Jump to content
Sign in to follow this  
simmonsstummer

Ultimaker 2 never fill well the tops

Recommended Posts

Posted · Ultimaker 2 never fill well the tops

Sorry! I see your post now. It fails at 3mm/sec. You have underextrusion problem. There are about 15 possible causes. Many of them shouldn't have changed since the printer was new. The most likely problems where something changed are:

1) clogged or partially clogged nozzle

2) tiny pieces of plastic in the Bowden causing it to be tight

3) Deformed isolator

4) Friction form filament at an angle or tangled filament

#3 is most likely

Testing #1 and #3 properly both require you to take the head completely apart.

Testing #2 is best done by sliding filament in and out of bowden with power off. Through the feeder. The feeder does not provide much resistance.

Testing #4 - simply put the filament on the floor so that the filament arrives at the feeder more vertically.

If you take the head apart, take the white teflon isolator and push some cold filament through it and check for resistance. Especially curved filament. Consider drilling the hole with 3mm drill. Consider ordering a new one (the new ones have glass fibers and are more resistant to deformation).

240C and hotter tend to deform the isolator over many weeks. I often print at 260C but try to avoid these temperatures if at all possible. Lower temperatures (210C) can possibly also deform the isolator. Especially if your temp sensor is inaccurate.

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

last test:

gallery_20815_489_219291.jpg

gr5 i'll respond by point.

1 - to try (maybe)

2 - the bowden is clean and new

3 - to try (and maybe deformed)

4 - i'm pretty sure this is not the case

My printer had so many troubles ( hot plate gone, power suppy gone, bowden tube gone ... and so many time clogged nozzle...) this year that i almost never use it. Like 4 days in 8 month. So i really can't accept a damage due to usage.

I'm start thinking that somehow the nozzle is so dirt or ruined i need to replace it.

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

Many many people have underextrusion just like this. It is amazing how many things people try that actually fix the problem. I wish I could say there is only one problem and one fix.

Just today someone put the filament on the floor and that fixed all their problems! Because the filament entered the extruder straight. That's my fix by the way.

The most common problem for new printers is the temperature sensor seems to be off such that the print head is too cold. For older printers like yours the most common problem seems to be the isolator. Fortunately 90% of the printers out there are fine.

Clogged nozzles are also common. You can remove the nozzle and put the entire thing in a flame to carbonize anything left in there.

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

:shock: :eek:

 

I think he means "early production series"

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

This saturday i meet the ultimaker team at the Maker Faire Rome and Chris give me some tricks how to perform the athomic method and other things. She was so kind to give me the new teflon isolator to test it.

So i've changed it and yes my former isolator was damaged but no... i did not get any improvement in the test print.

So i've done again the atomic method and as she said i pulled the filament just in the moment the nozzle reached 90°C but the results are the same..

gallery_20815_489_695235.jpg

A short video:

https://www.dropbox.com/s/7tesnk422udh1vf/2014-10-04%2016.17.25.mp4?dl=0

So i start noticing that my filament always come out the nozzle curly/crimped like the image below. Is it normal?

gallery_20815_489_58087.jpg

What else i can do?

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

Are you still running with the (excessively IMHO) high temperature of 230? That could make the PLA too runny and give you this effect. You can't extrude a liquid!

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

I had that curling issue once. Only once. It ended up being a partial blockage near the tip of the nozzle. I fixed it by taking a metal needle (I used a hypodermic needle but acupuncture needles work well also) and sticking it up into the nozzle hole from below and scriping around a bit to clean the surface. Took about 10 seconds. Be careful not to put holes in your isolator (don't stick the needle in very far).

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

Are you still running with the (excessively IMHO) high temperature of 230? That could make the PLA too runny and give you this effect. You can't extrude a liquid!

 

This theory has merit but I should say I've printed 3 hour prints entirely at 190C and entirely at 240C and didn't have problems. However at 190C I was printing slow and at 240C I was printing fast (75-150mm/sec).

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

I should say that I havent tried 240C with PLA myself, I was coming up with theories because Simmon asked for some.

I'm more curious on why Simmon is running it that hot with PLA. Given what we now know about the Teflon part, ISTM this is risking early deformation of the part, so I'm interested in why Simmon is doing it.

