Is it OK to turn off heated bed after a number of layers have been printed?

[umagi 8]

Hi,

Wondering if I can turn off the heated bed of a PLA print after a sufficient number of layers have been printed?

For long prints, it seems a waste of energy to have the heated bed on until the end of the print.

Thanks for sharing your experience on this!

[Labern 775]

It's not really a good idea for a few reasons.

One is that the glass expands and shrinks at different rates to PLA and when they cool down the PLA will pop off the glass and your print is the ruined.

Another reason is you need constant temperatures to give a nice print. Fluctuating temps can show uneven shells so the part might have a taper on the external surface as the glass cools.

You can print on cold glass if you want but it takes some experimenting with and you may have to print on blue tape.

Edited March 31, 2016 by Guest

[tommyph1208 55]

As @Labern says, its very likely that your print will pop off the print bed if you turn off the heat during printing. As far as energy goes I don't think you have to worry too much... The bed itself I think is only around 100W and has fairly good thermal properties, thus it isn't actually on all the time... It will run on-off cycles to keep the temp around your setting.

To reduce the sagging effect often seen in the bottom of prints (known as Elephants foot), you can reduce your bed temp a bit, and see if you still can get adhesion and no warping (this will also lower energy cost... but again, it really isn't that much)

If you get problems with adhesion, but still want to reduce elephants foot, try printing the first few layers at your normal temp, and then reduce bed temp a bit from layers 2-3 and up (you can use Curas "Tweak at Z" plugin for these things)

...Again, don't reduce it too much, or you'll ruin the print.

Edited April 1, 2016 by Guest

[umagi 8]

Labern, tommyph1208, thanks for sharing!

Chose the first answer as the "best" one, because, well it was first...