This post might still have some value to you, but is also outdated in large parts. 3D-printing is too fast for static blog posts... especially references to software might be outdated. I hope to update everything in the near future. Until then: Read careful and cross-check with the Ultimaker mailing list or forums in case of doubt.

This blog post covers common observations on your first print results and provides recommendations how to improve quickly. Let's do this with help of a quite typical photograph:

It's one of the first prints by Arthur van Hoff (Thanks for granting permission to use the photo!). What do we have? We see a quite nice version of the "Okay hand", but we can surely do better.

Let's differentiate between three areas of possible improvements: 

1. Software-related (Software choice and fine tuning)
2. Hardware-related (Tinkering with your Ultimaker machine setup)
3. Process-related (Rethinking your actual print process)

Here we go:

1. Software:

Make yourself familiar with my first blog post to clear up confusion about the four big subcategories of your software toolchain, which are:

• Prepress
• Slicing
• Machine Control
• Firmware

Let's see how we could fine tune the above print result by tuning some important things within each of this categories:

Prepress: Make sure to have a proper model at hand. You can't expect the printer to print something beautiful, if you feed him with a model which:

• isn't properly positioned on the print bed
  • RepG: "Move" --> "Put on platform"
  • Netfabb Engine for Ultimaker: "Keep parts on platform"
• has holes
  • Use Netfabb's repair routines.
  • Use Netfabb's awesome (& free) cloud service.
  • Use Meshlab (Free, open-source & cross-platform) or other CAD software to close holes.
    • Note: Remarkable blog on Meshlab: meshlabstuff.blogspot.com
• hasn't enough polygons to show off your Ultimaker's capabilities
  • Choose another model.
  • Try techniques to increase your model's resolution. Just google this together with the name of your CAD application.

Slicing: This is a tough one! Probably the most important step in the whole process. You could write a whole library full of books on how to use Skeinforge or Netfabb. So it's a bit out of scope of this quick & dirty blog post. I'll cover the most common flaws here which apply to both worlds (Netfabb & SF):

• Visible layers - can you still count them? BAD!
  • Obvious solution: Decrease layer height.
    • Dramatic improvements with sloped surfaces as sawtooth distortion is reduced.
    • You also gain better results with overhangs.
    • Disadvantage: Print time goes up!
• Stringing - as reversal/retract (method to quickly take back filament while moving the print head within gaps) doesn't work properly at the moment, we see quite some stringing in Ultimaker prints. How to reduce this?
  • Speed up your travel moves.
    • Speeds of >300mm/s should work fine with Marlin firmware (see below).
      • Note: Just got tipped of that we're restricted to max. 160mm/s by the default Marlin configuration file. But still: Just put in 300mm/s for Marlin - the firmware should handle the rest. Thanks Joel!
    • This works best with the latest revision of Ultimakers, as they are shipped with the stronger NEMA17 steppers.
  • Reduce layer height (see above), as the strings get thin as hairs. You can remove them quite easily.
  • Try to decrease your temperatures to the lowest possible value (see below), in order to reduce oozing.

Machine Control: There are quite some possibilites how to send the machine code off to the printer. All of them have their advantages and disadvantages. But some bugs have an actual influence on your print quality:

• Blobbing within RepG 24/25/26:
  • ALWAYS close the control panel during printing. The temperature monitoring is badly implemented and eats up the communication channel between your printer and computer. Therefore delays occur which will result in tiny pauses. 
  • Also make sure that the "monitor temperature" feature is DISABLED in RepG's properties. Same issue, same flaws in quality.
• Note: PrintRun is a really nice alternative to use. 
  • Use this guide or the readme as a starting point.

Firmware: Thanks to the hard work of quite some people (namely: Bernhard Kubicek, Matthijs Keuper, Bradley Feldman and Erik de Bruijn on the Ultimaker-specific side and of course Erik van der Zalm, Kliment, caru and Simen Svale Skogsrud on the underlying code base side) we have the choice between three different firmwares at the moment:

• 5D (original firmware)
• Sprinter
• Marlin

To shortcut this section: There's no doubt - if you want to achieve maximum results in no time you have to upgrade to Marlin. It gives you silk smooth acceleration and speed at the same time. But again you have two options how to upgrade:

• Via RepG (link to Ultimaker wiki)
  • Here you get Ultimaker's official build. It's nice, but the development of Bernhard's github fork is way more advanced at the moment.
• Via Arduino IDE (link to Ultimaker wiki)
  • Here you have to download the latest source code from github and compile it yourself. Sounds hard? It isn't. Trust me.
  • Note: Sadly github changed their website yesterday, and from my perspective it isn't possible to download an individual commit at the moment. Therefore it's not advised to use this method at the moment as long as you don't know what you're doing.

