Extruder and Print Challenges

I posted last year that we could not get the extruder drive to work. This is still causing us issues and we would love some advice. After leaving the printer a side for the last 6 months I purchased a new hobbed insert. This has imporved things and now the printer can extrude. But it still gets stuck and jitters every so often. I have filed the gears and made sure the hobbed insert is centrally aligned etc.

I attach a couple of pictures of the print quality we are getting. I assume that the gaps in the layers is were the extruder has got stuck and no material has come out.

As you can see I have been trying to print a new extruder body and gears but I am caught in a catch 22 that I cant print the parts I need to improve things.

So my questions;

1.Do you think the poor quality on these parts is due to the extruder getting stuck and hence not extruding for periods of time?
2. Are there any other factors that could be effecting this. eg Hot end and bed temp (195C and 57C respectively), inaccuracy/play in one of the axis, filament quality, slic3r set up?
3. Suggestions for which improved extruder design to build that might help with this problem (I was trying to build the sprung one) and where I can get one built?

Thanks

Ed

I have found the sprung one with herringbone gears very good.

When it jitters, does the motor jump backwards, or does the hobbed insert lose its grip on the filament?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Motor/gear jitters but the filament does not slip. Last night I took out the screw that holds the bearing against the filament and filed it down very slightly. It ran better but not perfectly so I may try tweaking that to find optimal diameter between filament slip and drive stiffness.

Gear I produced still did not have a great finish on the top and ID of part but at least did not have fibre missing.

That does not quite look like my prints when my extruder was skipping/not feeding.
What is the layer height, looks too tall or something.

What material type and brand? 195C looks like PLA, and for example 3DSolutech PLA would hate that temp, I have to run 210.
(granted sensors are not all the same)

Pic of your extruder setup, are you sure you are getting good tension?

Is the stepper motor calibrated and getting good voltage?

What hotend? I found a narrow working band in the E3dv6 all metal hotend, between feedrates and extraction rate.
If it jams it will cause the extruder to grind. I have my extraction set to 1mm@35mm/s

Finally, you could try Cura for one print, just to rule out a slicer issue. I still use Cura14 cause it is still super fast to load and run.

If your extruder motor current is still set to default (800,in the M906 command in your config.g), try increasing it (e.g. 1000)

If you're stuck in a catch 22 with parts, use a printing company such as i.materialise or Shapeways to get the parts you need. I used Shapeways recently for herringbone Z gears and they came out gorgeous.

My previous iamburnys herringbone Z parts I thought were a good print, but the polyvinyl SLS print blew them away.They needed almost no filing down and are so much quieter than before. (and small parts are pretty cheap)

InventEd - which slicer are you using?
How does the jittering sound - is there any whining noise, and is the stepper getting hot to the touch at all?

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Reprappro Ormerod2 (528.2, Duet 0.6, firmware 1.18.1 (2017-04-09), web interface Christian Hammacher 1.15a, Cura) & CNC 3020 (GRBL)