warping issues with PLA on UM3

[ultradryan 9]

 

I am usually printing small figurines so i didn't walk into much warping issues.

until now that i have to print a box-like object with a large base.

It seems the normal default print settings that worked in the past doesnt fit now.

 

I was printing with mostly default "fine" profile on UM3 with 0.4 nozzle PLA 185C at 50mm/s, with a Brim, 60C build plate as usual.

Sometimes the base of the model will warp up so far as it lift some of the brim around it off the build plate.

Lot's of tutorials out there talk about wrapping issues, some mentioned very different/contradicting solutions, but I still fail to perfect my print.

 

Printing with lower temperature sometimes cause even more warping/lifting the brim, that's to my surprise.

I am wondering if printing slower factor into issue?

 

[geert_2 557]

The first layer may be too cold. Hotter gives better bonding. Also, it needs to be squished well into the glass, thus into very thin flat layers, not round sausages.

 

You did not mention if you used any bonding agent, so I guess not?

 

Some people have excellent results with 10% dilluted wood glue in water (user gr5's method), some with the standard stick (sometimes with spreading the glue with a wet tissue), some with hairspray (user neotko).

 

I prefer my "salt method": after cleaning the glass, then clean again with pure warm tap water only. And then wipe it with a tissue moistened with salt water. Gently keep wiping while it dries. This leaves a thin mist of an almost invisible layer of salt stuck to the glass. It greatly improves bonding when the glass is hot (compared to printing on bare glass), especially in moist weather when bonding is low otherwise. After cooling down, the models pop off by themself. For the next print, just wipe the glass again with the salt water. No need to take it out anymore. For me the ease of application and the ease of taking the models out, makes this attractive.

 

It works very well for PLA, and for my low and wide models. But I do not recommend it for narrow and high models like statues or lantern poles: these tend to get knocked over. For these, use a glue that can absorb shocks better. Also, it does not work for ABS, PET (it makes PET a bit less sticky).

 

For my old but still usable manual, see:

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

 

 

The model at the front is freshly printed. The one at the back was heated in an oven at elevated temperature (70...80°C), to see how it would warp and shrink, which it did obviously, thereby showing the huge internal stresses. It prints fine without lifting corners at 100% infill.

 

Below is a small test model I use to try which bonding methods work well. It excerts huge warping forces due to the large overhangs and small bottom area, so good for testing and comparing. Stay with the printer, as this is likely to come off and produce "spaghetti".

 

Dimensions of my model above, to give an idea.

 

 

 

[ultradryan 9]

6 minutes ago, geert_2 said:

The first layer may be too cold. Hotter gives better bonding. Also, it needs to be squished well into the glass, thus into very thin flat layers, not round sausages.

 

You did not mention if you used any bonding agent, so I guess not?

 

Some people have excellent results with 10% dilluted wood glue in water (user gr5's method), some with the standard stick (sometimes with spreading the glue with a wet tissue), some with hairspray (user neotko).

 

I prefer my "salt method": after cleaning the glass, then clean again with pure warm tap water only. And then wipe it with a tissue moistened with salt water. Gently keep wiping while it dries. This leaves a thin mist of an almost invisible layer of salt stuck to the glass. It greatly improves bonding when the glass is hot (compared to printing on bare glass), especially in moist weather when bonding is low otherwise. After cooling down, the models pop off by themself. For the next print, just wipe the glass again with the salt water. No need to take it out anymore. For me the ease of application and the ease of taking the models out, makes this attractive.

 

It works very well for PLA, and for my low and wide models. But I do not recommend it for narrow and high models like statues or lantern poles: these tend to get knocked over. For these, use a glue that can absorb shocks better. Also, it does not work for ABS, PET (it makes PET a bit less sticky).

 

For my old but still usable manual, see:

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

 

 

The model at the front is freshly printed. The one at the back was heated in an oven at elevated temperature (70...80°C), to see how it would warp and shrink, which it did obviously, thereby showing the huge internal stresses. It prints fine without lifting corners at 100% infill.

 

Below is a small test model I use to try which bonding methods work well. It excerts huge warping forces due to the large overhangs and small bottom area, so good for testing and comparing. Stay with the printer, as this is likely to come off and produce "spaghetti".

 

Dimensions of my model above, to give an idea.

 

 

 

 

Thanks,

How much % of salt do u add to the water?

My bed is manually leveled, any other settings I should look into perfecting the print, if printing in lower temp wont help much?

[geert_2 557]

1 minute ago, ultradryan said:

 

Thanks,

How much % of salt do u add to the water?

My bed is manually leveled, any other settings I should look into perfecting the print, if printing in lower temp wont help much?

 

Actually I have no idea of the percent: I take an old glass bottle, fill it half with water, and just pour in quite a bit of salt. Enough to make it taste really salt, but not so much that it does not dissolve anymore. It is not critical. And if kept in the fridge, it stays good for months.

 

Concerning the rest of the settings: this is hard to say, since it is influenced by materials, model, circumstances and personal preferences. For me the standard settings work pretty well: 0.1mm layers, 60°C bed, 200...210°C nozzle, 50mm/s. For very small objects that need better quality, I print slower and cooler than standard: 190°C, 25mm/s. I rarely print large objects, but if so, I often use 0.2 or 0.3mm layer height, 50mm/s, 210...220°C. Also, overhangs come out better with thicker layers. Just try what works best for you.

 

[gr5 2,167]

Your problem is most likely you aren't squishing enough.  Or maybe the bed is dusty (you have to clean it once per month) but here's a video showing how to make your parts stick like hell.  My parts don't come loose.  No warping.  Ever.