PLA to ABS and Back

Talk about materials used in 3D printing

PLA to ABS and Back

Postby healthyfatboy » 2013-Sep-Sun-21-Sep

When printing in PLA and then switching to ABS and back, I know ideally, you should clean out the hot end. Can you get by just fine if you just run a lot of filament through it at temp instead to "flush" out the other material or does it contaminate the new material to the point where it's not worth it?
  • 0

Printrbot LC Kit in PrintrBOX
PB bed stabilizer, leveler, fan mount, Y belt tensioner
Printed X-axis belt tensioner, spur gears, Z stabilizer
GT2 belts and pulleys
ACME lead screws and nuts
Hotend support (http://www.printrbottalk.com/forum/viewtopic.php?f=15&t=1550)
0.4, 0.35 mm nozzles, eventually 0.2 mm
Reflectix and 3M metal tape under heated bed
Plain glass for now
healthyfatboy
Waiting for printbed temp...
 
Posts: 124
Joined: 2013-Jan-Sat-16-Jan
Reputation: 2

PLA to ABS and Back

Sponsor

Sponsor
 

Re: PLA to ABS and Back

Postby RetireeJay » 2013-Sep-Mon-06-Sep

I once ran an experiment with all three materials (PLA, ABS, and Nylon). Even though I ran quite a bit of PLA through before lowering the temperature, it still jammed because of un-melted ABS (or nylon) still retained inside the hot end. The solution was to take the brass nozzle off the extruder and push through a large quantity of PLA (maybe a foot or more) to clean off the walls of the hot end so there was no more high-temp plastic in there. I could tell it was working because even though the filament going in the top was 3mm, the stuff coming out the bottom was more like 3.2 or 3.5mm - whatever the diameter of the throat is.
  • 0

Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
User avatar
RetireeJay
My next printer is...
 
Posts: 5003
Joined: 2013-Jan-Wed-13-Jan
Location: Greenville, SC
Reputation: 498

Re: PLA to ABS and Back

Postby healthyfatboy » 2013-Sep-Mon-06-Sep

So it would seem that going from PLA to ABS is okay to just flush out because of temperature melting points but going from ABS to PLA needs a clearing without the nozzle. Would that seem correct?
  • 0

Printrbot LC Kit in PrintrBOX
PB bed stabilizer, leveler, fan mount, Y belt tensioner
Printed X-axis belt tensioner, spur gears, Z stabilizer
GT2 belts and pulleys
ACME lead screws and nuts
Hotend support (http://www.printrbottalk.com/forum/viewtopic.php?f=15&t=1550)
0.4, 0.35 mm nozzles, eventually 0.2 mm
Reflectix and 3M metal tape under heated bed
Plain glass for now
healthyfatboy
Waiting for printbed temp...
 
Posts: 124
Joined: 2013-Jan-Sat-16-Jan
Reputation: 2

Re: PLA to ABS and Back

Postby Lemm » 2013-Sep-Mon-06-Sep

what about cleaning the nozzle with high temp pla ? I mean when switching back from abs to pla just float the hotend/nozzle with pla @ 230°C . Do you think this works ?
  • 0

Printrbot Jr #11045
ACME TR10x2 Z Rod
GT2 Timing Belt with 20T aluminum pulleys
Octoprint + Raspberry Pi Wireless Printer Server
Printrbot Jr v1 -> v2 upgrade http://sdrv.ms/15fDDud
http://www.thingiverse.com/Lemm
User avatar
Lemm
ACME leadscrew
 
Posts: 357
Joined: 2013-Jul-Wed-09-Jul
Location: Berlin, Germany
Reputation: 24

Re: PLA to ABS and Back

Postby RetireeJay » 2013-Sep-Mon-06-Sep

Well, I think to really purge the hot end of all residue of former plastics you would need to remove the nozzle and push the new material through. But maybe that's just me. I have not done this a lot, so maybe someone with more experience should post their findings.
  • 0

Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
"My next printer is..." Prusa i3 MK3, upgraded to MK3S
User avatar
RetireeJay
My next printer is...
 
