Jump to content
Ultimaker Community of 3D Printing Experts
Sign in to follow this  
will_57

Difficulty With First Print

Recommended Posts

Hello everyone,

I just attempted a first print. It was supposed to 20mm test box, but after printing about 3 or 4 layers just fine, something seemed to begin blocking the extruder, as the flow rate began to drop until it completely stopped extruding material. I cancelled the build and tried printing the box a second time, but the extruder still wasn't extruding. Now, it has reached a point that I can't even get it to extrude anything, even pushing the material by hand. Is it possible that the extruder managed to get blocked this quickly? If so, what must be done to fix the issue?

Thanks,

William

Share this post


Link to post
Share on other sites

it sounds like a blockage in your bowden tube where it hits the first part of copper - or you are extruding to "cold" for your material. I think most of us extrude at 220-235 degrees for PLA.

1. First try to heat the head to about 260 degrees for 5 minutes and see if that loosens enough for your to manually extrude a bit. If that is the case - then it is a blockage. A high temperature will make the material softer and allow you to pull the material back (should not be done with a lot of force)

2. Let it cool - and then take the bottom head assembly off (from bottom plates) - and find a way to keep it stable. You should now be able to see the blockage on the top of the PTFE. Dont remove the material yet

3. Heat head to 180-200 degrees for a couple of minutes - and then use pliers to remove blockage.

4. Check the bowden tube sticks out 8 mm below the bottom plate. If it is less - then the material can work its way in between the bowden tube and the copper "tube" and create a blockage.

5. Adjust and reassemble

/kaz

Share this post


Link to post
Share on other sites

I had similar problems, but they were caused by a bowden tube with too small inner diameter.

Because the diameter of filament varies over its length, the filament would get stuck during printing.

You can try to disconnect the tube and see if you can push filament through it by hand.

It should not require much force. If you can measure the inner diameter, it should be at least 3.1 mm.

My problem was solved by contacting ultimaker support. They sent me a new tube.

Share this post


Link to post
Share on other sites

I get the feeling that this might have been caused by a combination of both of the problems you described. I followed the first suggestion and took apart the hot end. Removing the solidified filament from the hot end revealed that the bowden tube was about 2mm short of how far it was supposed to be inserted into the hot end. I then took out the bowden tube to test how easily filament passes through it. I can push filament through with one hand, but it certainly is not loose. The tube will not slide along the filament with gravity alone. Is this what it is supposed to be like?

Share this post


Link to post
Share on other sites

If you are getting the plug issue then her's what you need to do:

Take apart the hot end and stick the bowden tube down through the white plastic clip as normal, but make it stick out about 5mm farther than it says. Then put the blue horseshoe part on the white clip and re-attach the hot end. When tightening down the four long screws on the aluminum plate you should reach a solid end point with the end of the PEEK part about 5mm from the wood. The aluminum part is NOT FLUSH in this assembly, it sits about 5mm away from the wood. Get your screws pretty tight but make sure the aluminum part is roughly parallel to the wood.

Now, extrude. The extruder may jam again and form a plug. This is normal. What is happening is the force of extrusion is pushing the bowden tube up, but that is causing the white plastic clip to dig in to the PFA tubing, making a tighter grip. Take apart the hot end one last time, but DON'T disconnect the bowden tube or loosen it in any way. Take out the plug of PLA and reassemble the hot end again and make sure to get those four long screws TIGHT, but keep the aluminum part parallel to the wood. The PEEK part should now sit closer to the wood by a few mm.

After I did that I didn't get any more plugs, and I didn't ahve to cut off the end of my bowden tube or shorten it or anything.

Share this post


Link to post
Share on other sites
If you are getting the plug issue then her's what you need to do:

I followed your suggestion for removing the plug in the hot end and attempted a print. Once again, the first few layers printed fine, but then I began running into flow issues again. I cancelled the print and removed the hot end expecting another plug, but there was none. So, your suggestion did fix all issues with the hot end, but now there must be some other problem with the feed mechanism. It is extremely difficult to feed material through by hand, so I'm guessing this is an issue with the bowden tube being defective. Is there anything else that could cause these problems?

