PETG minimum time per layer comparison

I have recently been playing around with a spool of PETG from rigidInk. Attached is a side by side of two test cubes with different minimum layer times, all other settings the same. The left cube has no minimum layer time and printed in about 3 minutes excluding warm up time, whilst the right hand cube had a minimum 15 second layer time and took a total of 8 minutes. The left hand cube retained heat which, i think, caused the layers to collapse onto each other causing a wavy effect. The minimum layer time allows the previous layer enough time to cool and harden so that it can support the next layer.

For reference:
printer: mendel90 with E3Dv6 hotend
bed temp: 70c
hotend temp: 235c
layer height: 0.2mm
tool: slic3r/marlin(t3p3)
adhesion: glass plate with pritt stick

That's a nice comparison. Do you have a print cooling fan? It would be nice to see if you could get the same result with cooling the print and still have the faster print time.

Nice to see that minimum time works as well. I did what JamesK asks for and tried with and without a cooling fan and got nearly identical results to what your image shows.

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@JamesK Still have not got around to printing a new fan mount, but Srek seems to have the answer!

I have tried this since I cannot find slow down toggle in slic3r.

Printing PETG on 87deg bed. With Fan and without Fan. I see no difference. I still get the picture on the left. But for my prints, the most bubbly warping is on the opposite wall.

Can you please tell me where the settings are for "minimum layer time" in slicer? And how you input the numbers?

I found cooling thresholds and set Enable cooling at 15sec? Is this what you mean? I have not started printing with this setting yet until I hear back. Picutre attached

Hi, in your screen shot the box marked "Slow down if layer time is below:" is the minimum layer time, except it won't slow down to below the speed in "Min print speed:", so if the layer is really small you could still end up with quick layers.

If you still get warping on one side of the print with the fan running it may be that the cooling air isn't getting all around the print. One way to improve the flow is to use two fans, one on each side.