Printing quality very poor - was great

I have been trying to print these Nautilus Gears

I printed the gears some time ago but have not been able to print the connectors

I have tried about 5 times

Here are photos … ada%211031

The flat surface seems to print fine but the vertical connectors end up being a pile of melted plastic
The nozzle seems to get stuck in the previous layer and jus swirls the melted plastic
Having similar issues with with the final top cube on this

I have checked all pulleys, belts, and ensured all bolts are tightened
I have tried two different types of filament and same poor results

I think its to do with some bed levelling issue so I went back to normal Z-end stop and used mattercontrol s/ware based bed levellingbut still not change.

Any body any advice ?


My Mods
K8200 with upgraded Z trap rod from Velleman
GT2 belts and 20 teeth pulleys + tensioner
Fan funnel
3drag Auto Bed Leveling with Capacitive Proximity Switch -

Had a problem with printing as well, was fine in the beginning.

I thought a bow-den type feed would be better and solve most of my problems with feed rates so I stripped the extruder feed unit to see how I could modify it. On checking the parts in the extruder feed, [ drive unit feed unit (( the bolt with splines on it driven by the gears and motor )) I found them to be clogged up with somewhat ground up PLA dust which I cleaned up including the framework parts. Then decided to check the BEARING TYPE: 608. Found that these were also jamming slightly on the drive shaft and the tension adjustment bearing. I found this bearing to be completely clogged up with dust and not able to turn at all, cleaned up all the bearings. PITY THEY WERE NOT THE TYPES THAT HAVE DUST COVERS ON. SURELY velleman COULD HAVE PROVIDED BEARINGS WITH DUST COVERS WHICH ARE 608ZZ TYPES, so I have ordered 3 new bearings with rubber dust covers from eBay.
This caused the extruder to give me low feed rates [ mostly lack of feed at times ] causing many a failed printed project to be scrapped. I had spent many hours trying to find this fault, even replaced the extruder with a V6 extruder unit with cooling fan.

BTW The extruder feed unit can be separated from the nozzle by fitting it with bow-den type tubing and mounting the drive unit on the upright just above the CPU Board and remaking the brackets for the extruder unit [if you using a extruder head similar to the V6 unit] being careful to only use the 6mm type fittings and carefully tap out the entrance and exit points for the filament, also turn the spool mounting post to allow the filament to feed directly to the extruder drive unit. This also makes the feeder bar lighter and easier for the z axis motor to rotate easier.

velleman should have provided the extruder with 608 ZZ bearings I’m not saying this is your problem but might help