Share this post


Link to post
Share on other sites

Contact support and have them send you a new bowden tube. If it is difficult to push the filament through by hand, then the ID of the bowden tube is bad. Yours seems to be marginal: It almost works. Ultimaker say they have a long tube with just some sections that have a smaller inner diameter. Not simply a tube with the wrong specifications....

After heating the hot end, I can usually pull out the plug without taking the whole hot end apart.

I would also suggest that you try printing a bit hotter. I'm not sure at what temperature you're printing now, but I can manage printing at 200 and 210 (PLA) but hotter works as well. And when mine says 200 it might be something different than when yours says 200. So you can safely go up to 250 for pla without breaking anything (except maybe your print if it is really too hot).

Share this post


Link to post
Share on other sites

So, I contacted support about the issue, and they sent me a new bowden tube. It arrived today, so I tested the tube, and the friction of filament passing through it was significantly lower. After installing it in the machine, I started a print, and ran into no flow issues. However, it started becoming misaligned in the Y axis, and even skipped a few mm on one layer.

Print%2520Misalign.jpg

I knew my belts had always been a bit on the loose side, so I printed some belt tensioners and installed them in the machine. After trying the print a second time, two problems arose. The print was still getting misaligned in the Y direction, and it again ran into flow issues after 10 layers or so. I checked and there is no blockage in the extruder, and the bowden tube is no longer an issue. I can now see that there is some PLA that is leaking out between the PEEK and the aluminum block, as well as between the aluminum block and the nozzle. I'm guessing this is most likely what is causing the issue, so how should I go about taking apart the hot end, and what needs to be fixed now?

Share this post


Link to post
Share on other sites

First check the tension of the small Y belt, this could also be too lose causing the same kind of problem. Also check if all the pulleys are tightly attached to the axles.

One more thing, after installing belt tensioners, you need to lose up 1 pulley and screw it tight again, to even out the tension on the 2 sides of the belts.

Share this post


Link to post
Share on other sites

Hello all, I am a Newbie having a similar issue here with my first - also second, third, :( ... - print on my Ultimaker: It seems that I am having a steady flow during the first layers, but at a certain stage my print becomes absolutely sparsed until I have to stop it. I use the Netfabb Standard profiles for the generation of my GCode together with the Standard PLA parameters. I have also tried to increase temperature and reduce speed, I have fixed extruder issues - same bad results. My prints look like the one on this photo:

https://docs.google.com/open?id=0B0DE0h ... mJaTkpsTGs

I am not sure, but I think my extruder works. Is there a way to check out without unmounting the printhead? Can anyone experienced provide me an absolute failsafe GCode-file with an easy test object in PLA?

Thanks in advance for any suggestions!

--

Christoph

Share this post


Link to post
Share on other sites

Looking at your photo I say your GCode is fine. As it seems to print the first few layers quite fine.

At which temperature are you printing?

Is it easy to push the filament trough by hand one the printer is hot?

Is your big gear firmly fixed to the bolt? (this was my first, and biggest problem, the gear was turning, but the bolt was not, causing very little plastic to be pushed into the printer)

Which software/firmware are you using? (to generate the GCode, and to print that GCode)

If you have an plug, then eventually it will plug up completely, without you being able to get any filament trough. But seeing that there is still some PLA comming out of the nozzle, I would say that you don't have a plug.

Share this post


Link to post
Share on other sites

I'm having a similar issue with mine. Support sent me out a replacement bowden tube after the one that came with the kit was too tight to take filament.

Since that, there have been plugs on 3 occasions and get the same sparse prints, see here: viewtopic.php?f=21&t=1036

Yesterday I took the hotend apart and replaced it with the spare one I ordered with my kit, I trimmed the bowden tube a little and made sure that it was all the way into the PEEK and I'm now hopeful that this has remedied the problem once and for all.

Best of luck getting it sorted out.

Share this post


Link to post
Share on other sites
If you are getting the plug issue then her's what you need to do:

Take apart the hot end and stick the bowden tube down through the white plastic clip as normal, but make it stick out about 5mm farther than it says. Then put the blue horseshoe part on the white clip and re-attach the hot end. When tightening down the four long screws on the aluminum plate you should reach a solid end point with the end of the PEEK part about 5mm from the wood. The aluminum part is NOT FLUSH in this assembly, it sits about 5mm away from the wood. Get your screws pretty tight but make sure the aluminum part is roughly parallel to the wood.

