Interesting observation regarding PLA

[Agisis]

I've had lots of problems with stringing using PLA, and to solve it usually requires a combination of retraction / running at a lower temperature / slowing down a bit. The outcome is usually significantly less stringing but then a new problem comes up where the layers don't adhere as well due to running at a lower temperature. So, that got me thinking and after a few tests I think this can help me run cooler but increase layer adhesion. I determined adhersion has a lot to do not just with the filament coming out of the nozzle, but also the temperature of the layer it is adhering to (I know....duh, but stay with me here). I chose to run my hot end really cool for a few tests (175-180ish) and cranked the bed temperature up to 80c. Sure enough, the stringing was highly reduced but the adhesion really improved. So I basically trade some hot end temp for some hot bed temp. I figure are 3/1 ratio is fairly good where every degree I drop from the hot end, I raise the bed temp 3 degrees. There is a point of diminishing return if the print is tall of course, so it's not perfect, but I thought I might throw out this observation to others and see if they noticed it too (which I am sure they have).

[Earthbound]

High bed temp leads to elephant foot (spreading of bottom layers). You might try reducing the amount of cooling by slowing down your layer fan(s). If you've slowed down the printing speed to reduce stringing, layer fan has more time to cool the top layer.

[Agisis]

Good point, I keep forgetting about the layer fan and that I can control that. I haven't experienced the elephant footing, but it makes sense, especially if the model is heavy on top. I'll play with that.

[geneb]

When printing PLA, I've always used a 55C bed.

g.