How do pick the proper print temperature for ABS?

[Fastrack]

I've tried to search to no avail.   How do you pick the proper print temperature?

Using acceleration, Makerbot black/white I can print safely at 235 or 240.   Octave it seems a lot more stringy, if I try a print at 230 I get a TON of strings and yes I have my retraction distance at .5mm, restart extra distance is 0mm.  Which flies in the face of what others have said that aftermarket filament requires a higher temperature!

I did find a post on the reprap forums that you raise the temp 5C above where the extruder starts to skip??  

If strings is the way to test this, a cross section of a bowl I made it's 90mm diameter and I chopped off the top 10mm with 4mm walls showed the strings VERY well?

Going too hot can also make the plastic brittle?

Ben

[Andrew Plumb]

Hey Ben,

Bare in mind that absolute temperatures are often higher because that's how you get "cold" filament to melt faster as it's passing thru the heater and nozzle.

It's a heat transfer problem, not an ambient "baking" temperature problem.  You don't want to idle for long at hotter temperatures or the filament melts too far up the barrel.  PLA was really bad for this in the older MakerBot extruder designs where a lot of heat was transmitted up the barrel, onto the incoming filament.

Re. the reprap forum discussion, that's a lower temperature bound at a chosen flow rate.  If the extruder skips at 185C, set it for 190C.  However, if you raise the flow rate you also need to raise the temperature to compensate and melt the incoming filament fast enough; repeat the skip-test at the higher flow rate to find the new temperature.

It's all relative. :-)

Andrew.

--
You received this message because you are subscribed to the Google Groups "MakerBot Operators" group.
To view this discussion on the web visit https://groups.google.com/d/msg/makerbot/-/v2xf6WElwu4J.
To post to this group, send email to make...@googlegroups.com.
To unsubscribe from this group, send email to makerbot+u...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/makerbot?hl=en.

--

"The future is already here.  It's just not very evenly distributed" -- William Gibson

Me: http://clothbot.com/wiki/

[Fastrack]

I know it's tricky!  I've tried to read all about it I can.  The faster you print, the less time the filament has to conduct the heat!

Of course with lower temps it might not bond properly... :)

Is the stringy method sound?

Ben

[Shawn]

Ran into this the other day with a dual extrusion print. The print was
primarily from the right extruder, with the left extruder kicking in
near the end of the print. At 240c, the left extruder would burn the
red filament and get jammed from waiting around to be used. Had to edit
the GCode to select 220c for the left extruder - RepG overrides the
indicated values and makes both extruders the same when it merges the
two gcode files.

>> <https://groups.google.com/d/msg/makerbot/-/v2xf6WElwu4J>.

>> To post to this group, send email to make...@googlegroups.com

>> <javascript:>.

>> To unsubscribe from this group, send email to

>> makerbot+u...@googlegroups.com <javascript:>.

>> For more options, visit this group at
>> http://groups.google.com/group/makerbot?hl=en

>> <http://groups.google.com/group/makerbot?hl=en>.

>
> --
>
> "The future is already here. It's just not very evenly distributed"
> -- William Gibson
>
> Me: http://clothbot.com/wiki/
>
>
>

> --
> You received this message because you are subscribed to the Google
> Groups "MakerBot Operators" group.
> To view this discussion on the web visit

> https://groups.google.com/d/msg/makerbot/-/L9Dz7pJp2ZcJ.