Now, extrude. The extruder may jam again and form a plug. This is normal. What is happening is the force of extrusion is pushing the bowden tube up, but that is causing the white plastic clip to dig in to the PFA tubing, making a tighter grip. Take apart the hot end one last time, but DON'T disconnect the bowden tube or loosen it in any way. Take out the plug of PLA and reassemble the hot end again and make sure to get those four long screws TIGHT, but keep the aluminum part parallel to the wood. The PEEK part should now sit closer to the wood by a few mm.

After I did that I didn't get any more plugs, and I didn't ahve to cut off the end of my bowden tube or shorten it or anything.

Apologies for hijacking the thread and the double post.

Just wanted to thank destroyer2012 for this advice, after many attempts this seems to have fixed the problem for me. Just got through my first 90 minute print with nice consistent extrusion.

Best I can tell the issue is that the metal teeth on the white fitting need to be made to bite into the PFA bowden tube, the method above works great. To reiterate destroyer2012s post, as long as you have some pre-compression in the bowden tube between the PEEK and the white fitting with the blue clip, this holds the bowden tube in really snugly and prevents the tube from popping or sliding out.

I hope this helps others in the same situation.

Thanks again,

Share this post


Link to post
Share on other sites

Thanks for your answers first of all. It soon was evident that my problems are due to the "ordinary" hot-end-extruder issues. So I spent hours and hours to check all of the tips and workarounds found on this place - without success, so I am a bit disappointed at the moment. After the second or third cycle of dissassembling/assembling the hot-end, you begin to understand what it all is about - to my opinion it is an obvious design issue of the ultimaker. Of course I will continue my attempts, but otherwise I don't want to accept that the only way to fix it is to put some toothpicks inside and tape them firmly ...

Ultimaker Team - Please HELP!

--

Christoph

Share this post


Link to post
Share on other sites
If you are getting the plug issue then her's what you need to do:

I followed your suggestion for removing the plug in the hot end and attempted a print. Once again, the first few layers printed fine, but then I began running into flow issues again. I cancelled the print and removed the hot end expecting another plug, but there was none. So, your suggestion did fix all issues with the hot end, but now there must be some other problem with the feed mechanism. It is extremely difficult to feed material through by hand, so I'm guessing this is an issue with the bowden tube being defective. Is there anything else that could cause these problems?

This sounds exactly like my problems. How fast did they send you a new tube?

Share this post


Link to post
Share on other sites
Looking at your photo I say your GCode is fine. As it seems to print the first few layers quite fine.

At which temperature are you printing?

Is it easy to push the filament trough by hand one the printer is hot?

Is your big gear firmly fixed to the bolt? (this was my first, and biggest problem, the gear was turning, but the bolt was not, causing very little plastic to be pushed into the printer)

Which software/firmware are you using? (to generate the GCode, and to print that GCode)

If you have an plug, then eventually it will plug up completely, without you being able to get any filament trough. But seeing that there is still some PLA comming out of the nozzle, I would say that you don't have a plug.

I'm having fun with plugs at the moment - I printed fine for the first week, but started to have problems after that.

I was able to get a seemingly good extrusion for a while and then it would die off. I was able to use printrun to trigger an extrusion, and I was able to hand extrude. Eventually I bit the bullet and took the hot end apart - I'd been hesitant to take it apart in case there wasn't a plug and I was introducing a possibility of one.

Turned out there was a plug, about 3mm in height. I've currently got my printer right behind me taken apart again for exactly the same reason, and have a similar plug. It seems that whilst the plug is still small its possible to push an amount of filament through it, but once you start to print, and if you print at all slowly, then you have problems.

A hint when re-assembling the hot end, if all you do is push the bowden through the white clip again and then put it back together, then it's going to plug up again, because the teeth in the white clip will already have carved a path for the bowden to slide along. To avoid cutting a bit off the end of the bowden, try the idea of rotating it to give the teeth more purchase?

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  

×

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!