So yes - having a uniform ambient will assist matters.. but then you'll have fun and games with other areas that are 'assisted' by rapid cooling (such as bridging ). You gain some, you loose some...

yea, printing a small narrow vertical rod, the previous layer won't have time to cool and the next layer is printed on molton abs, and that area would stay soft and eventually fail. :-(

but, I think blowing 60c air into 190c abs will still cool it off, someone wanna test it?

That said, isn't the warping ultimately caused by upper layers cooling faster than bottom layers and so - depending on the amount of infill - pulling the bottom during that contraction?   That has led me to think that keeping the ambient environment at a warm consistent temperature was probably just as important as futzing with the stickiness of the print surface.

Doesn't even need to be upper layers vs lower layers.. just delta's in the temp across the part versus the ratio of cooling plastic... a long, flat, thin piece is far less likely to warp or lift compared to the same piece but doubled in thickness - because the plastic 'inside' is going to be molten still compared to the cooling exterior, which will now contract (shrink) as it cools.. but its overall volume is constrained by the still molten liquid.. so it warps...

This is why its often those thick 'chunky' pieces that warp but a relatively 'light' piece will print just fine... and punching circles (holes) in planes helps resolve the problem as the contraction will occur around the circular cutouts and not at the 'usual' points of strain (like say, a vertex).  This is also why you only ever see warping from a vertex, not mid-plane. (And all of this is different from small footprint objects which as you observed can 'lift' due to the contraction having a higher force vector than the adhesion to the buildplate.. simple matter of increasing surface area to the buildplate using Brim to win this battle.. and why it also helps with warping overall sometimes...)

A heated build area reduces the occurence of this, because it slows the overall rate of contraction of the exterior vs the interior. Likewise a hotter buildplate, because it slows the entire process down to a rate that is generally speaking, more uniform.

So yes - having a uniform ambient will assist matters.. but then you'll have fun and games with other areas that are 'assisted' by rapid cooling (such as bridging ). You gain some, you loose some...

Of course, opinions differ on this - and I'm no expert either, but unfortunately when luck combines with empirical evidence, you end up with a multitude of 'solutions' ...

Now that you mention it,there is a bed upgrade in this printer's future! I like your upgrade and have been reading about it here.

I draw a lot from my 30yrs of automotive street rodding experience,I like modifying something to suit me and at the same time to  increase it's performance and reliability.

@ mconsidine/RavensCrest,thanks about the tip.I've learned much by reading this forum and I consider it "paying it forward" if I can help with a tip of my own.

I've learned a lot in the month I've been doing this and I think it has much to do with thermal mass  in upper areas of the print,so I try to run infill at an absolute minimum.

Before I got my printer,I read a lot on "how" level the bed but not "when" to level it.When being temp wise.My common sense told me that measurements would be more precise if I did it with both extruder and bed at operating temp and not cold,so that's what I did.I don't know,maybe that's why I'm getting good prints.

I also remove the extruder nozzle once a week and soak it overnight in acetone to remove any garbage that's accumulated in there.That's one piece you can't ignore,you've got to maintain it.

That said, isn't the warping ultimately caused by upper layers cooling faster than bottom layers and so - depending on the amount of infill - pulling the bottom during that contraction?   That has led me to think that keeping the ambient environment at a warm consistent temperature was probably just as important as futzing with the stickiness of the print surface.

I guess I was starting think that ability to stick and ability to resist warping might be two different things, even if at some level having a high level of "stick" prevents warping with low-rise objects.

I'd be interested in others' thoughts or a pointer to what I'm missing.

Matt

Even when using hairspray and a 4-5mm brim I was still getting one edge or the other to lift on a larger print,it was driving me nuts.If you allow a print to continue after this you will only see layer separation and other problems further on so you might as well kill the print when you see a corner lift and save yourself the trouble.

What I did to solve my problem:

I now do all prints with a 5mm brim,I let my SD2 print the brim and print the first one or two layers of the print itself.I then hit "pause print" and lower the bed.Ideally,you want the nozzle to pause at the point where it would be doing "infill" so the restart would not be obvious....

I quickly take out my trusty knife and remove the "skirt" which has already performed it's purpose.I now get out my Q-Tips and acetone.The bed is hot and the acetone evaporates quickly so I go around the brim with acetone repeatedly and melt the brim into the bed.

When I hit "continue printing",the result is great!!!.In over a dozen prints I have yet to see one failure that is the result of base warpage!!

Hope this helps someone,Tony.

*Friends are like skittles: they come in many colors, and some are fruity!*