Cyrozap's Tech Projects

Computers. Circuits. Code.

5% off MakerBot Industries Cupcake CNC 3D Printer

I just got an email from MakerBot because I entered in the Thingiverse contest (which wasn't a very smart idea—see this post):

As a small thank you, if you'd like to get a MakerBot Industries Cupcake CNC 3D Printer, you can use the code M4K3R to get 5% off until the end of the month.

This offer is valid on any item in the MakerBot store.

Aluminum Idler Wheel

Well, I'd just about had it with my MakerBot's Idler Wheel; It keept ruining prints by separating from the bearing and letting the filament slip to the side, away from the extruder's drive wheel, so I decided to upgrade. I bought an aluminum idler wheel on ebay for $15 + $1.50 shipping (search for "reprap"). It has a groove cut in the side to keep the filament from slipping oast the wheel, and it has the bearing press-fit into the idler wheel, so the idler wheel will never slip off the bearing and slip past the filament! It's been running well during the prints I've been using it, and has made changing my skeinforge settings easier by making the MakerBot's extruder much less dynamic and much more reliable. I have also recently switched to skeinforge 7 from skeinforge 5 so I could use the new raftless plugin with PLA.

Failures and Succeses

This post summarizes the events of the past few days:

  • MakerBot randomly stops during large print (Mendel extruder), causing blob; blob makes print fail epicly.
  • Happens again; no idea what's going wrong.
  • I tighten the X/Y belts.
  • Happens AGAIN!
  • I sleep on the thought.
  • I tighten down the extruder.
  • I take a trip online to the MakerBot Google group; find out what I have to do.
  • I fix it.
  • I happily print out Mendel parts.
  • :D

Mendel Extruder

Extruder working better than EVER!

I printed a dodecahedron today. It printed fine, but plastic was building up on the nozzle.

Why was this? Because the extruder was extruding faster than the build base was moving.

Why is this good? Before, the settings I used worked with my extruder just fine. Now, because plastic is building up, it means that the extruder's motor speed is faster than it was before, meaning that it has become more efficient. This is probably because of the modifications I made to it (especially the filing job I did on the pinch wheel). I modified the Skeinforge settings and am going to print out another dodecahedron momentarily.

I'm so excited!

From MakerBot #000117 'Spartan'

In Other News: Fixing the "Fixed" Extruder

I believe that the repairs I just performed on the extruder are going to work this time! I tried building a test dodecahedron recently and my extruder just stalled on me. This has happened before, but I think I have found the problem. The pinch wheel was allowing the filament to slip next to it during extrusion, causing it to lose contact with the idler wheel and stop extruding to fix this, I simply filed down the pinch wheel. If this works, great! If not, I'll file down the pinch wheel more until it is impossible for the filament to slip. Actually, I think I'll just file it down anyways to prevent making ANOTHER cracked idler wheel.

Rebuilt Extruder Creates More Problems

As I said in the last update for this, I rebuilt the extruder. Yay!

The rebuilt extruder

But there is a slight problem: the extruder, for some reason, extruded for a while, but then just stopped. I think I just need to tighten it down better (I did it by hand first). Ugh. This run-it-for-a-bit-and-then-it-breaks-and-I-have-to-fix-it routine is really getting on my nerves.

MakerBot Extruder Woes

So I decide to finally fix the extruder. In doing so, I found more problems than I thought existed.


  1. Idler Wheel has cracked
  2. Insulator Retainer has cracked
  3. Nichrome wire insulation has turned to powder
  4. Overheating caused kapton tape and ceramic tape to burn
  5. The barrel and nozzle are full of eels ABS.

I have ordered replacement parts.

MakerBot pictures!

Ok, I finally got around to getting some pictures organized, so here they are: