How to clean and cool for optimal PLA printing

[LesHall 95]

INTRO

This is a really simple little trick that I just discovered and thought I would share.  It turns out that after all the figuring out and trying of different bed substrates and all the experimentation, a technique has emerged for printing effectively in PLA.  This technique is simply to print at your chosen nozzle temp (around 200 C or thereabouts) and with a plain glass bed temp of 60 C.  That's right, a plain super clean bed at 60 C does the trick.  Of course, you also have to let the print cool.  It is the cleaning process and the cooling process for which I have suggestions.  

BED CLEANING

I use a commercial Windex-like product that the maid left for me either by accident or as a courtesy.  It's an industrial cleaner doled out in a plain squirt bottle so I cannot give you an exact product name.  Just look for Windex or similar cleaner in your favorite store or on www.amazon.com.  K, also GET A SQUEEGEE.  I have a super squeegee with artsy design and double blade but really any squeegee will do.  My squeegee is exactly wide enough to cover the whole bed width yet narrow enough to fit in the Ultimaker.  I have no idea how my luck found that particular squeege width but i tell you it is the cat's meow.  My cleaning process is as follows:  

o Get two paper towels, squeegee, and glass cleaner out and ready for action

o Remove Glass From Bed

p Clean Glass and Bed top with cleaning fluid sprayed on a bunched up paper towel

o Allow Glass and Bed top to dry

o Reinstall Glass

o Spray cleaner on glass top, covering full width and back part of glass (avoid spraying back wall)

o Squeegee surface and clean first bed front where fluid deposits, then squeegee blade

o Put squeegee and cleaning fluit away

This should clean your print bed to perfecdtion so that even the smallest or largest deposit of PLA will show no flaws underneath when all is said and done.  Next up you print with the bed at 50 C and finally you allow to cool down, which has a small bit of technique as well, so here goes...

COOLING DOWN

When the print is done, the Ultimaker 2+ (I don't know about other models) will show a cool-down temperature down to 40 C.  You need to let it cool down an additional 10 C to 30 C as the final temperature, or as close to 30 C as you can get.  I just tried using a 6" fan to cool the PLA print and it worked very quickly.  There is an important safety warning here:  PET, PETG, and the PET family of filaments can take chips out of your glass bed if they are cooled too quickly.  These instructions apply only to PLA.  You are on your own for other materials.  

So anyway your printer will tell you at 40 C that the print has cooled sufficiently to remove it from the bed.  Ah, but you are smarter than your printer and you know from experience that the print will not separate easily from the bed until another ten degrees (or at least seven degrees) C of temperature cooling have occurred.  So how do you know when the bed is at 30C?  Easy:  you navigate the menu system into Maintenance > Advanced > Heat Up Build Plate to get a temp display and just leave it at 0 C as the target temperature.  Now your pinter is monitoring the bed temp again, you've got a fan (or not) on the print, and you can wait and/or watch the print cool down to 30C.  

You know you've reached the threshold of gripping when you hear some snappy clicking sounds which are the bed and the print separating.  These sounds should occur around 35 C or lower.  The print can be removed with a thin bladed painter's knife or similar thin-metal spatula-like tool or in most cases when the print has some height to it, you can just grasp and twist the print to release it.  

There you go, print in hand, mirror-like bottom surface, and the satisfaction of a job done to perfection.  Hope this helps a bit, it sure helped me.  See ya!  

Les

Edited July 2, 2016 by Guest