How necessary is the ceramic insulation tape on the extruder?

[Tom Chang]

I've read some people run their printers without it.  What are the implications of running their extruders without the ceramic tape?  I found it to be a nuisance because, but are there any disadvantages of not running it and printing PLA with it?

[Joe Larson (aka Cymon)]

It can transfer to much heat to your print, especially bad with PLA, causing your print to warp.

[Ryan Carlyle]

The insulation:
1) helps keep your print cooler, reducing heat damage from slow cooling on fine details, roofs, and overhangs
2) protects your (plastic?) carriage from radiant heat
3) reduces the amount of heat your heat sink & fan has to remove from the cooling bar

Higher-temp filaments like ABS and nylon often do ok without insulation. I print PC without any insulation (at 265C) and it works fine. And many people print PLA without insulation too. It's really just a function of airflow and heat shedding throughout the printer.

However PLA is already very marginal in many/most people's printers because of the low glass point. It's probably a good idea to keep as much heat in the hot block as possible, for all the reasons above. Unintuitive things can happen without insulation. You can get more air prints, or lose overhang quality.

It does matter, but feel free to experiment.

[WifiGuru10]

Ok the MK7 series extruder head, you want the insulation so that your thermocouple reads the correct extruder temperature. Especially if your using a cooling fan (PLA mainly). I've been playing with the mbot MF1 extruder recently that doesn't have insulation which reads the temperature from inside the heat-block. The cooling fan keeps the print cool enough where i don't get any warping. So far have had amazing success with PLA print quality versus the old MK7. Haven't printed anything too large with ABS.

With ABS tho, I only use the colling fan during bridging but would probably throw off the temp of the extruder so I'll probably end up wrapping it or running the cooling fan much slower.

[Bryon Miller]

My tape got ripped off during a print once, I ran it without the tape for a while.  I had more problems printing like that, it would usually effect larger prints.  The finish would look wavey or kind of warped.  I'm not sure, I can't really recall, but it might have caused clogs as well, but I honestly can't remember if that was the cause.

[Shawn Grover]

My understanding is that the ceramic helps the aluminium block keep the heat in a more linear manner.  (i.e. if you graph the heat it's almost a line, without the ceramic tape you get more of a sign wave type pattern...)  But I haven't really seen any hard data that says "must be there" or not.

I've replaced my ceramic tape a couple times.  A couple of bad prints tore it up right quick.  But I saw no degradation in printing when the tape was torn or missing.  But I wouldn't use that as solid evidence of anything either.  And, I'm printing ABS (on a Rep 1 dual)

My two cents.

Shawn

On 14-06-08 11:28 PM, Tom Chang wrote:

I've read some people run their printers without it.  What are the implications of running their extruders without the ceramic tape?  I found it to be a nuisance because, but are there any disadvantages of not running it and printing PLA with it?

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[Ryan Carlyle]

Shawn: nope. Temp oscillation has more to do with the heat capacity of the hot block vs PID tuning. Oscillation occurs when your PID parameters are tuned too aggressive for your hardware, end of story.

For example if you switch from a stock block to Carl's low-mass T-block and keep the default PID parameters, you may get some overshoot that did not occur before. It's not the lack of insulation, it's the increased ratio of heater power to heat capacity.

Now, the temp measurement may be more ACCURATE with insulation in place since the entire hot block should be at a more consistent temperature than if it's shedding a lot of heat to the air. But that would be more of a static offset which is easy enough to fix via slicer settings.

[Ken Hecker]

I've been running my 2X without insulation for several months now.  Since I replaced the heater blocks with Carl's t-blocks I've been tempted to re-insulate, and have the materials to do so (the original ceramic insulation disintegrated during the first upgrade). 

Ken