Humidity?
July 06, 2017 04:25PM
I have a Prusa I3 Rework V1 and I can take any model and print it fine in the late fall and winter in 0-10c temps using ABS. Now, that is amazing unto itself as it is cold and no warping but what is even odder is come mid spring and summer I cannot print anything even the same parts I printed a few months earlier. Now the temps in the room have went up to 24-32c (depending on the month) which ABS should love but come a 5-10mm off of the bed no matter what I do my prints will no longer stay down. This has to be humidity issue in the room as the filament is in a 10-22 RH box year round.

Am I right and the humidity is making ABS no longer stick because you would think that in the summer ABS would be overjoyed vs the cold of the dead of winter.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
Re: Humidity?
July 06, 2017 04:38PM
Not sure. I live in Florida where humidity is only 80% or so.
I dont store my ABS in boxes or anything and they print well.
Re: Humidity?
July 06, 2017 04:56PM
Quote
Floyd
Not sure. I live in Florida where humidity is only 80% or so.
I dont store my ABS in boxes or anything and they print well.
I live right off of the Mississippi river and over the last 4 years I just can't print in the summer and the only thing I can think of is the humidity. Even a brand new roll I can't use but come the cooler weather where the humidity drops to below 50% and I just don't have any issues.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
VDX
Re: Humidity?
July 06, 2017 05:47PM
... this could be changed viscosity and "macro-molecular behaviour", caused by the higher ambient temperature and so slower cool-down too ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Humidity?
July 06, 2017 06:01PM
Quote
VDX
... this could be changed viscosity and "macro-molecular behaviour", caused by the higher ambient temperature and so slower cool-down too ...
Well, I don't think that because ABS loves being in a heated chamber and actually is the best way to print ABS.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
VDX
Re: Humidity?
July 06, 2017 06:13PM
... do you print with heated chamber?

You have 2 or more different ambient conditions - humidity and temperature (or better temperature-gradient after extruding), air pressure, ...

Some years ago I had to solve a problem with different behaviour of a glue-dispenser between morning and noon - this was caused by varying temperature-gradients inside the glue reservoir while dispensing -- so not exactly your problem ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Humidity?
July 06, 2017 06:21PM
Quote
VDX
... do you print with heated chamber?

You have 2 or more different ambient conditions - humidity and temperature (or better temperature-gradient after extruding), air pressure, ...

Some years ago I had to solve a problem with different behaviour of a glue-dispenser between morning and noon - this was caused by varying temperature-gradients inside the glue reservoir while dispensing -- so not exactly your problem ...
I do not print in a heated chamber so open air printing. Windless day, or night, sitting in the same spot and in the summer something causes the print to lift and be ruined whereas in the winter the same print will easily succeed. Only two things change and that would be the ambient temp and the relative humidity.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
VDX
Re: Humidity?
July 06, 2017 06:35PM
... could be both or even a sort of relative dependency - warping and delamination is mostly connected to temperature, not humidity ... but can be influenced by storage conditions too, what's mostly defined by long term humidity conditions.

Other possible factors are the viscosity and extrusion speed (pressure, "caught" stress) and the cooldown time and curve-shape from printing to ambient temps ...


Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]
Re: Humidity?
July 06, 2017 07:23PM
Quote
VDX
... could be both or even a sort of relative dependency - warping and delamination is mostly connected to temperature, not humidity ... but can be influenced by storage conditions too, what's mostly defined by long term humidity conditions.

Other possible factors are the viscosity and extrusion speed (pressure, "caught" stress) and the cooldown time and curve-shape from printing to ambient temps ...
I have to eliminate the storage part of that because that does not change and the RH inside the storage box is enclosed with rechargeable desiccant and a digital RH meter to tell me when to recharge them. I also have tried brand new filament and the same end results and in brand new I mean I purchased it and cut open the bag, removed its desiccant and slapped it on my printer immediately with the same result. I store it away until winter and it prints then store it back where I pull that same roll out of the dry box in the summer and forget it but come winter I will not have any issues with that filament. Based on all of that I have to eliminate the filament, or its storage, as any part of this issue.

Warping, and delamination (I do not get this on even 150mm tall prints), are supposed to be caused by the lack of heat as the ABS cools it shrinks causing a tugging action, of great force, until it lifts off the bed. This is why a heated chamber works best for ABS because you will control its ambient temps until all are slowly drove down. This is why on a 0c day (I mean it is cold cold in there) that ABS should lift up very quickly while in the summer with it ~28c it has far less reason to do so.

