Jamezracer

In the paper I state "Change feeder motor steps/mm on line 366 of Configuration.h"

Looks slick Izzy! I'll give it a go when I'm back in the lab. JohnFox - The youmagine page says you have to cut away plastic to clear the wires. Izzy seems to have come up with a better solution though!

Eldrick- That's another good way to get close. I like to set my esteps such that an extrusion multoplier of 1.00 gives ideal results. Then I can bump it up and down by a percent if I purposely want under or overextrsuion. Additionally our printers are used by students who like to fiddle with settings that they shouldn't so having the multiplier at 1.00 helps. I'm glad your fan duct fit. What screws did you use?

You need to trim a little black plastic off right above the fan. Eldrick- i found you can crank up the tension up very high without issues.

You can right click on the github "raw" button to download. But I should put these on youmagine anyway so here you go https://www.youmagine.com/designs/ultimaker-2-heatsink-fan-duct

Hi Izzy, I just added a CAD render of the duct to the github and inline with the text. Thank you for the clip design. I also use your nozzle size indicator on our big printer! neotko- I put in the due credit to MostlyAtomicBob and my original calculation for estimated steps/mm. based purely on filament diameter it should be 332.5 but I found 327 worked best with my slicer multiplier set to 1.0

Since it fits for 2.85mm did you observe any 'flattening' of the filament from the bearing force? I'm wondering about changing my bearing to one with a inner curve (concave?) so the force it's focused on the grip area and the filament suffers a bit less and guides better the filament for flexibles (and for weak filaments like wood, etc). Interesting the 4% slipping ratio. Btw with all my criticism I forgot to say that it's indeed a great recollection of tunnings. Good job I too worried about flatenning when running high tension on Robert's feeder. I actually have spare bearings with built in curves from our 3DP Unlimited printer so I threw them on for fun. It didn't make any noticeable difference.... criticism is more useful than "good job" so thank you!

I've seen this described most places as the cold pull method. I will add credit to Atomic Bob. Most of these mods are actually community mods so I want to give credit wherever possible. I did gloss over the esteps calculation since I had to adjust it by testing after setting it based on diameter. The slip ratio actually came out to about 4%. I'll add this in. eldrick- You are right in that it is advertised as for 1.75mm but the diameter of the hobbed section is 3.2mm and fits around 2.85mm filament spectacularly. avogra- very lucky indeed! I found someone else at our university with an ultimaker 2 and he has all the same issues that I have. That was purchased around the same time as us though so they may be making improvements without telling us. Thank you for the feedback guys, I'm going to keep adding this.

In April 2015 we took delivery of two brand new Ultimaker 2 desktop 3D printers to complement our overworked large-format printer. Our first impressions were positive. We enjoyed the clean user interface, solid construction, and especially the low-inertia X & Y axis mechanism. It is now October 2015 and we have put over 2000 hours of printing on each of them along with countless rebuilds. Along the way we have come to appreciate the many strengths of this design which have no doubt been a result of the extensive testing and hacking of the original Ultimaker design by the opensource and DIY community. However, there are a couple of minor design faults which render the Ultimaker 2 unreliable and frustrating in a professional setting. Luckily these faults are cheap or free to remedy. In this paper we outline the various quibbles we have with the design of this printer and the steps we’ve taken to improve the performance and reliability. Along the way we provide empirical test data to demonstrate the improvements along with discussion on our own failures along the way. The main paper is here The complete repository with CAD files and software changes is here