new to utilimaker questions, second print no extrusion

[kerberg 0]

Thanks for your reply, I took the unit to the distributor where I bought it here in Dubai and they are working on it. The material is PLA , I mis-typed previously, sorry. they recommended I retract the filament after I am done printing so that it doesn't cool in the nozzle... I did not see that tip in the manual. I think I will order an "Olsen Block" to make the nozzle easier to remove... so you are saying that heating the filament up too much will cause a block ? From what I read in the forum it seems like heating it up is the method to remove the block. Lots to learn. also you are saying you drilled through the brass to push the temp sensor out from other side? Thanks again!

I didn't see a first print advice post here in the forum but it would be great to have such a thread stuck to the top of the forum somewhere...

[gr5 2,170]

so you are saying that heating the filament up too much will cause a block ? From what I read in the forum it seems like heating it up is the method to remove the block. Lots to learn.

 

180C is hot enough to loosen filament enough such that you can stick a toothpick in it and remove it. But yes, 260C might help greatly - but only for a few seconds. More than 60 seconds and it slowly gets more premanently solid. For PLA I hate going over 240C. For ABS I don't like going over 250C unless things are moving. And if I print at 255C ABS and print slow - (say .1mm layers [less volume] and only 30mm/sec) then it will eventuall clog everything but if I print much faster (.2mm layers) it will be fine.

PLA is a little more forgiving than ABS. PLA is much easier to work with and print and PLA prints usually work better. But ABS is a great material also. I recommend most people stick with PLA for at least 100 prints before moving on to ABS. Also everytime you switch from ABS to PLA you are likely to have trouble with clogs. It's not worth the hassle if you can just stick to one material always.

 

also you are saying you drilled through the brass to push the temp sensor out from other side?

yes. Very slowly and carefully.

[danilius 118]

If you have a brand new machine, chances are you don't have a major clog. It seems like you are using PLA. At 260C it will burn after a minute inside the nozzle, so you want to avoid doing that unless you are really desperate.

You might want to use the little white twist-ties that come with sandwich bags.

So:

1) Heat the nozzle to 220C.

2) While that is happening, remove the bowden tube from the print head

3) take a length (30cm) of PLA and straighten it out

4) by this time the nozzle is probably toasty, so insert the twist-tie into the nozzle. No need the strip the plastic off the wire, the hot nozzle will do that for you

5) Poke the twist-tie into the nozzle (use pliers) until it goes in around 4cm

6) Now carefully feed the short length of PLA into the nozzle and push down, you should get some PLA coming out slowly

7) If yes, it might require a fair bit of force, so push firmly until the blockage clears and the PLA runs quite quickly

Voila, nozzle unblocked. You can try this at 260C as well, but work quickly. Prepare everything in advance, and only then heat the nozzle up.

[kerberg 0]

Thanks for your replies. Interesting that you say that with PLA More than 60 seconds at 260 and it slowly gets more permanently solid. This seems counter intuitive. It seems like the more heat it gets the more melted it gets?

[neotko 1,417]

Pla it's sugar based (from corn) and the problem of sugar it's that once it has reach some C it changes to a molecular level and it's state can't be reversed. That why it goes dark-brown when overpasses it's limit. Also that why PLA it's so sticky.

Edited July 21, 2015 by Guest

[danilius 118]

And that's why it tastes so good in coffee. Ahem.

[neotko 1,417]

When I briefly had 3mm on my umo+ I used a 3mm ptfe tube to 'pump' the clogged nozzle. It's nice because you can reuse it as many times as you want. Also you can do an atomic pull very easily. For hard clogs lately I just get the head at a temperature that I know the material will be 'in theory' liquid, push a small thread from my metal brush inside the nozzle, and then after I know the nozzle has a bit of clearance I use 5-10cm of cleaning filament. It take's more time than atomics but it leaves a very nice and sweet nozzle. Ofc this it's on my umo+ that has a hot break barrel, I don't know how well/bad the cleaning filament works on an um2.