Topic: High Impact Polystyrene (HIPS)
Hips or High Impact Polystyrene should be extruded around 170-180c, although you should start high and move down until you reach a desired diameter.
In my case I usually aim for 2.8mm out of the melt filter 3mm nozzle, its very easy to attain this diameter with hips at around 170c, If your setup is horizontal you may want to be a little hotter than that.
Measured 10" per minute at 170c @ 2.8mm
For 1.75mm filament on a vertical setup I'm currently using 179c temp with stock 1.75 nozzle.
Measured 16-17" per minute @ 1.75mm
Printing temps are relatively the same as abs, I've used 235c temp for latest prints but can go higher.
Out of about 4lbs i've just extruded of 3mm filament and many measurements taken throughout the roll I measured a consistent range from the lowest being 2.68 to 2.81.
These numbers are very rough and taken with 2 different digital calipers, but the range is by far good enough for anything I will be doing with it.
I started using hips a year ago from my filastruder, originally thinking it would be for soluble supports, I still have most of the gallon of D-limonene since Hips can separate fairly easy once cooled from most materials.
I now commonly use it for rafts on all abs/pla prints since it peals off easy once cooled and holds well leaving the final product with a clean bottom, have also used as infill on larger abs prints since it has much better layer adhesion than abs, and prevents warping on larger parts.
Turned heated bed off after first few layers and was fairly cool with the AC on. would be hard pressed to do this with ABS.
Its really a great material, a little stiffer than abs, about as strong, more prone to cracking like PLA after a long time, but not as bad as PLA in this regard.
It doesn't smell so bad like ABS and i'd imagine that's why Lulzbot is pushing HIPS so much now.
Here is a link to a few pictures taken of this recent Hips extrusion session.
http://imgur.com/a/WtPcx
After this roll of 1.7 I'll be set on hips for a while so i'll be trying some nylons from 3dsupply source again, hope to have a better write up on that.
Since HIPS is such a great/easy materials for 3dp I'd recommend trying it if you haven't.
Finished roll of 1.7mm with +/- .03 very happy with this.