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Bobr

UM3 Not so good

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I am not one who complains...

The first day I was able to print one (1) time using PVA... after that I have not been able to print with PVA and i have tried over 15 times. Office temp is 72 and the humidity 40 .... so i doubt that that has anything to do with it.

Yes I have done a cool pull 6-10 times and a hot pull 6-10 time... it's so clog that i cannot unclog it.

I order a new BB core but dynamism does not them in-stock and cannot tell me when I can get one if ever.

Said I have to buy and pay for a new BB core that only worked once.

BR.

Edited by Guest

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Dynamism is generally really great with their support support responses. I'm surpised to hear they haven't been responsive.

It sounds like you may have PVA burnt into the end of your nozzle tip, creating a bockage. The best way I've seen for cleaning out PVA burnt into the nozzle is to do a cold and hot pulls described on Ultimaker's website, but to also use a needle (a 29 gage syringe from the pharmacy works well), to insert into the bottom of the nozzle while it's hot.

Insert the needle into the nozzle tip from the bottom while the nozzle is hot, and then do the hot and cold pulls described here: https://ultimaker.com/en/resources/23132-maintaining-the-bb-print-core I realize this is probably the same page Dynamism was directing you to, but the needle really does make a big difference.

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I give out free nozzle cleaning needles to anyone who orders anything on my store. For first time customers. Or customers who request the tool. They only cost me about 10 cents each but are worth so much more when you want to clean a clog in a hurry. thegr5store.com

Anyway usually dynamism has good customer support. @remy ? Also fbrc8.com might have some cores for sale.

PVA is much harder to print than PLA. It doesn't stick to itself so well and it doesn't behave as well. Melted PLA behaves similar to molten liquid glass in that it sticks to itself very well. Like honey but even better. Melted PVA behaves more like mortar (the stuff between bricks) in that it doesn't stick to itself very well until it hardens.

PVA also does not stick well on top of PLA so well. It works but barely. PVA works so much better with Nylon.

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Thank you for your reply …

I have redacted my original post (I was a little upset).

I have ordered a few needles in hopes that will do it trick.

I think I notice this happening after updating Cura 2.3.0 to 2.3.1

When I used Cura to print the first time (at the start) the BB core would flash blue...  and the AA core was flashing red. The last few time I tried printing PVA both cores were red for about 10 -15 minutes while printing the build plate adhesion layer (it a big first layer) ..  maybe because of the long time before printing the PVA is what clog the nozzle.

Again thank you for your input.

Kind regards

BR

Edited by Guest

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Thank you for your reply …

I have redacted my original post (I was a little upset).

I have ordered a few needles in hopes that will do it trick.

I think I notice this happening after updating Cura 2.3.0 to 2.3.1

When I used Cura to print the first time (at the start) the BB core would flash blue...  and the AA core was flashing red. The last few time I tried printing PVA both cores were red for about 10 -15 minutes while printing the build plate adhesion layer (it a big first layer) ..  maybe because of the long time before printing the PVA is what clog the nozzle.

Again thank you for your input.

Kind regards

BR

 

Hi;

out of experience I can tell you.. it's almost impossible to block the PVA core as long as you are using Cura and the latest firmware..

can you test the following for me;

can you please remove all material from your printer. take out the bb core, and take some pictures to show us. i'd love to see the nozzle.

then reinsert the BB core. now cut off about 50 cm of the PVA material. use the "load" option in the firmware to load the PVA filament in feeder 2. at a certain point, it will say press the button once you see filament coming out. take a picture as soon as the first bits of filament come out and just let it flow for about 5 to 10 minutes. a nice heap will start on the glassplate. take some pictures.

we can work from there :)

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Thank you for your reply …

I have redacted my original post (I was a little upset).

I have ordered a few needles in hopes that will do it trick.

I think I notice this happening after updating Cura 2.3.0 to 2.3.1

When I used Cura to print the first time (at the start) the BB core would flash blue...  and the AA core was flashing red. The last few time I tried printing PVA both cores were red for about 10 -15 minutes while printing the build plate adhesion layer (it a big first layer) ..  maybe because of the long time before printing the PVA is what clog the nozzle.

Again thank you for your input.

Kind regards

BR

 

Hi;

out of experience I can tell you.. it's almost impossible to block the PVA core as long as you are using Cura and the latest firmware..

can you test the following for me;

can you please remove all material from your printer. take out the bb core, and take some pictures to show us. i'd love to see the nozzle.

then reinsert the BB core. now cut off about 50 cm of the PVA material. use the "load"  option in the firmware to load the PVA filament in feeder 2. at a certain point, it will say press the button once you see filament coming out. take a picture as soon as the first bits of filament come out and just let it flow for about 5 to 10 minutes. a nice heap will start on the glassplate. take some pictures.

we can work from there :)

 

Thank you.

I am not sure how to take a picture of a clogged cord... all i see is the hole with pva in it.

I also see, when trying to load the PVA it does not come out of the nozzle and it makes a gringing noise and when you unload the the PVA filament you can see where it cut a big grove in the PVA trying to put the filament through nozzle.

I have heated-up the core to 230 and tried to manually push filament through nozzle ... and can not get filament to push through nozzle.

Kind regards

BR

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Well I recommend you print the wedge:

https://www.youmagine.com/designs/the-wedge

With your working nozzle. Then insert it into the side with the pva core. Do some cold pulls where you heat to about 210C, push the pva in hard, release the wedge to hold it in and let it cool to about 90C (not sure ideal cold temperature). Then put the wedge back in and pull hard. If it won't come out, raise by 5C at a time and let sit for 30 seconds and try again. If it comes out easily and doesn't bring the clog out then try a lower temperature.

I've never tried cold pulls with PVA as I haven't had a clog yet.

Also get a needle smaller than .4mm (such as one from my store) and insert that into the tip of the nozzle.

Also you *can* take the core apart but it's very very easy to destroy. Once you take the nozzle out you can heat in a flame and burn all the pva to ash. Or just soak it in a cup of water for 24 hours (not sure if that works with "cooked" pva).

I'm still relatively new to PVA but these techniques work with PLA just fine. I have a UM3 and have printed many things with it but I haven't had a clog yet.

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Thank you.

I am not sure how to take a picture of a clogged cord... all i see is the hole with pva in it.

I also see, when trying to load the PVA it does not come out of the nozzle and it makes a gringing noise and when you unload the the PVA filament you can see where it cut a big grove in the PVA trying to put the filament through nozzle.

I have heated-up the core to 230 and tried to manually push filament through nozzle ... and can not get filament to push through nozzle.

Kind regards

BR

 

When you try to load the PVA back in after unloading it, are you cutting off the portion that experienced the grinding? If there's any grinding, you want to start with a fresh piece.

Have you had a chance to try using a needle to break the burnt material yet?

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I'm sorry that I missed this thread, @Bobr. It's been a busy week. I'm very sorry that we were unable to provide a lead time for the BB Print Core. We have them on order, but aren't able to provide a ship date at this time. Since the UM3 is a brand-new product, we would rather provide realistic information instead of false lead times. I apologize for any trouble this may have caused.

Thanks @gr5 and @fbrc8-erin for stepping in here. Please let me know if there's anything further we can do. We're still learning on the UM3 as well, but we are always happy to help work with you to find the best solution. Since Erin and gr5 are here helping out (thank you!) you should be in good hands.

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