ALLAN JAMES EDGAR

TODO add supplementary pics and links

Upon arriving to my job in reading I was introduced to the 3D printer used sometimes for prototyping business stuff. It is highly encouraged for people interested in the process to get trained up on it and print stuff for fun. After a couple of months of printing stuff here and there I was having a lot of fun. I decided I needed one. Considering their cost at the time for even a basic one, at that I was sitting atop the Dunning Kruger curve, I decided to make one from scratch. I knew a couple of guys from the office that had built their own so I figured I couldn't go far wrong. After taking a look at the RepRap offerings I settled on the Haeckel Design. I chose this was becauseI liked the way it looked and it was known to be sturdier than the popular A frame style. I do tend to play rough with my toys.

My first step in making this was to download the the model in most of it's current forms. I had to then make some choices about which parts to use to get the desired finished product. My general philosophy for this project was that it would cost X to do it, but would only cost fractionally more to make it monstrous. As with many of my projects I aimed a touch too high. I tweaked the design so that the end product would host a 30cm x 30cm heated aluminium build plate with 30 cm of vertical travel. I decided on a silicone heater as the PCB styles have a tendancy to warp at that size which is no good for bed adhesion. I used a slightly outdated sanguinololu board flashed with Marlin. The whole thing was powered by an old evga psu as it had a beefy singular 12V rail (initial estimated power draw was around 24 amps, Yikes). I printed all the plastic components, ordered the 20mm aluminium extrusion and chrome plated rodes for the rails. After I got my hands on all the hardware the building of the frame went remarkably well.

The first snag I ran across was with the control board. Because of the LARGE power draw from the heated bed the mosfet on the board cooked almost instantly. The components on these boards aren’t renowned for being high quality. however even the more premium boards this power load would have been a stretch. I did the maths and eventually found a suitable logic level fet that could take that kind of power. I was lucky that I could even find one that had the optimal thermal properties for the V&A I was using. I then strapped a heat sink on it for good measure and it hasn’t been an issue since.

Another thermal issue arose around the wires from the PSU. The board's standard ATX connector only took two power and two ground wires from the supply. Unsurprisingly when the bed was on they would get so hot that the insulation became soft. To sort this out needed to perform some surgery on the PSU. I started off by cropping and terminating all of the wires from the other voltage rails. I routed all of the 12V wires (and an equal amount of ground) through a braided cable sheath and soldered them all into the ATX connector. Problem solved. After sorting these issues out there was still a bit left to be done but I could see the finish line. Next I figured out the control software, leveled the bed, calibrated the stepper drivers and finally had my first successful print! Happy days!

My first print was a giraffe from thingiverse. His body turned out fine but the neck was a bit squiffy. I suspected the long and thin nature was the cause but i was well out of my troubleshooting comfort zone. It turned out that the steppers were reversing directions so often that it was tripping their overheat protection leading to skipped steps. I liked how he lookd surprised so I kept him. His brother came out looking the way he is supposed to after some more calibration. Since then I have printed off some useful things (a broken boot bracket for my car, some camera casings and project boxes) and even more useless ones (a 30cmx30cmx30cm voronoi bunny and a large low poly fox.)

From the get go this printer was designed to be quite feature heavy but some ideas that I have for future expansion include a second print head (so many possibilities!!! ), auto bed leveling sensor and replacing the m8 threaded rods with honest to god lead screws. Until then I just have to avoid getting sucked into the delta printer that I spent a little too much time researching how to make...