K8200/3DRAG ...... literally stuck !!!

[ndillane]

Hi Folks
Man this 3D printing can be time consuming and frustrating some times :-)

I had some good success early one with this printer (K8200/3DRAG) and since made a few mods including:

• Upgraded Z trap rod from Velleman ( http://www.theelectronicsshop.co.uk/...670_k8204.html)
• GT2 belts and 20 teeth pulleys + printed tensioner
• 3drag Auto Bed Levelling with Capacitive Proximity Switch - http://www.thingiverse.com/thing:447719
  
  • in theory works fine - goes through 4 point routine, reports back plan issues and I can see Z-axis compensating while
  
  
• Glass Bed Panel

Have been tweaking away with various slicer and firmware (Marlin) settings
Levelling the bed in general has been a HUGE frustration ...even with glass bed and auto-bed levelling
Everything is in theory working to plan - printing large flat calibration circle works fine


However for last few days printing anything with more than 5 or 6 mm height leads very poor results
I have been trying to print these Nautilus Gears
http://www.thingiverse.com/thing:27233

I printed the gears some time ago but have not been able to print the connectors (V2) (the issue is with the vertical connectors)

I have tried about 5 times with different temps, fill densities, speeds

Here are photos of the offending items

https://onedrive.live.com/?cid=F5E59...4907ada%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 just swirls the melted plastic
(Thought it might be autobed levelling so reverted to old zend stop switch but no luck)
Having similar issues with with the final top cube on this
http://www.thingiverse.com/thing:24238

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

One would think its a Z-axis issue but when I check this through planned moves it seems fine
(Tell it move a certain distance and then checked with callipers)

I thought its to do with some bed levelling issue so I went back to normal Z-end stop and used mattercontrol s/ware based bed levelling but still no benefits.

Have ran out of ideas .......... extremely frustrated !!!
Any body any advice ?

tks
Noel