Go to homepage
21 / 21
Feb 2015

Using the brim is almost mandatory for large prints, specially during winter. However, it should be noted that brim can affect prints with holes in the bottom (see attached files). It can be easily removed with a sharp knife or cutter, but it might leave marks in the print. Sanding it with 320+ grain sandpaper and a drop or two of oil is an excellent way to remove it.

Additionally, replacing ultimaker 2’s feeder with this alternative version 12 is a great idea. This feeder allows you to quickly change filaments in mid-print (for multicolored prints), is easy to clean and see what’s wrong with filament jams.

If there’s one thing that I’d recommend it’s not to treat Cura as if it’s a “Drive Through McDonalds” experience where it’s just a quick place to pass your model through before printing. It’s actually more like a high class a la carte restaurant where you need to sit and spend time studying the menu properly to get the best printing experience. I would recommend going into the layer view and reviewing the layer stack before you print, that way you can often spot potential printing problems before you even switch on the printer. It’s far better to spot the problems before you start, rather than 6 hours into an 8 hour print.

A little time spent looking through all the options in Cura can sometimes save you hours in the long run.

Also I would recommend thinking about whether the model actually needs any infill at all, don’t automatically default to always printing with infill. I have made many models without infill because I’ve looked at the layer stack and seen that they don’t need that internal support. If that’s the case but strength is the reason why you’ve selected infill then it is usually more efficient in printing time to double the shell thickness from 0.4 to 0.8mm instead to make sure the model is strong enough.

The best guide to getting better prints I’ve found on the internet for Ultimaker printers can be found here :

http://support.3dverkstan.se/article/30-getting-better-prints 33

There’s also an associated troubleshooting guide on the same site which is invaluable in understanding why your print may have not turned out how you were expecting.

Hope all of the above helps.

Excellent point! you’re absolutely right and it can’t be said enough. Infill makes sense for some prints (like glowfill prints, where a fully filled print will glow longer and stronger), but for most pieces (like 3Dhub’s marvin) an outer shell of 1.2 or 1.6 is more than enough for a sturdy print.

What about tips for avoiding nozzle clogs when you’re printing with ABS and PLA on a daily basis. . .

Each printer is a different beast, and sometimes what works for one printer might not work for another. We print mostly in PLA and Co-Polyester, and we often switch colors constantly. We do a couple of thins to avoid clogging, which might work for you:

  • Perform the atomic method before each print (The Atomic Method - 3DVerkstan Knowledge Base 5)
  • Don’t leave your filament sitting too long while the nozzle is hot.
  • Store your filaments in a dry place, in order to ensure they don’t absorb too much moisture.
  • Use a dust filter (we use this one, it works fantastic https://www.youmagine.com/designs/dust-filter 7)
  • Print faster and slightly hotter for long prints (we usually add 10mms/s and 5º C), to ensure the filament keeps flowing and doesn’t remain too long in the nozzle.

Hope this helps!

ABS has a high temperature resistance, higher than most common thermoplastics for 3d printing, so it’s useful for parts that have to withstand high temperatures or a lot of friction. In these cases, you need to use ABS, at least until some other filament company comes up with another material which performs similarly.

Switching from ABS back to PLA is very problematic and often causes nozzle clogs. The best deterrent is to do a “cold pull” every time you change filament. This means you pull out all the plastic when the plastic is just above the glass temp such that it ALL comes out - in the shape of the nozzle tip including the .4mm shaft.

Step 1 is to melt the plastic and shove the filament in hard such that a little extrudes (usually UMs retract at the end of a print - if you are there at the end you can cut power and shove the filament back in (both for UM and UM2). 180C is plenty hot enough for PLA - any temp that lets you see some plastic come out of the nozzle is fine.

Step 2 is to cool it to the perfect cold pull temperature. For PLA this is 90 to 95C. For ABS this is I believe 130C (haven’t done it in a while). On the UM2 make sure power is off at the feeder! Pull hard - 10 to 20 pounds force. If it comes out easy you weren’t cold enough. If it won’t come out raise the temp by 10C and try a few seconds later. Also on the UM2 once you pull it out of the nozzle let it sit in the bowden for at least 10 seconds to harden before pulling it through the feeder.

I now do a cold pull on every filament change. When I change colors I don’t have to wait for the mixing to end and the new color to appear.

Thank you so much. I had been disassembling the nozzle every weekend, leaving it in acetone and then cleaning it out.

No. I print with Nylon occasionally which absorbs water very badly and it boils as it prints. You can hear it snap/crackle/pop/hiss as it comes out and you can see the plastic is foamier and whiter (less transparent) when it is humid. I’m pretty sure water content won’t cause clogs.

Simply leaving PLA or especially ABS in the nozzle for 5 minutes at 240C will caramelize it into a brown gunk. Doing a “cold pull” after every 10 hours of printing or on every filament change helps and printing PLA at say 220C rather than 240C helps quite a bit. And ABS I always print at 245C. In general printing too hot or too slow (stopped) can cause clogs. Printing too cold or too fast can cause problems feeding and underextrusion (feeder isn’t powerful enough).