SoliForum - 3D Printing Community — Printing PLA

Re: Printing PLA

null@example.com (digiprint) — Tue, 16 Apr 2013 18:41:32 +0000

Tried from 180°C down to 150. With 60°C bed-temp the PLA only drags around on the bed. Tried 0.1 offset with 120% extrusion on first layer. 110%. 100% ... reduced speed for 1st layer.
PLA sticks every now and then but almost it sticks to the extruder... I don't think that's "normal".

I have to use around 90 °C and the PLA begins to stick.
I'm using PLA from jet.

Re: Printing PLA

null@example.com (Rincewind) — Tue, 16 Apr 2013 10:20:38 +0000

Same here, I print PLA at 150 and fan always on (except for 1st layer). If you don't want to modify the firmware, you can send a M302 (allow cold extrudes) command before the print. It's a bit risky because it will allow extrusion at any temperature, but if you are careful it's a fast solution and doesn't need firmware modification.

Re: Printing PLA

null@example.com (adrian) — Tue, 16 Apr 2013 07:06:02 +0000

Line #205'ish of Configuration.h, alter the Extrude_Mintemp value. Recompile and upload.
Here's mine:

#define EXTRUDE_MINTEMP 145

Re: Printing PLA

null@example.com (digiprint) — Mon, 15 Apr 2013 20:37:52 +0000

Thanks for the answer. That PLA only need low temps I already read a few times.
I noticed that the Solidoodle won't extrude with hotend-temps like 150°C.
Is there a How-To with the code in the firmware that I have to change for PLA-printing?

Re: Printing PLA

null@example.com (adrian) — Mon, 15 Apr 2013 10:29:30 +0000

Back the temp off a bit - most PLA only needs 160-185 (as the Solidoodle reads 30oC cooler due to its thermistor placement -) - so if the PLA is recommended by the manufacture as a 175-215 melt point, then you want to use 145(which wont work without firmware mods) - 180oC... 190oC risks burning the PLA and causing clogs - as well as it being way to oozey at that temp anyway.

The bed shouldn't need more than 65oC-70oC, even with Kapton + Glass. I print onto a muuuuch thicker ceramic tile, and I still only need 65oC.

Most of my PLA has been done at 165oC in Slic3r.

This will also improve you overhangs - too hot and it will just droop. Colder bed + Colder Extruder will help tremendously with this.

However - for quality PLA printing - I had to resort to adding the fan to the extruder, as PLA is just too runny compared to ABS when melted even to low temps.

So drop the temp on bed and extruder, and see how that goes. With PLA you want to get it as close to the 'low end' of the temp spectrum your particular filament is designed for as possible. If unsure what this is - start at 180oC and keep working backwards. So far I've only seen one particular manufacturers Black PLA require anywhere need 190oC (and it was a clear stand out compared to the others I use). And I suggest you research the fan if you are going to use PLA regularly - you'll just be chasing your tail even with the lower temps you should be using without one.

hope that helps.

Printing PLA

null@example.com (digiprint) — Wed, 10 Apr 2013 20:11:40 +0000

PLA is the complete other way round.
No temperature for the bed. The enclosure should be removed ... just my first impression.
Cool the filament if you want it to stick together and don't stay some kind of bubblegum.
I' using 190 for the extruder and 80 for the bed with kapton on glass.
Reduced the speed for the first layer. 3mm retraction.
Works for normal stuff.
But if I'm printing something with a overhang.... The filament behaves like bubblegum.
Do I have to add a cooling-fan to the extruder?
Hope not! Getting some kind of bugged