2. Hardware

Your Ultimaker provides an incredible base hardware-wise. Most improvements are really software and process related. Nonetheless you have to bring your Ultimaker into a good shape before gaining maximum quality.

• Make sure your axes are properly aligned.
  • Use these little helpers to achieve best results:
    • Thing:8781 & Thing:12194
  • Note: Don't get crazy with this task. At some point just stop and continue printing. The next time you do some big-scale maintenance you have another go at it and will magically see that it's easier the second time.
• Tighten your belts to gain a better X/Y precision.
  • Use this video as reference and check if you have to increase tension:
  • Print some tensioners to fix the long belts.
    • Thing:10034 or Thing:10082
  • Don't forget about the short belts on your stepper motors!
    • Loosen the four screws and press the stepper downwards, while tightening the screws again.
• Grease your rods! In my opinion there's nothing like "too much grease" ;) 
  • Always ensure a proper lubrication of all axes. 
  • Note: To increase smoothness you can also spray WD40 oil onto a cloth and rub it onto the X & Y axes, instead of the stickier grease. 
  • Don't grease you're rods! All bearing in the Ultimaker are self-lubricating! Use the teflon-based grease ONLY for the Z spindle. That's where it belongs.
• Cooling
  • Make no mistake: Cooling is key to the quality of your surfaces. There's almost no scenario where you disable the fan.
  • From my perspective none of the current fan design suits my need for a powerful 360 degree cooling of the print bed. At the moment there are:
    • The original folded design, which isn't bad at all.
    • Thing:10501, derivative work by cello-ch, originally from Lampmaker. Quite nice, but not as cool as it looks. (Get it? ;))
    • Thing:12257, by Paul Candler. Very well designed, but Paul is still working on a better solution. I'll give this a try for sure.

3. Process

• Z Height
  • Hitting the right Z height is crucial to the success of the whole print job. In a perfect world the right Z height of the nozzle would be your chosen layer height. From my experience you aim for something just a little smaller in order to squeeze the material into the blue tape for optimal adhesion. 
  • The smaller the layer height the trickier it gets, because the tolerances get smaller and sometimes even more confusing: You actually can't see the first layers (depending on the contrast of your filament color compared to the blue tape).
  • A great way to improve the precision of your Z endstop ist this highly recommended modification by Geert: Thing:11033 
• Don't use a raft (a supporting structure which is printed below your actual object)
  • Raft is for girls. (I will stop saying this for the sake of political correctness by the time we have at least 10 female Ultimaker operators actively participating in the mailing list). Raft is for boys who don't know what they're doing. 
  • Seriously, just don't use rafts: There's no reason for it when printing PLA on an Ultimaker. It will ruin your downskins (bottom), increase print time, waste material, look noobish, won't help a lot for removal... you get the idea: I'm not a fan.
  • Try it once just to know what it looks like, then detach it from your print (if possible...), attach a necklace to the raft and give it to somebody you love. A quite practical approach to maintain a good "Social vs. Ultimaker life balance".
• Tune your temperature
  • Never just copy the numbers from some source. Use them as starting point and then:
    • Always try to find the perfect setting for your current material and speed.
    • Most of the times this is lower than you might think. You want to find the lowest possible value which still gives you an uniform extrusion.
      • Note: Paul's current Netfabb settings are set as low as 185 degrees Celsius!
    • I just realize that this blog post can't cover this quite extensive topic. We have to wait for another post about this.
• Use all these tiny helpers
  • Outline - this outlines the print area, which helps priming the nozzle and finding the right Z height.
    • Skeinforge: In older version this is called "Outline" and in the latest version you have to activate "Skirt". Pretty easy and effective.
    • Netfabb for Ultimaker: There's no outline feature in Netfabb at the moment. Feature request is pending.
  • Plain white paper - say what?
    • Use a plain white paper on your print bed before you start a print. You can slide it off the platform in the last second before your print actually starts. This really helps you to have all the small waste parts on the paper and not ruining your first layers.

That's it for now. I would love to see another print by Arthur after he applied some of these recommendations! Drop your best advise in the comments and I'll include it in the post itself.

Cheers,
Florian 

Additional ressources: 

• Ultimaker's official troubleshooting section: wiki.ultimaker.com/Troubleshooting
• RichRap's excellent blog post "The 'Art' of failure - When 3D prints go wrong and lessons from failure" which I already mentioned here.