went for it. We decided on building a Reprap Prusa i3 REWORK.

Sourcing the parts

We read through the Bill of matierals and decided which items we could source from china and which would make most sense to buy from european suppliers (due to Danish tax regulations it seldom makes sense to buy products that costs more than 80 dkk from outside europe). When we where done ordering from Ebay and AliExpress we only needed the frame, Nema 17 stepper motors, smooth rods and threaded rods and the 3D printed parts. Luckily, with exception to the frame, these parts where easy to source from eurpean sellers.

A couple of years ago I made [two custom touch screen tables[3] as part of a university project. The remains where still stored in our basement. Among MDF and IR diodes

We could not find a resonably priced frame for the 3D printer, so in the end we used some 10mm thick transparrent acryllic sheet that I had saved from a previous project and had it lasercut to fit the CAD drawings.

In the end the parts let us down 2.500 dkk

Construction

After receiving over 50 small packages we found a set a date for the construction to start. The mechanical part is well documented and easy to follow - much like building a large LEGO model. The electronics where a bit more tricky and required a lot of soldering. Software where easy to set up on a linux machine, however calibrating the endstops took some time. This process got extra complicated as we found that some of our soldered connections were flaky. We expected that we were 90% done when we had set up all the electronics and software and we were able to control all the moters from our computer. This, however, was far from the truth. When we started to push fillament into the Jhead we found that it would jam after a few seconds of continious flow. I will not burden you by explaining all the different tactics we tried in order to get the extrution right, but to sum up the important parts: - Buy decent quality filament. The super cheap filament we started using would simply jam inside the extruder after printing for a few minutes. - Make sure to fasten the heat sink to the hotend. If the two parts are not sufficiently tight coupled heat will not be transported away and in the end the filament will start to expand and, in worst case, melt inside the cold part of the extruder head.

We set out to solve the problem and surfed through thingiverse. User called “ssd” had created a model of a rj45 coupler for storage. After printing the model we decided to go for a even simpler solution and create a cap that could be put on the end of the cable. Using AutoDesk Inventor we created a simple model that would fit our cable. We did several iterations to minimize the amount of filament needed to print model and get the best possible fit. Lastly we removed even more material to make the cap look like a skull.

Different iterations of the Dead End