how to switch from abs to pla

[Orellana.arch]

hey guys whats up im a noob at this and was wondering if anyone can guide me to the right post. I want to switch from abs to pla what are the steps or is it just the temperature on the nozzle that has to be set? thanks for you help guys.

[IMBoring25]

Normally, you run both the nozzle and the bed (especially the bed) cooler for PLA. It's also customary to use slicing settings that make more aggressive use of the layer fan.

[gestalt73]

If you're asking how to switch filaments on the printer, here's what I do.
The general ghist is to remove the existing filament by heating to it's borderline glass transition temp, then heat to the hottest temp between your old material and new to flush out the nozzle.

**NOTE:** These temps are for my setup using E3DV6 hotends. Replace temps in the example below based on your setup and which materials you're moving between. Thanks!

For going ABS to PLA:
- heat hot end to 180 (close to glass transition temp for ABS)
- pull out ABS filament from hotend
- feed in PLA filament
- heat to 240-260c (print temp for ABS)
- extrude 40mm-100mm to clear out the nozzle
- set to your PLA printing temp and have fun

For going PLA to ABS:
- heat hot end to 165 (close to glass transition temp for ABS)
- pull out PLA filament from hotend
- feed in ABS filament
- heat to 240-260c (print temp for ABS)
- extrude 40mm-100mm to clear out the nozzle
- have fun

[Johncoffee]

I think there are some copy paste typos in this, as the switching info is not consistent.
Can you rephrase correct? Also ABS temp between 240-260 is way too high. I run at 228deg C for ABS

[Jimustanguitar]

I heat the hot end up to a temp that I know will melt both materials in question, and manually extrude filament through the nozzle. After the color changes completely, I go about that same distance a second time just to be sure.

In my experience, there isn't need for a complex or multi step process, just heat 'er up, purge out the old filament at a good temp for both materials, and proceed normally.

If you were switching from PLA to Nylon or something with a higher temperature differential, you'd want to do it gradually, but just ABS to PLA and back again in't anything to be worried about.

[IMBoring25]

I've heard of people running ABS that hot for layer bonding purposes but I've never seen the need for more than 225-235, and you certainly wouldn't want to do more than that on the stock hot end on the Max.

Be careful running materials well outside their normal extrusion ranges. If you ever do any PVA I've been told it will burn up and clog hard not much over 200 and I think I remember reading ABS will start putting off some nastier byproducts around 265.

[Captain Starfish]

Jimustanguitar's got it right I reckon - and I do the same for switching ABS and nylon too. Just whack it up to the temperature of the 'hotter' of the materials and extrude until the colour changes, next step is print

I run ABS at 255-260º but not on the stock hot end (using an E3D) and it makes a huge difference in strength - I was happily holding a gas seal at 2500psi with one part during a very disappointing (because it didn't) failure test.

[gestalt73]

Yikes, good catch. I updated my response with a note that I'm using E3DV6s and the temps I run at may not be everyone elses.

Also, interesting discussion about print temps.

There are no typos in my response. I generally print ABS at 260c, and PLA at 230c.
There are always exceptions, but most of my prints are functional, and I need the layer adhesion.

[Johncoffee]

Ok, didn't know you have a E3DV6 head
Interesting finding about the strength with ABS @255-260°C !