Heating Problem?  

Re: Heating Problem?

Alexander

I think you will find that this happens when the part fan turns on. Should you be using the part fan with PETG?

Peter

Re: Heating Problem?

Yes I also had that feeling about the fan, and yes, I would very much like to use the fan 😉
Is it that I am reaching the max power output of the machine?

Re: Heating Problem?

Alexander

Firstly, I have done a bit of research. PETG should be printed at about 230 degrees C without the part fan, as that causes excessive cooling and premature shrinkage which leads to lifting/warped printed models.

In answer to your question, no, you have not reached the limits for the components; it is possible to print at much higher temperatures with the fan than you are trying to achieve, but you will have to make some mods in order to do this.

Generally, you can print any material that the "original" was designed to print without any mods (subject to the heater cartridge issue which several users experiences a few months back), according to how the material is designed to be printed (ie PLA with fan, others without).

If you find that the fan lowers the temperature too much and you have to use the fan over (say) 220 degrees), then you will have to print a modified fan holder which directs the air current away from the heater block. Or (not recommended) you could upgrade to a 40W heater cartridge. Or you could turn the heater block the other way up (and modify the cable routing).

Hope this helps!

Peter

Re: Heating Problem?

So it is just the fan cooling the heat block? Lol, that possibility did not even occur to me 😀 sounds quite logical... Thanks for the info!
Well I did some tests at work and while I can agree on that the temps can be lowered without impact on print quality, I found that cooling leads to much higher part accuracy, with no shrinking/warping. Furthermore on my prusa yesterday I printed the famous all in one bearing ( http://www.thingiverse.com/thing:53451 ) with that setting and it came out like a charm ( did not even have to wiggle the parts free, it just came off the printbed ready to be rolled)

Re: Heating Problem?

Alexander

As an addition to my previous comments, the higher the extruder, the less effect the fan has on the temperatures.

I did a number of tests on this a while ago and ended up printing a modified fan holder that has no effect whatsoever on the extruder temperature. Of course the bed temp is affected when the print head is low and printing a small part in the centre of the bed).

Peter

Re: Heating Problem?

Hey Peter,
again thanks for your relentless efforts in this forum, your fan mod sounds very interesting, though as I am happy with my current setup i will so not touch it 😉
Care to show a picture of it anyways?

Re: Heating Problem?

Alexander

There's nothing to show; the outlet is only different by a couple of mm, plus an air flow refinement internally, which helps to push the air more downwards.

Nothing special, just simple airflow engineering...

Peter