printing quality at small parts

Hi,

Nearly everything works fine but when I try to print small objects or small sections of parts I got serious printing troubles (see attaches pictures)

I tried to use a 40mm fan but this little bastard kills my nozzle temperature (243 °C --> 230 °C)!

The extrusion multiplier ist set to " 1 " but there is still too many material melt at those small sections - and it seems that there is too less material when printing large objects (e.g. I can blow air through part 1 as the wall thickness is no more than 4mm)

please help!

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Reprap Prusa
243 °C extruder
95 °C glass bed with sugar layer to improve sticking
ABS natural (" <= 265 °C " )
0.35 nozzle
Repetier Host 0.51
Slic3r 0.9.7
0.15mm layer height, rectilinear pattern
3 top and bottom layers
1 perimeter (usually set to 2) and enabled option to generate more if needed
fill density 0.3
24mm/s speed for perimeters; 30 for infill
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... some people prints multiple parts, so the single segments can cool down before the next layer is printed.

Or search for a firmware with the 'cool'-option, where the firmware adds some time between two layers ... but this can cause other problems with retract and such ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I printed those two parts together - so there was time to cool down. :-/

Also I thought about adding the fan to the board (up to now it is set as on/off by plugging in) - but as mentioned it kills my nozzle temperature...

Edited 1 time(s). Last edit at 01/09/2013 09:57AM by Irgendwer_Aus_Irgendwo.

... add thermal shielding around your nozzle ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
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> ... add thermal shielding around your nozzle ...

What is cheap and easily available for this task?

looks like you are printing too hot, you should not have scorching in the material like in part1_.jpg.

A Wrote:
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> VDX Wrote:
> --------------------------------------------------
> -----
> > ... add thermal shielding around your nozzle
> ...
>
> What is cheap and easily available for this task?

... you can use cotton wool and aluminium foil as 'wind-shield' ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Issue solved! :-D

Simply changed the "solid infill threshold area" value from 70 to "2" and added a fan which can be controlled via my Sanguinololu (Link) I'm able to print also very small parts!

Unfortunately I'm still having problems to get the 2 perimeters sticking together - please see attached picture

Edited 1 time(s). Last edit at 01/16/2013 09:29AM by Irgendwer_Aus_Irgendwo.