Posts: 5003
Joined: 2013-Jan-Wed-13-Jan
Location: Greenville, SC
Reputation: 498

Re: PLA to ABS and Back

Postby bleeps » 2014-Jun-Mon-15-Jun

Hope it's okay to bump this and get some feedback from more experienced operators about switching back and forth. I actually have a spare Ubis that I was planning to use just for ABS. Is that the best plan of action or are there easier tricks for making the switch?
  • 0

bleeps
I'm an end stop.
 
Posts: 63
Joined: 2014-May-Sun-09-May
Reputation: 1

Re: PLA to ABS and Back

Postby plexus » 2014-Jun-Mon-15-Jun

YMMV but when I was using Ubis I would switch materials (PLA / ABS / Nylon / HIPS / PS / PC / Laywoo) without cleaning the hot end out. I would just purge out the old material and print. I rarely had issues. When I did I can't say it was attributed to the material switching - it just appeared to be isolated issues. I've switched to E3D and do the same thing with no issues. After using the Ubis I found the Ubis has a larger melt volume in it and requires more push-through to clear it with the new material. The E3D basically only has a path the diameter of the filament straight through to the nozzle aperture. I think the Ubis has more of a volume within the nozzle where material accumulates. I think it can get trapped in there and burn and cause clogs although I have never been able to verify that. I haven't had a nozzle clog with the E3D where as with the Ubis I would get clogs from time to time.
  • 0

User avatar
plexus
Site Admin
 
Posts: 2117
Joined: 2011-Dec-Mon-16-Dec
Location: Toronto, Canada
Reputation: 95

Re: PLA to ABS and Back

Postby Jdublu » 2014-Jun-Tue-08-Jun

I did this last night. Was printing PLA at 205C. Received my first roll of ABS from MatterHackers (thanks guys for the FAST delivery). Set the temp at 210 and retracted the PLA. Inserted ABS, cranked temp to 215 and extruded 100mm to clean out the extruder. Cranked temp up to 225 and successfully printed my first ABS spring clip.

I needed to print the stand for my T-rex I had done the day before in PLA. Set extruder to 225 and retracted the ABS. Let it cool to 210 and reinstalled the PLA and ran another 100mm through the nozzle to flush the ABS. Then I printed the T-Rex stand and support. No jams, no problems.

Maybe I just got lucky but I've done this with HIPS too without any problems. Just don't crank the extruder up to ABS printing temps without flushing the PLA first. I try to keep it at 215 or below with PLA in the chamber.
  • 0

Metal Simple
E stepper heatsink w/fan
Z axis stepper heatsink w/fan
Extruder fan
Hotbed relay fan
6"x6" Heater board
40 Amp power supply
Matrix-Precision 8" x 8" aluminum bed X-Y upgrade
Matrix-Precision 10" Z axis upgrade
S. Florida
User avatar
Jdublu
Honeycomb infill 25%...
 
Posts: 265
Joined: 2014-Apr-Mon-08-Apr
Reputation: 13

Re: PLA to ABS and Back

Postby spitfirehauser » 2014-Jun-Tue-08-Jun

I have been switching from nylon to ABS and back over the last several weeks with no apparent problems either. just flush the old stuff out until the new color is "true" and switch back to the lower setting. i print the ABS around 230 and the Nylon at 250. cheers
  • 0

Steve Hauser
Modified Simple 2014 kit
User avatar
spitfirehauser
Waiting for extruder temp...
 
Posts: 95
Joined: 2014-Feb-Mon-10-Feb
Reputation: 4

Re: PLA to ABS and Back

Postby rho-wan » 2014-Jun-Tue-11-Jun

What about the switch between ABS and Nylon and back? I expect nylon to flush out completely without issues also before extruding aBS (moreover, the temperatures are comparable).
  • 0

PrintrBot LCv2 and ABS. Flipped PCB with alu 3mm plate and then kapton on top, plus hairspray. Three paper rings ("frames") between PCB and alu plate, to compensate for the bulging PCB when warm.
Sunflower oil between PCB and alu plate to try to improve heat conduction (better than air anyway!)
rho-wan
Waiting for printbed temp...
 
Posts: 105
Joined: 2013-Jul-Fri-01-Jul
Reputation: 3


Return to Material talk

Who is online

Users browsing this forum: No registered users and 1 guest

cron