Total noob to printing problems.
What would be causing my prints to pop off the build plate? I’ve been trying to print off some heat towers with new filament. The tower keeps popping off the plate at around the 210-215 degree range. Friday I was 2/3 of the way into a 3 hour print when the model was pulled off the plate. Nothing like seeing a huge pile of filament around your model. Thanks in advance.
The temperature of the build plate matters. For PLA I use around 60°C, but this depends on the material you are using as print surface. Just keep in mind that the sensor is at the bottom and the print is on the top. There is usually around 5°C difference. Since I print on a 3mm glass plate, I set my temperature to 65°C and usually give the plate a little more.
Narrowing the nozzle to the build place can help, too.
Without knowing what surface and filament type you use, there is not much additional help I can provide yet.
i.e., Z-offset; what do the undersides of those towers look like?
As stated, details help! Material, temps, bed type, build plate adhesion settings and printing adhesives all affect part adhesion. Also, I ran into one temp tower STL that had a malformed base plate for the tower which caused me adhesion problems.
Cheers!
All of the responses so far plus, photos. They can help a lot. Make sure they are well lit, clear, and sharp.
Well cleaned print surface is a absolute must too.
I use isopropyl alcohol to clean my glasbed before every print. Never had adhesion problems
I followed the DrVAX advice to use Magigoo. One of its greatest attributes is that it releases prints from the printbed after the bed cools down. It’s funny to hear the sounds it makes as the bed cools. It sounds like ice cracking. The good news? once the bed is cool (and the cracking has stopped) the model will lift right off the bed without effort.
Same happens with PLA and a glass bed without any glue. When I need a perfect first layer (Print in Place) or have tiny parts that join the bigger part on a higher layer, I use “UHU Stic”. It works like a charm, is cheap and when you want to clean the build plate, you can use plain water.
You might try a bed temp of 65C or even 70C.
Maybe tune the PID of your bed. Inconsistent temperature may cause the print to pop of the bed.
it’s worth a try and shouldn’t take long
I like the bottom layers a tad more “squished.” I’d try lowering the z-offset by 0.02-0.05 mm. For PLA (currently using Hatchbox white), I use an initial bed temperature of 65C and lower it to 60C afterwards, fwiw. I doubt the latter makes much difference. The attached image is from a part printed on my MP10 mini with the stock plate.
Hope this helps!
Cheers
Sounds like something over my head. Not sure how to access the PID, let alone tune it.
Looks like your nozzle may be too far from the bed on the initial layer. I use regular paper for distance between nozzle and bed, make sure bed is level. I print PLA on a 60 degree heated bed.
I have perfect adhesion results with wood glue (PVA). I’ve previously used stick glue, but it was hard to remove from print object afterwards, and if applied more than needed it would leave uneven 1st layer. I’ve discovered PVA while printing nylon.
What is PVA? Where “PVA” is noted, we would define it in the USA as “Elmer’s Glue All” white wood glue. Elsewhere, and standard White water soluble wood glue.
Source: https://taulman3d.com/best-print-settings.html
When used, results were perfect so I’ve tested with PLA and PETG as well - worked without any issues. Any residue on printed object can be washed away with water or alcohol.
How to prepare and apply PVA:
- Prepare small container and a brush
- use small amount of glue (like to cover a container bottom)
- add tap water - I use 2-3x more than glue (you can really do it by eye)
- mix the glue and water with brush - glue should dissolve completely, and end mixture should be watery white
- clean the baseplate with alcohol
- apply mixture to baseplate with a brush
7a) while preheating bed - white watery mixture will evaporate leaving just thin transparent layer on baseplate
7b) if you don’t use preheat or have non heated bed, just wait for 10-15 minutes for mixture to dry out - when you remove object you can just re-apply the mixture over
- after several layers (3-4 prints later) I use alcohol to soften the adhesive and scraper to remove excess.
PVA is cheap and highly available anywhere over the world. Hope this will help someone!
Don´t shoot the beginner with too advanced answers here.
It comes down to the distance of the nozzle, which is to far from the bed and the temperature. I would go for at least 65°C at the bed. As mentioned before the sensor is on the bottom and not what you are actually printing on. The temperature shown in the display is at least 5°C lower than the temperature on the surface.
Just rub the first lines sideways while printing. When they feel round you are to high in the air, when printing. They should come loose quite easy when rubbed sideways, too. The filament acts like a bottle laying on its side. There is not much contact with the surface. It is enough to start the print, but in the end the air gabs between lines are kicking it off.
In that case glue or whatever will not help, as the glue has the same amount of contact with the print. Also the bottom layer will still look like an air mattress even if the print succeeds by accident. 
The pictures show clearly that the brim lines are not connected properly. This is a clear indication that the nose is to high. Not far, but enough to pop the prints of. Lower the nose in 0.05mm steps until it sticks and maybe change the extrusion for the first layer to 105% or so to give it a little more plastic. If the brim is not a resulting in a nice sheet foil it is useless and the print itself will not stick, too.
Thanks guys. Your suggestions make a ton of sense and will apply them post haste.
@mincevv, just for clarification, glue sticks like Elmer’s and UHU are also PVA, just in a thicker form. They can be watered down to a consistency like that of wood glue. Might be a good way to use up left over glue sticks ?
Nice to know - I know they are all starch based, but PVA is much more convenient for watering down and possibly has much less additives than stick glue.
While on topic (sorry if I am misusing this thread):
Glue sticks have been known for a long time and are used in particular for gluing paper, cardboard, pictures and other common materials. The known glue sticks usually contain aqueous preparations of an adhesively acting substance, such as polyvinylpyrrolidone, aqueous polyacrylates, polyvinyl alcohols, and blends in conjunction with structure-forming ingredients, such as fatty acids, which, in the form of a soap gel, provide the glue stick with the consistency which allows it to hold its shape. Starch-based glue sticks are also known, their adhesively acting substance being primarily starch. Propylene glycol is often added to the glue sticks as a softening agent.
For PLA I rarely heat the bed. There is no need. If the first layer sticks everything is fine.
I think it depends on the printbed surface. That said, I’ve been using Magigoo because of the way it releases the print after the bed cools. It really needs heat to activate.