Ultimaker 2 not printing small parts well

[lukem96 0]

Hello everyone! Thanks for all the help I've received so far!

I'm trying to print a small part for a switch mechanism, the actual object is 3cm x 1cm and 1.3mm thick, but there are 2 prongs coming off it that are about 3x1mm thick, but at the top of the prong a small bulge curves off it. I've attached all the pictures, and as you can see when it prints the prongs are basically just a mess. I printed it in the highest quality i could. How can i improve this please? this needs to be as accurate as possible, i really hope you can help!

Thankyou very much!

Edited July 14, 2015 by Guest

[jcoutts 5]

I had a Similiar issue, First make sure your fans are actually spinning when printing. Second if they are, you need to try a cool head lift, basically this usually happens when the plastic hasn't been given enough time to cool before trying to print the next layer. Also It looks like you may need to tighten your short belts, as your infil is not touching the sides properly on that print.

[jcoutts 5]

You can also trying printing at a slightly lower temperature, that might make it better.

[jcoutts 5]

to clarify I would try a cool head lift time of around 10 seconds, see if that helps. Its under the advanced tab

Edited July 14, 2015 by Guest

[ultiarjan 1,223]

And to provide more cooling time print 2 at the same time or print a small tower at the same time.

[lukem96 0]

Thank you very much for your reply! i tried doing the cool head lift, and everytime the nozzle went away to cool, a small amount of plastic still came out, so it messed up the end finish even more. And the same thing happened when printing 2, it just doesn't seem like its doing it accurately enough.

Could you elaborate on the short belts? I'm very new to all this and am trying to learn as much as i can as i don't know much.

Thank you very much for your help

Luke

[jcoutts 5]

So if material is drooping out of the nozzle you could have the temperature too high so the plastic is running quite a bit.  Also make sure you have retraction turned on in your print settings, that causes the plastic to be pulled back.  I would try turning down the temperature a touch.  

As for the short belt issue, there are two stepper motors that control the x and y directions of the print head.  Sometimes those motors can move up a bit causing the short belts (look where the stepper motors are, they are the pully belts attached to the stepper motor)  to become loose.  This makes slip, which can cause the infil lines not to touch the outer wall lines.

The solution is to undo the screws slightly on the side of your ultimaker and push the stepper motors down by hand, then tighten up the screws again't, while pushing down the stepper motors.  I suggest look at the visual ultimaker trouble guide (google it)  It explain this process better.  you will find infill not touching wall as one of the problems.

[gr5 2,172]

Other's have already said this but you didn't say if you checked these things.

FANS! Fans. Did anyone say fans? make sure both fans are at 100% by the time you get to these.

Tower. Put a 10mm by 10mm tower next to this that is .1mm taller than your part. This allows the two prongs to cool while it prints these. Place the tower such that the FANS will blow on the two prongs while printing the tower.

print at 20-35mm/sec. No slower than 20mm/sec. No faster than 35mm/sec.

Fans.

Lower temp of filament. At .1mm layers 20mm/sec (yes, that's slow) you can probably print around 180C.

Crank the fans. If you can add a window fan or desk fan that will definitely help.

Try another color filament. In general most white PLA filaments are more difficult and quality isn't as good.

Fans.

[gr5 2,172]

Oh - one thing that hasn't been mentioned. Look at all the advanced settings and make sure all the printing speeds are the same. If the inner shell is for example 50mm/sec and then the outer shell is at 40mm/sec it will look like crap because it will overextrude the outer shell. So make all the printing speeds 0mm/sec which uses the nominal speed and of course the move speed should be 150-300mm/sec (that's a non printing speed).

[gr5 2,172]

[lukem96 0]

Thank you so much for all of your replies! it improved the print a lot and taught me a lot of new things, however once the prints came out better i could see something wasn't right and was looking at the model on cura in layers and noticed this, the two objects aren't attached. So i'm going to get that sorted and fingers crossed it will be better.

[gr5 2,172]

It could be a floating point rounding issue where the object is slightly thinner than .8mm wall thickness just before it gets thicker. Or maybe that's intentional in the design. As a quick experiment set shell width to .39 .38 .37 .36mm and so on and see if/where the missing portions are once again printed.