Problems, Problems, and more problems

One of the things to be expected while building something as complex as a 3-D printer is problems. Not just "Oh I forgot to plug it in"  but "the thermistor is not capable of handling the amperage of the MOSFET in the way it is configured in the code" for example. Here are some of the problems I have run into so far:

Z motors were jumping around making irregular motion when instructed to do a morion. Some research and a magnifying glass revealed a fleck of solder bridging two solder joints under the stepper drivers. With a razor blade the joint was removed, and the Z axis worked.

Motors were not traveling correctly, would go 1mm one direction when inatrucyed, .4mm the other direction. After more research I figured out I missed checking for jumper pins having to do with the stepper drivers microstepping. These pins are crucial at getting the correct distances and proper motor steps based on the G code.

I did over spring break get my LCD up and running as well as Ocroprint setup on my Raspberry Pi with a webcam. This allows me to control my printer from any computer I want to, as well as using my phone. I can control the printers motion, heat up the bed and extruder, and start a print from anywhere with my phone wherever I am.

At this point in the build I am eager to print my first item. Unfortunately there are still more problems to work out.

Deliverable Day!

My printer is done! I have everything built and the software is good enough (more on this later). Anyhow, with the exception of bolting the extruder to the mount, and getting the plastic filament to print something there's not much else I can do.

The software for my printer is still a little bit iffy. There are many variables and settings in some 1000 lines of code, not to mention what is needed to get the LCD screen working. I have put test code on the Arduino and confirmed all my motors move. This is good. For some reason they move really fast when homing, I still may have to change some speed settings for that. The printer does connect to the computer, and takes commands. The software will be changed more as I go along to accommodate new parts or calibration. Some of the software on the computer is a little buggy and I may try a few other programs. After I get my filament I am going to just go for it and print something. It may not work the first time, or the second, or the third... but that's all part of the fun. I still have to do a little more calibration on the motor voltage, as well as frame calibration after I print a calibration piece. This will also show the quality of my printer, and how it stacks up against the commercially available $1000 dollar printer.

The 3-D printer ready to print, calibrated and all!

My cable problems!

Final Note: One of the things that I noticed was the excess of wires. Right now there are 20 motor wires (5 motors/ 4 wires each), 9 end stops wires (3 end stops/ 3 wires each) 4 temperature sensor wires (2 sensors/ 2 each), 4 heater wires (2 heaters/2 each) 2 fan wires (1 fan/ 2 wires) and 4 power wires (2+/2-). That's a grand total of 43 wires going to a board a little larger than a deck of cards, and most of the wires move while printing! I already have some cable management files to print when I get my filament.

More Software...

On Wednesday I received my last part for my 3-D printer, the hot end. Now I just have to get some filament (the plastic you print with) and be on my way!

Another thing that I did this week was do my first (and only) soldering for my project. From what I had read I was worried that everything would have to be soldered, and secured with heat shrink tubing. Luckily most of my parts came with connectors at the right spacing that plug right into the board! I could shorten the lengths of the wires, but for now I am going to leave them at the lengths they are and secure them with zip ties. Anyway I had to solder the heat resistant wire to the heated bed (it gets up to 250 degrees Fahrenheit, which would melt the insulation on regular wire) and then add extenders on to the wire to reach the board. This wasn't very detailed soldering so I didn't have much trouble with it.I will probably still have to add plugs on the ends for easy access to the RAMPS board. I also had to extend the wired on my fan with a length of doorbell wire (it was what I had in my garage).

As I may have mentioned before there is code for my 3-D printer available online for free. The downside is that it is written for many different types of printers in many shapes and sizes. This means that I have to do some math to calculate the steps my motors need to take based on rod pitch, belt pitch, pulley size, gear ratios etc. I also have to get my end stops positioned in the correct way, select my power supply, fan type, hotend type and so forth. This is easier than it seems as you just have to un-comment some things in the code, but looking through thousands of lines worth to find the correct item to configure is quite monotonous.