Layer Adhesion, and how to speed up part removal.

[smorgana 0]

I print with ABS on an Ultimaker 2...

The machine works great, but I have had occasional problems with layer adhesion on tall objects.

If I run .1 layers... no problem.., go up to .2 layers and I get cracks and the part is weak.

But this week I have a part to make that takes 11 hours at .1 layers, 20% infill.. and I need to make a bunch of them by Thursday... so I read this forum for advice on how to improve my print settings. Printing at .2 layers gets me a part every six hours.... I'd get about 4 parts a day.

So basically this is a repeat of what can already be found here...

The ABS I'm working with specs say to have the nozzle heat at 230 - 240c depending on printer model...

I have been running at 230, and found out here that increasing the temp would help fix the problem...

So I ran a part at .2 layers, 20% infill and at 240c... and it still had a few cracks...

Reading more here I found that the idea is that the plastic is cooling too fast (My basement is pretty cool)... so the advice was to also set the fan speed down to 25%, and try to enclose the printer...

So I set the fan speed, and taped a piece of heavy paper across the front opening and ran the part.

And wow... It worked... The part came out beautifully..

The next thing I'd like to learn is what's the fastest way to get the part out of the printer... I'd like to print as many parts per day as possible... If I start a print before bed that finishes during the night, by morning the printer is cool and the part has separated itself from the build platform... I use glue stick... so if the platform hasn't cooled enough you either can't get the part off, or you end up breaking the part trying to get it off.

is it safe to blow a fan at the build platform to speed cooling, or will that lead to cracking too?

[rigs 735]

Hi,

Layer Adhesion :

Thermography and weld strength

how to speed up part removal :

Dimafix

[smorgana 0]

Thanks.

Though Dimafix looks interesting... it can't be shipped to the USA, which is where I am located.

So the parts release themselves with glue stick too, but the platform has to be room temperature.

My question really is... can I speed the cooling process or do I risk cracking...

I suppose i could just try it when I'm not in a rush to get parts done.

Hi,

Layer Adhesion :

Thermography and weld strength

how to speed up part removal :

Dimafix

[kmanstudios 1,120]

I got several buildplates to speed up my transition times. Here is my basic process:

Take buildplate and put layer of PVA slurry on it. This puts a thin layer for adhesion, but also helps part separate when soaked in water.

Print and remove buildplate with part on it. Put that in shallow pan with water to start the layer dissolve process.

Put different buildplate on the bed, heat, clean nozzles (set the temp on the print cores to soften the material and preheat the cores) and level.

Clean glass with 99% Isopropyl alcohol and then PVA slurry. Heating the bed during this time will speed the evaporation of the alcohol and slurry as well as cut down on the  time from hitting print button to start printing. The print cores are closer to printing temps when doing the nozzle cleaning and letting the cores stay at temp.

While the print is printing away, I am free to let water take care of my supports and plate adhesion with no issues, no worries and no hurries. Once the print has been able to be removed, I can then put in water bath to recycle and remove all the PVA supports. If no supports, then just a bit of washing to clean the print up real nice. This is good because sometimes, I can jut go right back to bed in the middle of the night.

Final note is that I am now experimenting with just swapping out plates without active leveling at every plate change. Unless I accidentally bang the plate when removing or placing new glass (I am kinda clumsy sometimes as the prints will stop at odd times during the night and I wake to the sounds), I see no reason to level, so just now testing. Speeds the beddy bye time for return and catch more sleep.

But, if the print starts to curl, or has some sort of defect that makes the plate bounce a bit during printing, I will always run a level as it is pushing the springs about a bit.

Edited July 30, 2017 by Guest