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Second prints on Ultimaker 2 require more priming

Posted: December 6th, 2016, 10:21 am
by LePaul
Hey Nallath,

This might be a firmware question....

I know the retraction after a print is complete is a bit extreme. For a second print, I always wind up going through the UM2's menu's to heat the nozzle, move material, then load the next print.

It would be really neat if there was some means to fix this....I'm just not sure if this should be within Cura or not

Asides the manual approach...any ideas?

Re: Second prints on Ultimaker 2 require more priming

Posted: December 6th, 2016, 11:13 am
by nallath
Cura can fix this, but i'm not sure who put the retraction there in the first place. If the firmware does it, i'd say that it's also the firmware's problem of fixing it.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 6th, 2016, 1:06 pm
by LePaul
Can you tell me if that's an issue being worked on? Or maybe add it to the list :)

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 3:31 am
by nallath
Not as far as I'm aware. But we have about 800 open issues for Cura alone, so it's getting a bit tricky to keep track of everything.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 5:13 am
by Izzy
The only other quick fix I use is to always use the skirt to prime, that way everything settles in during the skirt print and seems fine for the main print.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 5:35 am
by reibuehl
Unfortunately that does not seem to work for me. I usually print two lines of skirt and have already doubled the amount of priming but often if not most of the time I need much more until I see the first plastic extruded.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 10:09 am
by LePaul
Same, I had skirt set to 3 and it still isn't primed enough for a successful print.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 10:58 am
by Izzy
Ok interesting, do you have an i2k fitted, and if so what does the filament end look like on the retraction and can you easyily manually prime or is there a bit of resistance?
It could be that the inner diameter is a bit small and just needs increasing by 0.05mm or so

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 11:26 am
by reibuehl
I have removed the I2K at the moment. Yes, there is resistance when priming. Sometimes the feeder even starts to skip when I do manual extrude via the move material command to get the flow started.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 11:29 am
by LePaul
I've got the 2+ setup, so I just crank away until I get filament moving through, I stop after about 12-15 inches of material has moved along

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 12:06 pm
by Izzy
That's a lot of priming Paul.
When I had this problems I checked my i2k which was a little snug for some filament tolerances, I think I increased the bore to 3.2mm and this solved my problems.
I seemed that the end of the filament was slightly larger and it took a little hike to become plyable enough to pass through into the nozzle area.
As for Paul, you must have a large amount of filament extruded through the nozzle on that amount of priming.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 12:12 pm
by LePaul
Well for the first print, I do not have this issue. It's the darn firmware doing this massive retraction that makes it necessary.

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 2:11 pm
by Izzy
That is strange, is it modified or straight downloaded

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 2:22 pm
by LePaul
Izzy wrote:That is strange, is it modified or straight downloaded
Latest firmware for 2+

Re: Second prints on Ultimaker 2 require more priming

Posted: December 8th, 2016, 3:46 pm
by Izzy
Ok in that case I think you need to dial down the bad luck demigod dial a tad :lol: