Problem with right ear on robot

[mark-hale 1]

Hi, wonder if anyone can shed some light on this problem.

I recently had a filament "blowout" around the print head where when printing overnight the print failed and the PLA got well and truly wrapped around the head and rear fan.

Never happens when im in the room of course

On removal I managed to bend the metal fan housing as well as damage one of the fans on the side as well.

When I cleared the head and replaced the fans (I ordered a complete set from Ultimaker - so decided to replace all three), I then attempted a test print but found that the right ear on the robot was not forming well and seemed to miss the bottom section.

Speaking to the guys at Ultimaker at a show in London, they suggested it might be the metal houisig and the fact that the fans were not directing the air. They send me a replacement housing and this is now in place. Whilst the ear has improved on the print as shown in the image, it is still not forming correctly. I am going to print the robot later tonight orientated the other way around as I guess in theory if it is the fans, then the problem should be reversed.

In the meantime I wonder if anyone has any thoughts on this

thanks

 

 

[DidierKlein 729]

It's the left ear

Typical problem with the robot, there are many ways to improve this, it's due to the fact that the right fan is to far from the head.

On way to solve this is to print the robot rotated 45° so that the left ear gets better cooling.

Ps: The robot is not an easy print and takes a bit of skill to master don't take it as a very good test print

 

[mark-hale 1]

LOL yes correct, left ear.

Appreciate it is not easy but I noticed that its not as good as it used to be. So im basing the print on earlier models before the PLA overload disaster.

Its not a major problem tbh as prints of other things I do are fine, I was just concerened that I had perhaps missed something else when putting the print head back together

 

[DidierKlein 729]

If it's worse than before it's probably something due to airflow. Check if both lateral fans work (i guess they do) and maybe check the metal support for the fans if it's oriented as it should be

 

[mark-hale 1]

all present and correct, im also tempted to put one of the older fans back on just in case there is an issue with the new ones, although all three seem to be functioning correctly.

 

[eldrick 65]

Better yet, rotate the robot 90-degrees, so both ears get the same cooling.

Then, print one of Venkel's fan ducts, and replace the under-designed metal fan shroud with one that works better.

 

[SandervG 1,521]

You can also lower the temperature so it cools faster, maybe this means you also have to modify your printing speed.

But it is possible to print it flawlessly on the Ultimaker 2 with reduced printing temps, even with the 'under-designed metal fan shroud'

What settings are you using?

The filament also doesn't look like it is Ultimakers? So maybe you need different temps anyway..

 

[gr5 2,172]

1) Fans at 100% (I'm sure you already did this)

2) Print cooler - try 200C or even 190C.

3) Print slower - try 30mm/sec (have some patience). Or even 20mm/sec.

This will improve quality. But who cares about quality?

The robot has lots of overhangs - it's time you moved onto some "real" prints.

 

[mark-hale 1]

I tend to use this one on the default settings as per when the UM2 arrived just to give me an indication on any changes if I tweak anything. This is the only reason I'm printing it. It's my base print test.

Actually Sander you are correct the filament is the only thing that is different as I have now run out of the blue. This is from Faberdashery so yes that could be a factor I didn't actually consider. Again I kept the blue for testing.

Certainly over what is almost a year of using the UM2 gosh that's gone fast, I have noticed the difference on some filaments. Tend to stick to either Ultimaker branded or the Faberdashery stuff, but even then there is some wide variation in the print output

Anyway other prints I do seem to be fine so probably not worth more messing around, it was just having stripped the unit or at least the head apart I was curious why my standard test failed this way.

[aroth 1]

Then, print one of Venkel's fan ducts, and replace the under-designed metal fan shroud with one that works better.

 

I second that recommendation. Though I'd say fan shroud is fine, what's under-designed is the nozzle placement. What I think Ultimaker should have done is this:

 

...instead of this:

Then there'd be symmetrical cooling with the stock fan shroud in both single- and dual-extruder setups. I'm sure that change would cascade through all of the printhead parts, however, and probably also have some implications for Cura.

 

[mark-hale 1]

That's a really interesting idea. Guess the rear fan would influence this change