I’ve been having a problem with prints starting to progressively get worse with no filament being extruded half way through the first layer. I thought I read about it when researching printers, but I cannot seem to find it again…
I’ve been getting by, by simply tightening up the tensioners… but I’m now pretty much bottoming them out, and I still have issues… I watched the filament slip, and why I went to tightening the tensioners… It seems like the cleaning routine retracts too much filament, and/or a combination with the hotend getting too hot and creates an air pocket when it loads the hotend up with filament?
The knurled bolt is clean…
Cura basic settings…
3MM ABS… although it happens with every filament I own.
I doubt this may be your problem, but what happen to me twice the filament on the roll was tight and caught between the layers of filament on the roll. I loosened up the filament on the roll and all was OK thereafter.
Make sure that the small blower fan that cools the top of the hot end turns on automatically when the printer is powered on. If it does not, contact us at Support@LulzBot.com with the following information:
I’ve had this issue too. What I do to combat it with some success is making sure the filament is tight in the hotend where those thumb screws are, but not tight enough to prevent movement in the bearings. Also, look in your expert settings and change your skirt number to something higher. I have mine set at 4 and usually when it’s half way through the skirt, I have a good line being put down.
The skirt line change is real winner for me as it primes the machine after the cleaning. There might be another way of fixing this issue, like messing with retraction distance, but that value in the expert settings doesnt seem to affect my cleaning cycle retraction.
Thanks HTiLewis!!!
Playing with the skirt does help!!!
I tried to work around it, by putting a “band-aid” on the extruder idler design… This actually helped my blank extrusions(although not 100%), and seems easier to change filaments…
Not to be ugly, but it’s a pretty wonky design…<-- especially the embedded nut on the backside of front-facing side…
An embedded nut on the back-side, with a collar that ran through and held the bearing would have been a little more ideal…<-- I’m sure that LB did this for costs and print times… Makes sense
I think the real problem is that they need to re-configure the “basic” settings…
They need to dump more filament into the hotend after the cleaning wipe(waiting for everything to heat up prior to printing)…
They also need to drop the 100% flow in their “basic” settings… 90% works almost perfect every time, otherwise, I have the hotend scraping the top of each layer…
always when i have a very small piece where the skirt would be very short, i add a “deadpiece” to the print (a second model on the plate) with 40x1mm that is 1layer high. it gets a skirt too, so the filament has more time to get back in the extruder.
also i edited the standart startgcode in cura: the second to last line: G1 Z2 E2.5 F75 ; extrude filament back into nozzle
i changed the value for E, so more filament is extrudet bevor the print starts.