Now with all of that said we know it is going to shrink as ABS does but in the winter it should shrink faster causing even more stress and lifting from the bed but here is where the humidity comes in at I do believe and that is the medium holding down the print. I use glue stick, hairspray, etc... and those are water soluble and in the summer it is basically sitting in water (that is in the air). My purple Elmer's glue stick never wants to dry and remains purple for a magnitude longer, if not longer, than it does in the winter so I think that the glue is just letting go because it never attains a good bond to the glass thanks to all of the humidity.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
Re: Humidity?
July 07, 2017 09:53AM
Have you tried printing with a big cardboard box over the printer itself? You said its not a heated chamber, but if it was enclosed the temperature of the bed and hotend would dry the air inside the chamber to a point that might rule out the humidity option. And I'm not suggesting you spend a ton of money trying it out, but would offer a large cardboard moving box would be large enough to cover most printers and work as a trial to semi-enclose a printer.
Re: Humidity?
July 07, 2017 03:03PM
Don't know about humidity but its hot in the UK right now, and both of my well calibrated machines have needed 110-115% extrusion multiplier to print ABS normally. Can't figure that out...


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Humidity?
July 07, 2017 08:53PM
Quote
PDBeal
Have you tried printing with a big cardboard box over the printer itself? You said its not a heated chamber, but if it was enclosed the temperature of the bed and hotend would dry the air inside the chamber to a point that might rule out the humidity option. And I'm not suggesting you spend a ton of money trying it out, but would offer a large cardboard moving box would be large enough to cover most printers and work as a trial to semi-enclose a printer.
I have and it did not help but the cardboard box isn't sealed and it doesn't dry anything out and lets not forget that the hotter it is the more moisture the atmosphere can hold and the RH goes up so in a nice hot box it would probably be even worse if humidity is the real culprit.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
Re: Humidity?
July 07, 2017 08:57PM
Quote
DjDemonD
Don't know about humidity but its hot in the UK right now, and both of my well calibrated machines have needed 110-115% extrusion multiplier to print ABS normally. Can't figure that out...
If I could get it to stay stuck to the heated bed I would have no other issues. sad smiley Hot + rain for 10-15 mins every single day = forget it.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
Re: Humidity?
July 08, 2017 07:50PM
I just did a 2h print out of 3h and it started to lift on all corners. I went to 1.5 times the brim I normally use (from 8 to 12) and tried an Elmer's glue and water mixture that I spread across the glass (gave it a frosted look). I even over did the first layer by 125% width and 95% height and the first layer height was closer to the glass of almost being too close. Not a thing I have tried works and it is currently 87f and Humidity: 54% outside but the room is about 90f.

Edited 1 time(s). Last edit at 07/08/2017 07:50PM by Dark Alchemist.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
Re: Humidity?
July 10, 2017 08:29AM
The thing is I wouldn't say 54% RH was a high number.

How about air conditioning?


Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Re: Humidity?
July 10, 2017 01:07PM
Quote
DjDemonD
The thing is I wouldn't say 54% RH was a high number.

How about air conditioning?
54% is low for this time of year but in this room the RH on my meter was 74% (I guess the national weather service's meter is at the airport while I am closer to the Mississippi river) as are our temps since we should be in the upper 90s and lower 100s (weather is funky this year) so I have no idea and AC is out of the question. I am baffled.

Edited 1 time(s). Last edit at 07/10/2017 02:06PM by Dark Alchemist.


_______
I await Skynet and my last vision will be of a RepRap self replicating the robots that is destroying the human race.
Re: Humidity?
July 11, 2017 11:02AM
Quote
Dark Alchemist
. . . I do believe and that is the medium holding down the print. I use glue stick, hairspray, etc... and those are water soluble and in the summer it is basically sitting in water (that is in the air). My purple Elmer's glue stick never wants to dry... so I think that the glue is just letting go because it never attains a good bond to the glass thanks to all of the humidity.

Could be you answered your own question.

Humidity is relative to temperature and 32C holds a lot of water.

Try Kapton tape. I'd never go back to glues and goos since using it.
Sorry, only registered users may post in this forum.

Click here to login