Bed Heat and its effect on warping

[3dPrintingMD]

I'm hoping to have some discussion on bed heat and how it effects warping.

Currently I am running into some problems with a particular model that likes to lift off the plate. The effect is increased when I print more than one of these items at a time, and therefore to me there is additional cooling time between each layer. I'm running a MIC 6 plate and heated bed at 60c.

I have an IR thermometer on the way that I am going to use to check the surface temp of the MIC 6 plate in relation to what the printer is registering.

As part of my testing I am going to bump the heat up to 70c and see the effects on the warping.

Just looking for some thoughts to kick around.

[Jules]

What filament are you printing, PLA? Does your Mic6 have PEI on it?

If you've got PEI, you'll do better with sanding the surface of the PEI a little bit with fine-grade sandpaper ( >1000 grit) or a damp Magic Eraser to rough it up a little and give it some tooth. Clean it off really well after (spritz of alcohol) to remove oils and all of the sanding residue.

If it's just a plain plate, you could try either hairspray or gluestick.

(Might work out better than just increasing the temp, but you could give that a try first. I sometimes have to up the temp a bit for certain filaments....particularly white or light colored ones.)

[3dPrintingMD]

PLA.

I'm using just a plate, no PEI.

Using it with hairspray. Many successes, but at the same point, a high rate of failure.

Wondering that if the heat is measured at the HBP is it significantly different (lower) at the top of the MIC 6.

[ednisley]

check the surface temp of the MIC 6 plate

IR thermometers assume a surface emissivity around 0.95 that's completely wrong for bare metals: bare aluminum can be well under 0.20. Stick masking tape on the plate as a target.

http://www.infrared-thermography.com/material.htm

Also, the laser dot gives you a general idea of what the IR sensor "sees", but the target area is about an inch in diameter half a foot from the snout and increases from there: 2 inches at a foot, 4 inches at two feet, and so on. It's definitely not a pinpoint sensor!

Make sure the tape on the platform completely fills the target area.

significantly different (lower) at the top of the MIC 6

Aluminum's thermal conductivity ensures the plate will be pretty much a uniform temperature. The thermistor isn't in contact with that plate, so you'll definitely see an offset.

Even the original glass isn't all that bad:
viewtopic.php?f=14&t=3532
viewtopic.php?f=14&t=3141

Also, IR thermometers don't work for hot ends:
viewtopic.php?f=7&t=3312

[M3Jim]

I have had good luck reducing warping by reducing the cooling fan speed. With ABS, which is all I print with anymore, I only use the fan if the area being printed doesn't have time to cool i.e. small cross sections.

Hope this helps,
Jim