Motivation for Building a printer
About a year ago I was telling my Grampa about some cool up-and-coming technologies and waxing poetic about open-source technologies. I mentioned off hand that I would like to build a 3D printer, and that I probably could, and basically my grampa called me out. He brought to my awareness the fact that I had almost no practical experience or theoretical knowledge of mechanical, electrical, or software engineering. (I still have almost no experience with the first two).
He also called into question the value of 3D printers in general by asking what I would want to print with it. I said I didn't know. Anyway, as a brilliant act of motivational bluff-calling, he asked me how much it would cost to build a 3D printer. I low-balled the answer, because I felt backed into a corner about the actual value of these things, but then he pulled out a check and wrote me a check for my quoted price. He might as well have written "Prove it" on the memo line.
Immediately after that I got a job doing software engineering, and I kindof lost interest in 3d printing, so the check sat uncashed for a year. My Grampa would periodically ask me how the printer was coming along, and I would always say I hadn't started yet, but I intended to.
Then my Grampa died. That was about 2 months ago. I was (and am) very sad about my his passing, and I wanted to do something that would totally blow him away. Something that would have made him very proud. I wish I could have done it while he was still alive. Sometimes I get mesmerized when I walk past that printer--when I hear the hum of the cooling fans and the squeaking of the polished rods and the buzz of the engines. My Grampa was an engineer, and I just think about how much he would have loved to see this.
The Particular Kit That I Built And Why I Chose It
Forgive me for not totally having the language to describe the ecosystem of technical language surrounding the design of the printer that I built. I guess I'll just start with a link the the exact printer that I bought. I found this printer on a blog post about the best clones of a RepRap Prusa i3. There's 3 key concepts lying behind why I got the particular printer that I got. The first is RepRap. I'm not totally clear about what makes a 3D printer a RepRap, but my understanding is that a RepRap is a 3D printer that can be easily made using another 3D printer. Rep Raps use open source technology and every aspect of the sofware seems to be open source. A Prusa i3 is a particular model of RepRap designed by a guy named Joseph Prusa. Prusa sells his 3D printer for a little over $1000 dollars, but he also open-sourced his design, so anyone can copy it. And copy it they did.
There was a wide range of prices, which was a major parameter in my decision, and I don't really remember the specifics of that decision, but basically I chose the kit that I got because it was available on Amazon Prime. In the future, I might look at the assembly directions before buying a kit. The directions were adequate--just pictures and descriptions on the nuts that you want to use--but definitely not great. Some of the pages showed objects that appear to have been from previous iterations of my printer. The videos showing assembly and troubleshooting were sketchy, usually used a different iteration of the printer, and had no words. To Hic Top's credit though, all of the information is there if you go slow and take some risks, and think about what you are doing.
A few selected setbacks and lessons.
the rods not aligning
I was very impressed with the vinyl skeleton of the printer. It's really stable and pretty easy to put together with just a handful of screws. The first setback that I hit in the building of the printer was that the rods that the z axis slides on did not fit through the hole cut out for them in the vinyl. I could not get the y-axis carriage to connect to the rods while they were stuck in the skeleton. I was so stumped about this that I ended up taking some pictures and emailing Hic Top about my problem. They print a support email address on the front of the instruction manual, and it says they will answer any question and get back to you within 24 hours. Sure enough they got back to me with a very short and cryptic email that really pissed me off for a few days until I figured out the solution and realized that their short email had answered my question.
Putting most of the frame on backwards
Pretty self explanatory. Basically as I was trying to figure out how to screw in the power supply, I was having tons of trouble. There did not appear to be screw holes where the power supply was supposed to go. Somehow I figured out that I had switched the left and right sides in the very first step of the entire manual. This required basically unscrewing the entire printer and then putting it back together properly. Don't do that. Make sure you are very careful and deliberate about following the directions.
Thermistor was broken
After having made several mistakes in producing this printer, I was pretty paranoid about actually turning the thing on. I checked every wiring connection over an over again and found no errors. The thing is, if I connected positive to negative or something like that there is a good chance that I would fry the electronics right off the bat. But so I just turned it on eventually, and straight away I found an error on the LCD screen about "Maxtemp" being met. A quick google search revealed that this is due to a thermistor being broken in the extruder. Since the kit was brand new, I figured there was a chance something else was wrong. So I disconnected the thermistor and tried loosening it up and inserting it again. That fixed the problem, so I assume there as some kind of electical short happening right at the tip. I was able to debug this using a volt meter and the extra thermistor that came with the kit.
One of the limit switches was also broken. It's kindof cool when things break, because it gives you the opportunity to figure out how something works. At some point this week I'll have to change out the fan that I broke one of the blades on while trying to insert filament for the first time. The fan hit my finger and one of the blades flew off. The printer still works fine with that fan broken, but it's a little loud and shaky.
The Bed Adhesion Problem
The last thing that I want to talk about is that, once I got the bed level and hit 'start' on my first print, the filament would not stick to the heated bed. I'm embarrassed to say I spent the better part of a week trying to figure out the optimal distance between the nozzle and the print bed. By chance, while a friend of mine was at my apartment checking out the printer, his cousin stopped by and mentioned that the technicians at his company use painter's tape to get prints to stick. That's when we noticed the giant roll of masking tape still in the kit--one of the last things in there.
I can use this printer to make some really good prints. Parts will break, and I will fix them. A laser cutter is high on my list of things to make. So are the many random things that I find on Thingiverse. I don't really know how to 3D model with anything besides SolidWorks (and I don't have a SolidWorks license), but I've been eyeing an open-source program called OpenSCAD that many Thingiverse designers use to make some really cool things.