PLA skipping after 45mm/min ?

hi guys

any ideas on whats causing this?

if i go any higher then 45 mm/min in pronterface when free extruding i get skips or bobbin up and down sometime even clicks it skips so bad

running faberdashery pla at 200c

no idea why this has happened i started having the problem around 4 weeks ago and have tried many things to try find out why i used to be able to run this same pla at 185c no problems.

changed out hobbed bolt for an achol hyena
checked esteps are okay (tested at 20mm/min)
checked hotend temps with a k type thermocouple
tried another j-head hotend

can you give anything else to try?

I may not have the right term, but PLA develops more friction at higher temperatures. Try lowering the temp and or putting a fan that directs air across the non-melt zone (generally the peek barrel above the heater block). I experienced this myself. For me 185 to 190 is the sweet spot.

It also depends on your hot end. Some have been designed to keep that area cooler with heat sinks or active fans.

Bob

always had a fan blowing across the barrier at the top

ill try going lower think i did try this and started skipping at 40 then but will have another check later

i take it 50 - 60 mm is not asking too much of these printers?

I test extrude 5mm of PLA fine at 185C and 300 mm/min, though I can only extrude 10-15mm at a time before it can't keep up and stalls.

Keep in mind test extruding is not a good way to test temperature nor speed, as they can be way higher than real world numbers used while printing.

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-Nudel
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basically i noticed a problem when doing solid infills i would get repetitive parts missing and not extruding enough plastic.

last time this happened when i was 1st starting out i found it to be hobbed bolt was rubbish replaced it and worked great for over 3 months.

happened this time round and i thought ill replace it and get a hyena bolt as that's gonna be better and might last a while longer. but still cannot get rid of the problem.

doing a test print atm at 185c see how that comes out but i have already seen a bit of skipping.

Try diffent filament to rule out bad batch or bad section especially if not a known good supplier (even they have bad batches).

Some colors are easier to print than others.

Could also be a problem with the extruder motor overheating or drive current to high. I was shocked at how hot the extruder motor would get when i first started printing until I adjusted the driver current. It still gets mighty warm but no longer scalding hot. Sometimes you just need to start at square one and check every thing as even a loose connection or sliping drive gear could be the source of your grief.

Also as others have mentioned your envoirimental operating conditions are changing depending on your location. Humidity etc.

Bob

not the filament very high grade supplier and iv got stuff iv ordered over a 4 month period and its all the same no matter which colour etc

but thinking it could be the stepper driver i suppose maybe its not got enough power going and then it skips !
ill give it a go maybe later if not tommrow

im getting round it just running all prints at 40mm speed would just to get parts and drafts of stuff printed much quicker.

month ago i was knocking out all my printrbot parts easy at 60mm speed no problems at all.