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edgar-meyer

it jams everytime

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Using Cura 12.08, starting with a clean feeder (v2) bolt and nozzle, clear passage of the PLA filament (no block at the PFL-brass tue connection), calibrating pink or silver PLA steps/E, using a nominal 50mm printing speed, locating a plausible temperature hi-low range, trying to optimize the tension of the white Deldrin or the ball-bering feed clamp, and with abundant optimism, I am able to print small 'wigets' .

However, a serious 9hr print job consistently fails after 1-9 hrs., after a month (actually more) of trying to optimize parameters to arrive at a successful model.

It is humbling to admit abject failure. surely some obvious but obscure parameter has been neglected, some detail overlooked. Print jobs start out fine, with smooth print patterns and clean lines. I watch diligently for a while, satisfied that all is well, but then, failure.

Often, there is a heat plug blocking further filament feeding.

I suppose that the plug must have formed from excess liquid PLA oozing up the brass tube rather than a later up-flow of heat after the printing jammed, but I do not 'catch it in the act', so I do not know the precise symptoms and surely not the cause, otherwise I would correct it.

I pleases me to hear of the successes of others, but the miserable results I consistently get in trying a longer print job leave me sadly disappointed, at myself, and at this miserable machine.

It jams EVERYTIME

EM

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Symptoms of the illness unto death...

The v2 drive bolt has a diameter of 0.307"=7.798mm, so the circumference is 24.5mm

The teeth of the bolt leave a repetitive pattern on the PLA filament with a periodicity of ca. 20mm. But, when the printer becomes sick, before dying, the periodicity drops to ca. 10mm.

The drive bolt tries valiantly to feed the filament properly, but it finally is packed with PLA and filament feed grinds to a stop, while the x-y-z drives speed merrily along.

So, have any of you UltiWizards encountered filament feed problems?

And how did you overcome them?

thanks,

EM

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I think you have way too much pressure on the thumb screw on the back... Doing some rough math, your bolt teeth impressions are 0.8 mm deep, or about 1/3 of the diameter. With this much pressure and teeth mark, you build a meat grinder, not a filament transport mechanism.

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the surface getting ragged is a cura specific issue, due to the very inspecific speed setting cura has (one speed fits all). try kisslicer, which does a nice ramping from infill speed to inner loops to outer loops in regards to dV (outer surface can be printed slower, and becomes nicer)... in addition, for PLA to flow nice at higher speeds, it needs to be hotter.

in regards to the bertho extruder add-on, it isn't made for super high pressure print scenarios, and yours seems one of them. we had a lengthy thread on the google group, called "reasonable expectations":

https://groups.google.com/d/msg/ultimak ... g0Zj4dJNYJ

in other words, I think you are trying to push more PLA through the tiny nozzle than the bertho extruder add-on can deliver, maybe due to a spring that is too weak? too low temp, try increasing it by 5C? if you follow bertho on his blog, he has very good explanations about the holding force of the springloaded bearing, and how to measure it. the great thing about the spring loaded thing is that is it almost immediately recover from a grind, where the delrin version will just dig in, and never recover. but it also has a lower clamping force, and hence will not allow for high filament force towards the nozzle. i think you need to make some calculations, and some tradeoffs.

the reason why the nozzle can fail after hours of printing are dynamics in the head... maybe it's a section with more retractions, and maybe you print too hot/slow for that section (i.e. tons of tiny islands), and high pressure from the filament pushes molten filament back up the tube... tons of things can go wrong, unfortunately, so manual tweaking, and getting a feel for molten plastic and how it behaves, becomes paramount.

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my new ultimaker at home. I need to finish a project for friday. every model yesterday printed brilliantly at the start and then maybe 20 minutes in, FLUFF HELLL :evil: :evil: :evil:

it seems like what ever amount of pressure i put on the extruder metal wheel, the filament is grinding to shi......t afer 10 or 20 minutes.

I am printing slow at only 50 in cura and printing at tempt 220, which normalls works fine.

I dont get it ?

