March 12, 2014
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This is the fourth and final installment of Sturdley’s misadventures in building a 3D printer. See here for the entire series. Last time I was experiencing power supply-related shenanigans and awaiting arrival of a 12V supply from the internets. The new supply was delayed several days due to weather. During the wait, I took the opportunity to measure the extruder rate and level the print bed. Once the supply was delivered, I took a brief 10 minutes to wire it up to the printer only to run into more problems with the electrical outlet near my workbench. Now I have had a new circuit installed just for the workbench, so I’ve got my fingers crossed that the power lines running to my house do not spontaneously combust.
Once the power situation was resolved, I loaded up the test cube for printing. The 1 inch cube took about an hour and 45 minutes. I followed this up with a different test pattern, a stair-step pattern that ran for about an hour. Both objects came out quite nicely. The stair-step pattern measurements were quite close to the 3D model. I printed a standard Lego block, but there were issues fitting with the real thing, and it lost one of the “round things” (studs – I had to look it up) on top after separating the pieces. I have since printed several other items: a squirrel, some brackets for a wall-mounted filament holder (they were insufficiently strong for the job), a knob for the printer, some spacers for the Z-axis threaded rods (no more vibrating against the wood frame!), a copy of Greg’s accessible extruder, a tardis, a star trek communicator, and more test patterns. Most of these objects are available on Thingiverse, by the way.
In the process of printing stuff, I noticed some printer issues that required attention. The Y-axis belt was skewed resulting in the edge rubbing against the pulley on one end and the wood frame on the other end. It was also a bit too tight. Reversing the pulley on the motor and loosening the belt tension drastically reduced the friction and noise. The stepper motors are running quite hot, and the extruder gears seem to be wearing a good deal faster than I expected (good thing I already have a backup printed). These things are rather minor, however, and easily fixed.
Then last night I ran into a new issue with – you guessed it – the power supply. The 12V supply that had been working so well for 2 weeks developed a slight buzzing sound and an inability to hold a voltage. It’s still within the return period (and unlike the ATX supply did not necessitate cutting parts off, voiding the warranty) so it is on its way back to whence it came and a new one scheduled to arrive later this week. At this time, I would like to request that if any of my readers have influence with the gods of electromagnetism that you please intervene on my behalf. My sanity is at stake.
All told, I am exceedingly happy with this printer. The prints were coming out great from day one, and almost every problem I encountered was the result of my own actions or simple bad luck.
February 20, 2014
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This is part 3 of my MakerFarm 8” Prusa i3 build progress, see here for previous posts. Last time I covered the final frame assembly. This update is focused on the electronics installation and testing. As an aside, I went to the local Home Depot to pick up my glass only to find out that they will not cut it for me. Derp. I bought a few 8×10 pieces anyway; I’ll only need to lop off one side.
Before I start running wires, I need to assemble the hot end and extruder. These will then be installed on the X Carriage.
Extruder with Hot End
Next up, I need to do a quick solder job on the three end-stop switches. I will also attach the thermistor to the underside of the heated bed, and then attach the bed to the frame. The last electronic component to install is the RAMPS board, which mounts onto the right side of the frame. So I will run all the wiring over to this location using the convenient wire guides, and after checking that everything works I can gather up all the loose wires with some strategically placed cable ties.
With all the wiring hooked up, it is time to test. Aside from a little user error with the end stop switches, everything seems to function properly. The motors move when instructed and in the correct direction, the switches are detected properly, and the extruder extrudes!
Here you see the fully assembled printer with cables tied back and loaded with a bit of filament for testing the extruder. My plan was to follow up the extruder test with a test print, but the electrical demands of the printer (along with who knows what else on the same circuit in my 90-year old house) were too great and I tripped a breaker. Since this was at 10:15 PM on a weeknight, it was a clear signal that it was time to stop for the night. Added to the to-do list: put in a dedicated breaker and outlet for my workbench.
My plans were foiled again the next evening when I encountered some issues with the power supply. Specifically that it is not able to provide sufficient current without tripping an internal shutdown. Rather than messing with it (I’ll shelve it for use on a less demanding project), I ordered a real 12V supply, which should arrive in a few days. In the meantime, I will work on some of the calibrations that can be done under limited power.
Next time I will have an update on the calibration and test print(s), possibly with some video of the machine in action.
February 16, 2014
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This is part two of my build progress. See part one here.
Last time I finished the X-Axis. Next up is the Y-Axis, which includes the frame.
The frame is the first part to give me any real trouble. I had to adjust the backplate on the bottom of the frame three times, mainly because I kept not paying close enough attention each time I changed it. Eventually I got it right…
Frame with X, Y, Z axis installed
This last photo is my current progress. I still have all of the electronics to wire up, followed by testing and calibration. I have to say that so far assembly has gone quite smoothly. A few spots where things fit a bit tight, but nothing that a little appropriately-placed squeezing couldn’t fix. I also need to take the time to stop at the hardware store for my glass.
More to come…
February 15, 2014
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The latest gizmo that has captured my attention is the 3D printer. For those that are absolutely clueless, it is a machine that “prints” small objects, usually plastic, by depositing layer upon layer of extruded material. Some of the objects that can be created are quite complex.
I started looking at commercially produced units, which are quite nice, but the price tag is too steep. Then I found RepRap. Thank you open source movement! I spent a few days reading through the material and forums, until I settled on building a Prusa Mendel model. The main advantage with this model is the low cost; estimates put the price tag from $400 to $600 depending on how you source parts and what is included in the build.
I was not looking forward to the time-consuming effort of hunting down parts myself so I decided to buy an assemble-it-yourself kit. I’ll get the satisfaction of building the printer without the headache of supply chain logistics (I’ve dealt with enough of that at work, thank you very much.) Based on a plethora of good reviews and praise for the company owner, I decided on a kit from MakerFarm, the 8” Prusa i3.
The box arrived the other day. Unpacked and sorted a bit, the kit looks like this:
MakerFarm 8″ Prusa i3 Kit (power supply not included)
I am following the MakerFarm build instructions and videos. The X Carriage and X Idler assemblies went together quite easily. After assembling the X Motor assembly and started on connecting these parts into the X Axis, I noticed my allen wrenches were somewhere I could not find. I did the best I could with the available tools and called it a night. Tomorrow will include a quick trip to the shop before continuing the build.
X Axis Assembly
To be continued…