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

I had that curling issue once. Only once. It ended up being a partial blockage near the tip of the nozzle. I fixed it by taking a metal needle (I used a hypodermic needle but acupuncture needles work well also) and sticking it up into the nozzle hole from below and scriping around a bit to clean the surface. Took about 10 seconds. Be careful not to put holes in your isolator (don't stick the needle in very far).

 

is there any chance to damage the nozzle scratching it with the needle?

 

I should say that I havent tried 240C with PLA myself, I was coming up with theories because Simmon asked for some.

I'm more curious on why Simmon is running it that hot with PLA. Given what we now know about the Teflon part, ISTM this is risking early deformation of the part, so I'm interested in why Simmon is doing it.

 

Because i've seen this suggestion on the cylinder test topic:

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

The test cylinder MUST be done at 230C as it is meant to run at that temperature. Any other temperature invalidates the test. I've been doing some limited printing with nylon at 260C. My isolator still seems okay (I have the glass filled one). Maybe 10 or 20 hours at 260C total. I also like to keep it cooler (240C or colder) to avoid warping the isolator.

 

is there any chance to damage the nozzle scratching it with the needle?

 

A small chance, yes. Mostly the danger is scratching the bottom surface of the nozzle. You want that very smooth and flat. It's easy to file it flat again if you scratch it using emory cloth.

So when you insert the needle the first time to it very gently until it's in the hole, then you can scrape the *side* of the needle in a circular motion against the *side* of the hole without being gentle. Also only insert the needle 10mm inside the hole so that you don't scratch the isolator (which is about 30mm from the nozzle tip).

You have to do this while the nozzle is at 180C or warmer so that the PLA is soft. I recommend a cold pull immediately after.

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

another thing I noticed on the picture is that it looks like the teflon part is pretty high up from the hot end isolator (ring with holes). Shouldn't that be like 1mm or so?

At what temperature are these tests done?

On October you say 230º, but perhaps that changed since receiving the new teflon.

Is your feeder also ticking?

If your feeder is pushing in filament, can you manually stop it from feeding by holding it between 2 fingers?

Thank you

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops
another thing I noticed on the picture is that it looks like the teflon part is pretty high up from the hot end isolator (ring with holes). Shouldn't that be like 1mm or so?

 

Well, changing it i push it as deep as i could.. and based on the measures i've made that time, should be ok. But who knows if inside even a little detachment from the hot end isolator is present?.

 

Is your feeder also ticking?

 

If your feeder is pushing in filament, can you manually stop it from feeding by holding it between 2 fingers?

 

Thank you

 

The feeder do not tick.

Indeed everything seems ok but the results are bad...

 

At what temperature are these tests done?

On October you say 230º, but perhaps that changed since receiving the new teflon.

 

Since i read this:

 

The test cylinder MUST be done at 230C as it is meant to run at that temperature.

 

I always done it at that temperature.

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

Well, changing it i push it as deep as i could..

 

The nozzle has a nut above it (with about 6 round holes). This allows you to adjust the nozzle up or down which is helpful for dual nozzle printing (which is not available). It is better if the nozzle is further down such that the isolator is also further down such that the spring above the isolator isn't pushing so hard. That's what Sander is talking about. The harder that spring is pushing, the sooner the isolator will deform again.

 

Share this post


Link to post
Share on other sites
Posted · Ultimaker 2 never fill well the tops

Looking back on your original photo it looks like you have "pillowing". I have recently learned more about pillowing (it never happens to me). It can be often fixed by simply increasing fan but sometimes that is not enough. It is caused because the thread is breaking too easily. It is almost always fixed by trying a different filament. Or doing thicker layers (.2mm) because the thread is now thicker and stronger. Or you can do 25% infill (huge difference from 24% infill!!!) which is a different infill pattern that supports the top layer. Or you can print slower (thread is not pulled so fast and hard). Summary:

1) 100% fan

2) different filament

3) thicker layers

4) print slower (half the previous speed - can slow down when you get to the "bad" layer).

5) 25% infill

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×
×
  • Create New...

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!