I printed a massive head using my ultimaker two days ago, perfect, now yesterday, was just crap......

i have about 5 meters of now cut out and unusable white PLA, with bite marks that look like dracula took an attack at it........

one day great, one day..... flush in the toilet......... :evil:

Ian

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Joergen,

thanks to your suggestions, especially increasing the temperature, I was able to complete a 9-hr print - joy upon joys!

unfortunately, I have ?wasted? a full roll of the pink PLA getting to this point and while I bought several different colors of PLA, I did not buy more pink.

I started working with silver PLA but it seems to have different physical characteristics (melting point, optimal temperature range?)

do you have any experience with the properties of the different color-types of PLA?

I have come to the conclusion that the Ultimaker is mechanically well designed but miserably supported:

1) originally available software had 99 variables and precious little guidance. Even more mature software makes it difficult=impossible to complete a simple, 9-hr production print, because

2) the system must have optimized parameters and there is little=no guidance in finding them from Ultimaker.

Besides the choice of material (PLA), there is the tension on the extruder bolt, the extrusion speed, the temperature of the extrusion nozzle, the x-y printing speed (latter two related to the viscosity of the molten PLA) - and what might I have omitted?

All these parameter work just fine for short runs, but this machine was made to make objects, not widgets, and after tens of minutes to hours, a metastable condition slips into instability and a good printing run dies.

It is like selling a sleek car that works well for driving around town but fails out on the highway, with no warning from the manufacturer that the engine can overheat and no advice how to prevent it - is this the way to run a business???

Edgar

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Cura will be the offical support software soon. And the defaults in Cura is what I have been using for prints well over 10 hours.

Cura has less then 99 variables (SF has about 260 settings, not 99 ;-) ) it has about 40 settings, most hidden in the advanced advanced expert settings. Which 80% of the users will never need to touch.

Most of the problems that people are having are mechanical problems. Just because your machine moves doesn't mean it's properly assembled and calibrated. For example, it took me 2 weeks of frustration to find out that I did not assemble the extruder drive mechism correctly causing a lot of slipping. I countered it with lots tweaks I tried in the settings up to the point where I could get a reasonable print with just wrong assembly.

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great

please point me to some of the pitfalls and corrective procedures you encountered

and can you point me to a table of physical properties of PLA filament? I find noticeable melting point differences in several color types - the official Ultimaker sales page is sparce

thanks,

EM

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The melting point of PLA depends on the base PLA used (should be the same for all Ultimaker PLA), and the color additive.

But I think it can also differ a bit per batch. However, all PLA should melt and print with ease at 230C. And most PLA starts to go soft around 180C but that doesn't make it liquid enough to print it in almost all cases.

As for common pitfalls:

1) Extruder drive. Make sure the big gear nut is very tightly screwed to the captive nut. With the V3 bolt this is much easier, as you can screw these together outside of the machine. If the gear nut slips you have major problems. (seen this a few times already, on my first machine and a few machines of other people)

2) Bed levelness. This comes less critical with Cura's default 0.3mm initial layer, but getting it right is important. Getting this wrong can cause anything from parts detaching from the printer to scratching your tape. And oozing on the first few layers.

3) Belts. Get the tension right. The latest long belts I saw yesterday where at the correct tension by default, but most belts are too long and need belt tensioners.

4) Short belts. People usually forget to check the short belts for tension. I finally had one with so little tension on it that it could jump over the pulley.

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This may be a non-issue for you Edgar, but It was for me and I thought that i might post a fix for it at the same time. In my experience, the bowden tube tends to slip up away from the PEEK insulator during printing, thus allowing melted plastic to flow up and between the bowden tube and the PEEK insulator. This hardens and causes a nasty jam, but adding this

http://www.thingiverse.com/thing:11864

cured the problem. If this particular quirk hasn't affected you, more power to you. Cheers.

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First, thanks to Daid and Joergen,

I installed the 'new and improved' rev.3 spring+ballbearing extruder drive and the v.2 extrusion head.

Mirable dictu, the printer ran flawlessly for 8 hrs to give an excellent model.

Now, a question, I would like to download and run Cura 12.10 on my iMac (10.6.8) but am overwhelmed by the insertion of Python, PySerial, xwPython, NumPY and PyOpenGL.

Help - is there a step-by-step recipe for creating a running update - or has it already been done and ready for me to download? Thanks,

EM

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