Rattling Issue

Tool Path for Reprap Endstop

The green pattern in the picture above made my Reprap Prusa printer rattle like crazy, but it didn't ruin the print. The tool path above is the result of rotating the part 90° on the Z axis, so it wasn't originally supposed to print this way. Actually, there's less rattling when the green zig-zags go up and down the Y-Axis instead of the X axis. This is probably because the Reprap is weaker when rattled in the X direction.

It would be interesting to see Slic3r rotate parts to avoid patterns like the one in the picture above. An user named tjhowse on the Reprap IRC put the idea of "optimal rotation" this way, 'minimize the occurrences of toolpaths that induce resonance in the machine'. I'll need to do more to compare quality and noise generated when parts are printed with the pattern above, and from when that pattern is rotated.

One Lens Cap To Rule Them All

Konica Hexanon Lens Cap

This brings the count of useful things printed with the printer up to 2. The cap was designed by my uncle, whose day job involves working with CAD. The design lives on Thingiverse now: http://www.thingiverse.com/thing:15626

Importance of E-Steps

The picture above shows some sagging and some bumps from where the infill seems to be overlapping the perimeter. Fixing the issue involved calibrating/reducing the E-steps (how much the stepper motor moves when it extrudes/retracts the plastic) in the Reprap's firmware. This guide describes the process: http://richrap.blogspot.com/2012/01/slic3r-is-nicer-part-1-settings-and.html

Here are some prints from after the adjustments were made:

Finally Making Something Useful

The hook that holds our mailbox has been broken for a while, and I decided to 3d print a new one before we start getting threats from our mailman.

The process: Create In Sketchup > Export to .3ds > Repair In NetFabb > Export To .stl > Slice in Slic3r > Print with PrintRun/Pronterface

I learned a few things about the process of making new objects:

1. Sketchup Pro is worth buying for it's ability to export to 3ds format (opening blender each time to convert can be a pain). NetFabb can't read .dae from the free version of Sketchup, but it can open .3ds files.
2. Need to use NetFabb's "convert inches to mm" feature each time something is imported.

Link: http://www.thingiverse.com/thing:15114

LED Lighting

Mouser sells an excellent sticky-backed LED array with a cable that can be easily attached to a reprap power supply. It should work especially well if you have your electronics mounted like this: http://reprap.org/wiki/Lulzbot/Acrylic_Electronics_Mounting_Plate

Here's the link: http://www.mouser.com/ProductDetail/Inspired-LED/4831/?qs=sGAEpiMZZMunSJzOHbijlt95UAhzdqP9

Aluminum Z Coupling

The first parts to break while operating my Reprap were the Z couplings. It was probably a combination of too much tightening, screwing down the Z motors (experts like PrusaJr seem to recommend taping them), and z rods which weren't exactly level. Epoxy got them back to a functional level, and I promptly printed new Z couplings. And they broke again...

Note: I've heard tons of people say good things about Nophead's Z Coupling design: http://www.thingiverse.com/thing:9622 I haven't tried them, but I wish I had some from the start.

Instead, I purchased Aluminum Z Couplings from an ebay seller named nrg24seven (for a few dollars), and they work flawlessly. Here are a few pictures I took before I installed them:

Frugally Powering A Heated Bed

Hindsight says I should have picked a power supply with 20+ amps to power my reprap from the start, but since I'm using RAMPs - it's really easy to use a separate power supply for only the heated bed. For me, a 203W X-Box 360 Power Supply has proven to be a functional, cheap solution for powering the heated bed or the electronics (~17 amps is not enough for both). This guide might help whoever is brave enough to try it:

Materials:

• 203W X-Box 360 Power Supply ($15 from Craigslist, remember to make sure it's 203W!)
• 2 Short Lengths of 12AWG Stranded THHN Wire ($0.37 a foot from Home Depot)
• 2 12-10AWG Butt Splices (~$2 for a package of 15 from Home Depot - Link)
  
  

Instructions:

1. Ensure the X-Box 360 Power Supply is unplugged and fully discharged.
   
2. Cut off the connector which goes into the back of the X-Box 360 (as close to the connector as possible, or just before the magnet).
 
3. Peel back the cable's shielding to expose the 4 yellow wires (12V), 4 black wires (Ground), 1 red wire (5V), and 1 blue wire (Standby I assume).
   
4. Strip a small amount of the red and blue wires and connect them to each other (optionally solder). This will prevent the power supply from staying in stand-by mode after you give it power.
   
5. Strip and twist the ends of the yellow wires together, then strip and twist the ends of the black wires together (possibly solder these and the yellow wires as well).
   
6. Place the yellow (remember these are 12V) and black (ground) wires into their own butt splices, crimp, then crimp the 12AWG wire into the other side of each of the butt spices. It will help you to remember which one of these is ground by splicing black wire to black.
   
7. Put some electrical tape around the connections.
 
8. Power up (you should see a green light on the power brick) and test with a voltmeter. If everything seems to be working, you're ready to attach the leads to your electronics. (below is a picture of the leads attached to RAMPs 1.4 electronics)